@@ -1,33 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (C) 2007 Oracle. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
+ * Copyright (C) 2007,2008 Oracle. All rights reserved.
*/
#include "kernel-lib/bitops.h"
-#include "kernel-lib/sizes.h"
-#include "kernel-shared/ctree.h"
-#include "kernel-shared/disk-io.h"
-#include "kernel-shared/transaction.h"
-#include "kernel-shared/print-tree.h"
-#include "kernel-shared/tree-checker.h"
-#include "kernel-shared/volumes.h"
-#include "common/internal.h"
-#include "common/messages.h"
-#include "common/utils.h"
-#include "check/repair.h"
+#include "kernel-lib/trace.h"
+#include "messages.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+#include "locking.h"
+#include "volumes.h"
+#include "tree-mod-log.h"
+#include "tree-checker.h"
+#include "accessors.h"
+#include "file-item.h"
+
+/* MODIFIED: use this instead of calling btrfs_ctree_init. */
+static struct kmem_cache btrfs_path_cache_struct = {
+ .size = sizeof(struct btrfs_path),
+};
+
+static struct kmem_cache *btrfs_path_cachep = &btrfs_path_cache_struct;
static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int level);
@@ -151,12 +146,19 @@ static inline void copy_leaf_items(const struct extent_buffer *dst,
nr_items * sizeof(struct btrfs_item));
}
-int btrfs_super_csum_size(const struct btrfs_super_block *sb)
+/* This exists for btrfs-progs usages. */
+u16 btrfs_csum_type_size(u16 type)
{
- const u16 csum_type = btrfs_super_csum_type(sb);
+ return btrfs_csums[type].size;
+}
- /* csum type is validated at mount time */
- return btrfs_csums[csum_type].size;
+int btrfs_super_csum_size(const struct btrfs_super_block *s)
+{
+ u16 t = btrfs_super_csum_type(s);
+ /*
+ * csum type is validated at mount time
+ */
+ return btrfs_csum_type_size(t);
}
const char *btrfs_super_csum_name(u16 csum_type)
@@ -182,16 +184,11 @@ size_t __attribute_const__ btrfs_get_num_csums(void)
return ARRAY_SIZE(btrfs_csums);
}
-u16 btrfs_csum_type_size(u16 csum_type)
-{
- return btrfs_csums[csum_type].size;
-}
-
struct btrfs_path *btrfs_alloc_path(void)
{
might_sleep();
- return kzalloc(sizeof(struct btrfs_path), GFP_NOFS);
+ return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
}
/* this also releases the path */
@@ -200,7 +197,7 @@ void btrfs_free_path(struct btrfs_path *p)
if (!p)
return;
btrfs_release_path(p);
- kfree(p);
+ kmem_cache_free(btrfs_path_cachep, p);
}
/*
@@ -224,7 +221,6 @@ noinline void btrfs_release_path(struct btrfs_path *p)
free_extent_buffer(p->nodes[i]);
p->nodes[i] = NULL;
}
- memset(p, 0, sizeof(*p));
}
/*
@@ -243,47 +239,84 @@ bool __cold abort_should_print_stack(int errno)
return true;
}
+/*
+ * safely gets a reference on the root node of a tree. A lock
+ * is not taken, so a concurrent writer may put a different node
+ * at the root of the tree. See btrfs_lock_root_node for the
+ * looping required.
+ *
+ * The extent buffer returned by this has a reference taken, so
+ * it won't disappear. It may stop being the root of the tree
+ * at any time because there are no locks held.
+ */
+struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
+{
+ struct extent_buffer *eb;
+
+ while (1) {
+ rcu_read_lock();
+ eb = rcu_dereference(root->node);
+
+ /*
+ * RCU really hurts here, we could free up the root node because
+ * it was COWed but we may not get the new root node yet so do
+ * the inc_not_zero dance and if it doesn't work then
+ * synchronize_rcu and try again.
+ */
+ if (atomic_inc_not_zero(&eb->refs)) {
+ rcu_read_unlock();
+ break;
+ }
+ rcu_read_unlock();
+ synchronize_rcu();
+ }
+ return eb;
+}
+
+/*
+ * Cowonly root (not-shareable trees, everything not subvolume or reloc roots),
+ * just get put onto a simple dirty list. Transaction walks this list to make
+ * sure they get properly updated on disk.
+ */
static void add_root_to_dirty_list(struct btrfs_root *root)
{
- if (test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state) &&
- list_empty(&root->dirty_list)) {
- list_add(&root->dirty_list,
- &root->fs_info->dirty_cowonly_roots);
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ if (test_bit(BTRFS_ROOT_DIRTY, &root->state) ||
+ !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state))
+ return;
+
+ spin_lock(&fs_info->trans_lock);
+ if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) {
+ /* Want the extent tree to be the last on the list */
+ if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID)
+ list_move_tail(&root->dirty_list,
+ &fs_info->dirty_cowonly_roots);
+ else
+ list_move(&root->dirty_list,
+ &fs_info->dirty_cowonly_roots);
}
+ spin_unlock(&fs_info->trans_lock);
}
-static void root_add_used(struct btrfs_root *root, u32 size)
-{
- btrfs_set_root_used(&root->root_item,
- btrfs_root_used(&root->root_item) + size);
-}
-
-static void root_sub_used(struct btrfs_root *root, u32 size)
-{
- btrfs_set_root_used(&root->root_item,
- btrfs_root_used(&root->root_item) - size);
-}
-
+/*
+ * used by snapshot creation to make a copy of a root for a tree with
+ * a given objectid. The buffer with the new root node is returned in
+ * cow_ret, and this func returns zero on success or a negative error code.
+ */
int btrfs_copy_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
struct extent_buffer **cow_ret, u64 new_root_objectid)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *cow;
int ret = 0;
int level;
- struct btrfs_root *new_root;
struct btrfs_disk_key disk_key;
- new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
- if (!new_root)
- return -ENOMEM;
-
- memcpy(new_root, root, sizeof(*new_root));
- new_root->root_key.objectid = new_root_objectid;
-
WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
- trans->transid != root->fs_info->running_transaction->transid);
+ trans->transid != fs_info->running_transaction->transid);
WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
trans->transid != root->last_trans);
@@ -293,13 +326,11 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
else
btrfs_node_key(buf, &disk_key, 0);
- cow = btrfs_alloc_tree_block(trans, new_root, 0, new_root_objectid,
+ cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid,
&disk_key, level, buf->start, 0,
- BTRFS_NESTING_NORMAL);
- if (IS_ERR(cow)) {
- kfree(new_root);
+ BTRFS_NESTING_NEW_ROOT);
+ if (IS_ERR(cow))
return PTR_ERR(cow);
- }
copy_extent_buffer_full(cow, buf);
btrfs_set_header_bytenr(cow, cow->start);
@@ -312,14 +343,19 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
else
btrfs_set_header_owner(cow, new_root_objectid);
- write_extent_buffer_fsid(cow, root->fs_info->fs_devices->metadata_uuid);
+ write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid);
WARN_ON(btrfs_header_generation(buf) > trans->transid);
- ret = btrfs_inc_ref(trans, new_root, cow, 0);
- kfree(new_root);
-
- if (ret)
+ if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
+ ret = btrfs_inc_ref(trans, root, cow, 1);
+ else
+ ret = btrfs_inc_ref(trans, root, cow, 0);
+ if (ret) {
+ btrfs_tree_unlock(cow);
+ free_extent_buffer(cow);
+ btrfs_abort_transaction(trans, ret);
return ret;
+ }
btrfs_mark_buffer_dirty(cow);
*cow_ret = cow;
@@ -329,8 +365,8 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
/*
* check if the tree block can be shared by multiple trees
*/
-static int btrfs_block_can_be_shared(struct btrfs_root *root,
- struct extent_buffer *buf)
+int btrfs_block_can_be_shared(struct btrfs_root *root,
+ struct extent_buffer *buf)
{
/*
* Tree blocks not in shareable trees and tree roots are never shared.
@@ -350,8 +386,10 @@ static int btrfs_block_can_be_shared(struct btrfs_root *root,
static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
- struct extent_buffer *cow)
+ struct extent_buffer *cow,
+ int *last_ref)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
u64 refs;
u64 owner;
u64 flags;
@@ -376,12 +414,20 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
*/
if (btrfs_block_can_be_shared(root, buf)) {
- ret = btrfs_lookup_extent_info(trans, trans->fs_info,
- buf->start,
+ ret = btrfs_lookup_extent_info(trans, fs_info, buf->start,
btrfs_header_level(buf), 1,
&refs, &flags);
- BUG_ON(ret);
- BUG_ON(refs == 0);
+ if (ret)
+ return ret;
+ if (unlikely(refs == 0)) {
+ btrfs_crit(fs_info,
+ "found 0 references for tree block at bytenr %llu level %d root %llu",
+ buf->start, btrfs_header_level(buf),
+ btrfs_root_id(root));
+ ret = -EUCLEAN;
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
} else {
refs = 1;
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
@@ -392,22 +438,25 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
}
owner = btrfs_header_owner(buf);
- BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) &&
- owner == BTRFS_TREE_RELOC_OBJECTID);
+ BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID &&
+ !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
if (refs > 1) {
if ((owner == root->root_key.objectid ||
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
ret = btrfs_inc_ref(trans, root, buf, 1);
- BUG_ON(ret);
+ if (ret)
+ return ret;
if (root->root_key.objectid ==
BTRFS_TREE_RELOC_OBJECTID) {
ret = btrfs_dec_ref(trans, root, buf, 0);
- BUG_ON(ret);
+ if (ret)
+ return ret;
ret = btrfs_inc_ref(trans, root, cow, 1);
- BUG_ON(ret);
+ if (ret)
+ return ret;
}
new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
} else {
@@ -417,11 +466,13 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
ret = btrfs_inc_ref(trans, root, cow, 1);
else
ret = btrfs_inc_ref(trans, root, cow, 0);
- BUG_ON(ret);
+ if (ret)
+ return ret;
}
if (new_flags != 0) {
ret = btrfs_set_disk_extent_flags(trans, buf, new_flags);
- BUG_ON(ret);
+ if (ret)
+ return ret;
}
} else {
if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
@@ -430,11 +481,14 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
ret = btrfs_inc_ref(trans, root, cow, 1);
else
ret = btrfs_inc_ref(trans, root, cow, 0);
- BUG_ON(ret);
+ if (ret)
+ return ret;
ret = btrfs_dec_ref(trans, root, buf, 1);
- BUG_ON(ret);
+ if (ret)
+ return ret;
}
btrfs_clear_buffer_dirty(trans, buf);
+ *last_ref = 1;
}
return 0;
}
@@ -456,14 +510,24 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
struct extent_buffer *buf,
struct extent_buffer *parent, int parent_slot,
struct extent_buffer **cow_ret,
- u64 search_start, u64 empty_size)
+ u64 search_start, u64 empty_size,
+ enum btrfs_lock_nesting nest)
{
- struct extent_buffer *cow;
+ struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_disk_key disk_key;
- int level;
+ struct extent_buffer *cow;
+ int level, ret;
+ int last_ref = 0;
+ int unlock_orig = 0;
+ u64 parent_start = 0;
+
+ if (*cow_ret == buf)
+ unlock_orig = 1;
+
+ btrfs_assert_tree_write_locked(buf);
WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
- trans->transid != root->fs_info->running_transaction->transid);
+ trans->transid != fs_info->running_transaction->transid);
WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
trans->transid != root->last_trans);
@@ -474,12 +538,17 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
else
btrfs_node_key(buf, &disk_key, 0);
- cow = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
- &disk_key, level, search_start, empty_size,
- BTRFS_NESTING_NORMAL);
+ if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent)
+ parent_start = parent->start;
+
+ cow = btrfs_alloc_tree_block(trans, root, parent_start,
+ root->root_key.objectid, &disk_key, level,
+ search_start, empty_size, nest);
if (IS_ERR(cow))
return PTR_ERR(cow);
+ /* cow is set to blocking by btrfs_init_new_buffer */
+
copy_extent_buffer_full(cow, buf);
btrfs_set_header_bytenr(cow, cow->start);
btrfs_set_header_generation(cow, trans->transid);
@@ -491,38 +560,76 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
else
btrfs_set_header_owner(cow, root->root_key.objectid);
- write_extent_buffer_fsid(cow, root->fs_info->fs_devices->metadata_uuid);
+ write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid);
- WARN_ON(!(buf->flags & EXTENT_BUFFER_BAD_TRANSID) &&
- btrfs_header_generation(buf) > trans->transid);
+ ret = update_ref_for_cow(trans, root, buf, cow, &last_ref);
+ if (ret) {
+ btrfs_tree_unlock(cow);
+ free_extent_buffer(cow);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
- update_ref_for_cow(trans, root, buf, cow);
+ if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) {
+ ret = btrfs_reloc_cow_block(trans, root, buf, cow);
+ if (ret) {
+ btrfs_tree_unlock(cow);
+ free_extent_buffer(cow);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+ }
if (buf == root->node) {
- root->node = cow;
- extent_buffer_get(cow);
+ WARN_ON(parent && parent != buf);
+ if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
+ btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
+ parent_start = buf->start;
- btrfs_free_extent(trans, buf->start, buf->len, 0,
- root->root_key.objectid, level, 0);
+ ret = btrfs_tree_mod_log_insert_root(root->node, cow, true);
+ if (ret < 0) {
+ btrfs_tree_unlock(cow);
+ free_extent_buffer(cow);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+ atomic_inc(&cow->refs);
+ rcu_assign_pointer(root->node, cow);
+
+ btrfs_free_tree_block(trans, btrfs_root_id(root), buf,
+ parent_start, last_ref);
free_extent_buffer(buf);
add_root_to_dirty_list(root);
} else {
+ WARN_ON(trans->transid != btrfs_header_generation(parent));
+ ret = btrfs_tree_mod_log_insert_key(parent, parent_slot,
+ BTRFS_MOD_LOG_KEY_REPLACE);
+ if (ret) {
+ btrfs_tree_unlock(cow);
+ free_extent_buffer(cow);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
btrfs_set_node_blockptr(parent, parent_slot,
cow->start);
- WARN_ON(trans->transid == 0);
btrfs_set_node_ptr_generation(parent, parent_slot,
trans->transid);
btrfs_mark_buffer_dirty(parent);
- WARN_ON(btrfs_header_generation(parent) != trans->transid);
-
- btrfs_free_extent(trans, buf->start, buf->len, 0,
- root->root_key.objectid, level, 0);
+ if (last_ref) {
+ ret = btrfs_tree_mod_log_free_eb(buf);
+ if (ret) {
+ btrfs_tree_unlock(cow);
+ free_extent_buffer(cow);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+ }
+ btrfs_free_tree_block(trans, btrfs_root_id(root), buf,
+ parent_start, last_ref);
}
- if (!list_empty(&buf->recow)) {
- list_del_init(&buf->recow);
- free_extent_buffer(buf);
- }
- free_extent_buffer(buf);
+ if (unlock_orig)
+ btrfs_tree_unlock(buf);
+ free_extent_buffer_stale(buf);
btrfs_mark_buffer_dirty(cow);
*cow_ret = cow;
return 0;
@@ -532,51 +639,91 @@ static inline int should_cow_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf)
{
+ if (btrfs_is_testing(root->fs_info))
+ return 0;
+
+ /* Ensure we can see the FORCE_COW bit */
+ smp_mb__before_atomic();
+
+ /*
+ * We do not need to cow a block if
+ * 1) this block is not created or changed in this transaction;
+ * 2) this block does not belong to TREE_RELOC tree;
+ * 3) the root is not forced COW.
+ *
+ * What is forced COW:
+ * when we create snapshot during committing the transaction,
+ * after we've finished copying src root, we must COW the shared
+ * block to ensure the metadata consistency.
+ */
if (btrfs_header_generation(buf) == trans->transid &&
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
!(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
- btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
+ btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) &&
+ !test_bit(BTRFS_ROOT_FORCE_COW, &root->state))
return 0;
return 1;
}
-int btrfs_cow_block(struct btrfs_trans_handle *trans,
+/*
+ * cows a single block, see __btrfs_cow_block for the real work.
+ * This version of it has extra checks so that a block isn't COWed more than
+ * once per transaction, as long as it hasn't been written yet
+ */
+noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *buf,
struct extent_buffer *parent, int parent_slot,
struct extent_buffer **cow_ret,
enum btrfs_lock_nesting nest)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
u64 search_start;
int ret;
- /*
- if (trans->transaction != root->fs_info->running_transaction) {
- printk(KERN_CRIT "trans %llu running %llu\n", trans->transid,
- root->fs_info->running_transaction->transid);
- WARN_ON(1);
- }
- */
- if (trans->transid != root->fs_info->generation) {
- printk(KERN_CRIT "trans %llu running %llu\n",
- (unsigned long long)trans->transid,
- (unsigned long long)root->fs_info->generation);
- WARN_ON(1);
- }
+
+ if (test_bit(BTRFS_ROOT_DELETING, &root->state))
+ btrfs_err(fs_info,
+ "COW'ing blocks on a fs root that's being dropped");
+
+ /* MODIFIED: We don't have trans->transaction. */
+#if 0
+ if (trans->transaction != fs_info->running_transaction)
+ WARN(1, KERN_CRIT "trans %llu running %llu\n",
+ trans->transid,
+ fs_info->running_transaction->transid);
+#endif
+
+ if (trans->transid != fs_info->generation)
+ WARN(1, KERN_CRIT "trans %llu running %llu\n",
+ trans->transid, fs_info->generation);
+
if (!should_cow_block(trans, root, buf)) {
*cow_ret = buf;
return 0;
}
search_start = buf->start & ~((u64)SZ_1G - 1);
+
+ /*
+ * Before CoWing this block for later modification, check if it's
+ * the subtree root and do the delayed subtree trace if needed.
+ *
+ * Also We don't care about the error, as it's handled internally.
+ */
+ btrfs_qgroup_trace_subtree_after_cow(trans, root, buf);
ret = __btrfs_cow_block(trans, root, buf, parent,
- parent_slot, cow_ret, search_start, 0);
+ parent_slot, cow_ret, search_start, 0, nest);
+
+ trace_btrfs_cow_block(root, buf, *cow_ret);
+
return ret;
}
+ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO);
/*
* helper function for defrag to decide if two blocks pointed to by a
* node are actually close by
*/
-static __attribute__((unused)) int close_blocks(u64 blocknr, u64 other, u32 blocksize)
+static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
{
if (blocknr < other && other - (blocknr + blocksize) < 32768)
return 1;
@@ -585,6 +732,35 @@ static __attribute__((unused)) int close_blocks(u64 blocknr, u64 other, u32 bloc
return 0;
}
+#ifdef __LITTLE_ENDIAN
+
+/*
+ * Compare two keys, on little-endian the disk order is same as CPU order and
+ * we can avoid the conversion.
+ */
+static int comp_keys(const struct btrfs_disk_key *disk_key,
+ const struct btrfs_key *k2)
+{
+ const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key;
+
+ return btrfs_comp_cpu_keys(k1, k2);
+}
+
+#else
+
+/*
+ * compare two keys in a memcmp fashion
+ */
+static int comp_keys(const struct btrfs_disk_key *disk,
+ const struct btrfs_key *k2)
+{
+ struct btrfs_key k1;
+
+ btrfs_disk_key_to_cpu(&k1, disk);
+
+ return btrfs_comp_cpu_keys(&k1, k2);
+}
+#endif
/*
* same as comp_keys only with two btrfs_key's
@@ -607,60 +783,151 @@ int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_ke
}
/*
- * compare two keys in a memcmp fashion
+ * this is used by the defrag code to go through all the
+ * leaves pointed to by a node and reallocate them so that
+ * disk order is close to key order
*/
-static int btrfs_comp_keys(struct btrfs_disk_key *disk,
- const struct btrfs_key *k2)
+int btrfs_realloc_node(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *parent,
+ int start_slot, u64 *last_ret,
+ struct btrfs_key *progress)
{
- struct btrfs_key k1;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct extent_buffer *cur;
+ u64 blocknr;
+ u64 search_start = *last_ret;
+ u64 last_block = 0;
+ u64 other;
+ u32 parent_nritems;
+ int end_slot;
+ int i;
+ int err = 0;
+ u32 blocksize;
+ int progress_passed = 0;
+ struct btrfs_disk_key disk_key;
- btrfs_disk_key_to_cpu(&k1, disk);
- return btrfs_comp_cpu_keys(&k1, k2);
-}
+ /* MODIFIED: We don't have trans->transaction.
+ WARN_ON(trans->transaction != fs_info->running_transaction);
+ */
+ WARN_ON(trans->transid != fs_info->generation);
-static int noinline check_block(struct btrfs_fs_info *fs_info,
- struct btrfs_path *path, int level)
-{
- enum btrfs_tree_block_status ret;
+ parent_nritems = btrfs_header_nritems(parent);
+ blocksize = fs_info->nodesize;
+ end_slot = parent_nritems - 1;
- if (path->skip_check_block)
+ if (parent_nritems <= 1)
return 0;
- if (level == 0)
- ret = __btrfs_check_leaf(path->nodes[0]);
- else
- ret = __btrfs_check_node(path->nodes[level]);
- if (ret == BTRFS_TREE_BLOCK_CLEAN)
- return 0;
- return -EIO;
+
+ for (i = start_slot; i <= end_slot; i++) {
+ int close = 1;
+
+ btrfs_node_key(parent, &disk_key, i);
+ if (!progress_passed && comp_keys(&disk_key, progress) < 0)
+ continue;
+
+ progress_passed = 1;
+ blocknr = btrfs_node_blockptr(parent, i);
+ if (last_block == 0)
+ last_block = blocknr;
+
+ if (i > 0) {
+ other = btrfs_node_blockptr(parent, i - 1);
+ close = close_blocks(blocknr, other, blocksize);
+ }
+ if (!close && i < end_slot) {
+ other = btrfs_node_blockptr(parent, i + 1);
+ close = close_blocks(blocknr, other, blocksize);
+ }
+ if (close) {
+ last_block = blocknr;
+ continue;
+ }
+
+ cur = btrfs_read_node_slot(parent, i);
+ if (IS_ERR(cur))
+ return PTR_ERR(cur);
+ if (search_start == 0)
+ search_start = last_block;
+
+ btrfs_tree_lock(cur);
+ err = __btrfs_cow_block(trans, root, cur, parent, i,
+ &cur, search_start,
+ min(16 * blocksize,
+ (end_slot - i) * blocksize),
+ BTRFS_NESTING_COW);
+ if (err) {
+ btrfs_tree_unlock(cur);
+ free_extent_buffer(cur);
+ break;
+ }
+ search_start = cur->start;
+ last_block = cur->start;
+ *last_ret = search_start;
+ btrfs_tree_unlock(cur);
+ free_extent_buffer(cur);
+ }
+ return err;
}
/*
- * search for key in the extent_buffer. The items start at offset p,
- * and they are item_size apart. There are 'max' items in p.
+ * Search for a key in the given extent_buffer.
*
- * the slot in the array is returned via slot, and it points to
- * the place where you would insert key if it is not found in
- * the array.
+ * The lower boundary for the search is specified by the slot number @first_slot.
+ * Use a value of 0 to search over the whole extent buffer. Works for both
+ * leaves and nodes.
*
- * slot may point to max if the key is bigger than all of the keys
+ * The slot in the extent buffer is returned via @slot. If the key exists in the
+ * extent buffer, then @slot will point to the slot where the key is, otherwise
+ * it points to the slot where you would insert the key.
+ *
+ * Slot may point to the total number of items (i.e. one position beyond the last
+ * key) if the key is bigger than the last key in the extent buffer.
+ *
+ * MODIFIED: Removed the in page optimization.
*/
-static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
- int item_size, const struct btrfs_key *key,
- int max, int *slot)
+int btrfs_bin_search(struct extent_buffer *eb, int first_slot,
+ const struct btrfs_key *key, int *slot)
{
- int low = 0;
- int high = max;
- int mid;
+ unsigned long p;
+ int item_size;
+ /*
+ * Use unsigned types for the low and high slots, so that we get a more
+ * efficient division in the search loop below.
+ */
+ u32 low = first_slot;
+ u32 high = btrfs_header_nritems(eb);
int ret;
- unsigned long offset;
- struct btrfs_disk_key *tmp;
+ const int key_size = sizeof(struct btrfs_disk_key);
+
+ if (unlikely(low > high)) {
+ btrfs_err(eb->fs_info,
+ "%s: low (%u) > high (%u) eb %llu owner %llu level %d",
+ __func__, low, high, eb->start,
+ btrfs_header_owner(eb), btrfs_header_level(eb));
+ return -EINVAL;
+ }
+
+ if (btrfs_header_level(eb) == 0) {
+ p = offsetof(struct btrfs_leaf, items);
+ item_size = sizeof(struct btrfs_item);
+ } else {
+ p = offsetof(struct btrfs_node, ptrs);
+ item_size = sizeof(struct btrfs_key_ptr);
+ }
+
+ while (low < high) {
+ unsigned long offset;
+ struct btrfs_disk_key *tmp;
+ struct btrfs_disk_key unaligned;
+ int mid;
- while(low < high) {
mid = (low + high) / 2;
offset = p + mid * item_size;
- tmp = (struct btrfs_disk_key *)(eb->data + offset);
- ret = btrfs_comp_keys(tmp, key);
+ read_extent_buffer(eb, &unaligned, offset, key_size);
+ tmp = &unaligned;
+
+ ret = comp_keys(tmp, key);
if (ret < 0)
low = mid + 1;
@@ -675,61 +942,53 @@ static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
return 1;
}
-/*
- * simple bin_search frontend that does the right thing for
- * leaves vs nodes
- */
-int btrfs_bin_search(struct extent_buffer *eb, int first_slot,
- const struct btrfs_key *key, int *slot)
+static void root_add_used(struct btrfs_root *root, u32 size)
{
- if (btrfs_header_level(eb) == 0)
- return generic_bin_search(eb,
- offsetof(struct btrfs_leaf, items),
- sizeof(struct btrfs_item),
- key, btrfs_header_nritems(eb),
- slot);
- else
- return generic_bin_search(eb,
- offsetof(struct btrfs_node, ptrs),
- sizeof(struct btrfs_key_ptr),
- key, btrfs_header_nritems(eb),
- slot);
+ spin_lock(&root->accounting_lock);
+ btrfs_set_root_used(&root->root_item,
+ btrfs_root_used(&root->root_item) + size);
+ spin_unlock(&root->accounting_lock);
}
+static void root_sub_used(struct btrfs_root *root, u32 size)
+{
+ spin_lock(&root->accounting_lock);
+ btrfs_set_root_used(&root->root_item,
+ btrfs_root_used(&root->root_item) - size);
+ spin_unlock(&root->accounting_lock);
+}
+
+/* given a node and slot number, this reads the blocks it points to. The
+ * extent buffer is returned with a reference taken (but unlocked).
+ */
struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
int slot)
{
- struct btrfs_fs_info *fs_info = parent->fs_info;
- struct extent_buffer *ret;
- struct btrfs_tree_parent_check check = { 0 };
int level = btrfs_header_level(parent);
+ struct btrfs_tree_parent_check check = { 0 };
+ struct extent_buffer *eb;
- if (slot < 0)
- return NULL;
- if (slot >= btrfs_header_nritems(parent))
- return NULL;
+ if (slot < 0 || slot >= btrfs_header_nritems(parent))
+ return ERR_PTR(-ENOENT);
- if (level == 0)
- return NULL;
+ ASSERT(level);
- check.owner_root = btrfs_header_owner(parent);
- check.transid = btrfs_node_ptr_generation(parent, slot);
check.level = level - 1;
+ check.transid = btrfs_node_ptr_generation(parent, slot);
+ check.owner_root = btrfs_header_owner(parent);
+ check.has_first_key = true;
+ btrfs_node_key_to_cpu(parent, &check.first_key, slot);
- ret = read_tree_block(fs_info, btrfs_node_blockptr(parent, slot),
- &check);
- if (!extent_buffer_uptodate(ret))
- return ERR_PTR(-EIO);
-
- if (btrfs_header_level(ret) != level - 1) {
- error(
-"child eb corrupted: parent bytenr=%llu item=%d parent level=%d child bytenr=%llu child level=%d",
- btrfs_header_bytenr(parent), slot, btrfs_header_level(parent),
- btrfs_header_bytenr(ret), btrfs_header_level(ret));
- free_extent_buffer(ret);
+ eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot),
+ &check);
+ if (IS_ERR(eb))
+ return eb;
+ if (!extent_buffer_uptodate(eb)) {
+ free_extent_buffer(eb);
return ERR_PTR(-EIO);
}
- return ret;
+
+ return eb;
}
/*
@@ -752,10 +1011,11 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
int orig_slot = path->slots[level];
u64 orig_ptr;
- if (level == 0)
- return 0;
+ ASSERT(level > 0);
mid = path->nodes[level];
+
+ WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK);
WARN_ON(btrfs_header_generation(mid) != trans->transid);
orig_ptr = btrfs_node_blockptr(mid, orig_slot);
@@ -777,48 +1037,82 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
/* promote the child to a root */
child = btrfs_read_node_slot(mid, 0);
- BUG_ON(!extent_buffer_uptodate(child));
- ret = btrfs_cow_block(trans, root, child, mid, 0, &child,
- BTRFS_NESTING_NORMAL);
- BUG_ON(ret);
+ if (IS_ERR(child)) {
+ ret = PTR_ERR(child);
+ goto out;
+ }
+
+ btrfs_tree_lock(child);
+ ret = btrfs_cow_block(trans, root, child, mid, 0, &child,
+ BTRFS_NESTING_COW);
+ if (ret) {
+ btrfs_tree_unlock(child);
+ free_extent_buffer(child);
+ goto out;
+ }
+
+ ret = btrfs_tree_mod_log_insert_root(root->node, child, true);
+ if (ret < 0) {
+ btrfs_tree_unlock(child);
+ free_extent_buffer(child);
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
+ rcu_assign_pointer(root->node, child);
- root->node = child;
add_root_to_dirty_list(root);
+ btrfs_tree_unlock(child);
+
+ path->locks[level] = 0;
path->nodes[level] = NULL;
btrfs_clear_buffer_dirty(trans, mid);
+ btrfs_tree_unlock(mid);
/* once for the path */
free_extent_buffer(mid);
root_sub_used(root, mid->len);
-
- ret = btrfs_free_extent(trans, mid->start, mid->len, 0,
- root->root_key.objectid, level, 0);
+ btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1);
/* once for the root ptr */
- free_extent_buffer(mid);
- return ret;
+ free_extent_buffer_stale(mid);
+ return 0;
}
if (btrfs_header_nritems(mid) >
BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4)
return 0;
- left = btrfs_read_node_slot(parent, pslot - 1);
- if (extent_buffer_uptodate(left)) {
+ if (pslot) {
+ left = btrfs_read_node_slot(parent, pslot - 1);
+ if (IS_ERR(left)) {
+ ret = PTR_ERR(left);
+ left = NULL;
+ goto out;
+ }
+
+ __btrfs_tree_lock(left, BTRFS_NESTING_LEFT);
wret = btrfs_cow_block(trans, root, left,
parent, pslot - 1, &left,
- BTRFS_NESTING_NORMAL);
+ BTRFS_NESTING_LEFT_COW);
if (wret) {
ret = wret;
- goto enospc;
+ goto out;
}
}
- right = btrfs_read_node_slot(parent, pslot + 1);
- if (extent_buffer_uptodate(right)) {
+
+ if (pslot + 1 < btrfs_header_nritems(parent)) {
+ right = btrfs_read_node_slot(parent, pslot + 1);
+ if (IS_ERR(right)) {
+ ret = PTR_ERR(right);
+ right = NULL;
+ goto out;
+ }
+
+ __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT);
wret = btrfs_cow_block(trans, root, right,
parent, pslot + 1, &right,
- BTRFS_NESTING_NORMAL);
+ BTRFS_NESTING_RIGHT_COW);
if (wret) {
ret = wret;
- goto enospc;
+ goto out;
}
}
@@ -838,23 +1132,28 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
if (wret < 0 && wret != -ENOSPC)
ret = wret;
if (btrfs_header_nritems(right) == 0) {
- u64 bytenr = right->start;
- u32 blocksize = right->len;
-
btrfs_clear_buffer_dirty(trans, right);
- free_extent_buffer(right);
+ btrfs_tree_unlock(right);
+ ret = btrfs_del_ptr(trans, root, path, level + 1, pslot + 1);
+ if (ret < 0) {
+ free_extent_buffer_stale(right);
+ right = NULL;
+ goto out;
+ }
+ root_sub_used(root, right->len);
+ btrfs_free_tree_block(trans, btrfs_root_id(root), right,
+ 0, 1);
+ free_extent_buffer_stale(right);
right = NULL;
- btrfs_del_ptr(trans, root, path, level + 1, pslot + 1);
-
- root_sub_used(root, blocksize);
- wret = btrfs_free_extent(trans, bytenr, blocksize, 0,
- root->root_key.objectid, level,
- 0);
- if (wret)
- ret = wret;
} else {
struct btrfs_disk_key right_key;
btrfs_node_key(right, &right_key, 0);
+ ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1,
+ BTRFS_MOD_LOG_KEY_REPLACE);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
btrfs_set_node_key(parent, &right_key, pslot + 1);
btrfs_mark_buffer_dirty(parent);
}
@@ -869,11 +1168,19 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
* otherwise we would have pulled some pointers from the
* right
*/
- BUG_ON(!left);
+ if (unlikely(!left)) {
+ btrfs_crit(fs_info,
+"missing left child when middle child only has 1 item, parent bytenr %llu level %d mid bytenr %llu root %llu",
+ parent->start, btrfs_header_level(parent),
+ mid->start, btrfs_root_id(root));
+ ret = -EUCLEAN;
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
wret = balance_node_right(trans, mid, left);
if (wret < 0) {
ret = wret;
- goto enospc;
+ goto out;
}
if (wret == 1) {
wret = push_node_left(trans, left, mid, 1);
@@ -883,23 +1190,28 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
BUG_ON(wret == 1);
}
if (btrfs_header_nritems(mid) == 0) {
- /* we've managed to empty the middle node, drop it */
- u64 bytenr = mid->start;
- u32 blocksize = mid->len;
btrfs_clear_buffer_dirty(trans, mid);
- free_extent_buffer(mid);
+ btrfs_tree_unlock(mid);
+ ret = btrfs_del_ptr(trans, root, path, level + 1, pslot);
+ if (ret < 0) {
+ free_extent_buffer_stale(mid);
+ mid = NULL;
+ goto out;
+ }
+ root_sub_used(root, mid->len);
+ btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1);
+ free_extent_buffer_stale(mid);
mid = NULL;
- btrfs_del_ptr(trans, root, path, level + 1, pslot);
-
- root_sub_used(root, blocksize);
- wret = btrfs_free_extent(trans, bytenr, blocksize, 0,
- root->root_key.objectid, level, 0);
- if (wret)
- ret = wret;
} else {
/* update the parent key to reflect our changes */
struct btrfs_disk_key mid_key;
btrfs_node_key(mid, &mid_key, 0);
+ ret = btrfs_tree_mod_log_insert_key(parent, pslot,
+ BTRFS_MOD_LOG_KEY_REPLACE);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
btrfs_set_node_key(parent, &mid_key, pslot);
btrfs_mark_buffer_dirty(parent);
}
@@ -907,27 +1219,34 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
/* update the path */
if (left) {
if (btrfs_header_nritems(left) > orig_slot) {
- extent_buffer_get(left);
+ atomic_inc(&left->refs);
+ /* left was locked after cow */
path->nodes[level] = left;
path->slots[level + 1] -= 1;
path->slots[level] = orig_slot;
- if (mid)
+ if (mid) {
+ btrfs_tree_unlock(mid);
free_extent_buffer(mid);
+ }
} else {
orig_slot -= btrfs_header_nritems(left);
path->slots[level] = orig_slot;
}
}
/* double check we haven't messed things up */
- check_block(root->fs_info, path, level);
if (orig_ptr !=
btrfs_node_blockptr(path->nodes[level], path->slots[level]))
BUG();
-enospc:
- if (right)
+out:
+ if (right) {
+ btrfs_tree_unlock(right);
free_extent_buffer(right);
- if (left)
+ }
+ if (left) {
+ if (path->nodes[level] != left)
+ btrfs_tree_unlock(left);
free_extent_buffer(left);
+ }
return ret;
}
@@ -963,18 +1282,23 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
if (!parent)
return 1;
- left = btrfs_read_node_slot(parent, pslot - 1);
-
/* first, try to make some room in the middle buffer */
- if (extent_buffer_uptodate(left)) {
+ if (pslot) {
u32 left_nr;
+
+ left = btrfs_read_node_slot(parent, pslot - 1);
+ if (IS_ERR(left))
+ return PTR_ERR(left);
+
+ __btrfs_tree_lock(left, BTRFS_NESTING_LEFT);
+
left_nr = btrfs_header_nritems(left);
if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) {
wret = 1;
} else {
ret = btrfs_cow_block(trans, root, left, parent,
pslot - 1, &left,
- BTRFS_NESTING_NORMAL);
+ BTRFS_NESTING_LEFT_COW);
if (ret)
wret = 1;
else {
@@ -987,37 +1311,54 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
struct btrfs_disk_key disk_key;
orig_slot += left_nr;
btrfs_node_key(mid, &disk_key, 0);
+ ret = btrfs_tree_mod_log_insert_key(parent, pslot,
+ BTRFS_MOD_LOG_KEY_REPLACE);
+ if (ret < 0) {
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
btrfs_set_node_key(parent, &disk_key, pslot);
btrfs_mark_buffer_dirty(parent);
if (btrfs_header_nritems(left) > orig_slot) {
path->nodes[level] = left;
path->slots[level + 1] -= 1;
path->slots[level] = orig_slot;
+ btrfs_tree_unlock(mid);
free_extent_buffer(mid);
} else {
orig_slot -=
btrfs_header_nritems(left);
path->slots[level] = orig_slot;
+ btrfs_tree_unlock(left);
free_extent_buffer(left);
}
return 0;
}
+ btrfs_tree_unlock(left);
free_extent_buffer(left);
}
- right= btrfs_read_node_slot(parent, pslot + 1);
/*
* then try to empty the right most buffer into the middle
*/
- if (extent_buffer_uptodate(right)) {
+ if (pslot + 1 < btrfs_header_nritems(parent)) {
u32 right_nr;
+
+ right = btrfs_read_node_slot(parent, pslot + 1);
+ if (IS_ERR(right))
+ return PTR_ERR(right);
+
+ __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT);
+
right_nr = btrfs_header_nritems(right);
- if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root->fs_info) - 1) {
+ if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) {
wret = 1;
} else {
ret = btrfs_cow_block(trans, root, right,
parent, pslot + 1,
- &right, BTRFS_NESTING_NORMAL);
+ &right, BTRFS_NESTING_RIGHT_COW);
if (ret)
wret = 1;
else {
@@ -1030,6 +1371,14 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
struct btrfs_disk_key disk_key;
btrfs_node_key(right, &disk_key, 0);
+ ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1,
+ BTRFS_MOD_LOG_KEY_REPLACE);
+ if (ret < 0) {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
btrfs_set_node_key(parent, &disk_key, pslot + 1);
btrfs_mark_buffer_dirty(parent);
@@ -1038,12 +1387,15 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
path->slots[level + 1] += 1;
path->slots[level] = orig_slot -
btrfs_header_nritems(mid);
+ btrfs_tree_unlock(mid);
free_extent_buffer(mid);
} else {
+ btrfs_tree_unlock(right);
free_extent_buffer(right);
}
return 0;
}
+ btrfs_tree_unlock(right);
free_extent_buffer(right);
}
return 1;
@@ -1061,222 +1413,1101 @@ static void reada_for_search(struct btrfs_fs_info *fs_info,
struct btrfs_disk_key disk_key;
u32 nritems;
u64 search;
- u64 lowest_read;
- u64 highest_read;
+ u64 target;
u64 nread = 0;
- int direction = path->reada;
- struct extent_buffer *eb;
+ u64 nread_max;
u32 nr;
+ u32 blocksize;
u32 nscan = 0;
- if (level != 1)
+ if (level != 1 && path->reada != READA_FORWARD_ALWAYS)
return;
if (!path->nodes[level])
return;
node = path->nodes[level];
- search = btrfs_node_blockptr(node, slot);
- eb = btrfs_find_tree_block(fs_info, search, fs_info->nodesize);
- if (eb) {
- free_extent_buffer(eb);
- return;
+
+ /*
+ * Since the time between visiting leaves is much shorter than the time
+ * between visiting nodes, limit read ahead of nodes to 1, to avoid too
+ * much IO at once (possibly random).
+ */
+ if (path->reada == READA_FORWARD_ALWAYS) {
+ if (level > 1)
+ nread_max = node->fs_info->nodesize;
+ else
+ nread_max = SZ_128K;
+ } else {
+ nread_max = SZ_64K;
}
- highest_read = search;
- lowest_read = search;
+ search = btrfs_node_blockptr(node, slot);
+ blocksize = fs_info->nodesize;
+ if (path->reada != READA_FORWARD_ALWAYS) {
+ struct extent_buffer *eb;
+
+ eb = find_extent_buffer(fs_info, search);
+ if (eb) {
+ free_extent_buffer(eb);
+ return;
+ }
+ }
+
+ target = search;
nritems = btrfs_header_nritems(node);
nr = slot;
- while(1) {
- if (direction < 0) {
+
+ while (1) {
+ if (path->reada == READA_BACK) {
if (nr == 0)
break;
nr--;
- } else if (direction > 0) {
+ } else if (path->reada == READA_FORWARD ||
+ path->reada == READA_FORWARD_ALWAYS) {
nr++;
if (nr >= nritems)
break;
}
- if (path->reada < 0 && objectid) {
+ if (path->reada == READA_BACK && objectid) {
btrfs_node_key(node, &disk_key, nr);
if (btrfs_disk_key_objectid(&disk_key) != objectid)
break;
}
search = btrfs_node_blockptr(node, nr);
- if ((search >= lowest_read && search <= highest_read) ||
- (search < lowest_read && lowest_read - search <= 32768) ||
- (search > highest_read && search - highest_read <= 32768)) {
- readahead_tree_block(fs_info, search,
- btrfs_node_ptr_generation(node, nr));
- nread += fs_info->nodesize;
+ if (path->reada == READA_FORWARD_ALWAYS ||
+ (search <= target && target - search <= 65536) ||
+ (search > target && search - target <= 65536)) {
+ btrfs_readahead_node_child(node, nr);
+ nread += blocksize;
}
nscan++;
- if (path->reada < 2 && (nread > SZ_256K || nscan > 32))
+ if (nread > nread_max || nscan > 32)
break;
- if(nread > SZ_1M || nscan > 128)
- break;
-
- if (search < lowest_read)
- lowest_read = search;
- if (search > highest_read)
- highest_read = search;
}
}
-int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path,
+static noinline void reada_for_balance(struct btrfs_path *path, int level)
+{
+ struct extent_buffer *parent;
+ int slot;
+ int nritems;
+
+ parent = path->nodes[level + 1];
+ if (!parent)
+ return;
+
+ nritems = btrfs_header_nritems(parent);
+ slot = path->slots[level + 1];
+
+ if (slot > 0)
+ btrfs_readahead_node_child(parent, slot - 1);
+ if (slot + 1 < nritems)
+ btrfs_readahead_node_child(parent, slot + 1);
+}
+
+
+/*
+ * when we walk down the tree, it is usually safe to unlock the higher layers
+ * in the tree. The exceptions are when our path goes through slot 0, because
+ * operations on the tree might require changing key pointers higher up in the
+ * tree.
+ *
+ * callers might also have set path->keep_locks, which tells this code to keep
+ * the lock if the path points to the last slot in the block. This is part of
+ * walking through the tree, and selecting the next slot in the higher block.
+ *
+ * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
+ * if lowest_unlock is 1, level 0 won't be unlocked
+ */
+static noinline void unlock_up(struct btrfs_path *path, int level,
+ int lowest_unlock, int min_write_lock_level,
+ int *write_lock_level)
+{
+ int i;
+ int skip_level = level;
+ bool check_skip = true;
+
+ for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+ if (!path->nodes[i])
+ break;
+ if (!path->locks[i])
+ break;
+
+ if (check_skip) {
+ if (path->slots[i] == 0) {
+ skip_level = i + 1;
+ continue;
+ }
+
+ if (path->keep_locks) {
+ u32 nritems;
+
+ nritems = btrfs_header_nritems(path->nodes[i]);
+ if (nritems < 1 || path->slots[i] >= nritems - 1) {
+ skip_level = i + 1;
+ continue;
+ }
+ }
+ }
+
+ if (i >= lowest_unlock && i > skip_level) {
+ check_skip = false;
+ btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]);
+ path->locks[i] = 0;
+ if (write_lock_level &&
+ i > min_write_lock_level &&
+ i <= *write_lock_level) {
+ *write_lock_level = i - 1;
+ }
+ }
+ }
+}
+
+/*
+ * Helper function for btrfs_search_slot() and other functions that do a search
+ * on a btree. The goal is to find a tree block in the cache (the radix tree at
+ * fs_info->buffer_radix), but if we can't find it, or it's not up to date, read
+ * its pages from disk.
+ *
+ * Returns -EAGAIN, with the path unlocked, if the caller needs to repeat the
+ * whole btree search, starting again from the current root node.
+ */
+static int
+read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
+ struct extent_buffer **eb_ret, int level, int slot,
+ const struct btrfs_key *key)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_tree_parent_check check = { 0 };
+ u64 blocknr;
+ u64 gen;
+ struct extent_buffer *tmp;
+ int ret;
+ int parent_level;
+ bool unlock_up;
+
+ unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]);
+ blocknr = btrfs_node_blockptr(*eb_ret, slot);
+ gen = btrfs_node_ptr_generation(*eb_ret, slot);
+ parent_level = btrfs_header_level(*eb_ret);
+ btrfs_node_key_to_cpu(*eb_ret, &check.first_key, slot);
+ check.has_first_key = true;
+ check.level = parent_level - 1;
+ check.transid = gen;
+ check.owner_root = root->root_key.objectid;
+
+ /*
+ * If we need to read an extent buffer from disk and we are holding locks
+ * on upper level nodes, we unlock all the upper nodes before reading the
+ * extent buffer, and then return -EAGAIN to the caller as it needs to
+ * restart the search. We don't release the lock on the current level
+ * because we need to walk this node to figure out which blocks to read.
+ */
+ tmp = find_extent_buffer(fs_info, blocknr);
+ if (tmp) {
+ if (p->reada == READA_FORWARD_ALWAYS)
+ reada_for_search(fs_info, p, level, slot, key->objectid);
+
+ /* first we do an atomic uptodate check */
+ if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) {
+ /*
+ * Do extra check for first_key, eb can be stale due to
+ * being cached, read from scrub, or have multiple
+ * parents (shared tree blocks).
+ */
+ if (btrfs_verify_level_key(tmp,
+ parent_level - 1, &check.first_key, gen)) {
+ free_extent_buffer(tmp);
+ return -EUCLEAN;
+ }
+ *eb_ret = tmp;
+ return 0;
+ }
+
+ if (p->nowait) {
+ free_extent_buffer(tmp);
+ return -EAGAIN;
+ }
+
+ if (unlock_up)
+ btrfs_unlock_up_safe(p, level + 1);
+
+ /* now we're allowed to do a blocking uptodate check */
+ ret = btrfs_read_extent_buffer(tmp, &check);
+ if (ret) {
+ free_extent_buffer(tmp);
+ btrfs_release_path(p);
+ return -EIO;
+ }
+ if (btrfs_check_eb_owner(tmp, root->root_key.objectid)) {
+ free_extent_buffer(tmp);
+ btrfs_release_path(p);
+ return -EUCLEAN;
+ }
+
+ if (unlock_up)
+ ret = -EAGAIN;
+
+ goto out;
+ } else if (p->nowait) {
+ return -EAGAIN;
+ }
+
+ if (unlock_up) {
+ btrfs_unlock_up_safe(p, level + 1);
+ ret = -EAGAIN;
+ } else {
+ ret = 0;
+ }
+
+ if (p->reada != READA_NONE)
+ reada_for_search(fs_info, p, level, slot, key->objectid);
+
+ tmp = read_tree_block(fs_info, blocknr, &check);
+ if (IS_ERR(tmp)) {
+ btrfs_release_path(p);
+ return PTR_ERR(tmp);
+ }
+ /*
+ * If the read above didn't mark this buffer up to date,
+ * it will never end up being up to date. Set ret to EIO now
+ * and give up so that our caller doesn't loop forever
+ * on our EAGAINs.
+ */
+ if (!extent_buffer_uptodate(tmp))
+ ret = -EIO;
+
+out:
+ if (ret == 0) {
+ *eb_ret = tmp;
+ } else {
+ free_extent_buffer(tmp);
+ btrfs_release_path(p);
+ }
+
+ return ret;
+}
+
+/*
+ * helper function for btrfs_search_slot. This does all of the checks
+ * for node-level blocks and does any balancing required based on
+ * the ins_len.
+ *
+ * If no extra work was required, zero is returned. If we had to
+ * drop the path, -EAGAIN is returned and btrfs_search_slot must
+ * start over
+ */
+static int
+setup_nodes_for_search(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *p,
+ struct extent_buffer *b, int level, int ins_len,
+ int *write_lock_level)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret = 0;
+
+ if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >=
+ BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) {
+
+ if (*write_lock_level < level + 1) {
+ *write_lock_level = level + 1;
+ btrfs_release_path(p);
+ return -EAGAIN;
+ }
+
+ reada_for_balance(p, level);
+ ret = split_node(trans, root, p, level);
+
+ b = p->nodes[level];
+ } else if (ins_len < 0 && btrfs_header_nritems(b) <
+ BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) {
+
+ if (*write_lock_level < level + 1) {
+ *write_lock_level = level + 1;
+ btrfs_release_path(p);
+ return -EAGAIN;
+ }
+
+ reada_for_balance(p, level);
+ ret = balance_level(trans, root, p, level);
+ if (ret)
+ return ret;
+
+ b = p->nodes[level];
+ if (!b) {
+ btrfs_release_path(p);
+ return -EAGAIN;
+ }
+ BUG_ON(btrfs_header_nritems(b) == 1);
+ }
+ return ret;
+}
+
+int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
u64 iobjectid, u64 ioff, u8 key_type,
struct btrfs_key *found_key)
{
int ret;
struct btrfs_key key;
struct extent_buffer *eb;
- struct btrfs_path *path;
+
+ ASSERT(path);
+ ASSERT(found_key);
key.type = key_type;
key.objectid = iobjectid;
key.offset = ioff;
- if (found_path == NULL) {
- path = btrfs_alloc_path();
- if (!path)
- return -ENOMEM;
- } else
- path = found_path;
-
ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
- if ((ret < 0) || (found_key == NULL))
- goto out;
+ if (ret < 0)
+ return ret;
eb = path->nodes[0];
if (ret && path->slots[0] >= btrfs_header_nritems(eb)) {
ret = btrfs_next_leaf(fs_root, path);
if (ret)
- goto out;
+ return ret;
eb = path->nodes[0];
}
btrfs_item_key_to_cpu(eb, found_key, path->slots[0]);
if (found_key->type != key.type ||
- found_key->objectid != key.objectid) {
- ret = 1;
+ found_key->objectid != key.objectid)
+ return 1;
+
+ return 0;
+}
+
+static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root,
+ struct btrfs_path *p,
+ int write_lock_level)
+{
+ struct extent_buffer *b;
+ int root_lock = 0;
+ int level = 0;
+
+ if (p->search_commit_root) {
+ b = root->commit_root;
+ atomic_inc(&b->refs);
+ level = btrfs_header_level(b);
+ /*
+ * Ensure that all callers have set skip_locking when
+ * p->search_commit_root = 1.
+ */
+ ASSERT(p->skip_locking == 1);
+
goto out;
}
+ if (p->skip_locking) {
+ b = btrfs_root_node(root);
+ level = btrfs_header_level(b);
+ goto out;
+ }
+
+ /* We try very hard to do read locks on the root */
+ root_lock = BTRFS_READ_LOCK;
+
+ /*
+ * If the level is set to maximum, we can skip trying to get the read
+ * lock.
+ */
+ if (write_lock_level < BTRFS_MAX_LEVEL) {
+ /*
+ * We don't know the level of the root node until we actually
+ * have it read locked
+ */
+ if (p->nowait) {
+ b = btrfs_try_read_lock_root_node(root);
+ if (IS_ERR(b))
+ return b;
+ } else {
+ b = btrfs_read_lock_root_node(root);
+ }
+ level = btrfs_header_level(b);
+ if (level > write_lock_level)
+ goto out;
+
+ /* Whoops, must trade for write lock */
+ btrfs_tree_read_unlock(b);
+ free_extent_buffer(b);
+ }
+
+ b = btrfs_lock_root_node(root);
+ root_lock = BTRFS_WRITE_LOCK;
+
+ /* The level might have changed, check again */
+ level = btrfs_header_level(b);
+
out:
- if (path != found_path)
- btrfs_free_path(path);
+ /*
+ * The root may have failed to write out at some point, and thus is no
+ * longer valid, return an error in this case.
+ */
+ if (!extent_buffer_uptodate(b)) {
+ if (root_lock)
+ btrfs_tree_unlock_rw(b, root_lock);
+ free_extent_buffer(b);
+ return ERR_PTR(-EIO);
+ }
+
+ p->nodes[level] = b;
+ if (!p->skip_locking)
+ p->locks[level] = root_lock;
+ /*
+ * Callers are responsible for dropping b's references.
+ */
+ return b;
+}
+
+/*
+ * Replace the extent buffer at the lowest level of the path with a cloned
+ * version. The purpose is to be able to use it safely, after releasing the
+ * commit root semaphore, even if relocation is happening in parallel, the
+ * transaction used for relocation is committed and the extent buffer is
+ * reallocated in the next transaction.
+ *
+ * This is used in a context where the caller does not prevent transaction
+ * commits from happening, either by holding a transaction handle or holding
+ * some lock, while it's doing searches through a commit root.
+ * At the moment it's only used for send operations.
+ */
+static int finish_need_commit_sem_search(struct btrfs_path *path)
+{
+ const int i = path->lowest_level;
+ const int slot = path->slots[i];
+ struct extent_buffer *lowest = path->nodes[i];
+ struct extent_buffer *clone;
+
+ ASSERT(path->need_commit_sem);
+
+ if (!lowest)
+ return 0;
+
+ lockdep_assert_held_read(&lowest->fs_info->commit_root_sem);
+
+ clone = btrfs_clone_extent_buffer(lowest);
+ if (!clone)
+ return -ENOMEM;
+
+ btrfs_release_path(path);
+ path->nodes[i] = clone;
+ path->slots[i] = slot;
+
+ return 0;
+}
+
+static inline int search_for_key_slot(struct extent_buffer *eb,
+ int search_low_slot,
+ const struct btrfs_key *key,
+ int prev_cmp,
+ int *slot)
+{
+ /*
+ * If a previous call to btrfs_bin_search() on a parent node returned an
+ * exact match (prev_cmp == 0), we can safely assume the target key will
+ * always be at slot 0 on lower levels, since each key pointer
+ * (struct btrfs_key_ptr) refers to the lowest key accessible from the
+ * subtree it points to. Thus we can skip searching lower levels.
+ */
+ if (prev_cmp == 0) {
+ *slot = 0;
+ return 0;
+ }
+
+ return btrfs_bin_search(eb, search_low_slot, key, slot);
+}
+
+static int search_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const struct btrfs_key *key,
+ struct btrfs_path *path,
+ int ins_len,
+ int prev_cmp)
+{
+ struct extent_buffer *leaf = path->nodes[0];
+ int leaf_free_space = -1;
+ int search_low_slot = 0;
+ int ret;
+ bool do_bin_search = true;
+
+ /*
+ * If we are doing an insertion, the leaf has enough free space and the
+ * destination slot for the key is not slot 0, then we can unlock our
+ * write lock on the parent, and any other upper nodes, before doing the
+ * binary search on the leaf (with search_for_key_slot()), allowing other
+ * tasks to lock the parent and any other upper nodes.
+ */
+ if (ins_len > 0) {
+ /*
+ * Cache the leaf free space, since we will need it later and it
+ * will not change until then.
+ */
+ leaf_free_space = btrfs_leaf_free_space(leaf);
+
+ /*
+ * !path->locks[1] means we have a single node tree, the leaf is
+ * the root of the tree.
+ */
+ if (path->locks[1] && leaf_free_space >= ins_len) {
+ struct btrfs_disk_key first_key;
+
+ ASSERT(btrfs_header_nritems(leaf) > 0);
+ btrfs_item_key(leaf, &first_key, 0);
+
+ /*
+ * Doing the extra comparison with the first key is cheap,
+ * taking into account that the first key is very likely
+ * already in a cache line because it immediately follows
+ * the extent buffer's header and we have recently accessed
+ * the header's level field.
+ */
+ ret = comp_keys(&first_key, key);
+ if (ret < 0) {
+ /*
+ * The first key is smaller than the key we want
+ * to insert, so we are safe to unlock all upper
+ * nodes and we have to do the binary search.
+ *
+ * We do use btrfs_unlock_up_safe() and not
+ * unlock_up() because the later does not unlock
+ * nodes with a slot of 0 - we can safely unlock
+ * any node even if its slot is 0 since in this
+ * case the key does not end up at slot 0 of the
+ * leaf and there's no need to split the leaf.
+ */
+ btrfs_unlock_up_safe(path, 1);
+ search_low_slot = 1;
+ } else {
+ /*
+ * The first key is >= then the key we want to
+ * insert, so we can skip the binary search as
+ * the target key will be at slot 0.
+ *
+ * We can not unlock upper nodes when the key is
+ * less than the first key, because we will need
+ * to update the key at slot 0 of the parent node
+ * and possibly of other upper nodes too.
+ * If the key matches the first key, then we can
+ * unlock all the upper nodes, using
+ * btrfs_unlock_up_safe() instead of unlock_up()
+ * as stated above.
+ */
+ if (ret == 0)
+ btrfs_unlock_up_safe(path, 1);
+ /*
+ * ret is already 0 or 1, matching the result of
+ * a btrfs_bin_search() call, so there is no need
+ * to adjust it.
+ */
+ do_bin_search = false;
+ path->slots[0] = 0;
+ }
+ }
+ }
+
+ if (do_bin_search) {
+ ret = search_for_key_slot(leaf, search_low_slot, key,
+ prev_cmp, &path->slots[0]);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (ins_len > 0) {
+ /*
+ * Item key already exists. In this case, if we are allowed to
+ * insert the item (for example, in dir_item case, item key
+ * collision is allowed), it will be merged with the original
+ * item. Only the item size grows, no new btrfs item will be
+ * added. If search_for_extension is not set, ins_len already
+ * accounts the size btrfs_item, deduct it here so leaf space
+ * check will be correct.
+ */
+ if (ret == 0 && !path->search_for_extension) {
+ ASSERT(ins_len >= sizeof(struct btrfs_item));
+ ins_len -= sizeof(struct btrfs_item);
+ }
+
+ ASSERT(leaf_free_space >= 0);
+
+ if (leaf_free_space < ins_len) {
+ int err;
+
+ err = split_leaf(trans, root, key, path, ins_len,
+ (ret == 0));
+ ASSERT(err <= 0);
+ if (WARN_ON(err > 0))
+ err = -EUCLEAN;
+ if (err)
+ ret = err;
+ }
+ }
+
return ret;
}
/*
- * look for key in the tree. path is filled in with nodes along the way
- * if key is found, we return zero and you can find the item in the leaf
- * level of the path (level 0)
+ * btrfs_search_slot - look for a key in a tree and perform necessary
+ * modifications to preserve tree invariants.
*
- * If the key isn't found, the path points to the slot where it should
- * be inserted, and 1 is returned. If there are other errors during the
- * search a negative error number is returned.
+ * @trans: Handle of transaction, used when modifying the tree
+ * @p: Holds all btree nodes along the search path
+ * @root: The root node of the tree
+ * @key: The key we are looking for
+ * @ins_len: Indicates purpose of search:
+ * >0 for inserts it's size of item inserted (*)
+ * <0 for deletions
+ * 0 for plain searches, not modifying the tree
*
- * if ins_len > 0, nodes and leaves will be split as we walk down the
- * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
- * possible)
+ * (*) If size of item inserted doesn't include
+ * sizeof(struct btrfs_item), then p->search_for_extension must
+ * be set.
+ * @cow: boolean should CoW operations be performed. Must always be 1
+ * when modifying the tree.
+ *
+ * If @ins_len > 0, nodes and leaves will be split as we walk down the tree.
+ * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible)
+ *
+ * If @key is found, 0 is returned and you can find the item in the leaf level
+ * of the path (level 0)
+ *
+ * If @key isn't found, 1 is returned and the leaf level of the path (level 0)
+ * points to the slot where it should be inserted
+ *
+ * If an error is encountered while searching the tree a negative error number
+ * is returned
*/
-int btrfs_search_slot(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, const struct btrfs_key *key,
- struct btrfs_path *p, int ins_len, int cow)
+int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ const struct btrfs_key *key, struct btrfs_path *p,
+ int ins_len, int cow)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *b;
int slot;
int ret;
+ int err;
int level;
- int should_reada = p->reada;
- struct btrfs_fs_info *fs_info = root->fs_info;
+ int lowest_unlock = 1;
+ /* everything at write_lock_level or lower must be write locked */
+ int write_lock_level = 0;
u8 lowest_level = 0;
+ int min_write_lock_level;
+ int prev_cmp;
+
+ might_sleep();
lowest_level = p->lowest_level;
WARN_ON(lowest_level && ins_len > 0);
WARN_ON(p->nodes[0] != NULL);
-again:
- b = root->node;
- extent_buffer_get(b);
- while (b) {
- level = btrfs_header_level(b);
- if (cow) {
- int wret;
- wret = btrfs_cow_block(trans, root, b,
- p->nodes[level + 1],
- p->slots[level + 1],
- &b, BTRFS_NESTING_NORMAL);
- if (wret) {
- free_extent_buffer(b);
- return wret;
- }
- }
- BUG_ON(!cow && ins_len);
- if (level != btrfs_header_level(b))
- WARN_ON(1);
- level = btrfs_header_level(b);
- p->nodes[level] = b;
- ret = check_block(fs_info, p, level);
- if (ret)
- return -1;
- ret = btrfs_bin_search(b, 0, key, &slot);
- if (level != 0) {
- if (ret && slot > 0)
- slot -= 1;
- p->slots[level] = slot;
- if ((p->search_for_split || ins_len > 0) &&
- btrfs_header_nritems(b) >=
- BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) {
- int sret = split_node(trans, root, p, level);
- BUG_ON(sret > 0);
- if (sret)
- return sret;
- b = p->nodes[level];
- slot = p->slots[level];
- } else if (ins_len < 0) {
- int sret = balance_level(trans, root, p,
- level);
- if (sret)
- return sret;
- b = p->nodes[level];
- if (!b) {
- btrfs_release_path(p);
- goto again;
- }
- slot = p->slots[level];
- BUG_ON(btrfs_header_nritems(b) == 1);
- }
- /* this is only true while dropping a snapshot */
- if (level == lowest_level)
- break;
+ BUG_ON(!cow && ins_len);
- if (should_reada)
- reada_for_search(fs_info, p, level, slot,
- key->objectid);
+ /*
+ * For now only allow nowait for read only operations. There's no
+ * strict reason why we can't, we just only need it for reads so it's
+ * only implemented for reads.
+ */
+ ASSERT(!p->nowait || !cow);
- b = btrfs_read_node_slot(b, slot);
- if (!extent_buffer_uptodate(b))
- return -EIO;
+ if (ins_len < 0) {
+ lowest_unlock = 2;
+
+ /* when we are removing items, we might have to go up to level
+ * two as we update tree pointers Make sure we keep write
+ * for those levels as well
+ */
+ write_lock_level = 2;
+ } else if (ins_len > 0) {
+ /*
+ * for inserting items, make sure we have a write lock on
+ * level 1 so we can update keys
+ */
+ write_lock_level = 1;
+ }
+
+ if (!cow)
+ write_lock_level = -1;
+
+ if (cow && (p->keep_locks || p->lowest_level))
+ write_lock_level = BTRFS_MAX_LEVEL;
+
+ min_write_lock_level = write_lock_level;
+
+ if (p->need_commit_sem) {
+ ASSERT(p->search_commit_root);
+ if (p->nowait) {
+ if (!down_read_trylock(&fs_info->commit_root_sem))
+ return -EAGAIN;
} else {
- p->slots[level] = slot;
- if (ins_len > 0 &&
- ins_len > btrfs_leaf_free_space(b)) {
- int sret = split_leaf(trans, root, key,
- p, ins_len, ret == 0);
- BUG_ON(sret > 0);
- if (sret)
- return sret;
- }
- return ret;
+ down_read(&fs_info->commit_root_sem);
}
}
+
+again:
+ prev_cmp = -1;
+ b = btrfs_search_slot_get_root(root, p, write_lock_level);
+ if (IS_ERR(b)) {
+ ret = PTR_ERR(b);
+ goto done;
+ }
+
+ while (b) {
+ int dec = 0;
+
+ level = btrfs_header_level(b);
+
+ if (cow) {
+ bool last_level = (level == (BTRFS_MAX_LEVEL - 1));
+
+ /*
+ * if we don't really need to cow this block
+ * then we don't want to set the path blocking,
+ * so we test it here
+ */
+ if (!should_cow_block(trans, root, b))
+ goto cow_done;
+
+ /*
+ * must have write locks on this node and the
+ * parent
+ */
+ if (level > write_lock_level ||
+ (level + 1 > write_lock_level &&
+ level + 1 < BTRFS_MAX_LEVEL &&
+ p->nodes[level + 1])) {
+ write_lock_level = level + 1;
+ btrfs_release_path(p);
+ goto again;
+ }
+
+ if (last_level)
+ err = btrfs_cow_block(trans, root, b, NULL, 0,
+ &b,
+ BTRFS_NESTING_COW);
+ else
+ err = btrfs_cow_block(trans, root, b,
+ p->nodes[level + 1],
+ p->slots[level + 1], &b,
+ BTRFS_NESTING_COW);
+ if (err) {
+ ret = err;
+ goto done;
+ }
+ }
+cow_done:
+ p->nodes[level] = b;
+
+ /*
+ * we have a lock on b and as long as we aren't changing
+ * the tree, there is no way to for the items in b to change.
+ * It is safe to drop the lock on our parent before we
+ * go through the expensive btree search on b.
+ *
+ * If we're inserting or deleting (ins_len != 0), then we might
+ * be changing slot zero, which may require changing the parent.
+ * So, we can't drop the lock until after we know which slot
+ * we're operating on.
+ */
+ if (!ins_len && !p->keep_locks) {
+ int u = level + 1;
+
+ if (u < BTRFS_MAX_LEVEL && p->locks[u]) {
+ btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]);
+ p->locks[u] = 0;
+ }
+ }
+
+ if (level == 0) {
+ if (ins_len > 0)
+ ASSERT(write_lock_level >= 1);
+
+ ret = search_leaf(trans, root, key, p, ins_len, prev_cmp);
+ if (!p->search_for_split)
+ unlock_up(p, level, lowest_unlock,
+ min_write_lock_level, NULL);
+ goto done;
+ }
+
+ ret = search_for_key_slot(b, 0, key, prev_cmp, &slot);
+ if (ret < 0)
+ goto done;
+ prev_cmp = ret;
+
+ if (ret && slot > 0) {
+ dec = 1;
+ slot--;
+ }
+ p->slots[level] = slot;
+ err = setup_nodes_for_search(trans, root, p, b, level, ins_len,
+ &write_lock_level);
+ if (err == -EAGAIN)
+ goto again;
+ if (err) {
+ ret = err;
+ goto done;
+ }
+ b = p->nodes[level];
+ slot = p->slots[level];
+
+ /*
+ * Slot 0 is special, if we change the key we have to update
+ * the parent pointer which means we must have a write lock on
+ * the parent
+ */
+ if (slot == 0 && ins_len && write_lock_level < level + 1) {
+ write_lock_level = level + 1;
+ btrfs_release_path(p);
+ goto again;
+ }
+
+ unlock_up(p, level, lowest_unlock, min_write_lock_level,
+ &write_lock_level);
+
+ if (level == lowest_level) {
+ if (dec)
+ p->slots[level]++;
+ goto done;
+ }
+
+ err = read_block_for_search(root, p, &b, level, slot, key);
+ if (err == -EAGAIN)
+ goto again;
+ if (err) {
+ ret = err;
+ goto done;
+ }
+
+ if (!p->skip_locking) {
+ level = btrfs_header_level(b);
+
+ btrfs_maybe_reset_lockdep_class(root, b);
+
+ if (level <= write_lock_level) {
+ btrfs_tree_lock(b);
+ p->locks[level] = BTRFS_WRITE_LOCK;
+ } else {
+ if (p->nowait) {
+ if (!btrfs_try_tree_read_lock(b)) {
+ free_extent_buffer(b);
+ ret = -EAGAIN;
+ goto done;
+ }
+ } else {
+ btrfs_tree_read_lock(b);
+ }
+ p->locks[level] = BTRFS_READ_LOCK;
+ }
+ p->nodes[level] = b;
+ }
+ }
+ ret = 1;
+done:
+ if (ret < 0 && !p->skip_release_on_error)
+ btrfs_release_path(p);
+
+ if (p->need_commit_sem) {
+ int ret2;
+
+ ret2 = finish_need_commit_sem_search(p);
+ up_read(&fs_info->commit_root_sem);
+ if (ret2)
+ ret = ret2;
+ }
+
+ return ret;
+}
+ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO);
+
+/*
+ * Like btrfs_search_slot, this looks for a key in the given tree. It uses the
+ * current state of the tree together with the operations recorded in the tree
+ * modification log to search for the key in a previous version of this tree, as
+ * denoted by the time_seq parameter.
+ *
+ * Naturally, there is no support for insert, delete or cow operations.
+ *
+ * The resulting path and return value will be set up as if we called
+ * btrfs_search_slot at that point in time with ins_len and cow both set to 0.
+ */
+int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
+ struct btrfs_path *p, u64 time_seq)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct extent_buffer *b;
+ int slot;
+ int ret;
+ int err;
+ int level;
+ int lowest_unlock = 1;
+ u8 lowest_level = 0;
+
+ lowest_level = p->lowest_level;
+ WARN_ON(p->nodes[0] != NULL);
+ ASSERT(!p->nowait);
+
+ if (p->search_commit_root) {
+ BUG_ON(time_seq);
+ return btrfs_search_slot(NULL, root, key, p, 0, 0);
+ }
+
+again:
+ b = btrfs_get_old_root(root, time_seq);
+ if (!b) {
+ ret = -EIO;
+ goto done;
+ }
+ level = btrfs_header_level(b);
+ p->locks[level] = BTRFS_READ_LOCK;
+
+ while (b) {
+ int dec = 0;
+
+ level = btrfs_header_level(b);
+ p->nodes[level] = b;
+
+ /*
+ * we have a lock on b and as long as we aren't changing
+ * the tree, there is no way to for the items in b to change.
+ * It is safe to drop the lock on our parent before we
+ * go through the expensive btree search on b.
+ */
+ btrfs_unlock_up_safe(p, level + 1);
+
+ ret = btrfs_bin_search(b, 0, key, &slot);
+ if (ret < 0)
+ goto done;
+
+ if (level == 0) {
+ p->slots[level] = slot;
+ unlock_up(p, level, lowest_unlock, 0, NULL);
+ goto done;
+ }
+
+ if (ret && slot > 0) {
+ dec = 1;
+ slot--;
+ }
+ p->slots[level] = slot;
+ unlock_up(p, level, lowest_unlock, 0, NULL);
+
+ if (level == lowest_level) {
+ if (dec)
+ p->slots[level]++;
+ goto done;
+ }
+
+ err = read_block_for_search(root, p, &b, level, slot, key);
+ if (err == -EAGAIN)
+ goto again;
+ if (err) {
+ ret = err;
+ goto done;
+ }
+
+ level = btrfs_header_level(b);
+ btrfs_tree_read_lock(b);
+ b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq);
+ if (!b) {
+ ret = -ENOMEM;
+ goto done;
+ }
+ p->locks[level] = BTRFS_READ_LOCK;
+ p->nodes[level] = b;
+ }
+ ret = 1;
+done:
+ if (ret < 0)
+ btrfs_release_path(p);
+
+ return ret;
+}
+
+/*
+ * Search the tree again to find a leaf with smaller keys.
+ * Returns 0 if it found something.
+ * Returns 1 if there are no smaller keys.
+ * Returns < 0 on error.
+ *
+ * This may release the path, and so you may lose any locks held at the
+ * time you call it.
+ *
+ * This is exported for use inside btrfs-progs, don't un-export it.
+ */
+int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
+{
+ struct btrfs_key key;
+ struct btrfs_key orig_key;
+ struct btrfs_disk_key found_key;
+ int ret;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
+ orig_key = key;
+
+ if (key.offset > 0) {
+ key.offset--;
+ } else if (key.type > 0) {
+ key.type--;
+ key.offset = (u64)-1;
+ } else if (key.objectid > 0) {
+ key.objectid--;
+ key.type = (u8)-1;
+ key.offset = (u64)-1;
+ } else {
+ return 1;
+ }
+
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret <= 0)
+ return ret;
+
+ /*
+ * Previous key not found. Even if we were at slot 0 of the leaf we had
+ * before releasing the path and calling btrfs_search_slot(), we now may
+ * be in a slot pointing to the same original key - this can happen if
+ * after we released the path, one of more items were moved from a
+ * sibling leaf into the front of the leaf we had due to an insertion
+ * (see push_leaf_right()).
+ * If we hit this case and our slot is > 0 and just decrement the slot
+ * so that the caller does not process the same key again, which may or
+ * may not break the caller, depending on its logic.
+ */
+ if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
+ btrfs_item_key(path->nodes[0], &found_key, path->slots[0]);
+ ret = comp_keys(&found_key, &orig_key);
+ if (ret == 0) {
+ if (path->slots[0] > 0) {
+ path->slots[0]--;
+ return 0;
+ }
+ /*
+ * At slot 0, same key as before, it means orig_key is
+ * the lowest, leftmost, key in the tree. We're done.
+ */
+ return 1;
+ }
+ }
+
+ btrfs_item_key(path->nodes[0], &found_key, 0);
+ ret = comp_keys(&found_key, &key);
+ /*
+ * We might have had an item with the previous key in the tree right
+ * before we released our path. And after we released our path, that
+ * item might have been pushed to the first slot (0) of the leaf we
+ * were holding due to a tree balance. Alternatively, an item with the
+ * previous key can exist as the only element of a leaf (big fat item).
+ * Therefore account for these 2 cases, so that our callers (like
+ * btrfs_previous_item) don't miss an existing item with a key matching
+ * the previous key we computed above.
+ */
+ if (ret <= 0)
+ return 0;
return 1;
}
/*
- * Helper to use instead of search slot if no exact match is needed but
+ * helper to use instead of search slot if no exact match is needed but
* instead the next or previous item should be returned.
* When find_higher is true, the next higher item is returned, the next lower
* otherwise.
@@ -1288,65 +2519,115 @@ again:
* < 0 on error
*/
int btrfs_search_slot_for_read(struct btrfs_root *root,
- const struct btrfs_key *key,
- struct btrfs_path *p, int find_higher,
- int return_any)
+ const struct btrfs_key *key,
+ struct btrfs_path *p, int find_higher,
+ int return_any)
{
- int ret;
- struct extent_buffer *leaf;
+ int ret;
+ struct extent_buffer *leaf;
again:
- ret = btrfs_search_slot(NULL, root, key, p, 0, 0);
- if (ret <= 0)
- return ret;
- /*
- * A return value of 1 means the path is at the position where the item
- * should be inserted. Normally this is the next bigger item, but in
- * case the previous item is the last in a leaf, path points to the
- * first free slot in the previous leaf, i.e. at an invalid item.
- */
- leaf = p->nodes[0];
+ ret = btrfs_search_slot(NULL, root, key, p, 0, 0);
+ if (ret <= 0)
+ return ret;
+ /*
+ * a return value of 1 means the path is at the position where the
+ * item should be inserted. Normally this is the next bigger item,
+ * but in case the previous item is the last in a leaf, path points
+ * to the first free slot in the previous leaf, i.e. at an invalid
+ * item.
+ */
+ leaf = p->nodes[0];
- if (find_higher) {
- if (p->slots[0] >= btrfs_header_nritems(leaf)) {
- ret = btrfs_next_leaf(root, p);
- if (ret <= 0)
- return ret;
- if (!return_any)
- return 1;
- /*
- * No higher item found, return the next lower instead
- */
- return_any = 0;
- find_higher = 0;
- btrfs_release_path(p);
- goto again;
- }
- } else {
- if (p->slots[0] == 0) {
- ret = btrfs_prev_leaf(root, p);
- if (ret < 0)
- return ret;
- if (!ret) {
- leaf = p->nodes[0];
- if (p->slots[0] == btrfs_header_nritems(leaf))
- p->slots[0]--;
- return 0;
- }
- if (!return_any)
- return 1;
- /*
- * No lower item found, return the next higher instead
- */
- return_any = 0;
- find_higher = 1;
- btrfs_release_path(p);
- goto again;
- } else {
- --p->slots[0];
- }
- }
- return 0;
+ if (find_higher) {
+ if (p->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, p);
+ if (ret <= 0)
+ return ret;
+ if (!return_any)
+ return 1;
+ /*
+ * no higher item found, return the next
+ * lower instead
+ */
+ return_any = 0;
+ find_higher = 0;
+ btrfs_release_path(p);
+ goto again;
+ }
+ } else {
+ if (p->slots[0] == 0) {
+ ret = btrfs_prev_leaf(root, p);
+ if (ret < 0)
+ return ret;
+ if (!ret) {
+ leaf = p->nodes[0];
+ if (p->slots[0] == btrfs_header_nritems(leaf))
+ p->slots[0]--;
+ return 0;
+ }
+ if (!return_any)
+ return 1;
+ /*
+ * no lower item found, return the next
+ * higher instead
+ */
+ return_any = 0;
+ find_higher = 1;
+ btrfs_release_path(p);
+ goto again;
+ } else {
+ --p->slots[0];
+ }
+ }
+ return 0;
+}
+
+/*
+ * Execute search and call btrfs_previous_item to traverse backwards if the item
+ * was not found.
+ *
+ * Return 0 if found, 1 if not found and < 0 if error.
+ */
+int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
+ struct btrfs_path *path)
+{
+ int ret;
+
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret > 0)
+ ret = btrfs_previous_item(root, path, key->objectid, key->type);
+
+ if (ret == 0)
+ btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]);
+
+ return ret;
+}
+
+/*
+ * Search for a valid slot for the given path.
+ *
+ * @root: The root node of the tree.
+ * @key: Will contain a valid item if found.
+ * @path: The starting point to validate the slot.
+ *
+ * Return: 0 if the item is valid
+ * 1 if not found
+ * <0 if error.
+ */
+int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
+ struct btrfs_path *path)
+{
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ int ret;
+
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ return ret;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]);
+ return 0;
}
/*
@@ -1355,18 +2636,24 @@ again:
* This is used after shifting pointers to the left, so it stops
* fixing up pointers when a given leaf/node is not in slot 0 of the
* higher levels
+ *
*/
-static void fixup_low_keys(struct btrfs_path *path, struct btrfs_disk_key *key,
- int level)
+static void fixup_low_keys(struct btrfs_path *path,
+ struct btrfs_disk_key *key, int level)
{
int i;
struct extent_buffer *t;
+ int ret;
for (i = level; i < BTRFS_MAX_LEVEL; i++) {
int tslot = path->slots[i];
+
if (!path->nodes[i])
break;
t = path->nodes[i];
+ ret = btrfs_tree_mod_log_insert_key(t, tslot,
+ BTRFS_MOD_LOG_KEY_REPLACE);
+ BUG_ON(ret < 0);
btrfs_set_node_key(t, key, tslot);
btrfs_mark_buffer_dirty(path->nodes[i]);
if (tslot != 0)
@@ -1392,11 +2679,31 @@ void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info,
slot = path->slots[0];
if (slot > 0) {
btrfs_item_key(eb, &disk_key, slot - 1);
- BUG_ON(btrfs_comp_keys(&disk_key, new_key) >= 0);
+ if (unlikely(comp_keys(&disk_key, new_key) >= 0)) {
+ btrfs_print_leaf(eb);
+ btrfs_crit(fs_info,
+ "slot %u key (%llu %u %llu) new key (%llu %u %llu)",
+ slot, btrfs_disk_key_objectid(&disk_key),
+ btrfs_disk_key_type(&disk_key),
+ btrfs_disk_key_offset(&disk_key),
+ new_key->objectid, new_key->type,
+ new_key->offset);
+ BUG();
+ }
}
if (slot < btrfs_header_nritems(eb) - 1) {
btrfs_item_key(eb, &disk_key, slot + 1);
- BUG_ON(btrfs_comp_keys(&disk_key, new_key) <= 0);
+ if (unlikely(comp_keys(&disk_key, new_key) <= 0)) {
+ btrfs_print_leaf(eb);
+ btrfs_crit(fs_info,
+ "slot %u key (%llu %u %llu) new key (%llu %u %llu)",
+ slot, btrfs_disk_key_objectid(&disk_key),
+ btrfs_disk_key_type(&disk_key),
+ btrfs_disk_key_offset(&disk_key),
+ new_key->objectid, new_key->type,
+ new_key->offset);
+ BUG();
+ }
}
btrfs_cpu_key_to_disk(&disk_key, new_key);
@@ -1406,6 +2713,62 @@ void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info,
fixup_low_keys(path, &disk_key, 1);
}
+/*
+ * Check key order of two sibling extent buffers.
+ *
+ * Return true if something is wrong.
+ * Return false if everything is fine.
+ *
+ * Tree-checker only works inside one tree block, thus the following
+ * corruption can not be detected by tree-checker:
+ *
+ * Leaf @left | Leaf @right
+ * --------------------------------------------------------------
+ * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 |
+ *
+ * Key f6 in leaf @left itself is valid, but not valid when the next
+ * key in leaf @right is 7.
+ * This can only be checked at tree block merge time.
+ * And since tree checker has ensured all key order in each tree block
+ * is correct, we only need to bother the last key of @left and the first
+ * key of @right.
+ */
+static bool check_sibling_keys(struct extent_buffer *left,
+ struct extent_buffer *right)
+{
+ struct btrfs_key left_last;
+ struct btrfs_key right_first;
+ int level = btrfs_header_level(left);
+ int nr_left = btrfs_header_nritems(left);
+ int nr_right = btrfs_header_nritems(right);
+
+ /* No key to check in one of the tree blocks */
+ if (!nr_left || !nr_right)
+ return false;
+
+ if (level) {
+ btrfs_node_key_to_cpu(left, &left_last, nr_left - 1);
+ btrfs_node_key_to_cpu(right, &right_first, 0);
+ } else {
+ btrfs_item_key_to_cpu(left, &left_last, nr_left - 1);
+ btrfs_item_key_to_cpu(right, &right_first, 0);
+ }
+
+ if (unlikely(btrfs_comp_cpu_keys(&left_last, &right_first) >= 0)) {
+ btrfs_crit(left->fs_info, "left extent buffer:");
+ btrfs_print_tree(left, false);
+ btrfs_crit(left->fs_info, "right extent buffer:");
+ btrfs_print_tree(right, false);
+ btrfs_crit(left->fs_info,
+"bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)",
+ left_last.objectid, left_last.type,
+ left_last.offset, right_first.objectid,
+ right_first.type, right_first.offset);
+ return true;
+ }
+ return false;
+}
+
/*
* try to push data from one node into the next node left in the
* tree.
@@ -1432,9 +2795,8 @@ static int push_node_left(struct btrfs_trans_handle *trans,
if (!empty && src_nritems <= 8)
return 1;
- if (push_items <= 0) {
+ if (push_items <= 0)
return 1;
- }
if (empty) {
push_items = min(src_nritems, push_items);
@@ -1451,12 +2813,27 @@ static int push_node_left(struct btrfs_trans_handle *trans,
} else
push_items = min(src_nritems - 8, push_items);
+ /* dst is the left eb, src is the middle eb */
+ if (check_sibling_keys(dst, src)) {
+ ret = -EUCLEAN;
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+ ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
copy_extent_buffer(dst, src,
btrfs_node_key_ptr_offset(dst, dst_nritems),
btrfs_node_key_ptr_offset(src, 0),
- push_items * sizeof(struct btrfs_key_ptr));
+ push_items * sizeof(struct btrfs_key_ptr));
if (push_items < src_nritems) {
+ /*
+ * btrfs_tree_mod_log_eb_copy handles logging the move, so we
+ * don't need to do an explicit tree mod log operation for it.
+ */
memmove_extent_buffer(src, btrfs_node_key_ptr_offset(src, 0),
btrfs_node_key_ptr_offset(src, push_items),
(src_nritems - push_items) *
@@ -1496,32 +2873,46 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
src_nritems = btrfs_header_nritems(src);
dst_nritems = btrfs_header_nritems(dst);
push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems;
- if (push_items <= 0) {
+ if (push_items <= 0)
return 1;
- }
- if (src_nritems < 4) {
+ if (src_nritems < 4)
return 1;
- }
max_push = src_nritems / 2 + 1;
/* don't try to empty the node */
- if (max_push >= src_nritems) {
+ if (max_push >= src_nritems)
return 1;
- }
if (max_push < push_items)
push_items = max_push;
+ /* dst is the right eb, src is the middle eb */
+ if (check_sibling_keys(src, dst)) {
+ ret = -EUCLEAN;
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+
+ /*
+ * btrfs_tree_mod_log_eb_copy handles logging the move, so we don't
+ * need to do an explicit tree mod log operation for it.
+ */
memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(dst, push_items),
btrfs_node_key_ptr_offset(dst, 0),
(dst_nritems) *
sizeof(struct btrfs_key_ptr));
+ ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items,
+ push_items);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
copy_extent_buffer(dst, src,
btrfs_node_key_ptr_offset(dst, 0),
btrfs_node_key_ptr_offset(src, src_nritems - push_items),
- push_items * sizeof(struct btrfs_key_ptr));
+ push_items * sizeof(struct btrfs_key_ptr));
btrfs_set_header_nritems(src, src_nritems - push_items);
btrfs_set_header_nritems(dst, dst_nritems + push_items);
@@ -1539,15 +2930,17 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
*
* returns zero on success or < 0 on failure.
*/
-static int noinline insert_new_root(struct btrfs_trans_handle *trans,
+static noinline int insert_new_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int level)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
u64 lower_gen;
struct extent_buffer *lower;
struct extent_buffer *c;
struct extent_buffer *old;
struct btrfs_disk_key lower_key;
+ int ret;
BUG_ON(path->nodes[level]);
BUG_ON(path->nodes[level-1] != root->node);
@@ -1560,23 +2953,13 @@ static int noinline insert_new_root(struct btrfs_trans_handle *trans,
c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
&lower_key, level, root->node->start, 0,
- BTRFS_NESTING_NORMAL);
-
+ BTRFS_NESTING_NEW_ROOT);
if (IS_ERR(c))
return PTR_ERR(c);
- memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
+ root_add_used(root, fs_info->nodesize);
+
btrfs_set_header_nritems(c, 1);
- btrfs_set_header_level(c, level);
- btrfs_set_header_bytenr(c, c->start);
- btrfs_set_header_generation(c, trans->transid);
- btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
- btrfs_set_header_owner(c, root->root_key.objectid);
-
- root_add_used(root, root->fs_info->nodesize);
-
- write_extent_buffer_fsid(c, root->fs_info->fs_devices->metadata_uuid);
- write_extent_buffer_chunk_tree_uuid(c, root->fs_info->chunk_tree_uuid);
btrfs_set_node_key(c, &lower_key, 0);
btrfs_set_node_blockptr(c, 0, lower->start);
lower_gen = btrfs_header_generation(lower);
@@ -1587,14 +2970,22 @@ static int noinline insert_new_root(struct btrfs_trans_handle *trans,
btrfs_mark_buffer_dirty(c);
old = root->node;
- root->node = c;
+ ret = btrfs_tree_mod_log_insert_root(root->node, c, false);
+ if (ret < 0) {
+ btrfs_free_tree_block(trans, btrfs_root_id(root), c, 0, 1);
+ btrfs_tree_unlock(c);
+ free_extent_buffer(c);
+ return ret;
+ }
+ rcu_assign_pointer(root->node, c);
/* the super has an extra ref to root->node */
free_extent_buffer(old);
add_root_to_dirty_list(root);
- extent_buffer_get(c);
+ atomic_inc(&c->refs);
path->nodes[level] = c;
+ path->locks[level] = BTRFS_WRITE_LOCK;
path->slots[level] = 0;
return 0;
}
@@ -1605,36 +2996,51 @@ static int noinline insert_new_root(struct btrfs_trans_handle *trans,
*
* slot and level indicate where you want the key to go, and
* blocknr is the block the key points to.
- *
- * returns zero on success and < 0 on any error
*/
-static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, struct btrfs_disk_key
- *key, u64 bytenr, int slot, int level)
+static int insert_ptr(struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ struct btrfs_disk_key *key, u64 bytenr,
+ int slot, int level)
{
struct extent_buffer *lower;
int nritems;
+ int ret;
BUG_ON(!path->nodes[level]);
+ btrfs_assert_tree_write_locked(path->nodes[level]);
lower = path->nodes[level];
nritems = btrfs_header_nritems(lower);
- if (slot > nritems)
- BUG();
- if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root->fs_info))
- BUG();
- if (slot < nritems) {
- /* shift the items */
+ BUG_ON(slot > nritems);
+ BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info));
+ if (slot != nritems) {
+ if (level) {
+ ret = btrfs_tree_mod_log_insert_move(lower, slot + 1,
+ slot, nritems - slot);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+ }
memmove_extent_buffer(lower,
btrfs_node_key_ptr_offset(lower, slot + 1),
btrfs_node_key_ptr_offset(lower, slot),
(nritems - slot) * sizeof(struct btrfs_key_ptr));
}
+ if (level) {
+ ret = btrfs_tree_mod_log_insert_key(lower, slot,
+ BTRFS_MOD_LOG_KEY_ADD);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+ }
btrfs_set_node_key(lower, key, slot);
btrfs_set_node_blockptr(lower, slot, bytenr);
WARN_ON(trans->transid == 0);
btrfs_set_node_ptr_generation(lower, slot, trans->transid);
btrfs_set_header_nritems(lower, nritems + 1);
btrfs_mark_buffer_dirty(lower);
+
return 0;
}
@@ -1647,21 +3053,31 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
*
* returns 0 on success and < 0 on failure
*/
-static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, int level)
+static noinline int split_node(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int level)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *c;
struct extent_buffer *split;
struct btrfs_disk_key disk_key;
int mid;
int ret;
- int wret;
u32 c_nritems;
c = path->nodes[level];
WARN_ON(btrfs_header_generation(c) != trans->transid);
if (c == root->node) {
- /* trying to split the root, lets make a new one */
+ /*
+ * trying to split the root, lets make a new one
+ *
+ * tree mod log: We don't log_removal old root in
+ * insert_new_root, because that root buffer will be kept as a
+ * normal node. We are going to log removal of half of the
+ * elements below with btrfs_tree_mod_log_eb_copy(). We're
+ * holding a tree lock on the buffer, which is why we cannot
+ * race with other tree_mod_log users.
+ */
ret = insert_new_root(trans, root, path, level + 1);
if (ret)
return ret;
@@ -1669,7 +3085,7 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
ret = push_nodes_for_insert(trans, root, path, level);
c = path->nodes[level];
if (!ret && btrfs_header_nritems(c) <
- BTRFS_NODEPTRS_PER_BLOCK(root->fs_info) - 3)
+ BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3)
return 0;
if (ret < 0)
return ret;
@@ -1681,47 +3097,49 @@ static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
&disk_key, level, c->start, 0,
- BTRFS_NESTING_NORMAL);
+ BTRFS_NESTING_SPLIT);
if (IS_ERR(split))
return PTR_ERR(split);
- memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
- btrfs_set_header_level(split, btrfs_header_level(c));
- btrfs_set_header_bytenr(split, split->start);
- btrfs_set_header_generation(split, trans->transid);
- btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
- btrfs_set_header_owner(split, root->root_key.objectid);
- write_extent_buffer_fsid(split, root->fs_info->fs_devices->metadata_uuid);
- write_extent_buffer_chunk_tree_uuid(split, root->fs_info->chunk_tree_uuid);
-
- root_add_used(root, root->fs_info->nodesize);
+ root_add_used(root, fs_info->nodesize);
+ ASSERT(btrfs_header_level(c) == level);
+ ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid);
+ if (ret) {
+ btrfs_tree_unlock(split);
+ free_extent_buffer(split);
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
copy_extent_buffer(split, c,
btrfs_node_key_ptr_offset(split, 0),
btrfs_node_key_ptr_offset(c, mid),
(c_nritems - mid) * sizeof(struct btrfs_key_ptr));
btrfs_set_header_nritems(split, c_nritems - mid);
btrfs_set_header_nritems(c, mid);
- ret = 0;
btrfs_mark_buffer_dirty(c);
btrfs_mark_buffer_dirty(split);
- wret = insert_ptr(trans, root, path, &disk_key, split->start,
- path->slots[level + 1] + 1,
- level + 1);
- if (wret)
- ret = wret;
+ ret = insert_ptr(trans, path, &disk_key, split->start,
+ path->slots[level + 1] + 1, level + 1);
+ if (ret < 0) {
+ btrfs_tree_unlock(split);
+ free_extent_buffer(split);
+ return ret;
+ }
if (path->slots[level] >= mid) {
path->slots[level] -= mid;
+ btrfs_tree_unlock(c);
free_extent_buffer(c);
path->nodes[level] = split;
path->slots[level + 1] += 1;
} else {
+ btrfs_tree_unlock(split);
free_extent_buffer(split);
}
- return ret;
+ return 0;
}
/*
@@ -1737,7 +3155,7 @@ static int leaf_space_used(const struct extent_buffer *l, int start, int nr)
if (!nr)
return 0;
- data_len = btrfs_item_data_end(l, start);
+ data_len = btrfs_item_offset(l, start) + btrfs_item_size(l, start);
data_len = data_len - btrfs_item_offset(l, end);
data_len += sizeof(struct btrfs_item) * nr;
WARN_ON(data_len < 0);
@@ -1751,101 +3169,76 @@ static int leaf_space_used(const struct extent_buffer *l, int start, int nr)
*/
int btrfs_leaf_free_space(const struct extent_buffer *leaf)
{
+ struct btrfs_fs_info *fs_info = leaf->fs_info;
int nritems = btrfs_header_nritems(leaf);
- u32 leaf_data_size;
int ret;
- BUG_ON(!leaf->fs_info);
- BUG_ON(leaf->fs_info->nodesize != leaf->len);
- leaf_data_size = BTRFS_LEAF_DATA_SIZE(leaf->fs_info);
- ret = leaf_data_size - leaf_space_used(leaf, 0 ,nritems);
+ ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems);
if (ret < 0) {
- printk("leaf free space ret %d, leaf data size %u, used %d nritems %d\n",
- ret, leaf_data_size, leaf_space_used(leaf, 0, nritems),
- nritems);
+ btrfs_crit(fs_info,
+ "leaf free space ret %d, leaf data size %lu, used %d nritems %d",
+ ret,
+ (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info),
+ leaf_space_used(leaf, 0, nritems), nritems);
}
return ret;
}
/*
- * push some data in the path leaf to the right, trying to free up at
- * least data_size bytes. returns zero if the push worked, nonzero otherwise
- *
- * returns 1 if the push failed because the other node didn't have enough
- * room, 0 if everything worked out and < 0 if there were major errors.
+ * min slot controls the lowest index we're willing to push to the
+ * right. We'll push up to and including min_slot, but no lower
*/
-static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, int data_size,
- int empty)
+static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ int data_size, int empty,
+ struct extent_buffer *right,
+ int free_space, u32 left_nritems,
+ u32 min_slot)
{
+ struct btrfs_fs_info *fs_info = right->fs_info;
struct extent_buffer *left = path->nodes[0];
- struct extent_buffer *right;
- struct extent_buffer *upper;
+ struct extent_buffer *upper = path->nodes[1];
+ struct btrfs_map_token token;
struct btrfs_disk_key disk_key;
int slot;
u32 i;
- int free_space;
int push_space = 0;
int push_items = 0;
- u32 left_nritems;
u32 nr;
u32 right_nritems;
u32 data_end;
u32 this_item_size;
- int ret;
-
- slot = path->slots[1];
- if (!path->nodes[1]) {
- return 1;
- }
- upper = path->nodes[1];
- if (slot >= btrfs_header_nritems(upper) - 1)
- return 1;
-
- right = btrfs_read_node_slot(upper, slot + 1);
- if (!extent_buffer_uptodate(right)) {
- if (IS_ERR(right))
- return PTR_ERR(right);
- return -EIO;
- }
- free_space = btrfs_leaf_free_space(right);
- if (free_space < data_size) {
- free_extent_buffer(right);
- return 1;
- }
-
- /* cow and double check */
- ret = btrfs_cow_block(trans, root, right, upper,
- slot + 1, &right, BTRFS_NESTING_NORMAL);
- if (ret) {
- free_extent_buffer(right);
- return 1;
- }
- free_space = btrfs_leaf_free_space(right);
- if (free_space < data_size) {
- free_extent_buffer(right);
- return 1;
- }
-
- left_nritems = btrfs_header_nritems(left);
- if (left_nritems == 0) {
- free_extent_buffer(right);
- return 1;
- }
if (empty)
nr = 0;
else
- nr = 1;
+ nr = max_t(u32, 1, min_slot);
+ if (path->slots[0] >= left_nritems)
+ push_space += data_size;
+
+ slot = path->slots[1];
i = left_nritems - 1;
while (i >= nr) {
+ if (!empty && push_items > 0) {
+ if (path->slots[0] > i)
+ break;
+ if (path->slots[0] == i) {
+ int space = btrfs_leaf_free_space(left);
+
+ if (space + push_space * 2 > free_space)
+ break;
+ }
+ }
+
if (path->slots[0] == i)
- push_space += data_size + sizeof(struct btrfs_item);
+ push_space += data_size;
this_item_size = btrfs_item_size(left, i);
- if (this_item_size + sizeof(struct btrfs_item) + push_space > free_space)
+ if (this_item_size + sizeof(struct btrfs_item) +
+ push_space > free_space)
break;
+
push_items++;
push_space += this_item_size + sizeof(struct btrfs_item);
if (i == 0)
@@ -1853,13 +3246,10 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
i--;
}
- if (push_items == 0) {
- free_extent_buffer(right);
- return 1;
- }
+ if (push_items == 0)
+ goto out_unlock;
- if (!empty && push_items == left_nritems)
- WARN_ON(1);
+ WARN_ON(!empty && push_items == left_nritems);
/* push left to right */
right_nritems = btrfs_header_nritems(right);
@@ -1869,32 +3259,26 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
/* make room in the right data area */
data_end = leaf_data_end(right);
- memmove_extent_buffer(right,
- btrfs_item_nr_offset(right, 0) + data_end - push_space,
- btrfs_item_nr_offset(right, 0) + data_end,
- BTRFS_LEAF_DATA_SIZE(root->fs_info) - data_end);
+ memmove_leaf_data(right, data_end - push_space, data_end,
+ BTRFS_LEAF_DATA_SIZE(fs_info) - data_end);
/* copy from the left data area */
- copy_extent_buffer(right, left, btrfs_item_nr_offset(right, 0) +
- BTRFS_LEAF_DATA_SIZE(root->fs_info) - push_space,
- btrfs_item_nr_offset(left, 0) + leaf_data_end(left), push_space);
+ copy_leaf_data(right, left, BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
+ leaf_data_end(left), push_space);
- memmove_extent_buffer(right, btrfs_item_nr_offset(right, push_items),
- btrfs_item_nr_offset(right, 0),
- right_nritems * sizeof(struct btrfs_item));
+ memmove_leaf_items(right, push_items, 0, right_nritems);
/* copy the items from left to right */
- copy_extent_buffer(right, left, btrfs_item_nr_offset(right, 0),
- btrfs_item_nr_offset(left, left_nritems - push_items),
- push_items * sizeof(struct btrfs_item));
+ copy_leaf_items(right, left, 0, left_nritems - push_items, push_items);
/* update the item pointers */
+ btrfs_init_map_token(&token, right);
right_nritems += push_items;
btrfs_set_header_nritems(right, right_nritems);
- push_space = BTRFS_LEAF_DATA_SIZE(root->fs_info);
+ push_space = BTRFS_LEAF_DATA_SIZE(fs_info);
for (i = 0; i < right_nritems; i++) {
- push_space -= btrfs_item_size(right, i);
- btrfs_set_item_offset(right, i, push_space);
+ push_space -= btrfs_token_item_size(&token, i);
+ btrfs_set_token_item_offset(&token, i, push_space);
}
left_nritems -= push_items;
@@ -1902,6 +3286,9 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
if (left_nritems)
btrfs_mark_buffer_dirty(left);
+ else
+ btrfs_clear_buffer_dirty(trans, left);
+
btrfs_mark_buffer_dirty(right);
btrfs_item_key(right, &disk_key, 0);
@@ -1911,36 +3298,260 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
/* then fixup the leaf pointer in the path */
if (path->slots[0] >= left_nritems) {
path->slots[0] -= left_nritems;
+ if (btrfs_header_nritems(path->nodes[0]) == 0)
+ btrfs_clear_buffer_dirty(trans, path->nodes[0]);
+ btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
path->slots[1] += 1;
} else {
+ btrfs_tree_unlock(right);
free_extent_buffer(right);
}
return 0;
+
+out_unlock:
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return 1;
}
+
+/*
+ * push some data in the path leaf to the right, trying to free up at
+ * least data_size bytes. returns zero if the push worked, nonzero otherwise
+ *
+ * returns 1 if the push failed because the other node didn't have enough
+ * room, 0 if everything worked out and < 0 if there were major errors.
+ *
+ * this will push starting from min_slot to the end of the leaf. It won't
+ * push any slot lower than min_slot
+ */
+static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path,
+ int min_data_size, int data_size,
+ int empty, u32 min_slot)
+{
+ struct extent_buffer *left = path->nodes[0];
+ struct extent_buffer *right;
+ struct extent_buffer *upper;
+ int slot;
+ int free_space;
+ u32 left_nritems;
+ int ret;
+
+ if (!path->nodes[1])
+ return 1;
+
+ slot = path->slots[1];
+ upper = path->nodes[1];
+ if (slot >= btrfs_header_nritems(upper) - 1)
+ return 1;
+
+ btrfs_assert_tree_write_locked(path->nodes[1]);
+
+ right = btrfs_read_node_slot(upper, slot + 1);
+ if (IS_ERR(right))
+ return PTR_ERR(right);
+
+ __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT);
+
+ free_space = btrfs_leaf_free_space(right);
+ if (free_space < data_size)
+ goto out_unlock;
+
+ ret = btrfs_cow_block(trans, root, right, upper,
+ slot + 1, &right, BTRFS_NESTING_RIGHT_COW);
+ if (ret)
+ goto out_unlock;
+
+ left_nritems = btrfs_header_nritems(left);
+ if (left_nritems == 0)
+ goto out_unlock;
+
+ if (check_sibling_keys(left, right)) {
+ ret = -EUCLEAN;
+ btrfs_abort_transaction(trans, ret);
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return ret;
+ }
+ if (path->slots[0] == left_nritems && !empty) {
+ /* Key greater than all keys in the leaf, right neighbor has
+ * enough room for it and we're not emptying our leaf to delete
+ * it, therefore use right neighbor to insert the new item and
+ * no need to touch/dirty our left leaf. */
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ path->nodes[0] = right;
+ path->slots[0] = 0;
+ path->slots[1]++;
+ return 0;
+ }
+
+ return __push_leaf_right(trans, path, min_data_size, empty, right,
+ free_space, left_nritems, min_slot);
+out_unlock:
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return 1;
+}
+
/*
* push some data in the path leaf to the left, trying to free up at
* least data_size bytes. returns zero if the push worked, nonzero otherwise
+ *
+ * max_slot can put a limit on how far into the leaf we'll push items. The
+ * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the
+ * items
*/
-static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, int data_size,
- int empty)
+static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
+ struct btrfs_path *path, int data_size,
+ int empty, struct extent_buffer *left,
+ int free_space, u32 right_nritems,
+ u32 max_slot)
{
+ struct btrfs_fs_info *fs_info = left->fs_info;
struct btrfs_disk_key disk_key;
struct extent_buffer *right = path->nodes[0];
- struct extent_buffer *left;
- int slot;
int i;
- int free_space;
int push_space = 0;
int push_items = 0;
u32 old_left_nritems;
- u32 right_nritems;
u32 nr;
int ret = 0;
u32 this_item_size;
u32 old_left_item_size;
+ struct btrfs_map_token token;
+
+ if (empty)
+ nr = min(right_nritems, max_slot);
+ else
+ nr = min(right_nritems - 1, max_slot);
+
+ for (i = 0; i < nr; i++) {
+ if (!empty && push_items > 0) {
+ if (path->slots[0] < i)
+ break;
+ if (path->slots[0] == i) {
+ int space = btrfs_leaf_free_space(right);
+
+ if (space + push_space * 2 > free_space)
+ break;
+ }
+ }
+
+ if (path->slots[0] == i)
+ push_space += data_size;
+
+ this_item_size = btrfs_item_size(right, i);
+ if (this_item_size + sizeof(struct btrfs_item) + push_space >
+ free_space)
+ break;
+
+ push_items++;
+ push_space += this_item_size + sizeof(struct btrfs_item);
+ }
+
+ if (push_items == 0) {
+ ret = 1;
+ goto out;
+ }
+ WARN_ON(!empty && push_items == btrfs_header_nritems(right));
+
+ /* push data from right to left */
+ copy_leaf_items(left, right, btrfs_header_nritems(left), 0, push_items);
+
+ push_space = BTRFS_LEAF_DATA_SIZE(fs_info) -
+ btrfs_item_offset(right, push_items - 1);
+
+ copy_leaf_data(left, right, leaf_data_end(left) - push_space,
+ btrfs_item_offset(right, push_items - 1), push_space);
+ old_left_nritems = btrfs_header_nritems(left);
+ BUG_ON(old_left_nritems <= 0);
+
+ btrfs_init_map_token(&token, left);
+ old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1);
+ for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
+ u32 ioff;
+
+ ioff = btrfs_token_item_offset(&token, i);
+ btrfs_set_token_item_offset(&token, i,
+ ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size));
+ }
+ btrfs_set_header_nritems(left, old_left_nritems + push_items);
+
+ /* fixup right node */
+ if (push_items > right_nritems)
+ WARN(1, KERN_CRIT "push items %d nr %u\n", push_items,
+ right_nritems);
+
+ if (push_items < right_nritems) {
+ push_space = btrfs_item_offset(right, push_items - 1) -
+ leaf_data_end(right);
+ memmove_leaf_data(right,
+ BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
+ leaf_data_end(right), push_space);
+
+ memmove_leaf_items(right, 0, push_items,
+ btrfs_header_nritems(right) - push_items);
+ }
+
+ btrfs_init_map_token(&token, right);
+ right_nritems -= push_items;
+ btrfs_set_header_nritems(right, right_nritems);
+ push_space = BTRFS_LEAF_DATA_SIZE(fs_info);
+ for (i = 0; i < right_nritems; i++) {
+ push_space = push_space - btrfs_token_item_size(&token, i);
+ btrfs_set_token_item_offset(&token, i, push_space);
+ }
+
+ btrfs_mark_buffer_dirty(left);
+ if (right_nritems)
+ btrfs_mark_buffer_dirty(right);
+ else
+ btrfs_clear_buffer_dirty(trans, right);
+
+ btrfs_item_key(right, &disk_key, 0);
+ fixup_low_keys(path, &disk_key, 1);
+
+ /* then fixup the leaf pointer in the path */
+ if (path->slots[0] < push_items) {
+ path->slots[0] += old_left_nritems;
+ btrfs_tree_unlock(path->nodes[0]);
+ free_extent_buffer(path->nodes[0]);
+ path->nodes[0] = left;
+ path->slots[1] -= 1;
+ } else {
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ path->slots[0] -= push_items;
+ }
+ BUG_ON(path->slots[0] < 0);
+ return ret;
+out:
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ return ret;
+}
+
+/*
+ * push some data in the path leaf to the left, trying to free up at
+ * least data_size bytes. returns zero if the push worked, nonzero otherwise
+ *
+ * max_slot can put a limit on how far into the leaf we'll push items. The
+ * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the
+ * items
+ */
+static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, int min_data_size,
+ int data_size, int empty, u32 max_slot)
+{
+ struct extent_buffer *right = path->nodes[0];
+ struct extent_buffer *left;
+ int slot;
+ int free_space;
+ u32 right_nritems;
+ int ret = 0;
slot = path->slots[1];
if (slot == 0)
@@ -1949,199 +3560,171 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
return 1;
right_nritems = btrfs_header_nritems(right);
- if (right_nritems == 0) {
+ if (right_nritems == 0)
return 1;
- }
+
+ btrfs_assert_tree_write_locked(path->nodes[1]);
left = btrfs_read_node_slot(path->nodes[1], slot - 1);
+ if (IS_ERR(left))
+ return PTR_ERR(left);
+
+ __btrfs_tree_lock(left, BTRFS_NESTING_LEFT);
+
free_space = btrfs_leaf_free_space(left);
if (free_space < data_size) {
- free_extent_buffer(left);
- return 1;
+ ret = 1;
+ goto out;
}
- /* cow and double check */
ret = btrfs_cow_block(trans, root, left,
path->nodes[1], slot - 1, &left,
- BTRFS_NESTING_NORMAL);
+ BTRFS_NESTING_LEFT_COW);
if (ret) {
/* we hit -ENOSPC, but it isn't fatal here */
- free_extent_buffer(left);
- return 1;
+ if (ret == -ENOSPC)
+ ret = 1;
+ goto out;
}
- free_space = btrfs_leaf_free_space(left);
- if (free_space < data_size) {
- free_extent_buffer(left);
- return 1;
+ if (check_sibling_keys(left, right)) {
+ ret = -EUCLEAN;
+ btrfs_abort_transaction(trans, ret);
+ goto out;
}
-
- if (empty)
- nr = right_nritems;
- else
- nr = right_nritems - 1;
-
- for (i = 0; i < nr; i++) {
- if (path->slots[0] == i)
- push_space += data_size + sizeof(struct btrfs_item);
-
- this_item_size = btrfs_item_size(right, i);
- if (this_item_size + sizeof(struct btrfs_item) + push_space > free_space)
- break;
-
- push_items++;
- push_space += this_item_size + sizeof(struct btrfs_item);
- }
-
- if (push_items == 0) {
- free_extent_buffer(left);
- return 1;
- }
- if (!empty && push_items == btrfs_header_nritems(right))
- WARN_ON(1);
-
- /* push data from right to left */
- copy_extent_buffer(left, right,
- btrfs_item_nr_offset(left, btrfs_header_nritems(left)),
- btrfs_item_nr_offset(right, 0),
- push_items * sizeof(struct btrfs_item));
-
- push_space = BTRFS_LEAF_DATA_SIZE(root->fs_info) -
- btrfs_item_offset(right, push_items -1);
-
- copy_extent_buffer(left, right, btrfs_item_nr_offset(left, 0) +
- leaf_data_end(left) - push_space,
- btrfs_item_nr_offset(right, 0) +
- btrfs_item_offset(right, push_items - 1),
- push_space);
- old_left_nritems = btrfs_header_nritems(left);
- BUG_ON(old_left_nritems == 0);
-
- old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1);
- for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
- u32 ioff;
-
- ioff = btrfs_item_offset(left, i);
- btrfs_set_item_offset(left, i,
- ioff - (BTRFS_LEAF_DATA_SIZE(root->fs_info) -
- old_left_item_size));
- }
- btrfs_set_header_nritems(left, old_left_nritems + push_items);
-
- /* fixup right node */
- if (push_items > right_nritems) {
- printk("push items %d nr %u\n", push_items, right_nritems);
- WARN_ON(1);
- }
-
- if (push_items < right_nritems) {
- push_space = btrfs_item_offset(right, push_items - 1) -
- leaf_data_end(right);
- memmove_extent_buffer(right, btrfs_item_nr_offset(right, 0) +
- BTRFS_LEAF_DATA_SIZE(root->fs_info) -
- push_space,
- btrfs_item_nr_offset(right, 0) +
- leaf_data_end(right), push_space);
-
- memmove_extent_buffer(right, btrfs_item_nr_offset(right, 0),
- btrfs_item_nr_offset(right, push_items),
- (btrfs_header_nritems(right) - push_items) *
- sizeof(struct btrfs_item));
- }
- right_nritems -= push_items;
- btrfs_set_header_nritems(right, right_nritems);
- push_space = BTRFS_LEAF_DATA_SIZE(root->fs_info);
- for (i = 0; i < right_nritems; i++) {
- push_space = push_space - btrfs_item_size(right, i);
- btrfs_set_item_offset(right, i, push_space);
- }
-
- btrfs_mark_buffer_dirty(left);
- if (right_nritems)
- btrfs_mark_buffer_dirty(right);
-
- btrfs_item_key(right, &disk_key, 0);
- fixup_low_keys(path, &disk_key, 1);
-
- /* then fixup the leaf pointer in the path */
- if (path->slots[0] < push_items) {
- path->slots[0] += old_left_nritems;
- free_extent_buffer(path->nodes[0]);
- path->nodes[0] = left;
- path->slots[1] -= 1;
- } else {
- free_extent_buffer(left);
- path->slots[0] -= push_items;
- }
- BUG_ON(path->slots[0] < 0);
+ return __push_leaf_left(trans, path, min_data_size, empty, left,
+ free_space, right_nritems, max_slot);
+out:
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
return ret;
}
/*
* split the path's leaf in two, making sure there is at least data_size
* available for the resulting leaf level of the path.
- *
- * returns 0 if all went well and < 0 on failure.
*/
static noinline int copy_for_split(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- struct btrfs_path *path,
- struct extent_buffer *l,
- struct extent_buffer *right,
- int slot, int mid, int nritems)
+ struct btrfs_path *path,
+ struct extent_buffer *l,
+ struct extent_buffer *right,
+ int slot, int mid, int nritems)
{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
int data_copy_size;
int rt_data_off;
int i;
- int ret = 0;
- int wret;
+ int ret;
struct btrfs_disk_key disk_key;
+ struct btrfs_map_token token;
nritems = nritems - mid;
btrfs_set_header_nritems(right, nritems);
data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l);
- copy_extent_buffer(right, l, btrfs_item_nr_offset(right, 0),
- btrfs_item_nr_offset(l, mid),
- nritems * sizeof(struct btrfs_item));
+ copy_leaf_items(right, l, 0, mid, nritems);
- copy_extent_buffer(right, l,
- btrfs_item_nr_offset(right, 0) +
- BTRFS_LEAF_DATA_SIZE(root->fs_info) - data_copy_size,
- btrfs_item_nr_offset(l, 0) + leaf_data_end(l), data_copy_size);
+ copy_leaf_data(right, l, BTRFS_LEAF_DATA_SIZE(fs_info) - data_copy_size,
+ leaf_data_end(l), data_copy_size);
- rt_data_off = BTRFS_LEAF_DATA_SIZE(root->fs_info) -
- btrfs_item_data_end(l, mid);
+ rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid);
+ btrfs_init_map_token(&token, right);
for (i = 0; i < nritems; i++) {
- u32 ioff = btrfs_item_offset(right, i);
- btrfs_set_item_offset(right, i, ioff + rt_data_off);
+ u32 ioff;
+
+ ioff = btrfs_token_item_offset(&token, i);
+ btrfs_set_token_item_offset(&token, i, ioff + rt_data_off);
}
btrfs_set_header_nritems(l, mid);
- ret = 0;
btrfs_item_key(right, &disk_key, 0);
- wret = insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1] + 1, 1);
- if (wret)
- ret = wret;
+ ret = insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1);
+ if (ret < 0)
+ return ret;
btrfs_mark_buffer_dirty(right);
btrfs_mark_buffer_dirty(l);
BUG_ON(path->slots[0] != slot);
if (mid <= slot) {
+ btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
path->slots[0] -= mid;
path->slots[1] += 1;
} else {
+ btrfs_tree_unlock(right);
free_extent_buffer(right);
}
BUG_ON(path->slots[0] < 0);
- return ret;
+ return 0;
+}
+
+/*
+ * double splits happen when we need to insert a big item in the middle
+ * of a leaf. A double split can leave us with 3 mostly empty leaves:
+ * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
+ * A B C
+ *
+ * We avoid this by trying to push the items on either side of our target
+ * into the adjacent leaves. If all goes well we can avoid the double split
+ * completely.
+ */
+static noinline int push_for_double_split(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ int data_size)
+{
+ int ret;
+ int progress = 0;
+ int slot;
+ u32 nritems;
+ int space_needed = data_size;
+
+ slot = path->slots[0];
+ if (slot < btrfs_header_nritems(path->nodes[0]))
+ space_needed -= btrfs_leaf_free_space(path->nodes[0]);
+
+ /*
+ * try to push all the items after our slot into the
+ * right leaf
+ */
+ ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot);
+ if (ret < 0)
+ return ret;
+
+ if (ret == 0)
+ progress++;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ /*
+ * our goal is to get our slot at the start or end of a leaf. If
+ * we've done so we're done
+ */
+ if (path->slots[0] == 0 || path->slots[0] == nritems)
+ return 0;
+
+ if (btrfs_leaf_free_space(path->nodes[0]) >= data_size)
+ return 0;
+
+ /* try to push all the items before our slot into the next leaf */
+ slot = path->slots[0];
+ space_needed = data_size;
+ if (slot > 0)
+ space_needed -= btrfs_leaf_free_space(path->nodes[0]);
+ ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot);
+ if (ret < 0)
+ return ret;
+
+ if (ret == 0)
+ progress++;
+
+ if (progress)
+ return 0;
+ return 1;
}
/*
@@ -2162,24 +3745,36 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
int mid;
int slot;
struct extent_buffer *right;
+ struct btrfs_fs_info *fs_info = root->fs_info;
int ret = 0;
int wret;
int split;
int num_doubles = 0;
+ int tried_avoid_double = 0;
l = path->nodes[0];
slot = path->slots[0];
if (extend && data_size + btrfs_item_size(l, slot) +
- sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info))
+ sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info))
return -EOVERFLOW;
/* first try to make some room by pushing left and right */
- if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
- wret = push_leaf_right(trans, root, path, data_size, 0);
+ if (data_size && path->nodes[1]) {
+ int space_needed = data_size;
+
+ if (slot < btrfs_header_nritems(l))
+ space_needed -= btrfs_leaf_free_space(l);
+
+ wret = push_leaf_right(trans, root, path, space_needed,
+ space_needed, 0, 0);
if (wret < 0)
return wret;
if (wret) {
- wret = push_leaf_left(trans, root, path, data_size, 0);
+ space_needed = data_size;
+ if (slot > 0)
+ space_needed -= btrfs_leaf_free_space(l);
+ wret = push_leaf_left(trans, root, path, space_needed,
+ space_needed, 0, (u32)-1);
if (wret < 0)
return wret;
}
@@ -2205,22 +3800,23 @@ again:
if (mid <= slot) {
if (nritems == 1 ||
leaf_space_used(l, mid, nritems - mid) + data_size >
- BTRFS_LEAF_DATA_SIZE(root->fs_info)) {
+ BTRFS_LEAF_DATA_SIZE(fs_info)) {
if (slot >= nritems) {
split = 0;
} else {
mid = slot;
if (mid != nritems &&
leaf_space_used(l, mid, nritems - mid) +
- data_size >
- BTRFS_LEAF_DATA_SIZE(root->fs_info)) {
+ data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) {
+ if (data_size && !tried_avoid_double)
+ goto push_for_double;
split = 2;
}
}
}
} else {
if (leaf_space_used(l, 0, mid) + data_size >
- BTRFS_LEAF_DATA_SIZE(root->fs_info)) {
+ BTRFS_LEAF_DATA_SIZE(fs_info)) {
if (!extend && data_size && slot == 0) {
split = 0;
} else if ((extend || !data_size) && slot == 0) {
@@ -2229,9 +3825,10 @@ again:
mid = slot;
if (mid != nritems &&
leaf_space_used(l, mid, nritems - mid) +
- data_size >
- BTRFS_LEAF_DATA_SIZE(root->fs_info)) {
- split = 2 ;
+ data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) {
+ if (data_size && !tried_avoid_double)
+ goto push_for_double;
+ split = 2;
}
}
}
@@ -2242,58 +3839,68 @@ again:
else
btrfs_item_key(l, &disk_key, mid);
+ /*
+ * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double
+ * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES
+ * subclasses, which is 8 at the time of this patch, and we've maxed it
+ * out. In the future we could add a
+ * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just
+ * use BTRFS_NESTING_NEW_ROOT.
+ */
right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
&disk_key, 0, l->start, 0,
- BTRFS_NESTING_NORMAL);
- if (IS_ERR(right)) {
- BUG_ON(1);
+ num_doubles ? BTRFS_NESTING_NEW_ROOT :
+ BTRFS_NESTING_SPLIT);
+ if (IS_ERR(right))
return PTR_ERR(right);
- }
- memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
- btrfs_set_header_bytenr(right, right->start);
- btrfs_set_header_generation(right, trans->transid);
- btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
- btrfs_set_header_owner(right, root->root_key.objectid);
- btrfs_set_header_level(right, 0);
- write_extent_buffer_fsid(right, root->fs_info->fs_devices->metadata_uuid);
- write_extent_buffer_chunk_tree_uuid(right, root->fs_info->chunk_tree_uuid);
-
- root_add_used(root, root->fs_info->nodesize);
+ root_add_used(root, fs_info->nodesize);
if (split == 0) {
if (mid <= slot) {
btrfs_set_header_nritems(right, 0);
- wret = insert_ptr(trans, root, path,
- &disk_key, right->start,
- path->slots[1] + 1, 1);
- if (wret)
- ret = wret;
-
+ ret = insert_ptr(trans, path, &disk_key,
+ right->start, path->slots[1] + 1, 1);
+ if (ret < 0) {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return ret;
+ }
+ btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
path->slots[0] = 0;
path->slots[1] += 1;
} else {
btrfs_set_header_nritems(right, 0);
- wret = insert_ptr(trans, root, path,
- &disk_key,
- right->start,
- path->slots[1], 1);
- if (wret)
- ret = wret;
+ ret = insert_ptr(trans, path, &disk_key,
+ right->start, path->slots[1], 1);
+ if (ret < 0) {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return ret;
+ }
+ btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
path->slots[0] = 0;
if (path->slots[1] == 0)
fixup_low_keys(path, &disk_key, 1);
}
- btrfs_mark_buffer_dirty(right);
+ /*
+ * We create a new leaf 'right' for the required ins_len and
+ * we'll do btrfs_mark_buffer_dirty() on this leaf after copying
+ * the content of ins_len to 'right'.
+ */
return ret;
}
- ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
- BUG_ON(ret);
+ ret = copy_for_split(trans, path, l, right, slot, mid, nritems);
+ if (ret < 0) {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return ret;
+ }
if (split == 2) {
BUG_ON(num_doubles != 0);
@@ -2301,9 +3908,148 @@ again:
goto again;
}
+ return 0;
+
+push_for_double:
+ push_for_double_split(trans, root, path, data_size);
+ tried_avoid_double = 1;
+ if (btrfs_leaf_free_space(path->nodes[0]) >= data_size)
+ return 0;
+ goto again;
+}
+
+static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int ins_len)
+{
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *fi;
+ u64 extent_len = 0;
+ u32 item_size;
+ int ret;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY &&
+ key.type != BTRFS_EXTENT_CSUM_KEY);
+
+ if (btrfs_leaf_free_space(leaf) >= ins_len)
+ return 0;
+
+ item_size = btrfs_item_size(leaf, path->slots[0]);
+ if (key.type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_len = btrfs_file_extent_num_bytes(leaf, fi);
+ }
+ btrfs_release_path(path);
+
+ path->keep_locks = 1;
+ path->search_for_split = 1;
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ path->search_for_split = 0;
+ if (ret > 0)
+ ret = -EAGAIN;
+ if (ret < 0)
+ goto err;
+
+ ret = -EAGAIN;
+ leaf = path->nodes[0];
+ /* if our item isn't there, return now */
+ if (item_size != btrfs_item_size(leaf, path->slots[0]))
+ goto err;
+
+ /* the leaf has changed, it now has room. return now */
+ if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len)
+ goto err;
+
+ if (key.type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ if (extent_len != btrfs_file_extent_num_bytes(leaf, fi))
+ goto err;
+ }
+
+ ret = split_leaf(trans, root, &key, path, ins_len, 1);
+ if (ret)
+ goto err;
+
+ path->keep_locks = 0;
+ btrfs_unlock_up_safe(path, 1);
+ return 0;
+err:
+ path->keep_locks = 0;
return ret;
}
+static noinline int split_item(struct btrfs_path *path,
+ const struct btrfs_key *new_key,
+ unsigned long split_offset)
+{
+ struct extent_buffer *leaf;
+ int orig_slot, slot;
+ char *buf;
+ u32 nritems;
+ u32 item_size;
+ u32 orig_offset;
+ struct btrfs_disk_key disk_key;
+
+ leaf = path->nodes[0];
+ /*
+ * Shouldn't happen because the caller must have previously called
+ * setup_leaf_for_split() to make room for the new item in the leaf.
+ */
+ if (WARN_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)))
+ return -ENOSPC;
+
+ orig_slot = path->slots[0];
+ orig_offset = btrfs_item_offset(leaf, path->slots[0]);
+ item_size = btrfs_item_size(leaf, path->slots[0]);
+
+ buf = kmalloc(item_size, GFP_NOFS);
+ if (!buf)
+ return -ENOMEM;
+
+ read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
+ path->slots[0]), item_size);
+
+ slot = path->slots[0] + 1;
+ nritems = btrfs_header_nritems(leaf);
+ if (slot != nritems) {
+ /* shift the items */
+ memmove_leaf_items(leaf, slot + 1, slot, nritems - slot);
+ }
+
+ btrfs_cpu_key_to_disk(&disk_key, new_key);
+ btrfs_set_item_key(leaf, &disk_key, slot);
+
+ btrfs_set_item_offset(leaf, slot, orig_offset);
+ btrfs_set_item_size(leaf, slot, item_size - split_offset);
+
+ btrfs_set_item_offset(leaf, orig_slot,
+ orig_offset + item_size - split_offset);
+ btrfs_set_item_size(leaf, orig_slot, split_offset);
+
+ btrfs_set_header_nritems(leaf, nritems + 1);
+
+ /* write the data for the start of the original item */
+ write_extent_buffer(leaf, buf,
+ btrfs_item_ptr_offset(leaf, path->slots[0]),
+ split_offset);
+
+ /* write the data for the new item */
+ write_extent_buffer(leaf, buf + split_offset,
+ btrfs_item_ptr_offset(leaf, slot),
+ item_size - split_offset);
+ btrfs_mark_buffer_dirty(leaf);
+
+ BUG_ON(btrfs_leaf_free_space(leaf) < 0);
+ kfree(buf);
+ return 0;
+}
+
/*
* This function splits a single item into two items,
* giving 'new_key' to the new item and splitting the
@@ -2325,96 +4071,22 @@ int btrfs_split_item(struct btrfs_trans_handle *trans,
const struct btrfs_key *new_key,
unsigned long split_offset)
{
- u32 item_size;
- struct extent_buffer *leaf;
- struct btrfs_key orig_key;
- int ret = 0;
- int slot;
- u32 nritems;
- u32 orig_offset;
- struct btrfs_disk_key disk_key;
- char *buf;
+ int ret;
+ ret = setup_leaf_for_split(trans, root, path,
+ sizeof(struct btrfs_item));
+ if (ret)
+ return ret;
- leaf = path->nodes[0];
- btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
- if (btrfs_leaf_free_space(leaf) >=
- sizeof(struct btrfs_item))
- goto split;
-
- item_size = btrfs_item_size(leaf, path->slots[0]);
- btrfs_release_path(path);
-
- path->search_for_split = 1;
-
- ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
- path->search_for_split = 0;
-
- /* if our item isn't there or got smaller, return now */
- if (ret != 0 || item_size != btrfs_item_size(path->nodes[0],
- path->slots[0])) {
- return -EAGAIN;
- }
-
- ret = split_leaf(trans, root, &orig_key, path, 0, 0);
- BUG_ON(ret);
-
- BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item));
- leaf = path->nodes[0];
-
-split:
- orig_offset = btrfs_item_offset(leaf, path->slots[0]);
- item_size = btrfs_item_size(leaf, path->slots[0]);
-
-
- buf = kmalloc(item_size, GFP_NOFS);
- BUG_ON(!buf);
- read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
- path->slots[0]), item_size);
- slot = path->slots[0] + 1;
- leaf = path->nodes[0];
-
- nritems = btrfs_header_nritems(leaf);
-
- if (slot < nritems) {
- /* shift the items */
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, slot + 1),
- btrfs_item_nr_offset(leaf, slot),
- (nritems - slot) * sizeof(struct btrfs_item));
-
- }
-
- btrfs_cpu_key_to_disk(&disk_key, new_key);
- btrfs_set_item_key(leaf, &disk_key, slot);
-
- btrfs_set_item_offset(leaf, slot, orig_offset);
- btrfs_set_item_size(leaf, slot, item_size - split_offset);
-
- btrfs_set_item_offset(leaf, path->slots[0],
- orig_offset + item_size - split_offset);
- btrfs_set_item_size(leaf, path->slots[0], split_offset);
-
- btrfs_set_header_nritems(leaf, nritems + 1);
-
- /* write the data for the start of the original item */
- write_extent_buffer(leaf, buf,
- btrfs_item_ptr_offset(leaf, path->slots[0]),
- split_offset);
-
- /* write the data for the new item */
- write_extent_buffer(leaf, buf + split_offset,
- btrfs_item_ptr_offset(leaf, slot),
- item_size - split_offset);
- btrfs_mark_buffer_dirty(leaf);
-
- ret = 0;
- if (btrfs_leaf_free_space(leaf) < 0) {
- btrfs_print_leaf(leaf);
- BUG();
- }
- kfree(buf);
+ ret = split_item(path, new_key, split_offset);
return ret;
}
+/*
+ * make the item pointed to by the path smaller. new_size indicates
+ * how small to make it, and from_end tells us if we just chop bytes
+ * off the end of the item or if we shift the item to chop bytes off
+ * the front.
+ */
void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
{
int slot;
@@ -2425,6 +4097,7 @@ void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
unsigned int old_size;
unsigned int size_diff;
int i;
+ struct btrfs_map_token token;
leaf = path->nodes[0];
slot = path->slots[0];
@@ -2447,17 +4120,18 @@ void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
* item0..itemN ... dataN.offset..dataN.size .. data0.size
*/
/* first correct the data pointers */
+ btrfs_init_map_token(&token, leaf);
for (i = slot; i < nritems; i++) {
u32 ioff;
- ioff = btrfs_item_offset(leaf, i);
- btrfs_set_item_offset(leaf, i, ioff + size_diff);
+
+ ioff = btrfs_token_item_offset(&token, i);
+ btrfs_set_token_item_offset(&token, i, ioff + size_diff);
}
/* shift the data */
if (from_end) {
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) +
- data_end + size_diff, btrfs_item_nr_offset(leaf, 0) +
- data_end, old_data_start + new_size - data_end);
+ memmove_leaf_data(leaf, data_end + size_diff, data_end,
+ old_data_start + new_size - data_end);
} else {
struct btrfs_disk_key disk_key;
u64 offset;
@@ -2477,15 +4151,13 @@ void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
BTRFS_FILE_EXTENT_INLINE) {
ptr = btrfs_item_ptr_offset(leaf, slot);
memmove_extent_buffer(leaf, ptr,
- (unsigned long)fi,
- offsetof(struct btrfs_file_extent_item,
- disk_bytenr));
+ (unsigned long)fi,
+ BTRFS_FILE_EXTENT_INLINE_DATA_START);
}
}
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) +
- data_end + size_diff, btrfs_item_nr_offset(leaf, 0) +
- data_end, old_data_start - data_end);
+ memmove_leaf_data(leaf, data_end + size_diff, data_end,
+ old_data_start - data_end);
offset = btrfs_disk_key_offset(&disk_key);
btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
@@ -2503,6 +4175,9 @@ void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
}
}
+/*
+ * make the item pointed to by the path bigger, data_size is the added size.
+ */
void btrfs_extend_item(struct btrfs_path *path, u32 data_size)
{
int slot;
@@ -2512,6 +4187,7 @@ void btrfs_extend_item(struct btrfs_path *path, u32 data_size)
unsigned int old_data;
unsigned int old_size;
int i;
+ struct btrfs_map_token token;
leaf = path->nodes[0];
@@ -2528,24 +4204,26 @@ void btrfs_extend_item(struct btrfs_path *path, u32 data_size)
BUG_ON(slot < 0);
if (slot >= nritems) {
btrfs_print_leaf(leaf);
- printk("slot %d too large, nritems %u\n", slot, nritems);
- BUG_ON(1);
+ btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d",
+ slot, nritems);
+ BUG();
}
/*
* item0..itemN ... dataN.offset..dataN.size .. data0.size
*/
/* first correct the data pointers */
+ btrfs_init_map_token(&token, leaf);
for (i = slot; i < nritems; i++) {
u32 ioff;
- ioff = btrfs_item_offset(leaf, i);
- btrfs_set_item_offset(leaf, i, ioff - data_size);
+
+ ioff = btrfs_token_item_offset(&token, i);
+ btrfs_set_token_item_offset(&token, i, ioff - data_size);
}
/* shift the data */
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) +
- data_end - data_size, btrfs_item_nr_offset(leaf, 0) +
- data_end, old_data - data_end);
+ memmove_leaf_data(leaf, data_end - data_size, data_end,
+ old_data - data_end);
data_end = old_data;
old_size = btrfs_item_size(leaf, slot);
@@ -2559,59 +4237,63 @@ void btrfs_extend_item(struct btrfs_path *path, u32 data_size)
}
/*
- * Given a key and some data, insert an item into the tree.
- * This does all the path init required, making room in the tree if needed.
+ * Make space in the node before inserting one or more items.
+ *
+ * @root: root we are inserting items to
+ * @path: points to the leaf/slot where we are going to insert new items
+ * @batch: information about the batch of items to insert
+ *
+ * Main purpose is to save stack depth by doing the bulk of the work in a
+ * function that doesn't call btrfs_search_slot
*/
-int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- struct btrfs_path *path,
- const struct btrfs_item_batch *batch)
+static void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
+ const struct btrfs_item_batch *batch)
{
- struct extent_buffer *leaf;
- int ret = 0;
- int slot;
+ struct btrfs_fs_info *fs_info = root->fs_info;
int i;
u32 nritems;
- u32 total_size = 0;
unsigned int data_end;
struct btrfs_disk_key disk_key;
+ struct extent_buffer *leaf;
+ int slot;
+ struct btrfs_map_token token;
+ u32 total_size;
- /* create a root if there isn't one */
- if (!root->node)
- BUG();
-
- total_size = batch->total_data_size +
- (batch->nr * sizeof(struct btrfs_item));
- ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1);
- if (ret == 0) {
- return -EEXIST;
+ /*
+ * Before anything else, update keys in the parent and other ancestors
+ * if needed, then release the write locks on them, so that other tasks
+ * can use them while we modify the leaf.
+ */
+ if (path->slots[0] == 0) {
+ btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]);
+ fixup_low_keys(path, &disk_key, 1);
}
- if (ret < 0)
- goto out;
+ btrfs_unlock_up_safe(path, 1);
leaf = path->nodes[0];
+ slot = path->slots[0];
nritems = btrfs_header_nritems(leaf);
data_end = leaf_data_end(leaf);
+ total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item));
if (btrfs_leaf_free_space(leaf) < total_size) {
btrfs_print_leaf(leaf);
- printk("not enough freespace need %u have %d\n",
- total_size, btrfs_leaf_free_space(leaf));
+ btrfs_crit(fs_info, "not enough freespace need %u have %d",
+ total_size, btrfs_leaf_free_space(leaf));
BUG();
}
- slot = path->slots[0];
- BUG_ON(slot < 0);
-
- if (slot < nritems) {
+ btrfs_init_map_token(&token, leaf);
+ if (slot != nritems) {
unsigned int old_data = btrfs_item_data_end(leaf, slot);
if (old_data < data_end) {
btrfs_print_leaf(leaf);
- printk("slot %d old_data %u data_end %u\n",
- slot, old_data, data_end);
- BUG_ON(1);
+ btrfs_crit(fs_info,
+ "item at slot %d with data offset %u beyond data end of leaf %u",
+ slot, old_data, data_end);
+ BUG();
}
/*
* item0..itemN ... dataN.offset..dataN.size .. data0.size
@@ -2620,22 +4302,16 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
for (i = slot; i < nritems; i++) {
u32 ioff;
- ioff = btrfs_item_offset(leaf, i);
- btrfs_set_item_offset(leaf, i,
- ioff - batch->total_data_size);
+ ioff = btrfs_token_item_offset(&token, i);
+ btrfs_set_token_item_offset(&token, i,
+ ioff - batch->total_data_size);
}
-
/* shift the items */
- memmove_extent_buffer(leaf,
- btrfs_item_nr_offset(leaf, slot + batch->nr),
- btrfs_item_nr_offset(leaf, slot),
- (nritems - slot) * sizeof(struct btrfs_item));
+ memmove_leaf_items(leaf, slot + batch->nr, slot, nritems - slot);
/* shift the data */
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) +
- data_end - batch->total_data_size,
- btrfs_item_nr_offset(leaf, 0) +
- data_end, old_data - data_end);
+ memmove_leaf_data(leaf, data_end - batch->total_data_size,
+ data_end, old_data - data_end);
data_end = old_data;
}
@@ -2644,34 +4320,76 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
btrfs_cpu_key_to_disk(&disk_key, &batch->keys[i]);
btrfs_set_item_key(leaf, &disk_key, slot + i);
data_end -= batch->data_sizes[i];
- btrfs_set_item_offset(leaf, slot + i, data_end);
- btrfs_set_item_size(leaf, slot + i, batch->data_sizes[i]);
+ btrfs_set_token_item_offset(&token, slot + i, data_end);
+ btrfs_set_token_item_size(&token, slot + i, batch->data_sizes[i]);
}
+
btrfs_set_header_nritems(leaf, nritems + batch->nr);
btrfs_mark_buffer_dirty(leaf);
- ret = 0;
- if (slot == 0) {
- btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]);
- fixup_low_keys(path, &disk_key, 1);
- }
-
if (btrfs_leaf_free_space(leaf) < 0) {
btrfs_print_leaf(leaf);
BUG();
}
+}
-out:
- return ret;
+/*
+ * Insert a new item into a leaf.
+ *
+ * @root: The root of the btree.
+ * @path: A path pointing to the target leaf and slot.
+ * @key: The key of the new item.
+ * @data_size: The size of the data associated with the new key.
+ */
+void btrfs_setup_item_for_insert(struct btrfs_root *root,
+ struct btrfs_path *path,
+ const struct btrfs_key *key,
+ u32 data_size)
+{
+ struct btrfs_item_batch batch;
+
+ batch.keys = key;
+ batch.data_sizes = &data_size;
+ batch.total_data_size = data_size;
+ batch.nr = 1;
+
+ setup_items_for_insert(root, path, &batch);
+}
+
+/*
+ * Given a key and some data, insert items into the tree.
+ * This does all the path init required, making room in the tree if needed.
+ */
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ const struct btrfs_item_batch *batch)
+{
+ int ret = 0;
+ int slot;
+ u32 total_size;
+
+ total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item));
+ ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1);
+ if (ret == 0)
+ return -EEXIST;
+ if (ret < 0)
+ return ret;
+
+ slot = path->slots[0];
+ BUG_ON(slot < 0);
+
+ setup_items_for_insert(root, path, batch);
+ return 0;
}
/*
* Given a key and some data, insert an item into the tree.
* This does all the path init required, making room in the tree if needed.
*/
-int btrfs_insert_item(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, const struct btrfs_key *cpu_key,
- void *data, u32 data_size)
+int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ const struct btrfs_key *cpu_key, void *data,
+ u32 data_size)
{
int ret = 0;
struct btrfs_path *path;
@@ -2681,7 +4399,6 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans,
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
-
ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
if (!ret) {
leaf = path->nodes[0];
@@ -2693,28 +4410,79 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans,
return ret;
}
+/*
+ * This function duplicates an item, giving 'new_key' to the new item.
+ * It guarantees both items live in the same tree leaf and the new item is
+ * contiguous with the original item.
+ *
+ * This allows us to split a file extent in place, keeping a lock on the leaf
+ * the entire time.
+ */
+int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ const struct btrfs_key *new_key)
+{
+ struct extent_buffer *leaf;
+ int ret;
+ u32 item_size;
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size(leaf, path->slots[0]);
+ ret = setup_leaf_for_split(trans, root, path,
+ item_size + sizeof(struct btrfs_item));
+ if (ret)
+ return ret;
+
+ path->slots[0]++;
+ btrfs_setup_item_for_insert(root, path, new_key, item_size);
+ leaf = path->nodes[0];
+ memcpy_extent_buffer(leaf,
+ btrfs_item_ptr_offset(leaf, path->slots[0]),
+ btrfs_item_ptr_offset(leaf, path->slots[0] - 1),
+ item_size);
+ return 0;
+}
+
/*
* delete the pointer from a given node.
*
- * If the delete empties a node, the node is removed from the tree,
- * continuing all the way the root if required. The root is converted into
- * a leaf if all the nodes are emptied.
+ * the tree should have been previously balanced so the deletion does not
+ * empty a node.
+ *
+ * This is exported for use inside btrfs-progs, don't un-export it.
*/
int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot)
{
struct extent_buffer *parent = path->nodes[level];
u32 nritems;
+ int ret;
nritems = btrfs_header_nritems(parent);
- if (slot < nritems - 1) {
- /* shift the items */
+ if (slot != nritems - 1) {
+ if (level) {
+ ret = btrfs_tree_mod_log_insert_move(parent, slot,
+ slot + 1, nritems - slot - 1);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+ }
memmove_extent_buffer(parent,
btrfs_node_key_ptr_offset(parent, slot),
btrfs_node_key_ptr_offset(parent, slot + 1),
sizeof(struct btrfs_key_ptr) *
(nritems - slot - 1));
+ } else if (level) {
+ ret = btrfs_tree_mod_log_insert_key(parent, slot,
+ BTRFS_MOD_LOG_KEY_REMOVE);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
}
+
nritems--;
btrfs_set_header_nritems(parent, nritems);
if (nritems == 0 && parent == root->node) {
@@ -2728,7 +4496,6 @@ int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
fixup_low_keys(path, &disk_key, level + 1);
}
btrfs_mark_buffer_dirty(parent);
-
return 0;
}
@@ -2750,15 +4517,23 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
int ret;
WARN_ON(btrfs_header_generation(leaf) != trans->transid);
- btrfs_del_ptr(trans, root, path, 1, path->slots[1]);
+ ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * btrfs_free_extent is expensive, we want to make sure we
+ * aren't holding any locks when we call it
+ */
+ btrfs_unlock_up_safe(path, 0);
root_sub_used(root, leaf->len);
- ret = btrfs_free_extent(trans, leaf->start, leaf->len, 0,
- root->root_key.objectid, 0, 0);
- return ret;
+ atomic_inc(&leaf->refs);
+ btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1);
+ free_extent_buffer_stale(leaf);
+ return 0;
}
-
/*
* delete the item at the leaf level in path. If that empties
* the leaf, remove it from the tree
@@ -2766,41 +4541,37 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int slot, int nr)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *leaf;
- int last_off;
- int dsize = 0;
int ret = 0;
int wret;
- int i;
u32 nritems;
leaf = path->nodes[0];
- last_off = btrfs_item_offset(leaf, slot + nr - 1);
-
- for (i = 0; i < nr; i++)
- dsize += btrfs_item_size(leaf, slot + i);
-
nritems = btrfs_header_nritems(leaf);
if (slot + nr != nritems) {
- int data_end = leaf_data_end(leaf);
+ const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1);
+ const int data_end = leaf_data_end(leaf);
+ struct btrfs_map_token token;
+ u32 dsize = 0;
+ int i;
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) +
- data_end + dsize,
- btrfs_item_nr_offset(leaf, 0) + data_end,
- last_off - data_end);
+ for (i = 0; i < nr; i++)
+ dsize += btrfs_item_size(leaf, slot + i);
+ memmove_leaf_data(leaf, data_end + dsize, data_end,
+ last_off - data_end);
+
+ btrfs_init_map_token(&token, leaf);
for (i = slot + nr; i < nritems; i++) {
u32 ioff;
- ioff = btrfs_item_offset(leaf, i);
- btrfs_set_item_offset(leaf, i, ioff + dsize);
+ ioff = btrfs_token_item_offset(&token, i);
+ btrfs_set_token_item_offset(&token, i, ioff + dsize);
}
- memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, slot),
- btrfs_item_nr_offset(leaf, slot + nr),
- sizeof(struct btrfs_item) *
- (nritems - slot - nr));
+ memmove_leaf_items(leaf, slot, slot + nr, nritems - slot - nr);
}
btrfs_set_header_nritems(leaf, nritems - nr);
nritems -= nr;
@@ -2811,10 +4582,9 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
btrfs_set_header_level(leaf, 0);
} else {
btrfs_clear_buffer_dirty(trans, leaf);
- wret = btrfs_del_leaf(trans, root, path, leaf);
- BUG_ON(ret);
- if (wret)
- ret = wret;
+ ret = btrfs_del_leaf(trans, root, path, leaf);
+ if (ret < 0)
+ return ret;
}
} else {
int used = leaf_space_used(leaf, 0, nritems);
@@ -2825,35 +4595,69 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
fixup_low_keys(path, &disk_key, 1);
}
- /* delete the leaf if it is mostly empty */
- if (used < BTRFS_LEAF_DATA_SIZE(root->fs_info) / 4) {
+ /*
+ * Try to delete the leaf if it is mostly empty. We do this by
+ * trying to move all its items into its left and right neighbours.
+ * If we can't move all the items, then we don't delete it - it's
+ * not ideal, but future insertions might fill the leaf with more
+ * items, or items from other leaves might be moved later into our
+ * leaf due to deletions on those leaves.
+ */
+ if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) {
+ u32 min_push_space;
+
/* push_leaf_left fixes the path.
* make sure the path still points to our leaf
- * for possible call to del_ptr below
+ * for possible call to btrfs_del_ptr below
*/
slot = path->slots[1];
- extent_buffer_get(leaf);
-
- wret = push_leaf_left(trans, root, path, 1, 1);
+ atomic_inc(&leaf->refs);
+ /*
+ * We want to be able to at least push one item to the
+ * left neighbour leaf, and that's the first item.
+ */
+ min_push_space = sizeof(struct btrfs_item) +
+ btrfs_item_size(leaf, 0);
+ wret = push_leaf_left(trans, root, path, 0,
+ min_push_space, 1, (u32)-1);
if (wret < 0 && wret != -ENOSPC)
ret = wret;
if (path->nodes[0] == leaf &&
btrfs_header_nritems(leaf)) {
- wret = push_leaf_right(trans, root, path, 1, 1);
+ /*
+ * If we were not able to push all items from our
+ * leaf to its left neighbour, then attempt to
+ * either push all the remaining items to the
+ * right neighbour or none. There's no advantage
+ * in pushing only some items, instead of all, as
+ * it's pointless to end up with a leaf having
+ * too few items while the neighbours can be full
+ * or nearly full.
+ */
+ nritems = btrfs_header_nritems(leaf);
+ min_push_space = leaf_space_used(leaf, 0, nritems);
+ wret = push_leaf_right(trans, root, path, 0,
+ min_push_space, 1, 0);
if (wret < 0 && wret != -ENOSPC)
ret = wret;
}
if (btrfs_header_nritems(leaf) == 0) {
- btrfs_clear_buffer_dirty(trans, leaf);
path->slots[1] = slot;
ret = btrfs_del_leaf(trans, root, path, leaf);
- BUG_ON(ret);
+ if (ret < 0)
+ return ret;
free_extent_buffer(leaf);
-
+ ret = 0;
} else {
- btrfs_mark_buffer_dirty(leaf);
+ /* if we're still in the path, make sure
+ * we're dirty. Otherwise, one of the
+ * push_leaf functions must have already
+ * dirtied this buffer
+ */
+ if (path->nodes[0] == leaf)
+ btrfs_mark_buffer_dirty(leaf);
free_extent_buffer(leaf);
}
} else {
@@ -2864,124 +4668,419 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
}
/*
- * walk up the tree as far as required to find the previous leaf.
- * returns 0 if it found something or 1 if there are no lesser leaves.
- * returns < 0 on io errors.
+ * A helper function to walk down the tree starting at min_key, and looking
+ * for nodes or leaves that are have a minimum transaction id.
+ * This is used by the btree defrag code, and tree logging
+ *
+ * This does not cow, but it does stuff the starting key it finds back
+ * into min_key, so you can call btrfs_search_slot with cow=1 on the
+ * key and get a writable path.
+ *
+ * This honors path->lowest_level to prevent descent past a given level
+ * of the tree.
+ *
+ * min_trans indicates the oldest transaction that you are interested
+ * in walking through. Any nodes or leaves older than min_trans are
+ * skipped over (without reading them).
+ *
+ * returns zero if something useful was found, < 0 on error and 1 if there
+ * was nothing in the tree that matched the search criteria.
*/
-int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
+int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
+ struct btrfs_path *path,
+ u64 min_trans)
{
+ struct extent_buffer *cur;
+ struct btrfs_key found_key;
int slot;
- int level = 1;
- struct extent_buffer *c;
- struct extent_buffer *next = NULL;
+ int sret;
+ u32 nritems;
+ int level;
+ int ret = 1;
+ int keep_locks = path->keep_locks;
- while(level < BTRFS_MAX_LEVEL) {
- if (!path->nodes[level])
- return 1;
+ ASSERT(!path->nowait);
+ path->keep_locks = 1;
+again:
+ cur = btrfs_read_lock_root_node(root);
+ level = btrfs_header_level(cur);
+ WARN_ON(path->nodes[level]);
+ path->nodes[level] = cur;
+ path->locks[level] = BTRFS_READ_LOCK;
- slot = path->slots[level];
- c = path->nodes[level];
- if (slot == 0) {
- level++;
- if (level == BTRFS_MAX_LEVEL)
- return 1;
- continue;
- }
- slot--;
-
- next = btrfs_read_node_slot(c, slot);
- if (!extent_buffer_uptodate(next)) {
- if (IS_ERR(next))
- return PTR_ERR(next);
- return -EIO;
- }
- break;
+ if (btrfs_header_generation(cur) < min_trans) {
+ ret = 1;
+ goto out;
}
- path->slots[level] = slot;
- while(1) {
- level--;
- c = path->nodes[level];
- free_extent_buffer(c);
- slot = btrfs_header_nritems(next);
- if (slot != 0)
+ while (1) {
+ nritems = btrfs_header_nritems(cur);
+ level = btrfs_header_level(cur);
+ sret = btrfs_bin_search(cur, 0, min_key, &slot);
+ if (sret < 0) {
+ ret = sret;
+ goto out;
+ }
+
+ /* at the lowest level, we're done, setup the path and exit */
+ if (level == path->lowest_level) {
+ if (slot >= nritems)
+ goto find_next_key;
+ ret = 0;
+ path->slots[level] = slot;
+ btrfs_item_key_to_cpu(cur, &found_key, slot);
+ goto out;
+ }
+ if (sret && slot > 0)
slot--;
- path->nodes[level] = next;
- path->slots[level] = slot;
- if (!level)
+ /*
+ * check this node pointer against the min_trans parameters.
+ * If it is too old, skip to the next one.
+ */
+ while (slot < nritems) {
+ u64 gen;
+
+ gen = btrfs_node_ptr_generation(cur, slot);
+ if (gen < min_trans) {
+ slot++;
+ continue;
+ }
break;
- next = btrfs_read_node_slot(next, slot);
- if (!extent_buffer_uptodate(next)) {
- if (IS_ERR(next))
- return PTR_ERR(next);
- return -EIO;
}
+find_next_key:
+ /*
+ * we didn't find a candidate key in this node, walk forward
+ * and find another one
+ */
+ if (slot >= nritems) {
+ path->slots[level] = slot;
+ sret = btrfs_find_next_key(root, path, min_key, level,
+ min_trans);
+ if (sret == 0) {
+ btrfs_release_path(path);
+ goto again;
+ } else {
+ goto out;
+ }
+ }
+ /* save our key for returning back */
+ btrfs_node_key_to_cpu(cur, &found_key, slot);
+ path->slots[level] = slot;
+ if (level == path->lowest_level) {
+ ret = 0;
+ goto out;
+ }
+ cur = btrfs_read_node_slot(cur, slot);
+ if (IS_ERR(cur)) {
+ ret = PTR_ERR(cur);
+ goto out;
+ }
+
+ btrfs_tree_read_lock(cur);
+
+ path->locks[level - 1] = BTRFS_READ_LOCK;
+ path->nodes[level - 1] = cur;
+ unlock_up(path, level, 1, 0, NULL);
}
- return 0;
+out:
+ path->keep_locks = keep_locks;
+ if (ret == 0) {
+ btrfs_unlock_up_safe(path, path->lowest_level + 1);
+ memcpy(min_key, &found_key, sizeof(found_key));
+ }
+ return ret;
}
/*
- * Walk up the tree as far as necessary to find the next sibling tree block.
- * More generic version of btrfs_next_leaf(), as it could find sibling nodes
- * if @path->lowest_level is not 0.
+ * this is similar to btrfs_next_leaf, but does not try to preserve
+ * and fixup the path. It looks for and returns the next key in the
+ * tree based on the current path and the min_trans parameters.
*
- * returns 0 if it found something or 1 if there are no greater leaves.
- * returns < 0 on io errors.
+ * 0 is returned if another key is found, < 0 if there are any errors
+ * and 1 is returned if there are no higher keys in the tree
+ *
+ * path->keep_locks should be set to 1 on the search made before
+ * calling this function.
*/
-int btrfs_next_sibling_tree_block(struct btrfs_fs_info *fs_info,
- struct btrfs_path *path)
+int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *key, int level, u64 min_trans)
{
int slot;
- int level = path->lowest_level + 1;
struct extent_buffer *c;
- struct extent_buffer *next = NULL;
- BUG_ON(path->lowest_level + 1 >= BTRFS_MAX_LEVEL);
- do {
+ WARN_ON(!path->keep_locks && !path->skip_locking);
+ while (level < BTRFS_MAX_LEVEL) {
if (!path->nodes[level])
return 1;
+ slot = path->slots[level] + 1;
+ c = path->nodes[level];
+next:
+ if (slot >= btrfs_header_nritems(c)) {
+ int ret;
+ int orig_lowest;
+ struct btrfs_key cur_key;
+ if (level + 1 >= BTRFS_MAX_LEVEL ||
+ !path->nodes[level + 1])
+ return 1;
+
+ if (path->locks[level + 1] || path->skip_locking) {
+ level++;
+ continue;
+ }
+
+ slot = btrfs_header_nritems(c) - 1;
+ if (level == 0)
+ btrfs_item_key_to_cpu(c, &cur_key, slot);
+ else
+ btrfs_node_key_to_cpu(c, &cur_key, slot);
+
+ orig_lowest = path->lowest_level;
+ btrfs_release_path(path);
+ path->lowest_level = level;
+ ret = btrfs_search_slot(NULL, root, &cur_key, path,
+ 0, 0);
+ path->lowest_level = orig_lowest;
+ if (ret < 0)
+ return ret;
+
+ c = path->nodes[level];
+ slot = path->slots[level];
+ if (ret == 0)
+ slot++;
+ goto next;
+ }
+
+ if (level == 0)
+ btrfs_item_key_to_cpu(c, key, slot);
+ else {
+ u64 gen = btrfs_node_ptr_generation(c, slot);
+
+ if (gen < min_trans) {
+ slot++;
+ goto next;
+ }
+ btrfs_node_key_to_cpu(c, key, slot);
+ }
+ return 0;
+ }
+ return 1;
+}
+
+int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
+ u64 time_seq)
+{
+ int slot;
+ int level;
+ struct extent_buffer *c;
+ struct extent_buffer *next;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_key key;
+ bool need_commit_sem = false;
+ u32 nritems;
+ int ret;
+ int i;
+
+ /*
+ * The nowait semantics are used only for write paths, where we don't
+ * use the tree mod log and sequence numbers.
+ */
+ if (time_seq)
+ ASSERT(!path->nowait);
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (nritems == 0)
+ return 1;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+again:
+ level = 1;
+ next = NULL;
+ btrfs_release_path(path);
+
+ path->keep_locks = 1;
+
+ if (time_seq) {
+ ret = btrfs_search_old_slot(root, &key, path, time_seq);
+ } else {
+ if (path->need_commit_sem) {
+ path->need_commit_sem = 0;
+ need_commit_sem = true;
+ if (path->nowait) {
+ if (!down_read_trylock(&fs_info->commit_root_sem)) {
+ ret = -EAGAIN;
+ goto done;
+ }
+ } else {
+ down_read(&fs_info->commit_root_sem);
+ }
+ }
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ }
+ path->keep_locks = 0;
+
+ if (ret < 0)
+ goto done;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ /*
+ * by releasing the path above we dropped all our locks. A balance
+ * could have added more items next to the key that used to be
+ * at the very end of the block. So, check again here and
+ * advance the path if there are now more items available.
+ */
+ if (nritems > 0 && path->slots[0] < nritems - 1) {
+ if (ret == 0)
+ path->slots[0]++;
+ ret = 0;
+ goto done;
+ }
+ /*
+ * So the above check misses one case:
+ * - after releasing the path above, someone has removed the item that
+ * used to be at the very end of the block, and balance between leafs
+ * gets another one with bigger key.offset to replace it.
+ *
+ * This one should be returned as well, or we can get leaf corruption
+ * later(esp. in __btrfs_drop_extents()).
+ *
+ * And a bit more explanation about this check,
+ * with ret > 0, the key isn't found, the path points to the slot
+ * where it should be inserted, so the path->slots[0] item must be the
+ * bigger one.
+ */
+ if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) {
+ ret = 0;
+ goto done;
+ }
+
+ while (level < BTRFS_MAX_LEVEL) {
+ if (!path->nodes[level]) {
+ ret = 1;
+ goto done;
+ }
+
slot = path->slots[level] + 1;
c = path->nodes[level];
if (slot >= btrfs_header_nritems(c)) {
level++;
- if (level == BTRFS_MAX_LEVEL)
- return 1;
+ if (level == BTRFS_MAX_LEVEL) {
+ ret = 1;
+ goto done;
+ }
continue;
}
- if (path->reada)
- reada_for_search(fs_info, path, level, slot, 0);
- next = btrfs_read_node_slot(c, slot);
- if (!extent_buffer_uptodate(next))
- return -EIO;
+ /*
+ * Our current level is where we're going to start from, and to
+ * make sure lockdep doesn't complain we need to drop our locks
+ * and nodes from 0 to our current level.
+ */
+ for (i = 0; i < level; i++) {
+ if (path->locks[level]) {
+ btrfs_tree_read_unlock(path->nodes[i]);
+ path->locks[i] = 0;
+ }
+ free_extent_buffer(path->nodes[i]);
+ path->nodes[i] = NULL;
+ }
+
+ next = c;
+ ret = read_block_for_search(root, path, &next, level,
+ slot, &key);
+ if (ret == -EAGAIN && !path->nowait)
+ goto again;
+
+ if (ret < 0) {
+ btrfs_release_path(path);
+ goto done;
+ }
+
+ if (!path->skip_locking) {
+ ret = btrfs_try_tree_read_lock(next);
+ if (!ret && path->nowait) {
+ ret = -EAGAIN;
+ goto done;
+ }
+ if (!ret && time_seq) {
+ /*
+ * If we don't get the lock, we may be racing
+ * with push_leaf_left, holding that lock while
+ * itself waiting for the leaf we've currently
+ * locked. To solve this situation, we give up
+ * on our lock and cycle.
+ */
+ free_extent_buffer(next);
+ btrfs_release_path(path);
+ cond_resched();
+ goto again;
+ }
+ if (!ret)
+ btrfs_tree_read_lock(next);
+ }
break;
- } while (level < BTRFS_MAX_LEVEL);
+ }
path->slots[level] = slot;
- while(1) {
+ while (1) {
level--;
- c = path->nodes[level];
- free_extent_buffer(c);
path->nodes[level] = next;
path->slots[level] = 0;
- /*
- * Fsck will happily load corrupt blocks in order to fix them,
- * so we need an extra check just to make sure this block isn't
- * marked uptodate but invalid.
- */
- if (check_block(fs_info, path, level))
- return -EIO;
- if (level == path->lowest_level)
+ if (!path->skip_locking)
+ path->locks[level] = BTRFS_READ_LOCK;
+ if (!level)
break;
- if (path->reada)
- reada_for_search(fs_info, path, level, 0, 0);
- next = btrfs_read_node_slot(next, 0);
- if (!extent_buffer_uptodate(next))
- return -EIO;
+
+ ret = read_block_for_search(root, path, &next, level,
+ 0, &key);
+ if (ret == -EAGAIN && !path->nowait)
+ goto again;
+
+ if (ret < 0) {
+ btrfs_release_path(path);
+ goto done;
+ }
+
+ if (!path->skip_locking) {
+ if (path->nowait) {
+ if (!btrfs_try_tree_read_lock(next)) {
+ ret = -EAGAIN;
+ goto done;
+ }
+ } else {
+ btrfs_tree_read_lock(next);
+ }
+ }
}
+ ret = 0;
+done:
+ unlock_up(path, 0, 1, 0, NULL);
+ if (need_commit_sem) {
+ int ret2;
+
+ path->need_commit_sem = 1;
+ ret2 = finish_need_commit_sem_search(path);
+ up_read(&fs_info->commit_root_sem);
+ if (ret2)
+ ret = ret2;
+ }
+
+ return ret;
+}
+
+int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq)
+{
+ path->slots[0]++;
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0]))
+ return btrfs_next_old_leaf(root, path, time_seq);
return 0;
}
+/*
+ * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
+ * searching until it gets past min_objectid or finds an item of 'type'
+ *
+ * returns 0 if something is found, 1 if nothing was found and < 0 on error
+ */
int btrfs_previous_item(struct btrfs_root *root,
struct btrfs_path *path, u64 min_objectid,
int type)
@@ -2991,7 +5090,7 @@ int btrfs_previous_item(struct btrfs_root *root,
u32 nritems;
int ret;
- while(1) {
+ while (1) {
if (path->slots[0] == 0) {
ret = btrfs_prev_leaf(root, path);
if (ret != 0)
@@ -3020,7 +5119,7 @@ int btrfs_previous_item(struct btrfs_root *root,
/*
* search in extent tree to find a previous Metadata/Data extent item with
- * min objectid.
+ * min objecitd.
*
* returns 0 if something is found, 1 if nothing was found and < 0 on error
*/
@@ -3059,3 +5158,18 @@ int btrfs_previous_extent_item(struct btrfs_root *root,
}
return 1;
}
+
+int __init btrfs_ctree_init(void)
+{
+ btrfs_path_cachep = kmem_cache_create("btrfs_path",
+ sizeof(struct btrfs_path), 0,
+ SLAB_MEM_SPREAD, NULL);
+ if (!btrfs_path_cachep)
+ return -ENOMEM;
+ return 0;
+}
+
+void __cold btrfs_ctree_exit(void)
+{
+ kmem_cache_destroy(btrfs_path_cachep);
+}
@@ -1057,8 +1057,9 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
return btrfs_insert_empty_items(trans, root, path, &batch);
}
-int btrfs_next_sibling_tree_block(struct btrfs_fs_info *fs_info,
- struct btrfs_path *path);
+int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
+ u64 time_seq);
+int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
/*
* Walk up the tree as far as necessary to find the next leaf.
@@ -1069,33 +1070,48 @@ int btrfs_next_sibling_tree_block(struct btrfs_fs_info *fs_info,
static inline int btrfs_next_leaf(struct btrfs_root *root,
struct btrfs_path *path)
{
- path->lowest_level = 0;
- return btrfs_next_sibling_tree_block(root->fs_info, path);
+ return btrfs_next_old_leaf(root, path, 0);
}
static inline int btrfs_next_item(struct btrfs_root *root,
struct btrfs_path *p)
{
- ++p->slots[0];
- if (p->slots[0] >= btrfs_header_nritems(p->nodes[0])) {
- int ret;
- ret = btrfs_next_leaf(root, p);
- /*
- * Revert the increased slot, or the path may point to
- * an invalid item.
- */
- if (ret)
- p->slots[0]--;
- return ret;
- }
- return 0;
+ return btrfs_next_old_item(root, p, 0);
}
+int btrfs_block_can_be_shared(struct btrfs_root *root,
+ struct extent_buffer *buf);
int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
int btrfs_leaf_free_space(const struct extent_buffer *leaf);
void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info,
struct btrfs_path *path,
const struct btrfs_key *new_key);
+struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
+int btrfs_realloc_node(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *parent,
+ int start_slot, u64 *last_ret,
+ struct btrfs_key *progress);
+int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
+ struct btrfs_path *p, u64 time_seq);
+int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
+ struct btrfs_path *path);
+int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
+ struct btrfs_path *path);
+void btrfs_setup_item_for_insert(struct btrfs_root *root,
+ struct btrfs_path *path,
+ const struct btrfs_key *key,
+ u32 data_size);
+int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ const struct btrfs_key *new_key);
+int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
+ struct btrfs_path *path,
+ u64 min_trans);
+int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *key, int level, u64 min_trans);
+int __init btrfs_ctree_init(void);
+void __cold btrfs_ctree_exit(void);
int btrfs_super_csum_size(const struct btrfs_super_block *sb);
const char *btrfs_super_csum_name(u16 csum_type);
This copies the current copy of ctree.c into btrfs-progs. There are a few modifications, they are all hi-lighted by a "MODIFIED" tag in the code. - The btrfs_path_cachep is a static struct to avoid needing to call btrfs_ctree_init to be able to use stuff. - There is a single page optimization in the search that is not relevant in btrfs-progs. - We have a few warnings around trans->transaction, but we don't have this distinction in btrfs-progs yet. - Obvious include cleanups The rest is a straight copy, the only "modifications" that I didn't note were in ctree.h to clean up some of the inline helpers that use different functions. Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- kernel-shared/ctree.c | 4258 ++++++++++++++++++++++++++++++----------- kernel-shared/ctree.h | 50 +- 2 files changed, 3219 insertions(+), 1089 deletions(-)