@@ -274,18 +274,32 @@ struct io_ctl {
};
static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode,
- struct btrfs_root *root)
+ struct btrfs_root *root, int write)
{
+ int num_pages;
+ int check_crcs = 0;
+
+ num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
+ PAGE_CACHE_SHIFT;
+
+ if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
+ check_crcs = 1;
+
+ /* Make sure we can fit our crcs into the first page */
+ if (write && check_crcs &&
+ (num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
+ return -ENOSPC;
+
memset(io_ctl, 0, sizeof(struct io_ctl));
- io_ctl->num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT;
- io_ctl->pages = kzalloc(sizeof(struct page *) * io_ctl->num_pages,
- GFP_NOFS);
+
+ io_ctl->pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS);
if (!io_ctl->pages)
return -ENOMEM;
+
+ io_ctl->num_pages = num_pages;
io_ctl->root = root;
- if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
- io_ctl->check_crcs = 1;
+ io_ctl->check_crcs = check_crcs;
+
return 0;
}
@@ -677,7 +691,7 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
if (!num_entries)
return 0;
- ret = io_ctl_init(&io_ctl, inode, root);
+ ret = io_ctl_init(&io_ctl, inode, root, 0);
if (ret)
return ret;
@@ -957,19 +971,18 @@ fail:
}
static noinline_for_stack int
-add_ioctl_entries(struct btrfs_root *root,
- struct inode *inode,
- struct btrfs_block_group_cache *block_group,
- struct io_ctl *io_ctl,
- struct extent_state **cached_state,
- struct list_head *bitmap_list,
- int *entries)
+write_pinned_extent_entries(struct btrfs_root *root,
+ struct btrfs_block_group_cache *block_group,
+ struct io_ctl *io_ctl,
+ int *entries)
{
u64 start, extent_start, extent_end, len;
- struct list_head *pos, *n;
struct extent_io_tree *unpin = NULL;
int ret;
+ if (!block_group)
+ return 0;
+
/*
* We want to add any pinned extents to our free space cache
* so we don't leak the space
@@ -979,23 +992,19 @@ add_ioctl_entries(struct btrfs_root *root,
*/
unpin = root->fs_info->pinned_extents;
- if (block_group)
- start = block_group->key.objectid;
+ start = block_group->key.objectid;
- while (block_group && (start < block_group->key.objectid +
- block_group->key.offset)) {
+ while (start < block_group->key.objectid + block_group->key.offset) {
ret = find_first_extent_bit(unpin, start,
&extent_start, &extent_end,
EXTENT_DIRTY, NULL);
- if (ret) {
- ret = 0;
- break;
- }
+ if (ret)
+ return 0;
/* This pinned extent is out of our range */
if (extent_start >= block_group->key.objectid +
block_group->key.offset)
- break;
+ return 0;
extent_start = max(extent_start, start);
extent_end = min(block_group->key.objectid +
@@ -1005,11 +1014,20 @@ add_ioctl_entries(struct btrfs_root *root,
*entries += 1;
ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
if (ret)
- goto out_nospc;
+ return -ENOSPC;
start = extent_end;
}
+ return 0;
+}
+
+static noinline_for_stack int
+write_bitmap_entries(struct io_ctl *io_ctl, struct list_head *bitmap_list)
+{
+ struct list_head *pos, *n;
+ int ret;
+
/* Write out the bitmaps */
list_for_each_safe(pos, n, bitmap_list) {
struct btrfs_free_space *entry =
@@ -1017,36 +1035,24 @@ add_ioctl_entries(struct btrfs_root *root,
ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
if (ret)
- goto out_nospc;
+ return -ENOSPC;
list_del_init(&entry->list);
}
- /* Zero out the rest of the pages just to make sure */
- io_ctl_zero_remaining_pages(io_ctl);
-
- ret = btrfs_dirty_pages(root, inode, io_ctl->pages, io_ctl->num_pages,
- 0, i_size_read(inode), cached_state);
- io_ctl_drop_pages(io_ctl);
- unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
- i_size_read(inode) - 1, cached_state, GFP_NOFS);
+ return 0;
+}
- if (ret)
- goto fail;
+static int flush_dirty_cache(struct inode *inode)
+{
+ int ret;
ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
- if (ret) {
+ if (ret)
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
GFP_NOFS);
- goto fail;
- }
- return 0;
-fail:
- return -1;
-
-out_nospc:
- return -ENOSPC;
+ return ret;
}
static void noinline_for_stack
@@ -1056,6 +1062,7 @@ cleanup_write_cache_enospc(struct inode *inode,
struct list_head *bitmap_list)
{
struct list_head *pos, *n;
+
list_for_each_safe(pos, n, bitmap_list) {
struct btrfs_free_space *entry =
list_entry(pos, struct btrfs_free_space, list);
@@ -1088,18 +1095,15 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
{
struct extent_state *cached_state = NULL;
struct io_ctl io_ctl;
- struct list_head bitmap_list;
+ LIST_HEAD(bitmap_list);
int entries = 0;
int bitmaps = 0;
int ret;
- int err = -1;
-
- INIT_LIST_HEAD(&bitmap_list);
if (!i_size_read(inode))
return -1;
- ret = io_ctl_init(&io_ctl, inode, root);
+ ret = io_ctl_init(&io_ctl, inode, root, 1);
if (ret)
return -1;
@@ -1109,42 +1113,65 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
0, &cached_state);
-
- /* Make sure we can fit our crcs into the first page */
- if (io_ctl.check_crcs &&
- (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
- goto out_nospc;
-
io_ctl_set_generation(&io_ctl, trans->transid);
+ /* Write out the extent entries in the free space cache */
ret = write_cache_extent_entries(&io_ctl, ctl,
block_group, &entries, &bitmaps,
&bitmap_list);
if (ret)
goto out_nospc;
- ret = add_ioctl_entries(root, inode, block_group, &io_ctl,
- &cached_state, &bitmap_list, &entries);
+ /*
+ * Some spaces that are freed in the current transaction are pinned,
+ * they will be added into free space cache after the transaction is
+ * committed, we shouldn't lose them.
+ */
+ ret = write_pinned_extent_entries(root, block_group, &io_ctl, &entries);
+ if (ret)
+ goto out_nospc;
+
+ /* At last, we write out all the bitmaps. */
+ ret = write_bitmap_entries(&io_ctl, &bitmap_list);
+ if (ret)
+ goto out_nospc;
- if (ret == -ENOSPC)
+ /* Zero out the rest of the pages just to make sure */
+ io_ctl_zero_remaining_pages(&io_ctl);
+
+ /* Everything is written out, now we dirty the pages in the file. */
+ ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
+ 0, i_size_read(inode), &cached_state);
+ if (ret)
goto out_nospc;
- else if (ret)
+
+ /*
+ * Release the pages and unlock the extent, we will flush
+ * them out later
+ */
+ io_ctl_drop_pages(&io_ctl);
+
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+ i_size_read(inode) - 1, &cached_state, GFP_NOFS);
+
+ /* Flush the dirty pages in the cache file. */
+ ret = flush_dirty_cache(inode);
+ if (ret)
goto out;
- err = update_cache_item(trans, root, inode, path, offset,
+ /* Update the cache item to tell everyone this cache file is valid. */
+ ret = update_cache_item(trans, root, inode, path, offset,
entries, bitmaps);
-
out:
io_ctl_free(&io_ctl);
- if (err) {
+ if (ret) {
invalidate_inode_pages2(inode->i_mapping);
BTRFS_I(inode)->generation = 0;
}
btrfs_update_inode(trans, root, inode);
- return err;
+ return ret;
out_nospc:
-
cleanup_write_cache_enospc(inode, &io_ctl, &cached_state, &bitmap_list);
goto out;
}
This patch makes the free space cache write out functions more readable, and beisdes that, it also reduces the stack space that the function -- __btrfs_write_out_cache uses from 194bytes to 144bytes. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> --- fs/btrfs/free-space-cache.c | 159 ++++++++++++++++++++++++++------------------ 1 file changed, 93 insertions(+), 66 deletions(-)