[38/43] btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root

Message ID	20200117212602.6737-39-josef@toxicpanda.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=6qVc=3G=vger.kernel.org=linux-btrfs-owner@kernel.org> From: Josef Bacik <josef@toxicpanda.com> To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 38/43] btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root Date: Fri, 17 Jan 2020 16:25:57 -0500 Message-Id: <20200117212602.6737-39-josef@toxicpanda.com> In-Reply-To: <20200117212602.6737-1-josef@toxicpanda.com> References: <20200117212602.6737-1-josef@toxicpanda.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk
Series	Cleanup how we handle root refs, part 1 \| expand [00/43,v4] Cleanup how we handle root refs, part 1 [01/43] btrfs: push __setup_root into btrfs_alloc_root [02/43] btrfs: move fs root init stuff into btrfs_init_fs_root [03/43] btrfs: make btrfs_find_orphan_roots use btrfs_get_fs_root [04/43] btrfs: export and use btrfs_read_tree_root [05/43] btrfs: make relocation use btrfs_read_tree_root() [06/43] btrfs: kill btrfs_read_fs_root [07/43] btrfs: kill the btrfs_read_fs_root_no_name helper [08/43] btrfs: make the fs root init functions static [09/43] btrfs: handle NULL roots in btrfs_put/btrfs_grab_fs_root [10/43] btrfs: hold a ref on fs roots while they're in the radix tree [11/43] btrfs: hold a ref on the root in resolve_indirect_ref [12/43] btrfs: hold a root ref in btrfs_get_dentry [13/43] btrfs: hold a ref on the root in __btrfs_run_defrag_inode [14/43] btrfs: hold a ref on the root in fixup_tree_root_location [15/43] btrfs: hold a ref on the root in create_subvol [16/43] btrfs: hold a ref on the root in search_ioctl [17/43] btrfs: hold a ref on the root in btrfs_search_path_in_tree [18/43] btrfs: hold a ref on the root in btrfs_search_path_in_tree_user [19/43] btrfs: hold a ref on the root in btrfs_ioctl_get_subvol_info [20/43] btrfs: hold ref on root in btrfs_ioctl_default_subvol [21/43] btrfs: hold a ref on the root in build_backref_tree [22/43] btrfs: hold a ref on the root in prepare_to_merge [23/43] btrfs: hold a ref on the root in merge_reloc_roots [24/43] btrfs: hold a ref on the root in record_reloc_root_in_trans [25/43] btrfs: hold a ref on the root in find_data_references [26/43] btrfs: hold a ref on the root in create_reloc_inode [27/43] btrfs: hold a ref on the root in btrfs_recover_relocation [28/43] btrfs: push grab_fs_root into read_fs_root [29/43] btrfs: hold a ref for the root in btrfs_find_orphan_roots [30/43] btrfs: hold a ref on the root in scrub_print_warning_inode [31/43] btrfs: hold a ref on the root in btrfs_ioctl_send [32/43] btrfs: hold a ref on the root in get_subvol_name_from_objectid [33/43] btrfs: hold a ref on the root in create_pending_snapshot [34/43] btrfs: hold a ref on the root in btrfs_recover_log_trees [35/43] btrfs: hold a ref on the root in btrfs_check_uuid_tree_entry [36/43] btrfs: hold a ref on the root in open_ctree [37/43] btrfs: use btrfs_put_fs_root to free roots always [38/43] btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root [39/43] btrfs: free more things in btrfs_free_fs_info [40/43] btrfs: move fs_info init work into it's own helper function [41/43] btrfs: make the init of static elements in fs_info separate [42/43] btrfs: add a leak check for roots [43/43] btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 193747b6e1f9..b69154d72529 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -527,12 +527,6 @@ static int resolve_indirect_ref(struct btrfs_fs_info *fs_info, goto out_free; } - if (!btrfs_grab_fs_root(root)) { - srcu_read_unlock(&fs_info->subvol_srcu, index); - ret = -ENOENT; - goto out_free; - } - if (btrfs_is_testing(fs_info)) { srcu_read_unlock(&fs_info->subvol_srcu, index); ret = -ENOENT; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index fa721ca1e732..ac306807e5cd 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1496,6 +1496,8 @@ static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info, spin_lock(&fs_info->fs_roots_radix_lock); root = radix_tree_lookup(&fs_info->fs_roots_radix, (unsigned long)root_id); + if (root) + root = btrfs_grab_fs_root(root); spin_unlock(&fs_info->fs_roots_radix_lock); return root; } @@ -1552,29 +1554,31 @@ struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info, int ret; if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) - return fs_info->tree_root; + return btrfs_grab_fs_root(fs_info->tree_root); if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID) - return fs_info->extent_root; + return btrfs_grab_fs_root(fs_info->extent_root); if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID) - return fs_info->chunk_root; + return btrfs_grab_fs_root(fs_info->chunk_root); if (location->objectid == BTRFS_DEV_TREE_OBJECTID) - return fs_info->dev_root; + return btrfs_grab_fs_root(fs_info->dev_root); if (location->objectid == BTRFS_CSUM_TREE_OBJECTID) - return fs_info->csum_root; + return btrfs_grab_fs_root(fs_info->csum_root); if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID) - return fs_info->quota_root ? fs_info->quota_root : - ERR_PTR(-ENOENT); + return btrfs_grab_fs_root(fs_info->quota_root) ? + fs_info->quota_root : ERR_PTR(-ENOENT); if (location->objectid == BTRFS_UUID_TREE_OBJECTID) - return fs_info->uuid_root ? fs_info->uuid_root : - ERR_PTR(-ENOENT); + return btrfs_grab_fs_root(fs_info->uuid_root) ? + fs_info->uuid_root : ERR_PTR(-ENOENT); if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) - return fs_info->free_space_root ? fs_info->free_space_root : - ERR_PTR(-ENOENT); + return btrfs_grab_fs_root(fs_info->free_space_root) ? + fs_info->free_space_root : ERR_PTR(-ENOENT); again: root = btrfs_lookup_fs_root(fs_info, location->objectid); if (root) { - if (check_ref && btrfs_root_refs(&root->root_item) == 0) + if (check_ref && btrfs_root_refs(&root->root_item) == 0) { + btrfs_put_fs_root(root); return ERR_PTR(-ENOENT); + } return root; } @@ -1607,8 +1611,18 @@ struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info, if (ret == 0) set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state); + /* + * All roots have two refs on them at all times, one for the mounted fs, + * and one for being in the radix tree. This way we only free the root + * when we are unmounting or deleting the subvolume. We get one ref + * from __setup_root, one for inserting it into the radix tree, and then + * we have the third for returning it, and the caller will put it when + * it's done with the root. + */ + btrfs_grab_fs_root(root); ret = btrfs_insert_fs_root(fs_info, root); if (ret) { + btrfs_put_fs_root(root); if (ret == -EEXIST) { btrfs_free_fs_root(root); goto again; @@ -3204,13 +3218,6 @@ int __cold open_ctree(struct super_block *sb, goto fail_qgroup; } - if (!btrfs_grab_fs_root(fs_info->fs_root)) { - fs_info->fs_root = NULL; - err = -ENOENT; - btrfs_warn(fs_info, "failed to grab a ref on the fs tree"); - goto fail_qgroup; - } - if (sb_rdonly(sb)) return 0; diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index eba6c6d27bad..f07c2300ade2 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -82,10 +82,6 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, err = PTR_ERR(root); goto fail; } - if (!btrfs_grab_fs_root(root)) { - err = -ENOENT; - goto fail; - } key.objectid = objectid; key.type = BTRFS_INODE_ITEM_KEY; diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 3abc7986052b..682f21ee6034 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -292,10 +292,6 @@ static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info, ret = PTR_ERR(inode_root); goto cleanup; } - if (!btrfs_grab_fs_root(inode_root)) { - ret = -ENOENT; - goto cleanup; - } key.objectid = defrag->ino; key.type = BTRFS_INODE_ITEM_KEY; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 85104886c1e7..c01dc2790a40 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -5026,10 +5026,6 @@ static int fixup_tree_root_location(struct btrfs_fs_info *fs_info, err = PTR_ERR(new_root); goto out; } - if (!btrfs_grab_fs_root(new_root)) { - err = -ENOENT; - goto out; - } *sub_root = new_root; location->objectid = btrfs_root_dirid(&new_root->root_item); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 47953d022328..20861cabe6a1 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -672,11 +672,6 @@ static noinline int create_subvol(struct inode *dir, btrfs_abort_transaction(trans, ret); goto fail; } - if (!btrfs_grab_fs_root(new_root)) { - ret = -ENOENT; - btrfs_abort_transaction(trans, ret); - goto fail; - } btrfs_record_root_in_trans(trans, new_root); @@ -2191,10 +2186,6 @@ static noinline int search_ioctl(struct inode *inode, btrfs_free_path(path); return PTR_ERR(root); } - if (!btrfs_grab_fs_root(root)) { - btrfs_free_path(path); - return -ENOENT; - } } key.objectid = sk->min_objectid; @@ -2332,11 +2323,6 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info, root = NULL; goto out; } - if (!btrfs_grab_fs_root(root)) { - ret = -ENOENT; - root = NULL; - goto out; - } key.objectid = dirid; key.type = BTRFS_INODE_REF_KEY; @@ -2433,10 +2419,6 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, ret = PTR_ERR(root); goto out; } - if (!btrfs_grab_fs_root(root)) { - ret = -ENOENT; - goto out; - } key.objectid = dirid; key.type = BTRFS_INODE_REF_KEY; @@ -2686,10 +2668,6 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp) ret = PTR_ERR(root); goto out_free; } - if (!btrfs_grab_fs_root(root)) { - ret = -ENOENT; - goto out; - } root_item = &root->root_item; subvol_info->treeid = key.objectid; @@ -4019,10 +3997,6 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) ret = PTR_ERR(new_root); goto out; } - if (!btrfs_grab_fs_root(root)) { - ret = -ENOENT; - goto out; - } if (!is_fstree(new_root->root_key.objectid)) { ret = -ENOENT; goto out_free; diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index d166cc742f75..c08aeb83a8f7 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -613,7 +613,6 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, u64 root_objectid) { struct btrfs_key key; - struct btrfs_root *root; key.objectid = root_objectid; key.type = BTRFS_ROOT_ITEM_KEY; @@ -622,12 +621,7 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, else key.offset = (u64)-1; - root = btrfs_get_fs_root(fs_info, &key, false); - if (IS_ERR(root)) - return root; - if (!btrfs_grab_fs_root(root)) - return ERR_PTR(-ENOENT); - return root; + return btrfs_get_fs_root(fs_info, &key, false); } static noinline_for_stack diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 25842527fd42..fca8334cb34d 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -257,8 +257,6 @@ int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info) root = btrfs_get_fs_root(fs_info, &root_key, false); err = PTR_ERR_OR_ZERO(root); - if (!err && !btrfs_grab_fs_root(root)) - err = -ENOENT; if (err && err != -ENOENT) { break; } else if (err == -ENOENT) { diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index f9ee327d7978..4f21f0b04a17 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -658,10 +658,6 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, ret = PTR_ERR(local_root); goto err; } - if (!btrfs_grab_fs_root(local_root)) { - ret = -ENOENT; - goto err; - } /* * this makes the path point to (inum INODE_ITEM ioff) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index ee2fc9ea9d7e..5ef4c6f75ecd 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -7200,11 +7200,6 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) ret = PTR_ERR(clone_root); goto out; } - if (!btrfs_grab_fs_root(clone_root)) { - srcu_read_unlock(&fs_info->subvol_srcu, index); - ret = -ENOENT; - goto out; - } spin_lock(&clone_root->root_item_lock); if (!btrfs_root_readonly(clone_root) || btrfs_root_dead(clone_root)) { @@ -7246,12 +7241,6 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) ret = PTR_ERR(sctx->parent_root); goto out; } - if (!btrfs_grab_fs_root(sctx->parent_root)) { - srcu_read_unlock(&fs_info->subvol_srcu, index); - ret = -ENOENT; - sctx->parent_root = ERR_PTR(ret); - goto out; - } spin_lock(&sctx->parent_root->root_item_lock); sctx->parent_root->send_in_progress++; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 0c81456df23e..8ce292a47634 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1101,10 +1101,6 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ret = PTR_ERR(fs_root); goto err; } - if (!btrfs_grab_fs_root(fs_root)) { - ret = -ENOENT; - goto err; - } /* * Walk up the filesystem tree by inode refs until we hit the diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 7008def3391b..e194d3e4e3a9 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1637,12 +1637,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, btrfs_abort_transaction(trans, ret); goto fail; } - if (!btrfs_grab_fs_root(pending->snap)) { - ret = -ENOENT; - pending->snap = NULL; - btrfs_abort_transaction(trans, ret); - goto fail; - } ret = btrfs_reloc_post_snapshot(trans, pending); if (ret) { diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index f06ad415faf8..e7525689b1e8 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -6114,10 +6114,6 @@ int btrfs_recover_log_trees(struct btrfs_root *log_root_tree) tmp_key.offset = (u64)-1; wc.replay_dest = btrfs_get_fs_root(fs_info, &tmp_key, true); - if (!IS_ERR(wc.replay_dest)) { - if (!btrfs_grab_fs_root(wc.replay_dest)) - wc.replay_dest = ERR_PTR(-ENOENT); - } if (IS_ERR(wc.replay_dest)) { ret = PTR_ERR(wc.replay_dest); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 527b0b41ebdc..4a922b9f6e2c 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4382,10 +4382,6 @@ static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info, ret = 1; goto out; } - if (!btrfs_grab_fs_root(subvol_root)) { - ret = 1; - goto out; - } switch (type) { case BTRFS_UUID_KEY_SUBVOL:

[38/43] btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root

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