From 3b96362cc8d314c935c335d5c3c42eb93c23166b Mon Sep 17 00:00:00 2001 From: Sven Wegener Date: Mon, 9 Jun 2008 21:57:42 -0400 Subject: [PATCH] Btrfs: Invalidate dcache entry after creating snapshot and We need to invalidate an existing dcache entry after creating a new snapshot or subvolume, because a negative dache entry will stop us from accessing the new snapshot or subvolume. --- ctree.h | 23 +++++++++++++++++++++++ inode.c | 4 ++++ transaction.c | 4 ++++ 3 files changed, 31 insertions(+) Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 3 +++ fs/btrfs/inode.c | 29 +++++++++++++++++++++++++++++ fs/btrfs/transaction.c | 8 +++++++- 3 files changed, 39 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 7b73a9c3d868..ad4eacca7f59 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1544,6 +1544,9 @@ int btrfs_csum_truncate(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 isize); /* inode.c */ +void btrfs_invalidate_dcache_root(struct btrfs_root *root, char *name, + int namelen); + int btrfs_merge_bio_hook(struct page *page, unsigned long offset, size_t size, struct bio *bio); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 1569fb864515..31aa4ba06fce 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2642,6 +2642,31 @@ static void btrfs_truncate(struct inode *inode) btrfs_throttle(root); } +/* + * Invalidate a single dcache entry at the root of the filesystem. + * Needed after creation of snapshot or subvolume. + */ +void btrfs_invalidate_dcache_root(struct btrfs_root *root, char *name, + int namelen) +{ + struct dentry *alias, *entry; + struct qstr qstr; + + alias = d_find_alias(root->fs_info->sb->s_root->d_inode); + if (alias) { + qstr.name = name; + qstr.len = namelen; + /* change me if btrfs ever gets a d_hash operation */ + qstr.hash = full_name_hash(qstr.name, qstr.len); + entry = d_lookup(alias, &qstr); + dput(alias); + if (entry) { + d_invalidate(entry); + dput(entry); + } + } +} + static int noinline create_subvol(struct btrfs_root *root, char *name, int namelen) { @@ -2761,6 +2786,10 @@ static int noinline create_subvol(struct btrfs_root *root, char *name, ret = btrfs_update_inode(trans, new_root, inode); if (ret) goto fail; + + /* Invalidate existing dcache entry for new subvolume. */ + btrfs_invalidate_dcache_root(root, name, namelen); + fail: nr = trans->blocks_used; err = btrfs_commit_transaction(trans, new_root); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 1cb084efd6ed..f04684f7fea3 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -560,6 +560,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root *root = pending->root; struct extent_buffer *tmp; int ret; + int namelen; u64 objectid; new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS); @@ -595,8 +596,9 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, * insert the directory item */ key.offset = (u64)-1; + namelen = strlen(pending->name); ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root, - pending->name, strlen(pending->name), + pending->name, namelen, root->fs_info->sb->s_root->d_inode->i_ino, &key, BTRFS_FT_DIR); @@ -606,6 +608,10 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root, pending->name, strlen(pending->name), objectid, root->fs_info->sb->s_root->d_inode->i_ino); + + /* Invalidate existing dcache entry for new snapshot. */ + btrfs_invalidate_dcache_root(root, pending->name, namelen); + fail: kfree(new_root_item); return ret; -- 2.20.1