[PATCH 6/8] btrfs: fix error check of btrfs_lookup_dentry()
From: Mark Fasheh <hidden>
Date: 2011-08-18 21:56:59
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
From: Tsutomu Itoh <redacted> Clean up btrfs_lookup_dentry() to never return NULL, but PTR_ERR(-ENOENT) instead. This keeps the return value convention consistent. Callers who pass to d_instatiate() require a trivial update. create_snapshot() in particular looks like it can also lose a BUG_ON(!inode) which is not really needed - there seems less harm in returning ENOENT to userspace at that point in the stack than there is to crash the machine. Mark: Fixed conflicts against latest tree, gave the patch a more thorough description. Signed-off-by: Tsutomu Itoh <redacted> Signed-off-by: Mark Fasheh <redacted> --- fs/btrfs/inode.c | 12 ++++++++++-- fs/btrfs/ioctl.c | 11 +++++++++-- 2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7028c0c..9f3a85d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c@@ -4027,7 +4027,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) return ERR_PTR(ret); if (location.objectid == 0) - return NULL; + return ERR_PTR(-ENOENT); if (location.type == BTRFS_INODE_ITEM_KEY) { inode = btrfs_iget(dir->i_sb, &location, root, NULL);
@@ -4085,7 +4085,15 @@ static void btrfs_dentry_release(struct dentry *dentry) static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { - return d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry); + struct inode *inode = btrfs_lookup_dentry(dir, dentry); + if (IS_ERR(inode)) { + if (PTR_ERR(inode) == -ENOENT) + inode = NULL; + else + return ERR_CAST(inode); + } + + return d_splice_alias(inode, dentry); } unsigned char btrfs_filetype_table[] = {
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b3440f5..692eac2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c@@ -325,6 +325,7 @@ static noinline int create_subvol(struct btrfs_root *root, struct btrfs_root *new_root; struct dentry *parent = dentry->d_parent; struct inode *dir; + struct inode *inode; int ret; int err; u64 objectid;
@@ -435,7 +436,13 @@ static noinline int create_subvol(struct btrfs_root *root, BUG_ON(ret); - d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); + inode = btrfs_lookup_dentry(dir, dentry); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + goto fail; + } + + d_instantiate(dentry, inode); fail: if (async_transid) { *async_transid = trans->transid;
@@ -505,7 +512,7 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, ret = PTR_ERR(inode); goto fail; } - BUG_ON(!inode); + d_instantiate(dentry, inode); ret = 0; fail:
--
1.7.6