From 5662344b3c0d9ddd9afd48716d795166f982d5e2 Mon Sep 17 00:00:00 2001 From: Tsutomu Itoh Date: Fri, 13 Dec 2013 09:51:42 +0900 Subject: [PATCH] Btrfs: fix error check of btrfs_lookup_dentry() Clean up btrfs_lookup_dentry() to never return NULL, but PTR_ERR(-ENOENT) instead. This keeps the return value convention consistent. Callers who use btrfs_lookup_dentry() 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. Signed-off-by: Tsutomu Itoh Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 15 +++++++++++---- fs/btrfs/ioctl.c | 13 ++++++++++--- 2 files changed, 21 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e889779c9b37..2bd4f7590c83 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4992,7 +4992,7 @@ 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); @@ -5056,10 +5056,17 @@ static void btrfs_dentry_release(struct dentry *dentry) static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { - struct dentry *ret; + struct inode *inode; - ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry); - return ret; + 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 60d3d37ef9a2..89c2f6169b92 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -393,6 +393,7 @@ static noinline int create_subvol(struct inode *dir, struct btrfs_root *new_root; struct btrfs_block_rsv block_rsv; struct timespec cur_time = CURRENT_TIME; + struct inode *inode; int ret; int err; u64 objectid; @@ -554,8 +555,14 @@ fail: if (err && !ret) ret = err; - if (!ret) - d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); + if (!ret) { + inode = btrfs_lookup_dentry(dir, dentry); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + goto out; + } + d_instantiate(dentry, inode); + } out: btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved); return ret; @@ -643,7 +650,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, ret = PTR_ERR(inode); goto fail; } - BUG_ON(!inode); + d_instantiate(dentry, inode); ret = 0; fail: -- 2.20.1