From 5662344b3c0d9ddd9afd48716d795166f982d5e2 Mon Sep 17 00:00:00 2001
From: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Date: Fri, 13 Dec 2013 09:51:42 +0900
Subject: 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 <t-itoh@jp.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
---
fs/btrfs/inode.c | 15 +++++++++++----
fs/btrfs/ioctl.c | 13 ++++++++++---
2 files changed, 21 insertions(+), 7 deletions(-)
(limited to 'fs')
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e889779..2bd4f75 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 60d3d37..89c2f61 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:
--
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