2009-02-18 00:09:48

by Andrew Morton

[permalink] [raw]
Subject: + ext2-return-eio-not-estale-on-directory-traversal-through-deleted-inode.patch added to -mm tree

The patch titled
ext2: return -EIO not -ESTALE on directory traversal through deleted inode
has been added to the -mm tree. Its filename is

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Subject: ext2: return -EIO not -ESTALE on directory traversal through deleted inode
From: Bryan Donlan <[email protected]>

ext2_iget() returns -ESTALE if invoked on a deleted inode, in order to
report errors to NFS properly. However, in ext[234]_lookup(), this
-ESTALE can be propagated to userspace if the filesystem is corrupted such
that a directory entry references a deleted inode. This leads to a
misleading error message - "Stale NFS file handle" - and confusion on the
part of the admin.

The bug can be easily reproduced by creating a new filesystem, making a
link to an unused inode using debugfs, then mounting and attempting to ls
-l said link.

This patch thus changes ext2_lookup to return -EIO if it receives -ESTALE
from ext2_iget(), as ext2 does for other filesystem metadata corruption;
and also invokes the appropriate ext*_error functions when this case is

Signed-off-by: Bryan Donlan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

fs/ext2/namei.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff -puN fs/ext2/namei.c~ext2-return-eio-not-estale-on-directory-traversal-through-deleted-inode fs/ext2/namei.c
--- a/fs/ext2/namei.c~ext2-return-eio-not-estale-on-directory-traversal-through-deleted-inode
+++ a/fs/ext2/namei.c
@@ -66,8 +66,16 @@ static struct dentry *ext2_lookup(struct
inode = NULL;
if (ino) {
inode = ext2_iget(dir->i_sb, ino);
- if (IS_ERR(inode))
- return ERR_CAST(inode);
+ if (unlikely(IS_ERR(inode))) {
+ if (PTR_ERR(inode) == -ESTALE) {
+ ext2_error(dir->i_sb, "ext2_lookup",
+ "deleted inode referenced: %lu",
+ ino);
+ return ERR_PTR(-EIO);
+ } else {
+ return ERR_CAST(inode);
+ }
+ }
return d_splice_alias(inode, dentry);

Patches currently in -mm which might be from [email protected] are