The ext[234]_iget() functions in the ext[234] family of filesystems 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, and a inode is linked even
though it is marked as deleted. 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 ext[234]_lookup to return -EIO if it receives -ESTALE
from ext[234]_iget(), as ext[234] does for other filesystem metadata
corruption.
Signed-off-by: Bryan Donlan <bdonlan@xxxxxxxxx>
---
Apologies for the resend so quickly for those on the CC list - my mailer was
misconfigured and the mail rejected by vger.
fs/ext2/namei.c | 8 ++++++--
fs/ext3/namei.c | 8 ++++++--
fs/ext4/namei.c | 8 ++++++--
3 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 90ea179..7dab3e8 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -66,8 +66,12 @@ static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, str
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)
+ return ERR_PTR(-EIO);
+ else
+ return ERR_CAST(inode);
+ }
}
return d_splice_alias(inode, dentry);
}
diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index 4db4ffa..625f5dc 100644
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -1047,8 +1047,12 @@ static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry, str
return ERR_PTR(-EIO);
}
inode = ext3_iget(dir->i_sb, ino);
- if (IS_ERR(inode))
- return ERR_CAST(inode);
+ if (unlikely(IS_ERR(inode))) {
+ if (PTR_ERR(inode) == -ESTALE)
+ return ERR_PTR(-EIO);
+ else
+ return ERR_CAST(inode);
+ }
}
return d_splice_alias(inode, dentry);
}
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index ba702bd..4b054b3 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1052,8 +1052,12 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, stru
return ERR_PTR(-EIO);
}
inode = ext4_iget(dir->i_sb, ino);
- if (IS_ERR(inode))
- return ERR_CAST(inode);
+ if (unlikely(IS_ERR(inode))) {
+ if (PTR_ERR(inode) == -ESTALE)
+ return ERR_PTR(-EIO);
+ else
+ return ERR_CAST(inode);
+ }
}
return d_splice_alias(inode, dentry);
}
--
1.5.6.3
--
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