Commit de18f3b2 authored Apr 02, 2009 by Bryan Donlan Committed by Linus Torvalds Apr 02, 2009

ext3: return -EIO not -ESTALE on directory traversal through deleted inode



ext3_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 ext3_lookup to return -EIO if it receives -ESTALE
from ext3_iget(), as ext3 does for other filesystem metadata corruption;
and also invokes the appropriate ext*_error functions when this case is
detected.

Signed-off-by: Bryan Donlan <bdonlan@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 45f90217

fs/ext3/namei.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -1047,9 +1047,17 @@ 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))
		if (unlikely(IS_ERR(inode))) {
		if (PTR_ERR(inode) == -ESTALE) {
		ext3_error(dir->i_sb, __func__,
		"deleted inode referenced: %lu",
		ino);
		return ERR_PTR(-EIO);
		} else {
		return ERR_CAST(inode);
		}
		}
		}
		return d_splice_alias(inode, dentry);
		}