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Revision 4d6c13f87db12ae1ce35ea6a15688ac72419b133 authored by Bryan Donlan on 30 June 2009, 18:41:24 UTC, committed by Linus Torvalds on 01 July 2009, 01:56:00 UTC 
ext2: return -EIO not -ESTALE on directory traversal through deleted inode
 
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
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>
1 parent 341c87b
Raw File
svcshare.c 
/*
 * linux/fs/lockd/svcshare.c
 *
 * Management of DOS shares.
 *
 * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/time.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/slab.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/share.h>

static inline int
nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
{
	return share->s_owner.len == oh->len
	    && !memcmp(share->s_owner.data, oh->data, oh->len);
}

__be32
nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
			struct nlm_args *argp)
{
	struct nlm_share	*share;
	struct xdr_netobj	*oh = &argp->lock.oh;
	u8			*ohdata;

	for (share = file->f_shares; share; share = share->s_next) {
		if (share->s_host == host && nlm_cmp_owner(share, oh))
			goto update;
		if ((argp->fsm_access & share->s_mode)
		 || (argp->fsm_mode   & share->s_access ))
			return nlm_lck_denied;
	}

	share = kmalloc(sizeof(*share) + oh->len,
						GFP_KERNEL);
	if (share == NULL)
		return nlm_lck_denied_nolocks;

	/* Copy owner handle */
	ohdata = (u8 *) (share + 1);
	memcpy(ohdata, oh->data, oh->len);

	share->s_file	    = file;
	share->s_host       = host;
	share->s_owner.data = ohdata;
	share->s_owner.len  = oh->len;
	share->s_next       = file->f_shares;
	file->f_shares      = share;

update:
	share->s_access = argp->fsm_access;
	share->s_mode   = argp->fsm_mode;
	return nlm_granted;
}

/*
 * Delete a share.
 */
__be32
nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
			struct nlm_args *argp)
{
	struct nlm_share	*share, **shpp;
	struct xdr_netobj	*oh = &argp->lock.oh;

	for (shpp = &file->f_shares; (share = *shpp) != NULL;
					shpp = &share->s_next) {
		if (share->s_host == host && nlm_cmp_owner(share, oh)) {
			*shpp = share->s_next;
			kfree(share);
			return nlm_granted;
		}
	}

	/* X/Open spec says return success even if there was no
	 * corresponding share. */
	return nlm_granted;
}

/*
 * Traverse all shares for a given file, and delete
 * those owned by the given (type of) host
 */
void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file,
		nlm_host_match_fn_t match)
{
	struct nlm_share	*share, **shpp;

	shpp = &file->f_shares;
	while ((share = *shpp) !=  NULL) {
		if (match(share->s_host, host)) {
			*shpp = share->s_next;
			kfree(share);
			continue;
		}
		shpp = &share->s_next;
	}
}
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