[2/9] quota: fix e2fsck so we update the quota file correctly

Submitted by Theodore Ts'o on May 11, 2014, 4:32 a.m.

Details

Message ID 1399782773-20029-3-git-send-email-tytso@mit.edu
State Accepted, archived
Headers show

Commit Message

Theodore Ts'o May 11, 2014, 4:32 a.m.
In scan_dquota_callback() we were copying dqb_off from the on-disk
dquot structure to the dqot structure that we have constructed in
memory.  This is a bad idea, because if we detect that the quota inode
is corrupted and needs to be replaced, when we later write out the
inode, the fact that we have a non-zero dqb_off value means that quota
routines will not bother updating the quota tree index, since
presumably the quota tree index already has an entry for this dqot.

The problem is that e2fsck, the only user of these functions, has
zapped the quota inode so it can be written from scratch.  So this
means the index for the quota records are not written out, so the
kernel can not find any of the records in the quota inodes.  Oops.

The fix is simple; there is no reason to copy the dqb_off field into
the quota_dict copy of struct dquot.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: adityakali@google.com
---
 lib/quota/mkquota.c | 1 -
 1 file changed, 1 deletion(-)

Comments

Aditya Kali May 13, 2014, 6:35 a.m.
Looks good.

On Sat, May 10, 2014 at 9:32 PM, Theodore Ts'o <tytso@mit.edu> wrote:
> In scan_dquota_callback() we were copying dqb_off from the on-disk
> dquot structure to the dqot structure that we have constructed in
> memory.  This is a bad idea, because if we detect that the quota inode
> is corrupted and needs to be replaced, when we later write out the
> inode, the fact that we have a non-zero dqb_off value means that quota
> routines will not bother updating the quota tree index, since
> presumably the quota tree index already has an entry for this dqot.
>
> The problem is that e2fsck, the only user of these functions, has
> zapped the quota inode so it can be written from scratch.  So this
> means the index for the quota records are not written out, so the
> kernel can not find any of the records in the quota inodes.  Oops.
>
> The fix is simple; there is no reason to copy the dqb_off field into
> the quota_dict copy of struct dquot.
>
> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
> Cc: adityakali@google.com

Reviewed-by: Aditya Kali <adityakali@google.com>

Thanks!

> ---
>  lib/quota/mkquota.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/lib/quota/mkquota.c b/lib/quota/mkquota.c
> index 3849ae1..f77e072 100644
> --- a/lib/quota/mkquota.c
> +++ b/lib/quota/mkquota.c
> @@ -458,7 +458,6 @@ static int scan_dquots_callback(struct dquot *dquot, void *cb_data)
>
>         dq = get_dq(quota_dict, dquot->dq_id);
>         dq->dq_id = dquot->dq_id;
> -       dq->dq_dqb.u.v2_mdqb.dqb_off = dquot->dq_dqb.u.v2_mdqb.dqb_off;
>
>         print_dquot("mem", dq);
>         print_dquot("dsk", dquot);
> --
> 1.9.0
>

Patch hide | download patch | download mbox

diff --git a/lib/quota/mkquota.c b/lib/quota/mkquota.c
index 3849ae1..f77e072 100644
--- a/lib/quota/mkquota.c
+++ b/lib/quota/mkquota.c
@@ -458,7 +458,6 @@  static int scan_dquots_callback(struct dquot *dquot, void *cb_data)
 
 	dq = get_dq(quota_dict, dquot->dq_id);
 	dq->dq_id = dquot->dq_id;
-	dq->dq_dqb.u.v2_mdqb.dqb_off = dquot->dq_dqb.u.v2_mdqb.dqb_off;
 
 	print_dquot("mem", dq);
 	print_dquot("dsk", dquot);