github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

tmpfs: keep the quota soft limits of an unused id

Browse Source 
When the last reference to a dquot goes away, shmem_release_dquot()
stores its limits in the rb tree of the mount, unless
shmem_is_empty_dquot() says that there is nothing worth storing. That
function looks at the usage and at the two hard limits only.

So if the administrator sets nothing but soft limits for an id that owns
no file yet, the entry is thrown away as soon as the dquot that
Q_SETQUOTA used is released, and the id never gets to see a limit.

To fix it, compare the soft limits as well: an entry can be empty only if
both soft limits are zero as well, which is exactly what
shmem_acquire_dquot() sets for a new entry.

Fix generated by an LLM and sent by Josef Bacik in private.

Fixes: de4c0e7ca8 ("shmem: Add default quota limit mount options")
Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Gregory Price (Meta) <gourry@gourry.net>
[ david: slightly adjusted description ]
Link: https://patch.msgid.link/20261029-fixes_shmem-v4-2-392fc715d8f6@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
This commit is contained in:
Josef Bacik 2026-10-29 11:43:23 +01:00 committed by David Hildenbrand (Arm)
parent 68b2aa37af
commit 968d734630
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
mm/shmem_quota.c
View File

@ -256,6 +256,8 @@ static bool shmem_is_empty_dquot(struct dquot *dquot)
if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
(dquot->dq_dqb.dqb_curspace == 0 &&
dquot->dq_dqb.dqb_curinodes == 0 &&
dquot->dq_dqb.dqb_bsoftlimit == 0 &&
dquot->dq_dqb.dqb_isoftlimit == 0 &&
dquot->dq_dqb.dqb_bhardlimit == bhardlimit &&
dquot->dq_dqb.dqb_ihardlimit == ihardlimit))
return true;