Jan Kara 4c6bb69663 quota: Fix quota corruption with generic/232 test ... Eric has reported that since commit d2faa41516 "quota: Do not acquire dqio_sem for dquot overwrites in v2 format" test generic/232 occasionally fails due to quota information being incorrect. Indeed that commit was too eager to remove dqio_sem completely from the path that just overwrites quota structure with updated information. Although that is innocent on its own, another process that inserts new quota structure to the same block can perform read-modify-write cycle of that block thus effectively discarding quota information update if they race in a wrong way. Fix the problem by acquiring dqio_sem for reading for overwrites of quota structure. Note that it *is* possible to completely avoid taking dqio_sem in the overwrite path however that will require modifying path inserting / deleting quota structures to avoid RMW cycles of the full block and for now it is not clear whether it is worth the hassle. Fixes: d2faa41516 Reported-and-tested-by: Eric Whitney <enwlinux@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>		2017-09-27 11:33:47 +02:00
..
compat.c	quota: split out compat_sys_quotactl support from quota.c	2010-03-05 00:20:25 +01:00
dquot.c	quota: add missing lock into __dquot_transfer()	2017-09-18 12:23:58 +02:00
Kconfig	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
kqid.c	fs/quota: kernel-doc warning fixes	2014-07-15 22:40:23 +02:00
Makefile	userns: Implement struct kqid	2012-09-18 01:01:38 -07:00
netlink.c	genetlink: mark families as __ro_after_init	2016-10-27 16:16:09 -04:00
quota.c	VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)	2017-07-17 08:45:34 +01:00
quota_tree.c	quota: Reduce contention on dq_data_lock	2017-08-17 22:07:59 +02:00
quota_tree.h	quota: Change quota error message to print out disk and function name	2010-07-21 16:05:58 +02:00
quota_v1.c	quota: Fix possible corruption of dqi_flags	2017-08-17 22:00:04 +02:00
quota_v2.c	quota: Fix quota corruption with generic/232 test	2017-09-27 11:33:47 +02:00
quotaio_v1.h
quotaio_v2.h	vfs: Add general support to enforce project quota limits	2015-03-18 21:55:08 +01:00