Jan Kara 54499e71ec quota: Fix race between dqput() and dquot_scan_active() ... commit 1362f4ea20 upstream. Currently last dqput() can race with dquot_scan_active() causing it to call callback for an already deactivated dquot. The race is as follows: CPU1 CPU2 dqput() spin_lock(&dq_list_lock); if (atomic_read(&dquot->dq_count) > 1) { - not taken if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { spin_unlock(&dq_list_lock); ->release_dquot(dquot); if (atomic_read(&dquot->dq_count) > 1) - not taken dquot_scan_active() spin_lock(&dq_list_lock); if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) - not taken atomic_inc(&dquot->dq_count); spin_unlock(&dq_list_lock); - proceeds to release dquot ret = fn(dquot, priv); - called for inactive dquot Fix the problem by making sure possible ->release_dquot() is finished by the time we call the callback and new calls to it will notice reference dquot_scan_active() has taken and bail out. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-03-11 16:10:02 -07:00
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compat.c	quota: split out compat_sys_quotactl support from quota.c	2010-03-05 00:20:25 +01:00
dquot.c	quota: Fix race between dqput() and dquot_scan_active()	2014-03-11 16:10:02 -07:00
Kconfig	quota: Make QUOTACTL config be selected by its users	2010-10-05 12:16:37 +02:00
Makefile	quota: split out compat_sys_quotactl support from quota.c	2010-03-05 00:20:25 +01:00
netlink.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
quota.c	Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs	2012-03-23 09:19:22 -07:00
quota_tree.c	quota: Use %pV and __attribute__((format (printf in __quota_error and fix fallout	2011-01-10 19:04:05 +01:00
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: Change quota error message to print out disk and function name	2010-07-21 16:05:58 +02:00
quota_v2.c	quota: return -ENOMEM when memory allocation fails	2011-02-24 11:42:44 +01:00
quotaio_v1.h
quotaio_v2.h	quota: Implement quota format with 64-bit space and inode limits	2009-12-10 15:02:54 +01:00