Commit fcaf3b26 authored by Jan Kara's avatar Jan Kara Committed by Andrew Morton
Browse files

ocfs2: stop quota recovery before disabling quotas 

Currently quota recovery is synchronized with unmount using sb->s_umount
semaphore.  That is however prone to deadlocks because
flush_workqueue(osb->ocfs2_wq) called from umount code can wait for quota
recovery to complete while ocfs2_finish_quota_recovery() waits for
sb->s_umount semaphore.

Grabbing of sb->s_umount semaphore in ocfs2_finish_quota_recovery() is
only needed to protect that function from disabling of quotas from
ocfs2_dismount_volume().  Handle this problem by disabling quota recovery
early during unmount in ocfs2_dismount_volume() instead so that we can
drop acquisition of sb->s_umount from ocfs2_finish_quota_recovery().

Link: https://lkml.kernel.org/r/20250424134515.18933-6-jack@suse.cz


Fixes: 5f530de6 ("ocfs2: Use s_umount for quota recovery protection")
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Reported-by: default avatarShichangkuo <shi.changkuo@h3c.com>
Reported-by: default avatarMurad Masimov <m.masimov@mt-integration.ru>
Reviewed-by: default avatarHeming Zhao <heming.zhao@suse.com>
Tested-by: default avatarHeming Zhao <heming.zhao@suse.com>
Acked-by: default avatarJoseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 8f947e0f

fs/ocfs2/journal.c

+18 −2
Original line number Diff line number Diff line
@@ -225,6 +225,11 @@ static void ocfs2_recovery_disable(struct ocfs2_super *osb, 
		flush_workqueue(osb->ocfs2_wq);

}



void ocfs2_recovery_disable_quota(struct ocfs2_super *osb)

{

	ocfs2_recovery_disable(osb, OCFS2_REC_QUOTA_WANT_DISABLE);

}



void ocfs2_recovery_exit(struct ocfs2_super *osb)

{

	struct ocfs2_recovery_map *rm;
@@ -1489,6 +1494,18 @@ static int __ocfs2_recovery_thread(void *arg) 
		}

	}

restart:

	if (quota_enabled) {

		mutex_lock(&osb->recovery_lock);

		/* Confirm that recovery thread will no longer recover quotas */

		if (osb->recovery_state == OCFS2_REC_QUOTA_WANT_DISABLE) {

			osb->recovery_state = OCFS2_REC_QUOTA_DISABLED;

			wake_up(&osb->recovery_event);

		}

		if (osb->recovery_state >= OCFS2_REC_QUOTA_DISABLED)

			quota_enabled = 0;

		mutex_unlock(&osb->recovery_lock);

	}



	status = ocfs2_super_lock(osb, 1);

	if (status < 0) {

		mlog_errno(status);
@@ -1592,7 +1609,6 @@ static int __ocfs2_recovery_thread(void *arg) 


	mutex_unlock(&osb->recovery_lock);



	if (quota_enabled)

	kfree(rm_quota);



	return status;

fs/ocfs2/journal.h

+1 −0
Original line number Diff line number Diff line
@@ -148,6 +148,7 @@ void ocfs2_wait_for_recovery(struct ocfs2_super *osb); 


int ocfs2_recovery_init(struct ocfs2_super *osb);

void ocfs2_recovery_exit(struct ocfs2_super *osb);

void ocfs2_recovery_disable_quota(struct ocfs2_super *osb);



int ocfs2_compute_replay_slots(struct ocfs2_super *osb);

void ocfs2_free_replay_slots(struct ocfs2_super *osb);

fs/ocfs2/ocfs2.h

+6 −0
Original line number Diff line number Diff line
@@ -310,6 +310,12 @@ void ocfs2_initialize_journal_triggers(struct super_block *sb, 


enum ocfs2_recovery_state {

	OCFS2_REC_ENABLED = 0,

	OCFS2_REC_QUOTA_WANT_DISABLE,

	/*

	 * Must be OCFS2_REC_QUOTA_WANT_DISABLE + 1 for

	 * ocfs2_recovery_disable_quota() to work.

	 */

	OCFS2_REC_QUOTA_DISABLED,

	OCFS2_REC_WANT_DISABLE,

	/*

	 * Must be OCFS2_REC_WANT_DISABLE + 1 for ocfs2_recovery_exit() to work

fs/ocfs2/quota_local.c

+2 −7
Original line number Diff line number Diff line
@@ -453,8 +453,7 @@ struct ocfs2_quota_recovery *ocfs2_begin_quota_recovery( 


/* Sync changes in local quota file into global quota file and

 * reinitialize local quota file.

 * The function expects local quota file to be already locked and

 * s_umount locked in shared mode. */

 * The function expects local quota file to be already locked. */

static int ocfs2_recover_local_quota_file(struct inode *lqinode,

					  int type,

					  struct ocfs2_quota_recovery *rec)
@@ -588,7 +587,6 @@ int ocfs2_finish_quota_recovery(struct ocfs2_super *osb, 
{

	unsigned int ino[OCFS2_MAXQUOTAS] = { LOCAL_USER_QUOTA_SYSTEM_INODE,

					      LOCAL_GROUP_QUOTA_SYSTEM_INODE };

	struct super_block *sb = osb->sb;

	struct ocfs2_local_disk_dqinfo *ldinfo;

	struct buffer_head *bh;

	handle_t *handle;
@@ -600,7 +598,6 @@ int ocfs2_finish_quota_recovery(struct ocfs2_super *osb, 
	printk(KERN_NOTICE "ocfs2: Finishing quota recovery on device (%s) for "

	       "slot %u\n", osb->dev_str, slot_num);



	down_read(&sb->s_umount);

	for (type = 0; type < OCFS2_MAXQUOTAS; type++) {

		if (list_empty(&(rec->r_list[type])))

			continue;
@@ -677,7 +674,6 @@ int ocfs2_finish_quota_recovery(struct ocfs2_super *osb, 
			break;

	}

out:

	up_read(&sb->s_umount);

	kfree(rec);

	return status;

}
@@ -843,8 +839,7 @@ static int ocfs2_local_free_info(struct super_block *sb, int type) 
	ocfs2_release_local_quota_bitmaps(&oinfo->dqi_chunk);



	/*

	 * s_umount held in exclusive mode protects us against racing with

	 * recovery thread...

	 * ocfs2_dismount_volume() has already aborted quota recovery...

	 */

	if (oinfo->dqi_rec) {

		ocfs2_free_quota_recovery(oinfo->dqi_rec);

fs/ocfs2/super.c

+3 −0
Original line number Diff line number Diff line
@@ -1812,6 +1812,9 @@ static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err) 
	/* Orphan scan should be stopped as early as possible */

	ocfs2_orphan_scan_stop(osb);



	/* Stop quota recovery so that we can disable quotas */

	ocfs2_recovery_disable_quota(osb);



	ocfs2_disable_quotas(osb);



	/* All dquots should be freed by now */