Commit 71b0576b authored by Jan Kara's avatar Jan Kara
Browse files

reiserfs: Make cancel_old_flush() reliable 



Currently canceling of delayed work that flushes old data using
cancel_old_flush() does not prevent work from being requeued. Thus
in theory new work can be queued after cancel_old_flush() from
reiserfs_freeze() has run. This will become larger problem once
flush_old_commits() can requeue the work itself.

Fix the problem by recording in sbi->work_queue that flushing work is
canceled and should not be requeued.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 65547661

fs/reiserfs/journal.c

+1 −1
Original line number Diff line number Diff line
@@ -1961,7 +1961,7 @@ static int do_journal_release(struct reiserfs_transaction_handle *th, 
	 * will be requeued because superblock is being shutdown and doesn't

	 * have MS_ACTIVE set.

	 */

	cancel_delayed_work_sync(&REISERFS_SB(sb)->old_work);

	reiserfs_cancel_old_flush(sb);

	/* wait for all commits to finish */

	cancel_delayed_work_sync(&SB_JOURNAL(sb)->j_work);

fs/reiserfs/reiserfs.h

+1 −0
Original line number Diff line number Diff line
@@ -2948,6 +2948,7 @@ int reiserfs_allocate_list_bitmaps(struct super_block *s, 
				   struct reiserfs_list_bitmap *, unsigned int);



void reiserfs_schedule_old_flush(struct super_block *s);

void reiserfs_cancel_old_flush(struct super_block *s);

void add_save_link(struct reiserfs_transaction_handle *th,

		   struct inode *inode, int truncate);

int remove_save_link(struct inode *inode, int truncate);

fs/reiserfs/super.c

+15 −6
Original line number Diff line number Diff line
@@ -90,6 +90,8 @@ static void flush_old_commits(struct work_struct *work) 
	s = sbi->s_journal->j_work_sb;



	spin_lock(&sbi->old_work_lock);

	/* Avoid clobbering the cancel state... */

	if (sbi->work_queued == 1)

		sbi->work_queued = 0;

	spin_unlock(&sbi->old_work_lock);
@@ -117,21 +119,22 @@ void reiserfs_schedule_old_flush(struct super_block *s) 
	spin_unlock(&sbi->old_work_lock);

}



static void cancel_old_flush(struct super_block *s)

void reiserfs_cancel_old_flush(struct super_block *s)

{

	struct reiserfs_sb_info *sbi = REISERFS_SB(s);



	cancel_delayed_work_sync(&REISERFS_SB(s)->old_work);

	spin_lock(&sbi->old_work_lock);

	sbi->work_queued = 0;

	/* Make sure no new flushes will be queued */

	sbi->work_queued = 2;

	spin_unlock(&sbi->old_work_lock);

	cancel_delayed_work_sync(&REISERFS_SB(s)->old_work);

}



static int reiserfs_freeze(struct super_block *s)

{

	struct reiserfs_transaction_handle th;



	cancel_old_flush(s);

	reiserfs_cancel_old_flush(s);



	reiserfs_write_lock(s);

	if (!(s->s_flags & MS_RDONLY)) {
@@ -152,7 +155,13 @@ static int reiserfs_freeze(struct super_block *s) 


static int reiserfs_unfreeze(struct super_block *s)

{

	struct reiserfs_sb_info *sbi = REISERFS_SB(s);



	reiserfs_allow_writes(s);

	spin_lock(&sbi->old_work_lock);

	/* Allow old_work to run again */

	sbi->work_queued = 0;

	spin_unlock(&sbi->old_work_lock);

	return 0;

}
@@ -2194,7 +2203,7 @@ error_unlocked: 
	if (sbi->commit_wq)

		destroy_workqueue(sbi->commit_wq);



	cancel_delayed_work_sync(&REISERFS_SB(s)->old_work);

	reiserfs_cancel_old_flush(s);



	reiserfs_free_bitmap_cache(s);

	if (SB_BUFFER_WITH_SB(s))

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