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reiserfs: Make cancel_old_flush() reliable

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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: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2017-04-05 14:09:48 +02:00
parent 6554766150
commit 71b0576bdb
3 changed files with 17 additions and 7 deletions
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2
fs/reiserfs/journal.c
View file

@ -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);

1
fs/reiserfs/reiserfs.h
View file

@ -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);

21
fs/reiserfs/super.c
View file

@ -90,7 +90,9 @@ static void flush_old_commits(struct work_struct *work)
s = sbi->s_journal->j_work_sb;
spin_lock(&sbi->old_work_lock);
sbi->work_queued = 0;
/* Avoid clobbering the cancel state... */
if (sbi->work_queued == 1)
sbi->work_queued = 0;
spin_unlock(&sbi->old_work_lock);
reiserfs_sync_fs(s, 1);
@ -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))