From 71b0576bdb862e964a82c73327cdd1a249c53e67 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 5 Apr 2017 14:09:48 +0200 Subject: 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: Jan Kara --- fs/reiserfs/journal.c | 2 +- fs/reiserfs/reiserfs.h | 1 + fs/reiserfs/super.c | 21 +++++++++++++++------ 3 files changed, 17 insertions(+), 7 deletions(-) (limited to 'fs/reiserfs') diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c index aa40c242f1db..da01f497180a 100644 --- a/fs/reiserfs/journal.c +++ b/fs/reiserfs/journal.c @@ -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); diff --git a/fs/reiserfs/reiserfs.h b/fs/reiserfs/reiserfs.h index 5dcf3ab83886..6ca00471afbf 100644 --- a/fs/reiserfs/reiserfs.h +++ b/fs/reiserfs/reiserfs.h @@ -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); diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index feabcde0290d..91cf5cbd6332 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -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)) -- cgit v1.2.3