From ff09c4ca5992b839b4e8b411f55aecd75735fc16 Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Wed, 30 Jan 2019 14:45:02 +0800 Subject: [PATCH] btrfs: scrub: convert scrub_workers_refcnt to refcount_t Use the refcount_t for fs_info::scrub_workers_refcnt instead of int so we get the extra checks. All reference changes are still done under scrub_lock. Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 2 +- fs/btrfs/disk-io.c | 2 +- fs/btrfs/scrub.c | 9 ++++++--- 3 files changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 9306925b67904..7efa1edb30cdc 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1075,7 +1075,7 @@ struct btrfs_fs_info { atomic_t scrubs_paused; atomic_t scrub_cancel_req; wait_queue_head_t scrub_pause_wait; - int scrub_workers_refcnt; + refcount_t scrub_workers_refcnt; struct btrfs_workqueue *scrub_workers; struct btrfs_workqueue *scrub_wr_completion_workers; struct btrfs_workqueue *scrub_nocow_workers; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 8c0038de73ee2..5216e7b3f9ada 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2109,7 +2109,7 @@ static void btrfs_init_scrub(struct btrfs_fs_info *fs_info) atomic_set(&fs_info->scrubs_paused, 0); atomic_set(&fs_info->scrub_cancel_req, 0); init_waitqueue_head(&fs_info->scrub_pause_wait); - fs_info->scrub_workers_refcnt = 0; + refcount_set(&fs_info->scrub_workers_refcnt, 0); } static void btrfs_init_balance(struct btrfs_fs_info *fs_info) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 17925af759ae4..d20150d68a904 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -3743,7 +3743,7 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info, lockdep_assert_held(&fs_info->scrub_lock); - if (fs_info->scrub_workers_refcnt == 0) { + if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) { fs_info->scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub", flags, is_dev_replace ? 1 : max_active, 4); if (!fs_info->scrub_workers) @@ -3760,8 +3760,11 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info, max_active, 2); if (!fs_info->scrub_parity_workers) goto fail_scrub_parity_workers; + + refcount_set(&fs_info->scrub_workers_refcnt, 1); + } else { + refcount_inc(&fs_info->scrub_workers_refcnt); } - ++fs_info->scrub_workers_refcnt; return 0; fail_scrub_parity_workers: @@ -3927,7 +3930,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, mutex_lock(&fs_info->scrub_lock); dev->scrub_ctx = NULL; - if (--fs_info->scrub_workers_refcnt == 0) { + if (refcount_dec_and_test(&fs_info->scrub_workers_refcnt)) { scrub_workers = fs_info->scrub_workers; scrub_wr_comp = fs_info->scrub_wr_completion_workers; scrub_parity = fs_info->scrub_parity_workers; -- 2.39.5