From: Josef Bacik <josef@toxicpanda.com>
To: linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH 7/8] btrfs: be more explicit about allowed flush states
Date: Mon, 3 Dec 2018 10:24:58 -0500 [thread overview]
Message-ID: <20181203152459.21630-8-josef@toxicpanda.com> (raw)
In-Reply-To: <20181203152459.21630-1-josef@toxicpanda.com>
For FLUSH_LIMIT flushers (think evict, truncate) we can deadlock when
running delalloc because we may be holding a tree lock. We can also
deadlock with delayed refs rsv's that are running via the committing
mechanism. The only safe operations for FLUSH_LIMIT is to run the
delayed operations and to allocate chunks, everything else has the
potential to deadlock. Future proof this by explicitly specifying the
states that FLUSH_LIMIT is allowed to use. This will keep us from
introducing bugs later on when adding new flush states.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/extent-tree.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0e1a499035ac..ab9d915d9289 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5123,12 +5123,18 @@ void btrfs_init_async_reclaim_work(struct work_struct *work)
INIT_WORK(work, btrfs_async_reclaim_metadata_space);
}
+static const enum btrfs_flush_state priority_flush_states[] = {
+ FLUSH_DELAYED_ITEMS_NR,
+ FLUSH_DELAYED_ITEMS,
+ ALLOC_CHUNK,
+};
+
static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info,
struct reserve_ticket *ticket)
{
u64 to_reclaim;
- int flush_state = FLUSH_DELAYED_ITEMS_NR;
+ int flush_state = 0;
spin_lock(&space_info->lock);
to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
@@ -5140,7 +5146,8 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
spin_unlock(&space_info->lock);
do {
- flush_space(fs_info, space_info, to_reclaim, flush_state);
+ flush_space(fs_info, space_info, to_reclaim,
+ priority_flush_states[flush_state]);
flush_state++;
spin_lock(&space_info->lock);
if (ticket->bytes == 0) {
@@ -5148,15 +5155,7 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
return;
}
spin_unlock(&space_info->lock);
-
- /*
- * Priority flushers can't wait on delalloc without
- * deadlocking.
- */
- if (flush_state == FLUSH_DELALLOC ||
- flush_state == FLUSH_DELALLOC_WAIT)
- flush_state = ALLOC_CHUNK;
- } while (flush_state < COMMIT_TRANS);
+ } while (flush_state < ARRAY_SIZE(priority_flush_states));
}
static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
--
2.14.3
next prev parent reply other threads:[~2018-12-03 15:25 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 15:24 [PATCH 0/8][V2] Enospc cleanups and fixeS Josef Bacik
2018-12-03 15:24 ` [PATCH 1/8] btrfs: check if free bgs for commit Josef Bacik
2018-12-03 15:24 ` [PATCH 2/8] btrfs: dump block_rsv whe dumping space info Josef Bacik
2018-12-03 15:24 ` [PATCH 3/8] btrfs: don't use global rsv for chunk allocation Josef Bacik
2018-12-11 9:59 ` Nikolay Borisov
2018-12-03 15:24 ` [PATCH 4/8] btrfs: add ALLOC_CHUNK_FORCE to the flushing code Josef Bacik
2018-12-11 10:08 ` Nikolay Borisov
2018-12-11 16:47 ` David Sterba
2018-12-11 16:51 ` Nikolay Borisov
2018-12-11 19:04 ` David Sterba
2018-12-03 15:24 ` [PATCH 5/8] btrfs: don't enospc all tickets on flush failure Josef Bacik
2018-12-11 14:32 ` Nikolay Borisov
2018-12-03 15:24 ` [PATCH 6/8] btrfs: loop in inode_rsv_refill Josef Bacik
2018-12-12 16:01 ` Nikolay Borisov
2019-02-06 18:20 ` David Sterba
2019-01-30 16:41 ` David Sterba
2018-12-03 15:24 ` Josef Bacik [this message]
2018-12-11 18:28 ` [PATCH 7/8] btrfs: be more explicit about allowed flush states David Sterba
2018-12-12 8:40 ` Nikolay Borisov
2018-12-03 15:24 ` [PATCH 8/8] btrfs: reserve extra space during evict() Josef Bacik
2018-12-14 8:20 ` Nikolay Borisov
2018-12-13 14:11 ` [PATCH 0/8][V2] Enospc cleanups and fixeS David Sterba
2018-12-13 14:36 ` Nikolay Borisov
2018-12-13 14:45 ` Josef Bacik
2018-12-13 18:17 ` David Sterba
2018-12-13 18:28 ` Josef Bacik
2018-12-13 18:41 ` David Sterba
2019-02-08 16:08 ` David Sterba
-- strict thread matches above, loose matches on Subject: below --
2018-11-21 19:03 [PATCH 0/8] Enospc cleanups and fixes Josef Bacik
2018-11-21 19:03 ` [PATCH 7/8] btrfs: be more explicit about allowed flush states Josef Bacik
2018-11-26 12:41 ` Nikolay Borisov
2018-11-26 12:45 ` Nikolay Borisov
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