From 1cc127b5d1b71453091859301de4a7dd6ee96fa8 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 12 Jun 2008 14:46:17 -0400 Subject: [PATCH] Btrfs: Add a thread pool just for submit_bio If a bio submission is after a lock holder waiting for the bio on the work queue, it is possible to deadlock. Move the bios into their own pool. Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 4 ++++ fs/btrfs/disk-io.c | 4 ++++ fs/btrfs/volumes.c | 3 ++- 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 181c81d29897..dcea9d706d9b 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -529,9 +529,13 @@ struct btrfs_fs_info { * can run with FS locks held, and the writers may be waiting for * those locks. We don't want ordering in the pending list to cause * deadlocks, and so the two are serviced separately. + * + * A third pool does submit_bio to avoid deadlocking with the other + * two */ struct btrfs_workers workers; struct btrfs_workers endio_workers; + struct btrfs_workers submit_workers; int thread_pool_size; #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index c6a710a668cb..e5c758e306d5 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1233,8 +1233,10 @@ struct btrfs_root *open_ctree(struct super_block *sb, * cannot dynamically grow. */ btrfs_init_workers(&fs_info->workers, fs_info->thread_pool_size); + btrfs_init_workers(&fs_info->submit_workers, fs_info->thread_pool_size); btrfs_init_workers(&fs_info->endio_workers, fs_info->thread_pool_size); btrfs_start_workers(&fs_info->workers, 1); + btrfs_start_workers(&fs_info->submit_workers, 1); btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size); @@ -1343,6 +1345,7 @@ fail_sb_buffer: extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree); btrfs_stop_workers(&fs_info->workers); btrfs_stop_workers(&fs_info->endio_workers); + btrfs_stop_workers(&fs_info->submit_workers); fail_iput: iput(fs_info->btree_inode); fail: @@ -1597,6 +1600,7 @@ int close_ctree(struct btrfs_root *root) btrfs_stop_workers(&fs_info->workers); btrfs_stop_workers(&fs_info->endio_workers); + btrfs_stop_workers(&fs_info->submit_workers); iput(fs_info->btree_inode); #if 0 diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c57458ce6339..ba3968571024 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2112,7 +2112,8 @@ int schedule_bio(struct btrfs_root *root, struct btrfs_device *device, spin_unlock(&device->io_lock); if (should_queue) - btrfs_queue_worker(&root->fs_info->workers, &device->work); + btrfs_queue_worker(&root->fs_info->submit_workers, + &device->work); return 0; }