From bf6b9497252d55fa23720ab4c2686dfdb6868985 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 17 Jan 2020 09:02:20 -0500 Subject: [PATCH] btrfs: don't set path->leave_spinning for truncate The only time we actually leave the path spinning is if we're truncating a small amount and don't actually free an extent, which is not a common occurrence. We have to set the path blocking in order to add the delayed ref anyway, so the first extent we find we set the path to blocking and stay blocking for the duration of the operation. With the upcoming file extent map stuff there will be another case that we have to have the path blocking, so just swap to blocking always. Note: this patch also fixes a warning after 1fd8a23c4aa1 ("Btrfs: fix race between shrinking truncate and fiemap") got merged that inserts extent locks around truncation so the path must not leave spinning locks after btrfs_search_slot. [70.794783] BUG: sleeping function called from invalid context at mm/slab.h:565 [70.794834] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1141, name: rsync [70.794863] 5 locks held by rsync/1141: [70.794876] #0: ffff888417b9c408 (sb_writers#17){.+.+}, at: mnt_want_write+0x20/0x50 [70.795030] #1: ffff888428de28e8 (&type->i_mutex_dir_key#13/1){+.+.}, at: lock_rename+0xf1/0x100 [70.795051] #2: ffff888417b9c608 (sb_internal#2){.+.+}, at: start_transaction+0x394/0x560 [70.795124] #3: ffff888403081768 (btrfs-fs-01){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160 [70.795203] #4: ffff888403086568 (btrfs-fs-00){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160 [70.795222] CPU: 5 PID: 1141 Comm: rsync Not tainted 5.6.0-rc2-backup+ #2 [70.795362] Call Trace: [70.795374] dump_stack+0x71/0xa0 [70.795445] ___might_sleep.part.96.cold.106+0xa6/0xb6 [70.795459] kmem_cache_alloc+0x1d3/0x290 [70.795471] alloc_extent_state+0x22/0x1c0 [70.795544] __clear_extent_bit+0x3ba/0x580 [70.795557] ? _raw_spin_unlock_irq+0x24/0x30 [70.795569] btrfs_truncate_inode_items+0x339/0xe50 [70.795647] btrfs_evict_inode+0x269/0x540 [70.795659] ? dput.part.38+0x29/0x460 [70.795671] evict+0xcd/0x190 [70.795682] __dentry_kill+0xd6/0x180 [70.795754] dput.part.38+0x2ad/0x460 [70.795765] do_renameat2+0x3cb/0x540 [70.795777] __x64_sys_rename+0x1c/0x20 Reported-by: Dave Jones Fixes: 1fd8a23c4aa1 ("Btrfs: fix race between shrinking truncate and fiemap") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Reviewed-by: David Sterba [ add note ] Signed-off-by: David Sterba --- fs/btrfs/inode.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 7d26b4bfb2c6a..36deef69f847c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4142,7 +4142,6 @@ search_again: goto out; } - path->leave_spinning = 1; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) goto out; @@ -4294,7 +4293,6 @@ delete: root == fs_info->tree_root)) { struct btrfs_ref ref = { 0 }; - btrfs_set_path_blocking(path); bytes_deleted += extent_num_bytes; btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, -- 2.39.5