OpenE2K/linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

btrfs: don't set path->leave_spinning for truncate

Browse Source 
commit 52e29e3310 upstream.

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 28553fa992 ("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 <davej@codemonkey.org.uk>
Fixes: 28553fa992 ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Josef Bacik 2020-01-17 09:02:20 -05:00 committed by Greg Kroah-Hartman
parent d3d0fb9d42
commit 73e1f26632
1 changed files with 0 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/btrfs/inode.c
View File

@ -4791,7 +4791,6 @@ search_again:
goto out;
}
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
@ -4943,7 +4942,6 @@ 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,