diff options
| author | Nikolay Borisov <nborisov@suse.com> | 2018-04-05 10:40:15 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-30 07:50:41 +0200 |
| commit | 4367fb9e86c303887a6fe8f8f47866373f17a7e6 (patch) | |
| tree | b293676718f4138aca6c4862929fb6eb7a750391 /fs | |
| parent | 14c4d5f6e9f39070f1cfdbf4483e4c7ddc827f52 (diff) | |
btrfs: Fix possible softlock on single core machines
[ Upstream commit 1e1c50a929bc9e49bc3f9935b92450d9e69f8158 ]
do_chunk_alloc implements a loop checking whether there is a pending
chunk allocation and if so causes the caller do loop. Generally this
loop is executed only once, however testing with btrfs/072 on a single
core vm machines uncovered an extreme case where the system could loop
indefinitely. This is due to a missing cond_resched when loop which
doesn't give a chance to the previous chunk allocator finish its job.
The fix is to simply add the missing cond_resched.
Fixes: 6d74119f1a3e ("Btrfs: avoid taking the chunk_mutex in do_chunk_alloc")
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a29730c44850..44a43851404a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4527,6 +4527,7 @@ again: if (wait_for_alloc) { mutex_unlock(&fs_info->chunk_mutex); wait_for_alloc = 0; + cond_resched(); goto again; } |