diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index c70625560265..658c39b70fba 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -834,7 +834,21 @@ static struct list_head *find_workspace(int type) * workspace preallocated for each type and the compression * time is bounded so we get to a workspace eventually. This * makes our caller's life easier. + * + * To prevent silent and low-probability deadlocks (when the + * initial preallocation fails), check if there are any + * workspaces at all. */ + if (atomic_read(total_ws) == 0) { + static DEFINE_RATELIMIT_STATE(_rs, + /* once per minute */ 60 * HZ, + /* no burst */ 1); + + if (__ratelimit(&_rs)) { + printk(KERN_WARNING + "no compression workspaces, low memory, retrying"); + } + } goto again; } return workspace;