diff options
| -rw-r--r-- | fs/btrfs/file.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index f406a662e942..687fb372093f 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1971,11 +1971,25 @@ again: if (is_sync_write) iocb->ki_flags |= IOCB_DSYNC; - /* If 'err' is -ENOTBLK then it means we must fallback to buffered IO. */ + /* + * If 'err' is -ENOTBLK or we have not written all data, then it means + * we must fallback to buffered IO. + */ if ((err < 0 && err != -ENOTBLK) || !iov_iter_count(from)) goto out; buffered: + /* + * If we are in a NOWAIT context, then return -EAGAIN to signal the caller + * it must retry the operation in a context where blocking is acceptable, + * since we currently don't have NOWAIT semantics support for buffered IO + * and may block there for many reasons (reserving space for example). + */ + if (iocb->ki_flags & IOCB_NOWAIT) { + err = -EAGAIN; + goto out; + } + pos = iocb->ki_pos; written_buffered = btrfs_buffered_write(iocb, from); if (written_buffered < 0) { |