Merge branch 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel...

Pull btrfs fix from David Sterba:
 "This fixes a user-visible bug introduced by the nowait-aio patches
  merged in this cycle"

* 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: nowait aio: Correct assignment of pos

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index a85d7903fbdd3b697fb79748191ef754a1bedad1..9e75d8a39aacf7dbcfdd961dd41ddd71e924a3a3 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1881,16 +1881,25 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
        ssize_t num_written = 0;
        bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
        ssize_t err;
-       loff_t pos = iocb->ki_pos;
+       loff_t pos;
        size_t count = iov_iter_count(from);
        loff_t oldsize;
        int clean_page = 0;
 
-       if ((iocb->ki_flags & IOCB_NOWAIT) &&
-                       (iocb->ki_flags & IOCB_DIRECT)) {
-               /* Don't sleep on inode rwsem */
-               if (!inode_trylock(inode))
+       if (!inode_trylock(inode)) {
+               if (iocb->ki_flags & IOCB_NOWAIT)
                        return -EAGAIN;
+               inode_lock(inode);
+       }
+
+       err = generic_write_checks(iocb, from);
+       if (err <= 0) {
+               inode_unlock(inode);
+               return err;
+       }
+
+       pos = iocb->ki_pos;
+       if (iocb->ki_flags & IOCB_NOWAIT) {
                /*
                 * We will allocate space in case nodatacow is not set,
                 * so bail
@@ -1901,13 +1910,6 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
                        inode_unlock(inode);
                        return -EAGAIN;
                }
-       } else
-               inode_lock(inode);
-
-       err = generic_write_checks(iocb, from);
-       if (err <= 0) {
-               inode_unlock(inode);
-               return err;
        }
 
        current->backing_dev_info = inode_to_bdi(inode);