Merge tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayto...

[mirror_ubuntu-artful-kernel.git] / fs / xfs / xfs_file.c

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 6600b264b0b6970f5ba87ba2aa5d3b15c1967ea7..51dfae5576a4ca9f10ccf425fa192950038186d4 100644 (file)
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -237,7 +237,11 @@ xfs_file_dax_read(
        if (!count)
                return 0; /* skip atime */
 
-       xfs_ilock(ip, XFS_IOLOCK_SHARED);
+       if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
+               if (iocb->ki_flags & IOCB_NOWAIT)
+                       return -EAGAIN;
+               xfs_ilock(ip, XFS_IOLOCK_SHARED);
+       }
        ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
 
@@ -541,7 +545,11 @@ xfs_file_dio_aio_write(
                iolock = XFS_IOLOCK_SHARED;
        }
 
-       xfs_ilock(ip, iolock);
+       if (!xfs_ilock_nowait(ip, iolock)) {
+               if (iocb->ki_flags & IOCB_NOWAIT)
+                       return -EAGAIN;
+               xfs_ilock(ip, iolock);
+       }
 
        ret = xfs_file_aio_write_checks(iocb, from, &iolock);
        if (ret)
@@ -553,9 +561,15 @@ xfs_file_dio_aio_write(
         * otherwise demote the lock if we had to take the exclusive lock
         * for other reasons in xfs_file_aio_write_checks.
         */
-       if (unaligned_io)
-               inode_dio_wait(inode);
-       else if (iolock == XFS_IOLOCK_EXCL) {
+       if (unaligned_io) {
+               /* If we are going to wait for other DIO to finish, bail */
+               if (iocb->ki_flags & IOCB_NOWAIT) {
+                       if (atomic_read(&inode->i_dio_count))
+                               return -EAGAIN;
+               } else {
+                       inode_dio_wait(inode);
+               }
+       } else if (iolock == XFS_IOLOCK_EXCL) {
                xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
                iolock = XFS_IOLOCK_SHARED;
        }
@@ -585,7 +599,12 @@ xfs_file_dax_write(
        size_t                  count;
        loff_t                  pos;
 
-       xfs_ilock(ip, iolock);
+       if (!xfs_ilock_nowait(ip, iolock)) {
+               if (iocb->ki_flags & IOCB_NOWAIT)
+                       return -EAGAIN;
+               xfs_ilock(ip, iolock);
+       }
+
        ret = xfs_file_aio_write_checks(iocb, from, &iolock);
        if (ret)
                goto out;
@@ -892,6 +911,7 @@ xfs_file_open(
                return -EFBIG;
        if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
                return -EIO;
+       file->f_mode |= FMODE_AIO_NOWAIT;
        return 0;
 }