1 files changed, 17 insertions, 10 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 1f2e2845eb76..a7ceae90110e 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -529,18 +529,17 @@ xfs_file_dio_aio_write(
         count = iov_iter_count(from);
 
         /*
-         * If we are doing unaligned IO, wait for all other IO to drain,
-         * otherwise demote the lock if we had to take the exclusive lock
-         * for other reasons in xfs_file_aio_write_checks.
+         * If we are doing unaligned IO, we can't allow any other overlapping IO
+         * in-flight at the same time or we risk data corruption. Wait for all
+         * other IO to drain before we submit. If the IO is aligned, demote the
+         * iolock if we had to take the exclusive lock in
+         * xfs_file_aio_write_checks() for other reasons.
          */
         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);
-                }
+                /* unaligned dio always waits, bail */
+                if (iocb->ki_flags & IOCB_NOWAIT)
+                        return -EAGAIN;
+                inode_dio_wait(inode);
         } else if (iolock == XFS_IOLOCK_EXCL) {
                 xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
                 iolock = XFS_IOLOCK_SHARED;
@@ -548,6 +547,14 @@ xfs_file_dio_aio_write(
 
         trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
         ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io);
+
+        /*
+         * If unaligned, this is the only IO in-flight. If it has not yet
+         * completed, wait on it before we release the iolock to prevent
+         * subsequent overlapping IO.
+         */
+        if (ret == -EIOCBQUEUED && unaligned_io)
+                inode_dio_wait(inode);
 out:
         xfs_iunlock(ip, iolock);