1 files changed, 38 insertions, 0 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index b1e35a392ca5..145f4533a936 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2038,6 +2038,23 @@ out:
         return ret;
 }
 
+static void ocfs2_aiodio_wait(struct inode *inode)
+{
+        wait_queue_head_t *wq = ocfs2_ioend_wq(inode);
+
+        wait_event(*wq, (atomic_read(&OCFS2_I(inode)->ip_unaligned_aio) == 0));
+}
+
+static int ocfs2_is_io_unaligned(struct inode *inode, size_t count, loff_t pos)
+{
+        int blockmask = inode->i_sb->s_blocksize - 1;
+        loff_t final_size = pos + count;
+
+        if ((pos & blockmask) || (final_size & blockmask))
+                return 1;
+        return 0;
+}
+
 static int ocfs2_prepare_inode_for_refcount(struct inode *inode,
                                             struct file *file,
                                             loff_t pos, size_t count,
@@ -2216,6 +2233,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
         int full_coherency = !(osb->s_mount_opt &
                                OCFS2_MOUNT_COHERENCY_BUFFERED);
+        int unaligned_dio = 0;
 
         trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
@@ -2284,6 +2302,10 @@ relock:
                 goto out;
         }
 
+        if (direct_io && !is_sync_kiocb(iocb))
+                unaligned_dio = ocfs2_is_io_unaligned(inode, iocb->ki_left,
+                                                      *ppos);
+
         /*
          * We can't complete the direct I/O as requested, fall back to
          * buffered I/O.
@@ -2299,6 +2321,18 @@ relock:
                 goto relock;
         }
 
+        if (unaligned_dio) {
+                /*
+                 * Wait on previous unaligned aio to complete before
+                 * proceeding.
+                 */
+                ocfs2_aiodio_wait(inode);
+
+                /* Mark the iocb as needing a decrement in ocfs2_dio_end_io */
+                atomic_inc(&OCFS2_I(inode)->ip_unaligned_aio);
+                ocfs2_iocb_set_unaligned_aio(iocb);
+        }
+
         /*
          * To later detect whether a journal commit for sync writes is
          * necessary, we sample i_size, and cluster count here.
@@ -2371,8 +2405,12 @@ out_dio:
         if ((ret == -EIOCBQUEUED) || (!ocfs2_iocb_is_rw_locked(iocb))) {
                 rw_level = -1;
                 have_alloc_sem = 0;
+                unaligned_dio = 0;
         }
 
+        if (unaligned_dio)
+                atomic_dec(&OCFS2_I(inode)->ip_unaligned_aio);
+
 out:
         if (rw_level != -1)
                 ocfs2_rw_unlock(inode, rw_level);