direct-io: Handle O_(D)SYNC AIO

[~andy/linux] / fs / direct-io.c

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 8b31b9f449f4603f0a68336f3f716aab751a6231..1782023bd68a6655d6def2258263d22080c06c33 100644 (file)
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -266,8 +266,18 @@ static ssize_t dio_complete(struct dio *dio, loff_t offset, ssize_t ret,
                dio->end_io(dio->iocb, offset, transferred, dio->private);
 
        inode_dio_done(dio->inode);
-       if (is_async)
+       if (is_async) {
+               if (dio->rw & WRITE) {
+                       int err;
+
+                       err = generic_write_sync(dio->iocb->ki_filp, offset,
+                                                transferred);
+                       if (err < 0 && ret > 0)
+                               ret = err;
+               }
+
                aio_complete(dio->iocb, ret, 0);
+       }
 
        kmem_cache_free(dio_cache, dio);
        return ret;
@@ -1182,11 +1192,6 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
                }
        }
 
-       /*
-        * Will be decremented at I/O completion time.
-        */
-       atomic_inc(&inode->i_dio_count);
-
        /*
         * For file extending writes updating i_size before data
         * writeouts complete can expose uninitialized blocks. So
@@ -1195,11 +1200,33 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
         */
        dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) &&
                (end > i_size_read(inode)));
-
-       retval = 0;
-
        dio->inode = inode;
        dio->rw = rw;
+
+       /*
+        * For AIO O_(D)SYNC writes we need to defer completions to a workqueue
+        * so that we can call ->fsync.
+        */
+       if (dio->is_async && (rw & WRITE) &&
+           ((iocb->ki_filp->f_flags & O_DSYNC) ||
+            IS_SYNC(iocb->ki_filp->f_mapping->host))) {
+               retval = dio_set_defer_completion(dio);
+               if (retval) {
+                       /*
+                        * We grab i_mutex only for reads so we don't have
+                        * to release it here
+                        */
+                       kmem_cache_free(dio_cache, dio);
+                       goto out;
+               }
+       }
+
+       /*
+        * Will be decremented at I/O completion time.
+        */
+       atomic_inc(&inode->i_dio_count);
+
+       retval = 0;
        sdio.blkbits = blkbits;
        sdio.blkfactor = i_blkbits - blkbits;
        sdio.block_in_file = offset >> blkbits;