1 files changed, 33 insertions, 46 deletions

diff --git a/fs/aio.c b/fs/aio.c
index b8f2969..9edc0e4 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -741,19 +741,9 @@ static ssize_t aio_run_iocb(struct kiocb *iocb)
 	ret = retry(iocb);
 	current->io_wait = NULL;
 
-	if (-EIOCBRETRY != ret) {
- 		if (-EIOCBQUEUED != ret) {
-			BUG_ON(!list_empty(&iocb->ki_wait.task_list));
-			aio_complete(iocb, ret, 0);
-			/* must not access the iocb after this */
-		}
-	} else {
-		/*
-		 * Issue an additional retry to avoid waiting forever if
-		 * no waits were queued (e.g. in case of a short read).
-		 */
-		if (list_empty(&iocb->ki_wait.task_list))
-			kiocbSetKicked(iocb);
+	if (ret != -EIOCBRETRY && ret != -EIOCBQUEUED) {
+		BUG_ON(!list_empty(&iocb->ki_wait.task_list));
+		aio_complete(iocb, ret, 0);
 	}
 out:
 	spin_lock_irq(&ctx->ctx_lock);
@@ -1327,8 +1317,11 @@ asmlinkage long sys_io_destroy(aio_context_t ctx)
 }
 
 /*
- * Default retry method for aio_read (also used for first time submit)
- * Responsible for updating iocb state as retries progress
+ * aio_p{read,write} are the default  ki_retry methods for
+ * IO_CMD_P{READ,WRITE}.  They maintains kiocb retry state around potentially
+ * multiple calls to f_op->aio_read().  They loop around partial progress
+ * instead of returning -EIOCBRETRY because they don't have the means to call
+ * kick_iocb().
  */
 static ssize_t aio_pread(struct kiocb *iocb)
 {
@@ -1337,25 +1330,25 @@ static ssize_t aio_pread(struct kiocb *iocb)
 	struct inode *inode = mapping->host;
 	ssize_t ret = 0;
 
-	ret = file->f_op->aio_read(iocb, iocb->ki_buf,
-		iocb->ki_left, iocb->ki_pos);
+	do {
+		ret = file->f_op->aio_read(iocb, iocb->ki_buf,
+			iocb->ki_left, iocb->ki_pos);
+		/*
+		 * Can't just depend on iocb->ki_left to determine
+		 * whether we are done. This may have been a short read.
+		 */
+		if (ret > 0) {
+			iocb->ki_buf += ret;
+			iocb->ki_left -= ret;
+		}
 
-	/*
-	 * Can't just depend on iocb->ki_left to determine
-	 * whether we are done. This may have been a short read.
-	 */
-	if (ret > 0) {
-		iocb->ki_buf += ret;
-		iocb->ki_left -= ret;
 		/*
-		 * For pipes and sockets we return once we have
-		 * some data; for regular files we retry till we
-		 * complete the entire read or find that we can't
-		 * read any more data (e.g short reads).
+		 * For pipes and sockets we return once we have some data; for
+		 * regular files we retry till we complete the entire read or
+		 * find that we can't read any more data (e.g short reads).
 		 */
-		if (!S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode))
-			ret = -EIOCBRETRY;
-	}
+	} while (ret > 0 &&
+		 !S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode));
 
 	/* This means we must have transferred all that we could */
 	/* No need to retry anymore */
@@ -1365,27 +1358,21 @@ static ssize_t aio_pread(struct kiocb *iocb)
 	return ret;
 }
 
-/*
- * Default retry method for aio_write (also used for first time submit)
- * Responsible for updating iocb state as retries progress
- */
+/* see aio_pread() */
 static ssize_t aio_pwrite(struct kiocb *iocb)
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t ret = 0;
 
-	ret = file->f_op->aio_write(iocb, iocb->ki_buf,
-		iocb->ki_left, iocb->ki_pos);
-
-	if (ret > 0) {
-		iocb->ki_buf += ret;
-		iocb->ki_left -= ret;
-
-		ret = -EIOCBRETRY;
-	}
+	do {
+		ret = file->f_op->aio_write(iocb, iocb->ki_buf,
+			iocb->ki_left, iocb->ki_pos);
+		if (ret > 0) {
+			iocb->ki_buf += ret;
+			iocb->ki_left -= ret;
+		}
+	} while (ret > 0);
 
-	/* This means we must have transferred all that we could */
-	/* No need to retry anymore */
 	if ((ret == 0) || (iocb->ki_left == 0))
 		ret = iocb->ki_nbytes - iocb->ki_left;