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-rw-r--r--fs/aio.c79
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;
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