aio: do not return ERESTARTSYS as a result of AIO

OCFS2 can return ERESTARTSYS from its write function when the process is
signalled while waiting for a cluster lock (and the filesystem is mounted
with intr mount option).  Generally, it seems reasonable to allow
filesystems to return this error code from its IO functions.  As we must
not leak ERESTARTSYS (and similar error codes) to userspace as a result of
an AIO operation, we have to properly convert it to EINTR inside AIO code
(restarting the syscall isn't really an option because other AIO could
have been already submitted by the same io_submit syscall).

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/aio.c b/fs/aio.c
index 1320b2a05fb2aaed4b261965683d814855abefe6..250b0a73c8a8ca92b78c3a0282d2425ce7649dcf 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -712,8 +712,16 @@ static ssize_t aio_run_iocb(struct kiocb *iocb)
         */
        ret = retry(iocb);
 
-       if (ret != -EIOCBRETRY && ret != -EIOCBQUEUED)
+       if (ret != -EIOCBRETRY && ret != -EIOCBQUEUED) {
+               /*
+                * There's no easy way to restart the syscall since other AIO's
+                * may be already running. Just fail this IO with EINTR.
+                */
+               if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR ||
+                            ret == -ERESTARTNOHAND || ret == -ERESTART_RESTARTBLOCK))
+                       ret = -EINTR;
                aio_complete(iocb, ret, 0);
+       }
 out:
        spin_lock_irq(&ctx->ctx_lock);