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From: lishan <lishan24@huawei.com>
To: <qemu-devel@nongnu.org>
Cc: kwolf@redhat.com, hreitz@redhat.com, lishan24@huawei.com,
	qemu-block@nongnu.org, eric.fangyi@huawei.com
Subject: [PATCH] block/file-posix: Limit max_iov to IOV_MAX
Date: Sat, 18 Sep 2021 15:33:00 +0800	[thread overview]
Message-ID: <20210918073300.30224-1-lishan24@huawei.com> (raw)

AIO read/write. The size of iocb->aio_nbytes in the kernel cannot exceed UIO_MAXIOV = 1024.
max_segments read from the block device layer may be greater than UIO_MAXIOV,
this causes the ioq_submit interface to return a -22(-EINVAL) error result.
---
 block/file-posix.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index d81e15efa4..27ab8d8784 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1273,7 +1273,8 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
 
         ret = hdev_get_max_segments(s->fd, &st);
         if (ret > 0) {
-            bs->bl.max_iov = ret;
+            /* The maximum segment size allowed by the kernel is UIO_MAXIOV = 1024. */
+            bs->bl.max_iov = MIN(ret, bs->bl.max_iov);
         }
     }
 }
-- 
2.19.1.windows.1



             reply	other threads:[~2021-09-18  7:34 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-18  7:33 lishan [this message]
2021-09-20  8:14 ` Kevin Wolf
  -- strict thread matches above, loose matches on Subject: below --
2021-09-18  4:06 lishan
2021-09-20  4:47 ` Markus Armbruster
2021-09-20  9:03 ` Daniel P. Berrangé

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