|
 |
9ae3a8 |
From 69fe324e32aad7e1afc6ad14021a6a08ad52646c Mon Sep 17 00:00:00 2001
|
|
|
9ae3a8 |
From: Max Reitz <mreitz@redhat.com>
|
|
|
9ae3a8 |
Date: Sat, 13 Jun 2015 16:22:27 +0200
|
|
|
9ae3a8 |
Subject: [PATCH 33/42] block: Respect underlying file's EOF
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
Message-id: <1434212556-3927-34-git-send-email-mreitz@redhat.com>
|
|
|
9ae3a8 |
Patchwork-id: 66052
|
|
|
9ae3a8 |
O-Subject: [RHEL-7.2 qemu-kvm PATCH 33/42] block: Respect underlying file's EOF
|
|
|
9ae3a8 |
Bugzilla: 1129893
|
|
|
9ae3a8 |
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
|
|
|
9ae3a8 |
RH-Acked-by: Fam Zheng <famz@redhat.com>
|
|
|
9ae3a8 |
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
BZ: 1129893
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
When falling through to the underlying file in
|
|
|
9ae3a8 |
bdrv_co_get_block_status(), if it returns that the query offset is
|
|
|
9ae3a8 |
beyond the file end (by setting *pnum to 0), return the range to be
|
|
|
9ae3a8 |
zero and do not let the number of sectors for which information could be
|
|
|
9ae3a8 |
obtained be overwritten.
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
Signed-off-by: Max Reitz <mreitz@redhat.com>
|
|
|
9ae3a8 |
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
|
|
|
9ae3a8 |
(cherry picked from commit 59c9a95fd29cfb3296ee58e8a446df251d14a459)
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
Signed-off-by: Max Reitz <mreitz@redhat.com>
|
|
|
9ae3a8 |
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
9ae3a8 |
---
|
|
|
9ae3a8 |
block.c | 15 +++++++++++++--
|
|
|
9ae3a8 |
1 file changed, 13 insertions(+), 2 deletions(-)
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
diff --git a/block.c b/block.c
|
|
|
9ae3a8 |
index 22ab762..fa6e192 100644
|
|
|
9ae3a8 |
--- a/block.c
|
|
|
9ae3a8 |
+++ b/block.c
|
|
|
9ae3a8 |
@@ -3797,13 +3797,24 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
|
|
|
9ae3a8 |
if (bs->file &&
|
|
|
9ae3a8 |
(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
|
|
|
9ae3a8 |
(ret & BDRV_BLOCK_OFFSET_VALID)) {
|
|
|
9ae3a8 |
+ int file_pnum;
|
|
|
9ae3a8 |
+
|
|
|
9ae3a8 |
ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
|
|
|
9ae3a8 |
- *pnum, pnum);
|
|
|
9ae3a8 |
+ *pnum, &file_pnum);
|
|
|
9ae3a8 |
if (ret2 >= 0) {
|
|
|
9ae3a8 |
/* Ignore errors. This is just providing extra information, it
|
|
|
9ae3a8 |
* is useful but not necessary.
|
|
|
9ae3a8 |
*/
|
|
|
9ae3a8 |
- ret |= (ret2 & BDRV_BLOCK_ZERO);
|
|
|
9ae3a8 |
+ if (!file_pnum) {
|
|
|
9ae3a8 |
+ /* !file_pnum indicates an offset at or beyond the EOF; it is
|
|
|
9ae3a8 |
+ * perfectly valid for the format block driver to point to such
|
|
|
9ae3a8 |
+ * offsets, so catch it and mark everything as zero */
|
|
|
9ae3a8 |
+ ret |= BDRV_BLOCK_ZERO;
|
|
|
9ae3a8 |
+ } else {
|
|
|
9ae3a8 |
+ /* Limit request to the range reported by the protocol driver */
|
|
|
9ae3a8 |
+ *pnum = file_pnum;
|
|
|
9ae3a8 |
+ ret |= (ret2 & BDRV_BLOCK_ZERO);
|
|
|
9ae3a8 |
+ }
|
|
|
9ae3a8 |
}
|
|
|
9ae3a8 |
}
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
--
|
|
|
9ae3a8 |
1.8.3.1
|
|
|
9ae3a8 |
|