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[PULL v3 27/28] block/io: fix bdrv_is_allocated_above
From: |
Stefan Hajnoczi |
Subject: |
[PULL v3 27/28] block/io: fix bdrv_is_allocated_above |
Date: |
Fri, 23 Oct 2020 16:21:46 +0100 |
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
bdrv_is_allocated_above wrongly handles short backing files: it reports
after-EOF space as UNALLOCATED which is wrong, as on read the data is
generated on the level of short backing file (if all overlays have
unallocated areas at that place).
Reusing bdrv_common_block_status_above fixes the issue and unifies code
path.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20200924194003.22080-5-vsementsov@virtuozzo.com
[Fix s/has/have/ as suggested by Eric Blake. Fix s/area/areas/.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/io.c | 43 +++++--------------------------------------
1 file changed, 5 insertions(+), 38 deletions(-)
diff --git a/block/io.c b/block/io.c
index b616bc4ada..02528b3823 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2477,52 +2477,19 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState
*bs, int64_t offset,
* at 'offset + *pnum' may return the same allocation status (in other
* words, the result is not necessarily the maximum possible range);
* but 'pnum' will only be 0 when end of file is reached.
- *
*/
int bdrv_is_allocated_above(BlockDriverState *top,
BlockDriverState *base,
bool include_base, int64_t offset,
int64_t bytes, int64_t *pnum)
{
- BlockDriverState *intermediate;
- int ret;
- int64_t n = bytes;
-
- assert(base || !include_base);
-
- intermediate = top;
- while (include_base || intermediate != base) {
- int64_t pnum_inter;
- int64_t size_inter;
-
- assert(intermediate);
- ret = bdrv_is_allocated(intermediate, offset, bytes, &pnum_inter);
- if (ret < 0) {
- return ret;
- }
- if (ret) {
- *pnum = pnum_inter;
- return 1;
- }
-
- size_inter = bdrv_getlength(intermediate);
- if (size_inter < 0) {
- return size_inter;
- }
- if (n > pnum_inter &&
- (intermediate == top || offset + pnum_inter < size_inter)) {
- n = pnum_inter;
- }
-
- if (intermediate == base) {
- break;
- }
-
- intermediate = bdrv_filter_or_cow_bs(intermediate);
+ int ret = bdrv_common_block_status_above(top, base, include_base, false,
+ offset, bytes, pnum, NULL, NULL);
+ if (ret < 0) {
+ return ret;
}
- *pnum = n;
- return 0;
+ return !!(ret & BDRV_BLOCK_ALLOCATED);
}
int coroutine_fn
--
2.26.2
- [PULL v3 16/28] block/export: report flush errors, (continued)
- [PULL v3 16/28] block/export: report flush errors, Stefan Hajnoczi, 2020/10/23
- [PULL v3 21/28] block: move block exports to libblockdev, Stefan Hajnoczi, 2020/10/23
- [PULL v3 25/28] block/io: bdrv_common_block_status_above: support include_base, Stefan Hajnoczi, 2020/10/23
- [PULL v3 24/28] block/io: fix bdrv_co_block_status_above, Stefan Hajnoczi, 2020/10/23
- [PULL v3 26/28] block/io: bdrv_common_block_status_above: support bs == base, Stefan Hajnoczi, 2020/10/23
- [PULL v3 17/28] block/export: convert vhost-user-blk server to block export API, Stefan Hajnoczi, 2020/10/23
- [PULL v3 18/28] util/vhost-user-server: move header to include/, Stefan Hajnoczi, 2020/10/23
- [PULL v3 19/28] util/vhost-user-server: use static library in meson.build, Stefan Hajnoczi, 2020/10/23
- [PULL v3 23/28] block/export: add vhost-user-blk multi-queue support, Stefan Hajnoczi, 2020/10/23
- [PULL v3 28/28] iotests: add commit top->base cases to 274, Stefan Hajnoczi, 2020/10/23
- [PULL v3 27/28] block/io: fix bdrv_is_allocated_above,
Stefan Hajnoczi <=
- [PULL v3 20/28] qemu-storage-daemon: avoid compiling blockdev_ss twice, Stefan Hajnoczi, 2020/10/23
- [PULL v3 22/28] block/export: add iothread and fixed-iothread options, Stefan Hajnoczi, 2020/10/23
- Re: [PULL v3 00/28] Block patches, no-reply, 2020/10/23
- Re: [PULL v3 00/28] Block patches, Peter Maydell, 2020/10/26