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[Qemu-devel] [PATCH v2 1/3] block: include base when checking image chai
From: |
Andrey Shinkevich |
Subject: |
[Qemu-devel] [PATCH v2 1/3] block: include base when checking image chain for block allocation |
Date: |
Mon, 1 Apr 2019 15:06:03 +0300 |
This patch is used in the 'block/stream: introduce a bottom node'
that is following. Instead of the base node, the caller may pass
the node that has the base as its backing image to the new function
bdrv_is_allocated_above_inclusive() and get rid of the dependency
on the base that may change during commit/stream parallel jobs.
If the specified base is not found in the backing image chain, the
function fails.
Suggested-by: Vladimir Sementsov-Ogievskiy <address@hidden>
Signed-off-by: Andrey Shinkevich <address@hidden>
---
block/io.c | 32 +++++++++++++++++++++++++++-----
include/block/block.h | 5 ++++-
2 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/block/io.c b/block/io.c
index dfc153b..7edeeb2 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2317,7 +2317,8 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs,
int64_t offset,
* Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
*
* Return true if (a prefix of) the given range is allocated in any image
- * between BASE and TOP (inclusive). BASE can be NULL to check if the given
+ * between BASE and TOP (TOP included). To check the BASE image, set the
+ * 'base_included' to 'true'. The BASE can be NULL to check if the given
* offset is allocated in any image of the chain. Return false otherwise,
* or negative errno on failure.
*
@@ -2329,16 +2330,18 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState
*bs, int64_t offset,
* but 'pnum' will only be 0 when end of file is reached.
*
*/
-int bdrv_is_allocated_above(BlockDriverState *top,
- BlockDriverState *base,
- int64_t offset, int64_t bytes, int64_t *pnum)
+static int bdrv_do_is_allocated_above(BlockDriverState *top,
+ BlockDriverState *base,
+ bool base_included, int64_t offset,
+ int64_t bytes, int64_t *pnum)
{
BlockDriverState *intermediate;
int ret;
int64_t n = bytes;
+ assert(base || !base_included);
intermediate = top;
- while (intermediate && intermediate != base) {
+ while (base_included || intermediate != base) {
int64_t pnum_inter;
int64_t size_inter;
@@ -2360,6 +2363,10 @@ int bdrv_is_allocated_above(BlockDriverState *top,
n = pnum_inter;
}
+ if (intermediate == base) {
+ break;
+ }
+
intermediate = backing_bs(intermediate);
}
@@ -2367,6 +2374,21 @@ int bdrv_is_allocated_above(BlockDriverState *top,
return 0;
}
+int bdrv_is_allocated_above(BlockDriverState *top,
+ BlockDriverState *base,
+ int64_t offset, int64_t bytes, int64_t *pnum)
+{
+ return bdrv_do_is_allocated_above(top, base, false, offset, bytes, pnum);
+}
+
+int bdrv_is_allocated_above_inclusive(BlockDriverState *top,
+ BlockDriverState *base,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum)
+{
+ return bdrv_do_is_allocated_above(top, base, true, offset, bytes, pnum);
+}
+
typedef struct BdrvVmstateCo {
BlockDriverState *bs;
QEMUIOVector *qiov;
diff --git a/include/block/block.h b/include/block/block.h
index c7a2619..a7846d9 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -448,7 +448,10 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t
offset, int64_t bytes,
int64_t *pnum);
int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
int64_t offset, int64_t bytes, int64_t *pnum);
-
+int bdrv_is_allocated_above_inclusive(BlockDriverState *top,
+ BlockDriverState *base,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum);
bool bdrv_is_read_only(BlockDriverState *bs);
int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
bool ignore_allow_rdw, Error **errp);
--
1.8.3.1