[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 24/26] stream: tweak usage of bdrv_co_is_allocated
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 24/26] stream: tweak usage of bdrv_co_is_allocated |
Date: |
Thu, 12 Apr 2012 14:01:14 +0200 |
is_allocated_base has complex semantics that are not really usable
outside streaming. Split the check in two parts, where the allocated
state for the top bs is moved to the caller. The resulting function
is more generally useful.
Signed-off-by: Paolo Bonzini <address@hidden>
---
block/stream.c | 52 ++++++++++++++++++++++++++--------------------------
1 file changed, 26 insertions(+), 26 deletions(-)
diff --git a/block/stream.c b/block/stream.c
index f9766db..e63deac 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -101,45 +101,33 @@ static void close_unused_images(BlockDriverState *top,
BlockDriverState *base,
/*
* Given an image chain: [BASE] -> [INTER1] -> [INTER2] -> [TOP]
*
- * Return true if the given sector is allocated in top.
- * Return false if the given sector is allocated in intermediate images.
- * Return true otherwise.
+ * Return true if the given sector is allocated in any image between
+ * BASE and TOP (inclusive). BASE can be NULL to check if the given
+ * sector is allocated in any image of the chain. Return false otherwise.
*
* 'pnum' is set to the number of sectors (including and immediately following
* the specified sector) that are known to be in the same
* allocated/unallocated state.
*
*/
-static int coroutine_fn is_allocated_base(BlockDriverState *top,
- BlockDriverState *base,
- int64_t sector_num,
- int nb_sectors, int *pnum)
+static int coroutine_fn is_allocated_above(BlockDriverState *top,
+ BlockDriverState *base,
+ int64_t sector_num,
+ int nb_sectors, int *pnum)
{
BlockDriverState *intermediate;
- int ret, n;
-
- ret = bdrv_co_is_allocated(top, sector_num, nb_sectors, &n);
- if (ret) {
- *pnum = n;
- return ret;
- }
-
- /*
- * Is the unallocated chunk [sector_num, n] also
- * unallocated between base and top?
- */
- intermediate = top->backing_hd;
+ int ret, n = nb_sectors;
+ intermediate = top;
while (intermediate != base) {
int pnum_inter;
-
ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors,
&pnum_inter);
if (ret < 0) {
return ret;
} else if (ret) {
*pnum = pnum_inter;
- return 0;
+ return 1;
}
/*
@@ -156,7 +144,7 @@ static int coroutine_fn is_allocated_base(BlockDriverState
*top,
}
*pnum = n;
- return 1;
+ return 0;
}
static void coroutine_fn stream_run(void *opaque)
@@ -188,16 +176,28 @@ static void coroutine_fn stream_run(void *opaque)
}
for (sector_num = 0; sector_num < end; sector_num += n) {
+ bool copy;
+
retry:
if (block_job_is_cancelled(&s->common)) {
break;
}
s->common.busy = true;
- ret = is_allocated_base(bs, base, sector_num,
- STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
+ ret = bdrv_co_is_allocated(bs, sector_num,
+ STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
+ if (ret == 1) {
+ /* Allocated in the top, no need to copy. */
+ copy = false;
+ } else {
+ /* Copy if allocated in the intermediate images. Limit to the
+ * known-unallocated area [sector_num, sector_num+n). */
+ ret = is_allocated_above(bs->backing_hd, base, sector_num, n, &n);
+ copy = (ret == 1);
+ }
+
trace_stream_one_iteration(s, sector_num, n, ret);
- if (ret == 0) {
+ if (ret >= 0 && copy) {
if (s->common.speed) {
uint64_t delay_ns = ratelimit_calculate_delay(&s->limit, n);
if (delay_ns > 0) {
--
1.7.9.3
- [Qemu-devel] [PATCH 08/26] block: add mode argument to blockdev-snapshot-sync, (continued)
- [Qemu-devel] [PATCH 08/26] block: add mode argument to blockdev-snapshot-sync, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 06/26] aio: simplify qemu_aio_wait, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 09/26] block: fail live snapshot if disk has no medium, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 10/26] block: fix snapshot on QED, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 14/26] block: fix allocation size for dirty bitmap, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 12/26] block: update in-memory backing file and format, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 11/26] block: push bdrv_change_backing_file error checking up from drivers, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 13/26] block: open backing file as read-only when probing for size, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 22/26] stream: do not copy unallocated sectors from the base, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 23/26] block: implement is_allocated for raw, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 24/26] stream: tweak usage of bdrv_co_is_allocated,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 16/26] qemu-io: correctly print non-integer values as decimals, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 25/26] stream: move is_allocated_above to block.c, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 17/26] qemu-io: fix the alloc command, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 15/26] qemu-iotests: strip spaces from qemu-img/qemu-io/qemu command lines, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 21/26] stream: fix ratelimiting corner case, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 18/26] stream: fix sectors not allocated test, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 19/26] stream: add testcase for partial streaming, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 26/26] stream: move rate limiting to a separate header file, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 20/26] stream: pass new base image format to bdrv_change_backing_file, Paolo Bonzini, 2012/04/12
- [Qemu-devel] [PATCH 27/26] block: another bdrv_append fix, Paolo Bonzini, 2012/04/17