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[Qemu-block] [PATCH for-2.10 10/16] block/qcow2: Lock s->lock in preallo
From: |
Max Reitz |
Subject: |
[Qemu-block] [PATCH for-2.10 10/16] block/qcow2: Lock s->lock in preallocate() |
Date: |
Mon, 13 Mar 2017 22:41:11 +0100 |
preallocate() is and will be called only from places that do not lock
s->lock: Currently that is qcow2_create2(), as of a future patch it will
be called from qcow2_truncate(), too.
It therefore makes sense to move locking that mutex into preallocate()
itself.
Signed-off-by: Max Reitz <address@hidden>
---
block/qcow2.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 9abdf9e0fb..5479fed938 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2036,12 +2036,15 @@ static int qcow2_change_backing_file(BlockDriverState
*bs,
static int preallocate(BlockDriverState *bs, int64_t offset, int64_t
new_length)
{
+ BDRVQcow2State *s = bs->opaque;
uint64_t bytes;
uint64_t host_offset = 0;
unsigned int cur_bytes;
int ret;
QCowL2Meta *meta;
+ qemu_co_mutex_lock(&s->lock);
+
assert(offset <= new_length);
bytes = new_length - offset;
@@ -2050,7 +2053,7 @@ static int preallocate(BlockDriverState *bs, int64_t
offset, int64_t new_length)
ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes,
&host_offset, &meta);
if (ret < 0) {
- return ret;
+ goto done;
}
while (meta) {
@@ -2060,7 +2063,7 @@ static int preallocate(BlockDriverState *bs, int64_t
offset, int64_t new_length)
if (ret < 0) {
qcow2_free_any_clusters(bs, meta->alloc_offset,
meta->nb_clusters,
QCOW2_DISCARD_NEVER);
- return ret;
+ goto done;
}
/* There are no dependent requests, but we need to remove our
@@ -2087,11 +2090,15 @@ static int preallocate(BlockDriverState *bs, int64_t
offset, int64_t new_length)
ret = bdrv_pwrite(bs->file, (host_offset + cur_bytes) - 1,
&data, 1);
if (ret < 0) {
- return ret;
+ goto done;
}
}
- return 0;
+ ret = 0;
+
+done:
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
}
static int qcow2_create2(const char *filename, int64_t total_size,
@@ -2310,10 +2317,7 @@ static int qcow2_create2(const char *filename, int64_t
total_size,
/* And if we're supposed to preallocate metadata, do that now */
if (prealloc != PREALLOC_MODE_OFF) {
- BDRVQcow2State *s = blk_bs(blk)->opaque;
- qemu_co_mutex_lock(&s->lock);
ret = preallocate(blk_bs(blk), 0, total_size);
- qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not preallocate metadata");
goto out;
--
2.12.0
- Re: [Qemu-block] [Qemu-devel] [PATCH for-2.10 07/16] block/file-posix: Generalize raw_regular_truncate, (continued)
[Qemu-block] [PATCH for-2.10 08/16] block/file-posix: Preallocation for truncate, Max Reitz, 2017/03/13
[Qemu-block] [PATCH for-2.10 09/16] block/qcow2: Generalize preallocate(), Max Reitz, 2017/03/13
[Qemu-block] [PATCH for-2.10 10/16] block/qcow2: Lock s->lock in preallocate(),
Max Reitz <=
[Qemu-block] [PATCH for-2.10 11/16] block/qcow2: Metadata preallocation for truncate, Max Reitz, 2017/03/13
[Qemu-block] [PATCH for-2.10 12/16] block/qcow2: Extract qcow2_calc_size_usage(), Max Reitz, 2017/03/13
[Qemu-block] [PATCH for-2.10 13/16] block/qcow2: qcow2_calc_size_usage() for truncate, Max Reitz, 2017/03/13
[Qemu-block] [PATCH for-2.10 14/16] block/qcow2: falloc/full preallocating growth, Max Reitz, 2017/03/13