* [Qemu-devel] [PATCH 1/3] vmdk: Fix COW
2010-04-16 19:59 [Qemu-devel] [PATCH 0/3] vmdk: Backing file fix and cleanup Kevin Wolf
@ 2010-04-16 19:59 ` Kevin Wolf
2010-04-17 9:08 ` Stefan Hajnoczi
2010-04-16 19:59 ` [Qemu-devel] [PATCH 2/3] vmdk: Clean up backing file handling Kevin Wolf
2010-04-16 19:59 ` [Qemu-devel] [PATCH 3/3] vmdk: Convert to bdrv_open Kevin Wolf
2 siblings, 1 reply; 10+ messages in thread
From: Kevin Wolf @ 2010-04-16 19:59 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, stefanha
When trying to do COW, VMDK wrote the data back to the backing file. This
problem was revealed by the patch that made backing files read-only. This patch
does not only fix the problem, but also simplifies the VMDK code a bit.
This fixes the backing file qemu-iotests cases for VMDK.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/vmdk.c | 35 +++++++++++------------------------
1 files changed, 11 insertions(+), 24 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index 5ef4375..ae34121 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -87,14 +87,6 @@ typedef struct VmdkMetaData {
int valid;
} VmdkMetaData;
-typedef struct ActiveBDRVState{
- BlockDriverState *hd; // active image handler
- uint64_t cluster_offset; // current write offset
-}ActiveBDRVState;
-
-static ActiveBDRVState activeBDRV;
-
-
static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
{
uint32_t magic;
@@ -492,30 +484,28 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
uint64_t offset, int allocate)
{
- uint64_t parent_cluster_offset;
BDRVVmdkState *s = bs->opaque;
uint8_t whole_grain[s->cluster_sectors*512]; // 128 sectors * 512 bytes each = grain size 64KB
// we will be here if it's first write on non-exist grain(cluster).
// try to read from parent image, if exist
if (bs->backing_hd) {
- BDRVVmdkState *ps = bs->backing_hd->opaque;
+ int ret;
if (!vmdk_is_cid_valid(bs))
return -1;
- parent_cluster_offset = get_cluster_offset(bs->backing_hd, NULL,
- offset, allocate);
-
- if (parent_cluster_offset) {
- BDRVVmdkState *act_s = activeBDRV.hd->opaque;
-
- if (bdrv_pread(ps->hd, parent_cluster_offset, whole_grain, ps->cluster_sectors*512) != ps->cluster_sectors*512)
- return -1;
+ ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain,
+ s->cluster_sectors);
+ if (ret < 0) {
+ return -1;
+ }
- //Write grain only into the active image
- if (bdrv_pwrite(act_s->hd, activeBDRV.cluster_offset << 9, whole_grain, sizeof(whole_grain)) != sizeof(whole_grain))
- return -1;
+ //Write grain only into the active image
+ ret = bdrv_write(s->hd, cluster_offset, whole_grain,
+ s->cluster_sectors);
+ if (ret < 0) {
+ return -1;
}
}
return 0;
@@ -601,9 +591,6 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
cluster_offset >>= 9;
tmp = cpu_to_le32(cluster_offset);
l2_table[l2_index] = tmp;
- // Save the active image state
- activeBDRV.cluster_offset = cluster_offset;
- activeBDRV.hd = bs;
}
/* First of all we write grain itself, to avoid race condition
* that may to corrupt the image.
--
1.6.6.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [Qemu-devel] [PATCH 2/3] vmdk: Clean up backing file handling
2010-04-16 19:59 [Qemu-devel] [PATCH 0/3] vmdk: Backing file fix and cleanup Kevin Wolf
2010-04-16 19:59 ` [Qemu-devel] [PATCH 1/3] vmdk: Fix COW Kevin Wolf
@ 2010-04-16 19:59 ` Kevin Wolf
2010-04-17 17:38 ` Stefan Hajnoczi
2010-04-19 12:40 ` [Qemu-devel] [PATCH v2 " Kevin Wolf
2010-04-16 19:59 ` [Qemu-devel] [PATCH 3/3] vmdk: Convert to bdrv_open Kevin Wolf
2 siblings, 2 replies; 10+ messages in thread
From: Kevin Wolf @ 2010-04-16 19:59 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, stefanha
VMDK is doing interesting things when it needs to open a backing file. This
patch changes that part to look more like in other drivers. The nice side
effect is that the file name isn't needed any more in the open function.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/vmdk.c | 50 +++++++++-----------------------------------------
1 files changed, 9 insertions(+), 41 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index ae34121..781518a 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -76,7 +76,6 @@ typedef struct BDRVVmdkState {
unsigned int cluster_sectors;
uint32_t parent_cid;
- int is_parent;
} BDRVVmdkState;
typedef struct VmdkMetaData {
@@ -344,13 +343,11 @@ static void vmdk_parent_close(BlockDriverState *bs)
bdrv_close(bs->backing_hd);
}
-static int parent_open = 0;
-static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
+static int vmdk_parent_open(BlockDriverState *bs)
{
BDRVVmdkState *s = bs->opaque;
char *p_name;
char desc[DESC_SIZE];
- char parent_img_name[1024];
/* the descriptor offset = 0x200 */
if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
@@ -358,7 +355,6 @@ static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
if ((p_name = strstr(desc,"parentFileNameHint")) != NULL) {
char *end_name;
- struct stat file_buf;
p_name += sizeof("parentFileNameHint") + 1;
if ((end_name = strchr(p_name,'\"')) == NULL)
@@ -367,24 +363,6 @@ static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
return -1;
pstrcpy(bs->backing_file, end_name - p_name + 1, p_name);
- if (stat(bs->backing_file, &file_buf) != 0) {
- path_combine(parent_img_name, sizeof(parent_img_name),
- filename, bs->backing_file);
- } else {
- pstrcpy(parent_img_name, sizeof(parent_img_name),
- bs->backing_file);
- }
-
- bs->backing_hd = bdrv_new("");
- if (!bs->backing_hd) {
- failure:
- bdrv_close(s->hd);
- return -1;
- }
- parent_open = 1;
- if (bdrv_open(bs->backing_hd, parent_img_name, 0, NULL) < 0)
- goto failure;
- parent_open = 0;
}
return 0;
@@ -396,11 +374,6 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
uint32_t magic;
int l1_size, i, ret;
- if (parent_open) {
- /* Parent must be opened as RO, no RDWR. */
- flags = 0;
- }
-
ret = bdrv_file_open(&s->hd, filename, flags);
if (ret < 0)
return ret;
@@ -436,13 +409,8 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
- if (parent_open)
- s->is_parent = 1;
- else
- s->is_parent = 0;
-
// try to open parent images, if exist
- if (vmdk_parent_open(bs, filename) != 0)
+ if (vmdk_parent_open(bs) != 0)
goto fail;
// write the CID once after the image creation
s->parent_cid = vmdk_read_cid(bs,1);
@@ -583,15 +551,15 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
if (!cluster_offset) {
if (!allocate)
return 0;
+
// Avoid the L2 tables update for the images that have snapshots.
- if (!s->is_parent) {
- cluster_offset = bdrv_getlength(s->hd);
- bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
+ cluster_offset = bdrv_getlength(s->hd);
+ bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
+
+ cluster_offset >>= 9;
+ tmp = cpu_to_le32(cluster_offset);
+ l2_table[l2_index] = tmp;
- cluster_offset >>= 9;
- tmp = cpu_to_le32(cluster_offset);
- l2_table[l2_index] = tmp;
- }
/* First of all we write grain itself, to avoid race condition
* that may to corrupt the image.
* This problem may occur because of insufficient space on host disk
--
1.6.6.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [Qemu-devel] [PATCH 3/3] vmdk: Convert to bdrv_open
2010-04-16 19:59 [Qemu-devel] [PATCH 0/3] vmdk: Backing file fix and cleanup Kevin Wolf
2010-04-16 19:59 ` [Qemu-devel] [PATCH 1/3] vmdk: Fix COW Kevin Wolf
2010-04-16 19:59 ` [Qemu-devel] [PATCH 2/3] vmdk: Clean up backing file handling Kevin Wolf
@ 2010-04-16 19:59 ` Kevin Wolf
2010-04-17 9:39 ` Stefan Hajnoczi
2 siblings, 1 reply; 10+ messages in thread
From: Kevin Wolf @ 2010-04-16 19:59 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, stefanha
It's a format driver, so implement bdrv_open instead of bdrv_file_open.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/vmdk.c | 53 ++++++++++++++++++++++-------------------------------
1 files changed, 22 insertions(+), 31 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index 781518a..27b6360 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -108,14 +108,13 @@ static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
{
- BDRVVmdkState *s = bs->opaque;
char desc[DESC_SIZE];
uint32_t cid;
const char *p_name, *cid_str;
size_t cid_str_size;
/* the descriptor offset = 0x200 */
- if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
+ if (bdrv_pread(bs->file, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return 0;
if (parent) {
@@ -136,12 +135,11 @@ static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
{
- BDRVVmdkState *s = bs->opaque;
char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
char *p_name, *tmp_str;
/* the descriptor offset = 0x200 */
- if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
+ if (bdrv_pread(bs->file, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return -1;
tmp_str = strstr(desc,"parentCID");
@@ -152,7 +150,7 @@ static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
pstrcat(desc, sizeof(desc), tmp_desc);
}
- if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
+ if (bdrv_pwrite(bs->file, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return -1;
return 0;
}
@@ -345,12 +343,11 @@ static void vmdk_parent_close(BlockDriverState *bs)
static int vmdk_parent_open(BlockDriverState *bs)
{
- BDRVVmdkState *s = bs->opaque;
char *p_name;
char desc[DESC_SIZE];
/* the descriptor offset = 0x200 */
- if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
+ if (bdrv_pread(bs->file, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return -1;
if ((p_name = strstr(desc,"parentFileNameHint")) != NULL) {
@@ -368,23 +365,20 @@ static int vmdk_parent_open(BlockDriverState *bs)
return 0;
}
-static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
+static int vmdk_open(BlockDriverState *bs, int flags)
{
BDRVVmdkState *s = bs->opaque;
uint32_t magic;
- int l1_size, i, ret;
+ int l1_size, i;
- ret = bdrv_file_open(&s->hd, filename, flags);
- if (ret < 0)
- return ret;
- if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
+ if (bdrv_pread(bs->file, 0, &magic, sizeof(magic)) != sizeof(magic))
goto fail;
magic = be32_to_cpu(magic);
if (magic == VMDK3_MAGIC) {
VMDK3Header header;
- if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
+ if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header)) != sizeof(header))
goto fail;
s->cluster_sectors = le32_to_cpu(header.granularity);
s->l2_size = 1 << 9;
@@ -396,7 +390,7 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
} else if (magic == VMDK4_MAGIC) {
VMDK4Header header;
- if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
+ if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header)) != sizeof(header))
goto fail;
bs->total_sectors = le64_to_cpu(header.capacity);
s->cluster_sectors = le64_to_cpu(header.granularity);
@@ -421,7 +415,7 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
/* read the L1 table */
l1_size = s->l1_size * sizeof(uint32_t);
s->l1_table = qemu_malloc(l1_size);
- if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
+ if (bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
goto fail;
for(i = 0; i < s->l1_size; i++) {
le32_to_cpus(&s->l1_table[i]);
@@ -429,7 +423,7 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
if (s->l1_backup_table_offset) {
s->l1_backup_table = qemu_malloc(l1_size);
- if (bdrv_pread(s->hd, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
+ if (bdrv_pread(bs->file, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
goto fail;
for(i = 0; i < s->l1_size; i++) {
le32_to_cpus(&s->l1_backup_table[i]);
@@ -442,7 +436,6 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
qemu_free(s->l1_backup_table);
qemu_free(s->l1_table);
qemu_free(s->l2_cache);
- bdrv_delete(s->hd);
return -1;
}
@@ -470,7 +463,7 @@ static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
}
//Write grain only into the active image
- ret = bdrv_write(s->hd, cluster_offset, whole_grain,
+ ret = bdrv_write(bs->file, cluster_offset, whole_grain,
s->cluster_sectors);
if (ret < 0) {
return -1;
@@ -484,13 +477,13 @@ static int vmdk_L2update(BlockDriverState *bs, VmdkMetaData *m_data)
BDRVVmdkState *s = bs->opaque;
/* update L2 table */
- if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
+ if (bdrv_pwrite(bs->file, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
&(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
return -1;
/* update backup L2 table */
if (s->l1_backup_table_offset != 0) {
m_data->l2_offset = s->l1_backup_table[m_data->l1_index];
- if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
+ if (bdrv_pwrite(bs->file, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
&(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
return -1;
}
@@ -538,7 +531,7 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
}
}
l2_table = s->l2_cache + (min_index * s->l2_size);
- if (bdrv_pread(s->hd, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
+ if (bdrv_pread(bs->file, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
s->l2_size * sizeof(uint32_t))
return 0;
@@ -553,8 +546,8 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
return 0;
// Avoid the L2 tables update for the images that have snapshots.
- cluster_offset = bdrv_getlength(s->hd);
- bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
+ cluster_offset = bdrv_getlength(bs->file);
+ bdrv_truncate(bs->file, cluster_offset + (s->cluster_sectors << 9));
cluster_offset >>= 9;
tmp = cpu_to_le32(cluster_offset);
@@ -621,7 +614,7 @@ static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
memset(buf, 0, 512 * n);
}
} else {
- if(bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
+ if(bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
return -1;
}
nb_sectors -= n;
@@ -657,7 +650,7 @@ static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
if (!cluster_offset)
return -1;
- if (bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
+ if (bdrv_pwrite(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
return -1;
if (m_data.valid) {
/* update L2 tables */
@@ -835,14 +828,12 @@ static void vmdk_close(BlockDriverState *bs)
qemu_free(s->l1_table);
qemu_free(s->l2_cache);
// try to close parent image, if exist
- vmdk_parent_close(s->hd);
- bdrv_delete(s->hd);
+ vmdk_parent_close(bs->file);
}
static void vmdk_flush(BlockDriverState *bs)
{
- BDRVVmdkState *s = bs->opaque;
- bdrv_flush(s->hd);
+ bdrv_flush(bs->file);
}
@@ -869,7 +860,7 @@ static BlockDriver bdrv_vmdk = {
.format_name = "vmdk",
.instance_size = sizeof(BDRVVmdkState),
.bdrv_probe = vmdk_probe,
- .bdrv_file_open = vmdk_open,
+ .bdrv_open = vmdk_open,
.bdrv_read = vmdk_read,
.bdrv_write = vmdk_write,
.bdrv_close = vmdk_close,
--
1.6.6.1
^ permalink raw reply related [flat|nested] 10+ messages in thread