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authorKevin Wolf <kwolf@redhat.com>2016-05-30 17:13:09 +0200
committerKevin Wolf <kwolf@redhat.com>2016-07-05 16:46:26 +0200
commiteecc77473b153fbd3700d68802b48fd0fe8ce4bc (patch)
tree5a8efc45c9671ebfe957cb5415e5b1b1690bf6c4 /block/vvfat.c
parenta9d52a75634ac9aa7d101bf7f63e10bf6655a865 (diff)
vvfat: Use BdrvChild for s->qcow
vvfat uses a temporary qcow file to cache written data in read-write mode. In order to do things properly, this should show up in the BDS graph and I/O should go through BdrvChild like for every other node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/vvfat.c')
-rw-r--r--block/vvfat.c66
1 files changed, 43 insertions, 23 deletions
diff --git a/block/vvfat.c b/block/vvfat.c
index 55b5759a84..be9036e643 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -341,9 +341,8 @@ typedef struct BDRVVVFATState {
unsigned int current_cluster;
/* write support */
- BlockDriverState* write_target;
char* qcow_filename;
- BlockDriverState* qcow;
+ BdrvChild* qcow;
void* fat2;
char* used_clusters;
array_t commits;
@@ -981,7 +980,7 @@ static int init_directories(BDRVVVFATState* s,
static BDRVVVFATState *vvv = NULL;
#endif
-static int enable_write_target(BDRVVVFATState *s, Error **errp);
+static int enable_write_target(BlockDriverState *bs, Error **errp);
static int is_consistent(BDRVVVFATState *s);
static QemuOptsList runtime_opts = {
@@ -1159,7 +1158,7 @@ static int vvfat_open(BlockDriverState *bs, QDict *options, int flags,
/* read only is the default for safety */
bs->read_only = true;
- s->qcow = s->write_target = NULL;
+ s->qcow = NULL;
s->qcow_filename = NULL;
s->fat2 = NULL;
s->downcase_short_names = 1;
@@ -1170,7 +1169,7 @@ static int vvfat_open(BlockDriverState *bs, QDict *options, int flags,
s->sector_count = cyls * heads * secs - (s->first_sectors_number - 1);
if (qemu_opt_get_bool(opts, "rw", false)) {
- ret = enable_write_target(s, errp);
+ ret = enable_write_target(bs, errp);
if (ret < 0) {
goto fail;
}
@@ -1391,9 +1390,10 @@ static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
return -1;
if (s->qcow) {
int n;
- if (bdrv_is_allocated(s->qcow, sector_num, nb_sectors-i, &n)) {
-DLOG(fprintf(stderr, "sectors %d+%d allocated\n", (int)sector_num, n));
- if (bdrv_read(s->qcow, sector_num, buf + i*0x200, n)) {
+ if (bdrv_is_allocated(s->qcow->bs, sector_num, nb_sectors-i, &n)) {
+ DLOG(fprintf(stderr, "sectors %d+%d allocated\n",
+ (int)sector_num, n));
+ if (bdrv_read(s->qcow->bs, sector_num, buf + i * 0x200, n)) {
return -1;
}
i += n - 1;
@@ -1669,12 +1669,15 @@ static inline int cluster_was_modified(BDRVVVFATState* s, uint32_t cluster_num)
int was_modified = 0;
int i, dummy;
- if (s->qcow == NULL)
- return 0;
+ if (s->qcow == NULL) {
+ return 0;
+ }
- for (i = 0; !was_modified && i < s->sectors_per_cluster; i++)
- was_modified = bdrv_is_allocated(s->qcow,
- cluster2sector(s, cluster_num) + i, 1, &dummy);
+ for (i = 0; !was_modified && i < s->sectors_per_cluster; i++) {
+ was_modified = bdrv_is_allocated(s->qcow->bs,
+ cluster2sector(s, cluster_num) + i,
+ 1, &dummy);
+ }
return was_modified;
}
@@ -1823,11 +1826,17 @@ static uint32_t get_cluster_count_for_direntry(BDRVVVFATState* s,
vvfat_close_current_file(s);
for (i = 0; i < s->sectors_per_cluster; i++) {
- if (!bdrv_is_allocated(s->qcow, offset + i, 1, &dummy)) {
- if (vvfat_read(s->bs, offset, s->cluster_buffer, 1)) {
+ int res;
+
+ res = bdrv_is_allocated(s->qcow->bs, offset + i, 1, &dummy);
+ if (!res) {
+ res = vvfat_read(s->bs, offset, s->cluster_buffer, 1);
+ if (res) {
return -1;
}
- if (bdrv_write(s->qcow, offset, s->cluster_buffer, 1)) {
+ res = bdrv_write(s->qcow->bs, offset,
+ s->cluster_buffer, 1);
+ if (res) {
return -2;
}
}
@@ -2783,8 +2792,8 @@ static int do_commit(BDRVVVFATState* s)
return ret;
}
- if (s->qcow->drv->bdrv_make_empty) {
- s->qcow->drv->bdrv_make_empty(s->qcow);
+ if (s->qcow->bs->drv->bdrv_make_empty) {
+ s->qcow->bs->drv->bdrv_make_empty(s->qcow->bs);
}
memset(s->used_clusters, 0, sector2cluster(s, s->sector_count));
@@ -2880,7 +2889,7 @@ DLOG(checkpoint());
* Use qcow backend. Commit later.
*/
DLOG(fprintf(stderr, "Write to qcow backend: %d + %d\n", (int)sector_num, nb_sectors));
- ret = bdrv_write(s->qcow, sector_num, buf, nb_sectors);
+ ret = bdrv_write(s->qcow->bs, sector_num, buf, nb_sectors);
if (ret < 0) {
fprintf(stderr, "Error writing to qcow backend\n");
return ret;
@@ -2950,7 +2959,7 @@ write_target_commit(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
static void write_target_close(BlockDriverState *bs) {
BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
- bdrv_unref(s->qcow);
+ bdrv_unref_child(s->bs, s->qcow);
g_free(s->qcow_filename);
}
@@ -2960,8 +2969,19 @@ static BlockDriver vvfat_write_target = {
.bdrv_close = write_target_close,
};
-static int enable_write_target(BDRVVVFATState *s, Error **errp)
+static void vvfat_qcow_options(int *child_flags, QDict *child_options,
+ int parent_flags, QDict *parent_options)
{
+ *child_flags = BDRV_O_RDWR | BDRV_O_NO_FLUSH;
+}
+
+static const BdrvChildRole child_vvfat_qcow = {
+ .inherit_options = vvfat_qcow_options,
+};
+
+static int enable_write_target(BlockDriverState *bs, Error **errp)
+{
+ BDRVVVFATState *s = bs->opaque;
BlockDriver *bdrv_qcow = NULL;
BlockDriverState *backing;
QemuOpts *opts = NULL;
@@ -3000,8 +3020,8 @@ static int enable_write_target(BDRVVVFATState *s, Error **errp)
options = qdict_new();
qdict_put(options, "driver", qstring_from_str("qcow"));
- s->qcow = bdrv_open(s->qcow_filename, NULL, options,
- BDRV_O_RDWR | BDRV_O_NO_FLUSH, errp);
+ s->qcow = bdrv_open_child(s->qcow_filename, options, "write-target", bs,
+ &child_vvfat_qcow, false, errp);
if (!s->qcow) {
ret = -EINVAL;
goto err;