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-rw-r--r--block-qcow.c2
-rw-r--r--block-qcow2.c2
-rw-r--r--block-vmdk.c2
-rw-r--r--block.c74
-rw-r--r--block.h1
-rw-r--r--block_int.h1
6 files changed, 79 insertions, 3 deletions
diff --git a/block-qcow.c b/block-qcow.c
index 730ae67..7de8a3f 100644
--- a/block-qcow.c
+++ b/block-qcow.c
@@ -95,7 +95,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
int len, i, shift, ret;
QCowHeader header;
- ret = bdrv_file_open(&s->hd, filename, flags);
+ ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_AUTOGROW);
if (ret < 0)
return ret;
if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header))
diff --git a/block-qcow2.c b/block-qcow2.c
index 577210b..30c13f3 100644
--- a/block-qcow2.c
+++ b/block-qcow2.c
@@ -191,7 +191,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
int len, i, shift, ret;
QCowHeader header;
- ret = bdrv_file_open(&s->hd, filename, flags);
+ ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_AUTOGROW);
if (ret < 0)
return ret;
if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header))
diff --git a/block-vmdk.c b/block-vmdk.c
index 9b5fb73..79de09b 100644
--- a/block-vmdk.c
+++ b/block-vmdk.c
@@ -378,7 +378,7 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
flags = BDRV_O_RDONLY;
fprintf(stderr, "(VMDK) image open: flags=0x%x filename=%s\n", flags, bs->filename);
- ret = bdrv_file_open(&s->hd, filename, flags);
+ ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_AUTOGROW);
if (ret < 0)
return ret;
if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
diff --git a/block.c b/block.c
index 0730954..7836cd2 100644
--- a/block.c
+++ b/block.c
@@ -123,6 +123,60 @@ void path_combine(char *dest, int dest_size,
}
}
+static int bdrv_rd_badreq_sectors(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors)
+{
+ return
+ nb_sectors < 0 ||
+ sector_num < 0 ||
+ nb_sectors > bs->total_sectors ||
+ sector_num > bs->total_sectors - nb_sectors;
+}
+
+static int bdrv_rd_badreq_bytes(BlockDriverState *bs,
+ int64_t offset, int count)
+{
+ int64_t size = bs->total_sectors << SECTOR_BITS;
+ return
+ count < 0 ||
+ size < 0 ||
+ count > size ||
+ offset > size - count;
+}
+
+static int bdrv_wr_badreq_sectors(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors)
+{
+ if (sector_num < 0 ||
+ nb_sectors < 0)
+ return 1;
+
+ if (sector_num > bs->total_sectors - nb_sectors) {
+ if (bs->autogrow)
+ bs->total_sectors = sector_num + nb_sectors;
+ else
+ return 1;
+ }
+ return 0;
+}
+
+static int bdrv_wr_badreq_bytes(BlockDriverState *bs,
+ int64_t offset, int count)
+{
+ int64_t size = bs->total_sectors << SECTOR_BITS;
+ if (count < 0 ||
+ offset < 0)
+ return 1;
+
+ if (offset > size - count) {
+ if (bs->autogrow)
+ bs->total_sectors = (offset + count + SECTOR_SIZE - 1) >> SECTOR_BITS;
+ else
+ return 1;
+ }
+ return 0;
+}
+
static void bdrv_register(BlockDriver *bdrv)
{
@@ -335,6 +389,10 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
bs->read_only = 0;
bs->is_temporary = 0;
bs->encrypted = 0;
+ bs->autogrow = 0;
+
+ if (flags & BDRV_O_AUTOGROW)
+ bs->autogrow = 1;
if (flags & BDRV_O_SNAPSHOT) {
BlockDriverState *bs1;
@@ -379,6 +437,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
}
bs->drv = drv;
bs->opaque = qemu_mallocz(drv->instance_size);
+ bs->total_sectors = 0; /* driver will set if it does not do getlength */
if (bs->opaque == NULL && drv->instance_size > 0)
return -1;
/* Note: for compatibility, we open disk image files as RDWR, and
@@ -444,6 +503,7 @@ void bdrv_close(BlockDriverState *bs)
bs->drv = NULL;
/* call the change callback */
+ bs->total_sectors = 0;
bs->media_changed = 1;
if (bs->change_cb)
bs->change_cb(bs->change_opaque);
@@ -509,6 +569,8 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
if (!drv)
return -ENOMEDIUM;
+ if (bdrv_rd_badreq_sectors(bs, sector_num, nb_sectors))
+ return -EDOM;
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
memcpy(buf, bs->boot_sector_data, 512);
sector_num++;
@@ -549,6 +611,8 @@ int bdrv_write(BlockDriverState *bs, int64_t sector_num,
return -ENOMEDIUM;
if (bs->read_only)
return -EACCES;
+ if (bdrv_wr_badreq_sectors(bs, sector_num, nb_sectors))
+ return -EDOM;
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
memcpy(bs->boot_sector_data, buf, 512);
}
@@ -674,6 +738,8 @@ int bdrv_pread(BlockDriverState *bs, int64_t offset,
return -ENOMEDIUM;
if (!drv->bdrv_pread)
return bdrv_pread_em(bs, offset, buf1, count1);
+ if (bdrv_rd_badreq_bytes(bs, offset, count1))
+ return -EDOM;
return drv->bdrv_pread(bs, offset, buf1, count1);
}
@@ -689,6 +755,8 @@ int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
return -ENOMEDIUM;
if (!drv->bdrv_pwrite)
return bdrv_pwrite_em(bs, offset, buf1, count1);
+ if (bdrv_wr_badreq_bytes(bs, offset, count1))
+ return -EDOM;
return drv->bdrv_pwrite(bs, offset, buf1, count1);
}
@@ -955,6 +1023,8 @@ int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
return -ENOMEDIUM;
if (!drv->bdrv_write_compressed)
return -ENOTSUP;
+ if (bdrv_wr_badreq_sectors(bs, sector_num, nb_sectors))
+ return -EDOM;
return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
}
@@ -1101,6 +1171,8 @@ BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
if (!drv)
return NULL;
+ if (bdrv_rd_badreq_sectors(bs, sector_num, nb_sectors))
+ return NULL;
/* XXX: we assume that nb_sectors == 0 is suppored by the async read */
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
@@ -1132,6 +1204,8 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
return NULL;
if (bs->read_only)
return NULL;
+ if (bdrv_wr_badreq_sectors(bs, sector_num, nb_sectors))
+ return NULL;
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
memcpy(bs->boot_sector_data, buf, 512);
}
diff --git a/block.h b/block.h
index b730505..0673a63 100644
--- a/block.h
+++ b/block.h
@@ -45,6 +45,7 @@ typedef struct QEMUSnapshotInfo {
it (default for
bdrv_file_open()) */
#define BDRV_O_DIRECT 0x0020
+#define BDRV_O_AUTOGROW 0x0040 /* Allow backing file to extend when writing past end of file */
#ifndef QEMU_IMG
void bdrv_info(void);
diff --git a/block_int.h b/block_int.h
index 137000e..27e90b8 100644
--- a/block_int.h
+++ b/block_int.h
@@ -97,6 +97,7 @@ struct BlockDriverState {
int locked; /* if true, the media cannot temporarily be ejected */
int encrypted; /* if true, the media is encrypted */
int sg; /* if true, the device is a /dev/sg* */
+ int autogrow; /* if true, the backing store can auto-extend to allocate new extents */
/* event callback when inserting/removing */
void (*change_cb)(void *opaque);
void *change_opaque;