@@ -664,7 +664,7 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
open_flags |= BDRV_O_RDWR;
}
- bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
+ bs->read_only = !(open_flags & BDRV_O_RDWR);
/* Open the image, either directly or using a protocol */
if (drv->bdrv_file_open) {
@@ -804,6 +804,12 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
goto unlink_and_fail;
}
+ if (flags & BDRV_O_RDWR) {
+ flags |= BDRV_O_ALLOW_RDWR;
+ }
+
+ bs->keep_read_only = !(flags & BDRV_O_ALLOW_RDWR);
+
/* Open the image */
ret = bdrv_open_common(bs, filename, flags, drv);
if (ret < 0) {
@@ -833,12 +839,6 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
bdrv_close(bs);
return ret;
}
- if (bs->is_temporary) {
- bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
- } else {
- /* base image inherits from "parent" */
- bs->backing_hd->keep_read_only = bs->keep_read_only;
- }
}
if (!bdrv_key_required(bs)) {
@@ -80,6 +80,7 @@ typedef struct BlockDevOps {
#define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
#define BDRV_O_INCOMING 0x0800 /* consistency hint for incoming migration */
#define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
+#define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
I believe the bs->keep_read_only flag is supposed to reflect the initial open state of the device. If the device is initially opened R/O, then commit operations, or reopen operations changing to R/W, are prohibited. Currently, the keep_read_only flag is only accurate for the active layer, and its backing file. Subsequent images end up always having the keep_read_only flag set. For instance, what happens now: [ base ] kro = 1, ro = 1 | v [ snap-1 ] kro = 1, ro = 1 | v [ snap-2 ] kro = 0, ro = 1 | v [ active ] kro = 0, ro = 0 What we want: [ base ] kro = 0, ro = 1 | v [ snap-1 ] kro = 0, ro = 1 | v [ snap-2 ] kro = 0, ro = 1 | v [ active ] kro = 0, ro = 0 Signed-off-by: Jeff Cody <jcody@redhat.com> --- block.c | 14 +++++++------- block.h | 1 + 2 files changed, 8 insertions(+), 7 deletions(-)