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authorJeff Cody <jcody@redhat.com>2012-09-20 15:13:17 -0400
committerKevin Wolf <kwolf@redhat.com>2012-09-24 15:15:11 +0200
commitbe028adcedd68ca4d78fdc43e7e2fa4f1cdbc653 (patch)
treea0b6e1f83e5df634dda9323648879e7572784b09
parent80dd1aae3657a902d262f5d20a7a3c655b23705e (diff)
downloadqemu-arm-be028adcedd68ca4d78fdc43e7e2fa4f1cdbc653.tar.gz
block: correctly set the keep_read_only flag
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> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--block.c14
-rw-r--r--block.h1
2 files changed, 8 insertions, 7 deletions
diff --git a/block.c b/block.c
index e78039bd5a..4c0e7f5439 100644
--- a/block.c
+++ b/block.c
@@ -668,7 +668,7 @@ 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) {
@@ -808,6 +808,12 @@ 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) {
@@ -837,12 +843,6 @@ 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)) {
diff --git a/block.h b/block.h
index 2e2be11071..4d919c249f 100644
--- a/block.h
+++ b/block.h
@@ -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)