|
 |
5544c1 |
From 48f550221420bd90ddca06c6c7492ea3aca9b644 Mon Sep 17 00:00:00 2001
|
|
|
5544c1 |
From: Jeff Cody <jcody@redhat.com>
|
|
|
5544c1 |
Date: Thu, 20 Sep 2012 15:13:17 -0400
|
|
|
5544c1 |
Subject: [PATCH] block: correctly set the keep_read_only flag
|
|
|
5544c1 |
|
|
|
5544c1 |
I believe the bs->keep_read_only flag is supposed to reflect
|
|
|
5544c1 |
the initial open state of the device. If the device is initially
|
|
|
5544c1 |
opened R/O, then commit operations, or reopen operations changing
|
|
|
5544c1 |
to R/W, are prohibited.
|
|
|
5544c1 |
|
|
|
5544c1 |
Currently, the keep_read_only flag is only accurate for the active
|
|
|
5544c1 |
layer, and its backing file. Subsequent images end up always having
|
|
|
5544c1 |
the keep_read_only flag set.
|
|
|
5544c1 |
|
|
|
5544c1 |
For instance, what happens now:
|
|
|
5544c1 |
|
|
|
5544c1 |
[ base ] kro = 1, ro = 1
|
|
|
5544c1 |
|
|
|
|
5544c1 |
v
|
|
|
5544c1 |
[ snap-1 ] kro = 1, ro = 1
|
|
|
5544c1 |
|
|
|
|
5544c1 |
v
|
|
|
5544c1 |
[ snap-2 ] kro = 0, ro = 1
|
|
|
5544c1 |
|
|
|
|
5544c1 |
v
|
|
|
5544c1 |
[ active ] kro = 0, ro = 0
|
|
|
5544c1 |
|
|
|
5544c1 |
What we want:
|
|
|
5544c1 |
|
|
|
5544c1 |
[ base ] kro = 0, ro = 1
|
|
|
5544c1 |
|
|
|
|
5544c1 |
v
|
|
|
5544c1 |
[ snap-1 ] kro = 0, ro = 1
|
|
|
5544c1 |
|
|
|
|
5544c1 |
v
|
|
|
5544c1 |
[ snap-2 ] kro = 0, ro = 1
|
|
|
5544c1 |
|
|
|
|
5544c1 |
v
|
|
|
5544c1 |
[ active ] kro = 0, ro = 0
|
|
|
5544c1 |
|
|
|
5544c1 |
Signed-off-by: Jeff Cody <jcody@redhat.com>
|
|
|
5544c1 |
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
|
|
|
5544c1 |
(cherry picked from commit be028adcedd68ca4d78fdc43e7e2fa4f1cdbc653)
|
|
|
5544c1 |
|
|
|
5544c1 |
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
|
|
|
5544c1 |
---
|
|
|
5544c1 |
block.c | 14 +++++++-------
|
|
|
5544c1 |
block.h | 1 +
|
|
|
5544c1 |
2 files changed, 8 insertions(+), 7 deletions(-)
|
|
|
5544c1 |
|
|
|
5544c1 |
diff --git a/block.c b/block.c
|
|
|
5544c1 |
index e78039b..4c0e7f5 100644
|
|
|
5544c1 |
--- a/block.c
|
|
|
5544c1 |
+++ b/block.c
|
|
|
5544c1 |
@@ -668,7 +668,7 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
|
|
|
5544c1 |
open_flags |= BDRV_O_RDWR;
|
|
|
5544c1 |
}
|
|
|
5544c1 |
|
|
|
5544c1 |
- bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
|
|
|
5544c1 |
+ bs->read_only = !(open_flags & BDRV_O_RDWR);
|
|
|
5544c1 |
|
|
|
5544c1 |
/* Open the image, either directly or using a protocol */
|
|
|
5544c1 |
if (drv->bdrv_file_open) {
|
|
|
5544c1 |
@@ -808,6 +808,12 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
|
|
|
5544c1 |
goto unlink_and_fail;
|
|
|
5544c1 |
}
|
|
|
5544c1 |
|
|
|
5544c1 |
+ if (flags & BDRV_O_RDWR) {
|
|
|
5544c1 |
+ flags |= BDRV_O_ALLOW_RDWR;
|
|
|
5544c1 |
+ }
|
|
|
5544c1 |
+
|
|
|
5544c1 |
+ bs->keep_read_only = !(flags & BDRV_O_ALLOW_RDWR);
|
|
|
5544c1 |
+
|
|
|
5544c1 |
/* Open the image */
|
|
|
5544c1 |
ret = bdrv_open_common(bs, filename, flags, drv);
|
|
|
5544c1 |
if (ret < 0) {
|
|
|
5544c1 |
@@ -837,12 +843,6 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
|
|
|
5544c1 |
bdrv_close(bs);
|
|
|
5544c1 |
return ret;
|
|
|
5544c1 |
}
|
|
|
5544c1 |
- if (bs->is_temporary) {
|
|
|
5544c1 |
- bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
|
|
|
5544c1 |
- } else {
|
|
|
5544c1 |
- /* base image inherits from "parent" */
|
|
|
5544c1 |
- bs->backing_hd->keep_read_only = bs->keep_read_only;
|
|
|
5544c1 |
- }
|
|
|
5544c1 |
}
|
|
|
5544c1 |
|
|
|
5544c1 |
if (!bdrv_key_required(bs)) {
|
|
|
5544c1 |
diff --git a/block.h b/block.h
|
|
|
5544c1 |
index 2e2be11..4d919c2 100644
|
|
|
5544c1 |
--- a/block.h
|
|
|
5544c1 |
+++ b/block.h
|
|
|
5544c1 |
@@ -80,6 +80,7 @@ typedef struct BlockDevOps {
|
|
|
5544c1 |
#define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
|
|
|
5544c1 |
#define BDRV_O_INCOMING 0x0800 /* consistency hint for incoming migration */
|
|
|
5544c1 |
#define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
|
|
|
5544c1 |
+#define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
|
|
|
5544c1 |
|
|
|
5544c1 |
#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
|
|
|
5544c1 |
|
|
|
5544c1 |
--
|
|
|
5544c1 |
1.7.12.1
|
|
|
5544c1 |
|