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