From 3298345cd406450194d46bd4cd6c505c0f8b5712 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 3 Jun 2014 10:27:07 +0200
Subject: [PATCH 2/9] block: Fix bdrv_is_allocated() for short backing files
RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1401791227-26801-1-git-send-email-kwolf@redhat.com>
Patchwork-id: 59113
O-Subject: [RHEL-6.6 qemu-kvm PATCH] block: Fix bdrv_is_allocated() for short backing files
Bugzilla: 1092117
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Brew: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=7529975
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1092117
bdrv_is_allocated() shouldn't return true for sectors that are
unallocated, but after the end of a short backing file, even though
such sectors are (correctly) marked as containing zeros.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit e88ae2264d93f98e4b656fa76555c745abe57684)
Conflicts:
block.c
block.h
Conflicts because some bdrv_co_get_block_status() patches are missing in
RHEL 6:
* 92bc50a5 block/get_block_status: avoid redundant callouts on raw
devices
* c3d86884 block/get_block_status: fix BDRV_BLOCK_ZERO for unallocated
blocks
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
git-backport-diff output:
Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively
001/1:[0008] [FC] 'block: Fix bdrv_is_allocated() for short backing files'
---
block.c | 10 ++++++----
block.h | 3 +++
2 files changed, 9 insertions(+), 4 deletions(-)
Signed-off-by: jen <jen@redhat.com>
---
block.c | 10 ++++++----
block.h | 3 +++
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/block.c b/block.c
index abae182..be28eec 100644
--- a/block.c
+++ b/block.c
@@ -2790,7 +2790,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
if (!bs->drv->bdrv_co_get_block_status) {
*pnum = nb_sectors;
- ret = BDRV_BLOCK_DATA;
+ ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
if (bs->drv->protocol_name) {
ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
}
@@ -2803,6 +2803,10 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
return ret;
}
+ if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
+ ret |= BDRV_BLOCK_ALLOCATED;
+ }
+
if (!(ret & BDRV_BLOCK_DATA)) {
if (bdrv_has_zero_init(bs)) {
ret |= BDRV_BLOCK_ZERO;
@@ -2865,9 +2869,7 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
if (ret < 0) {
return ret;
}
- return
- (ret & BDRV_BLOCK_DATA) ||
- ((ret & BDRV_BLOCK_ZERO) && !bdrv_has_zero_init(bs));
+ return (ret & BDRV_BLOCK_ALLOCATED);
}
/*
diff --git a/block.h b/block.h
index a93425a..84ad858 100644
--- a/block.h
+++ b/block.h
@@ -91,6 +91,8 @@ typedef struct BlockDevOps {
/* BDRV_BLOCK_DATA: data is read from bs->file or another file
* BDRV_BLOCK_ZERO: sectors read as zero
* BDRV_BLOCK_OFFSET_VALID: sector stored in bs->file as raw data
+ * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
+ * layer (as opposed to the backing file)
*
* If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
* bs->file where sector data can be read from as raw data.
@@ -112,6 +114,7 @@ typedef struct BlockDevOps {
#define BDRV_BLOCK_DATA 1
#define BDRV_BLOCK_ZERO 2
#define BDRV_BLOCK_OFFSET_VALID 4
+#define BDRV_BLOCK_ALLOCATED 0x10
#define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK
typedef enum {
--
1.7.1