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[Qemu-devel] [PATCH 1/2] qcow2: add overlap check for bitmap directory
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-devel] [PATCH 1/2] qcow2: add overlap check for bitmap directory |
Date: |
Thu, 30 Nov 2017 19:47:49 +0300 |
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/qcow2.h | 7 +++++--
block/qcow2-refcount.c | 12 ++++++++++++
block/qcow2.c | 6 ++++++
3 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/block/qcow2.h b/block/qcow2.h
index 6f0ff15dd0..8f226a3609 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -98,6 +98,7 @@
#define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
#define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
#define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
+#define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
#define QCOW2_OPT_CACHE_SIZE "cache-size"
#define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
#define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
@@ -406,8 +407,9 @@ typedef enum QCow2MetadataOverlap {
QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
QCOW2_OL_INACTIVE_L1_BITNR = 6,
QCOW2_OL_INACTIVE_L2_BITNR = 7,
+ QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
- QCOW2_OL_MAX_BITNR = 8,
+ QCOW2_OL_MAX_BITNR = 9,
QCOW2_OL_NONE = 0,
QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
@@ -420,12 +422,13 @@ typedef enum QCow2MetadataOverlap {
/* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
* reads. */
QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
+ QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
} QCow2MetadataOverlap;
/* Perform all overlap checks which can be done in constant time */
#define QCOW2_OL_CONSTANT \
(QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
- QCOW2_OL_SNAPSHOT_TABLE)
+ QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
/* Perform all overlap checks which don't require disk access */
#define QCOW2_OL_CACHED \
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 3de1ab51ba..a7a2703f26 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -2585,6 +2585,18 @@ int qcow2_check_metadata_overlap(BlockDriverState *bs,
int ign, int64_t offset,
}
}
+ if ((chk & QCOW2_OL_BITMAP_DIRECTORY) &&
+ (s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS))
+ {
+ /* update_ext_header_and_dir_in_place firstly drop autoclear flag,
+ * so it will not fail */
+ if (overlaps_with(s->bitmap_directory_offset,
+ s->bitmap_directory_size))
+ {
+ return QCOW2_OL_BITMAP_DIRECTORY;
+ }
+ }
+
return 0;
}
diff --git a/block/qcow2.c b/block/qcow2.c
index 1914a940e5..8278c0e124 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -655,6 +655,11 @@ static QemuOptsList qcow2_runtime_opts = {
.help = "Check for unintended writes into an inactive L2 table",
},
{
+ .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into the bitmap directory",
+ },
+ {
.name = QCOW2_OPT_CACHE_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Maximum combined metadata (L2 tables and refcount blocks)
"
@@ -690,6 +695,7 @@ static const char
*overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = {
[QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE,
[QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1,
[QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2,
+ [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
};
static void cache_clean_timer_cb(void *opaque)
--
2.11.1