From e7b1acac8246a203ed0ed55a83cec29a4fa6252c Mon Sep 17 00:00:00 2001

From: John Snow <jsnow@redhat.com>

Date: Wed, 18 Jul 2018 22:54:45 +0200

Subject: [PATCH 227/268] qcow2: add overlap check for bitmap directory

RH-Author: John Snow <jsnow@redhat.com>

Message-id: <20180718225511.14878-10-jsnow@redhat.com>

Patchwork-id: 81394

O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH 09/35] qcow2: add overlap check for bitmap directory

Bugzilla: 1207657

RH-Acked-by: Eric Blake <eblake@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Fam Zheng <famz@redhat.com>

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Message-id: 20180705151515.779173-1-vsementsov@virtuozzo.com

Signed-off-by: Max Reitz <mreitz@redhat.com>

(cherry picked from commit 0e4e4318eaa56c831001bdf617094807ec6d451c)

Signed-off-by: John Snow <jsnow@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 block/qcow2-bitmap.c   |  7 ++++++-

 block/qcow2-refcount.c | 10 ++++++++++

 block/qcow2.c          | 22 ++++++++++++++--------

 block/qcow2.h          | 45 ++++++++++++++++++++++++---------------------

 qapi/block-core.json   | 21 ++++++++++++---------

 5 files changed, 66 insertions(+), 39 deletions(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c

index 3e4e4e4..14050eb 100644

--- a/block/qcow2-bitmap.c

+++ b/block/qcow2-bitmap.c

@@ -775,7 +775,12 @@ static int bitmap_list_store(BlockDriverState *bs, Qcow2BitmapList *bm_list,

         }

     }

-    ret = qcow2_pre_write_overlap_check(bs, 0, dir_offset, dir_size);

+    /* Actually, even in in-place case ignoring QCOW2_OL_BITMAP_DIRECTORY is not

+     * necessary, because we drop QCOW2_AUTOCLEAR_BITMAPS when updating bitmap

+     * directory in-place (actually, turn-off the extension), which is checked

+     * in qcow2_check_metadata_overlap() */

+    ret = qcow2_pre_write_overlap_check(

+            bs, in_place ? QCOW2_OL_BITMAP_DIRECTORY : 0, dir_offset, dir_size);

     if (ret < 0) {

         goto fail;

     }

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c

index 4e14c0a..1307069 100644

--- a/block/qcow2-refcount.c

+++ b/block/qcow2-refcount.c

@@ -2705,6 +2705,16 @@ int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,

         }

     }

+    if ((chk & QCOW2_OL_BITMAP_DIRECTORY) &&

+        (s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS))

+    {

+        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 71fbfcd..c5341a4 100644

--- a/block/qcow2.c

+++ b/block/qcow2.c

@@ -676,6 +676,11 @@ 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) "

@@ -708,14 +713,15 @@ static QemuOptsList qcow2_runtime_opts = {

 };

 static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = {

-    [QCOW2_OL_MAIN_HEADER_BITNR]    = QCOW2_OPT_OVERLAP_MAIN_HEADER,

-    [QCOW2_OL_ACTIVE_L1_BITNR]      = QCOW2_OPT_OVERLAP_ACTIVE_L1,

-    [QCOW2_OL_ACTIVE_L2_BITNR]      = QCOW2_OPT_OVERLAP_ACTIVE_L2,

-    [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,

-    [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,

-    [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_MAIN_HEADER_BITNR]      = QCOW2_OPT_OVERLAP_MAIN_HEADER,

+    [QCOW2_OL_ACTIVE_L1_BITNR]        = QCOW2_OPT_OVERLAP_ACTIVE_L1,

+    [QCOW2_OL_ACTIVE_L2_BITNR]        = QCOW2_OPT_OVERLAP_ACTIVE_L2,

+    [QCOW2_OL_REFCOUNT_TABLE_BITNR]   = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,

+    [QCOW2_OL_REFCOUNT_BLOCK_BITNR]   = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,

+    [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)

diff --git a/block/qcow2.h b/block/qcow2.h

index b5e2aa3..d2c63e4 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_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"

@@ -401,34 +402,36 @@ typedef enum QCow2ClusterType {

 } QCow2ClusterType;

 typedef enum QCow2MetadataOverlap {

-    QCOW2_OL_MAIN_HEADER_BITNR    = 0,

-    QCOW2_OL_ACTIVE_L1_BITNR      = 1,

-    QCOW2_OL_ACTIVE_L2_BITNR      = 2,

-    QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,

-    QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,

-    QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,

-    QCOW2_OL_INACTIVE_L1_BITNR    = 6,

-    QCOW2_OL_INACTIVE_L2_BITNR    = 7,

-

-    QCOW2_OL_MAX_BITNR            = 8,

-

-    QCOW2_OL_NONE           = 0,

-    QCOW2_OL_MAIN_HEADER    = (1 << QCOW2_OL_MAIN_HEADER_BITNR),

-    QCOW2_OL_ACTIVE_L1      = (1 << QCOW2_OL_ACTIVE_L1_BITNR),

-    QCOW2_OL_ACTIVE_L2      = (1 << QCOW2_OL_ACTIVE_L2_BITNR),

-    QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),

-    QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),

-    QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),

-    QCOW2_OL_INACTIVE_L1    = (1 << QCOW2_OL_INACTIVE_L1_BITNR),

+    QCOW2_OL_MAIN_HEADER_BITNR      = 0,

+    QCOW2_OL_ACTIVE_L1_BITNR        = 1,

+    QCOW2_OL_ACTIVE_L2_BITNR        = 2,

+    QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,

+    QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,

+    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              = 9,

+

+    QCOW2_OL_NONE             = 0,

+    QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),

+    QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),

+    QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),

+    QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),

+    QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),

+    QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),

+    QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),

     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv

      * reads. */

-    QCOW2_OL_INACTIVE_L2    = (1 << QCOW2_OL_INACTIVE_L2_BITNR),

+    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/qapi/block-core.json b/qapi/block-core.json

index 9a9cfa0..b2de7af 100644

--- a/qapi/block-core.json

+++ b/qapi/block-core.json

@@ -2666,18 +2666,21 @@

 # @template: Specifies a template mode which can be adjusted using the other

 #            flags, defaults to 'cached'

 #

+# @bitmap-directory: since 3.0

+#

 # Since: 2.9

 ##

 { 'struct': 'Qcow2OverlapCheckFlags',

-  'data': { '*template':       'Qcow2OverlapCheckMode',

-            '*main-header':    'bool',

-            '*active-l1':      'bool',

-            '*active-l2':      'bool',

-            '*refcount-table': 'bool',

-            '*refcount-block': 'bool',

-            '*snapshot-table': 'bool',

-            '*inactive-l1':    'bool',

-            '*inactive-l2':    'bool' } }

+  'data': { '*template':         'Qcow2OverlapCheckMode',

+            '*main-header':      'bool',

+            '*active-l1':        'bool',

+            '*active-l2':        'bool',

+            '*refcount-table':   'bool',

+            '*refcount-block':   'bool',

+            '*snapshot-table':   'bool',

+            '*inactive-l1':      'bool',

+            '*inactive-l2':      'bool',

+            '*bitmap-directory': 'bool' } }

 ##

 # @Qcow2OverlapChecks:

-- 

1.8.3.1