Commit 0e4e4318 authored by Vladimir Sementsov-Ogievskiy's avatar Vladimir Sementsov-Ogievskiy Committed by Max Reitz
Browse files

qcow2: add overlap check for bitmap directory 



Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180705151515.779173-1-vsementsov@virtuozzo.com
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent 85456e0d

block/qcow2-bitmap.c

+6 −1
Original line number Diff line number Diff line
@@ -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;

    }

block/qcow2-refcount.c

+10 −0
Original line number Diff line number Diff line
@@ -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;

}

block/qcow2.c

+14 −8
Original line number Diff line number Diff line
@@ -679,6 +679,11 @@ static QemuOptsList qcow2_runtime_opts = { 
            .type = QEMU_OPT_BOOL,

            .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,
@@ -720,6 +725,7 @@ 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)

block/qcow2.h

+24 −21
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ 
#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"
@@ -408,8 +409,9 @@ 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),
@@ -422,12 +424,13 @@ 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 \

qapi/block-core.json

+12 −9
Original line number Diff line number Diff line
@@ -2696,6 +2696,8 @@ 
# @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',
@@ -2707,7 +2709,8 @@ 
            '*refcount-block':   'bool',

            '*snapshot-table':   'bool',

            '*inactive-l1':      'bool',

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

            '*inactive-l2':      'bool',

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



##

# @Qcow2OverlapChecks: