Commit 5e344dd8 authored by Eric Blake's avatar Eric Blake Committed by Kevin Wolf
Browse files

qemu-img: Switch get_block_status() to byte-based 



We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Continue by converting
an internal function (no semantic change), and simplifying its
caller accordingly.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarJohn Snow <jsnow@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 7286d610

qemu-img.c

+11 −13
Original line number Diff line number Diff line
@@ -2671,14 +2671,16 @@ static void dump_map_entry(OutputFormat output_format, MapEntry *e, 
    }

}



static int get_block_status(BlockDriverState *bs, int64_t sector_num,

                            int nb_sectors, MapEntry *e)

static int get_block_status(BlockDriverState *bs, int64_t offset,

                            int64_t bytes, MapEntry *e)

{

    int64_t ret;

    int depth;

    BlockDriverState *file;

    bool has_offset;

    int nb_sectors = bytes >> BDRV_SECTOR_BITS;



    assert(bytes < INT_MAX);

    /* As an optimization, we could cache the current range of unallocated

     * clusters in each file of the chain, and avoid querying the same

     * range repeatedly.
@@ -2686,8 +2688,8 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num, 


    depth = 0;

    for (;;) {

        ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors,

                                    &file);

        ret = bdrv_get_block_status(bs, offset >> BDRV_SECTOR_BITS, nb_sectors,

                                    &nb_sectors, &file);

        if (ret < 0) {

            return ret;

        }
@@ -2707,7 +2709,7 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num, 
    has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID);



    *e = (MapEntry) {

        .start = sector_num * BDRV_SECTOR_SIZE,

        .start = offset,

        .length = nb_sectors * BDRV_SECTOR_SIZE,

        .data = !!(ret & BDRV_BLOCK_DATA),

        .zero = !!(ret & BDRV_BLOCK_ZERO),
@@ -2837,16 +2839,12 @@ static int img_map(int argc, char **argv) 


    length = blk_getlength(blk);

    while (curr.start + curr.length < length) {

        int64_t nsectors_left;

        int64_t sector_num;

        int n;



        sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS;

        int64_t offset = curr.start + curr.length;

        int64_t n;



        /* Probe up to 1 GiB at a time.  */

        nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num;

        n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left);

        ret = get_block_status(bs, sector_num, n, &next);

        n = QEMU_ALIGN_DOWN(MIN(1 << 30, length - offset), BDRV_SECTOR_SIZE);

        ret = get_block_status(bs, offset, n, &next);



        if (ret < 0) {

            error_report("Could not read file metadata: %s", strerror(-ret));