Commit 07d27a44 authored by Markus Armbruster's avatar Markus Armbruster Committed by Kevin Wolf
Browse files

block: Factor bdrv_read_unthrottled() out of guess_disk_lchs() 



To prepare move of guess_disk_lchs() into hw/, where it poking
BlockDriverState member io_limits_enabled directly would be unclean.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent bb494a50

block.c

+17 −7
Original line number Diff line number Diff line
@@ -1639,6 +1639,20 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num, 
    return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false);

}



/* Just like bdrv_read(), but with I/O throttling temporarily disabled */

int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,

                          uint8_t *buf, int nb_sectors)

{

    bool enabled;

    int ret;



    enabled = bs->io_limits_enabled;

    bs->io_limits_enabled = false;

    ret = bdrv_read(bs, 0, buf, 1);

    bs->io_limits_enabled = enabled;

    return ret;

}



#define BITS_PER_LONG  (sizeof(unsigned long) * 8)



static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
@@ -2136,11 +2150,10 @@ static int guess_disk_lchs(BlockDriverState *bs, 
                           int *pcylinders, int *pheads, int *psectors)

{

    uint8_t buf[BDRV_SECTOR_SIZE];

    int ret, i, heads, sectors, cylinders;

    int i, heads, sectors, cylinders;

    struct partition *p;

    uint32_t nr_sects;

    uint64_t nb_sectors;

    bool enabled;



    bdrv_get_geometry(bs, &nb_sectors);
@@ -2149,12 +2162,9 @@ static int guess_disk_lchs(BlockDriverState *bs, 
     * but also in async I/O mode. So the I/O throttling function has to

     * be disabled temporarily here, not permanently.

     */

    enabled = bs->io_limits_enabled;

    bs->io_limits_enabled = false;

    ret = bdrv_read(bs, 0, buf, 1);

    bs->io_limits_enabled = enabled;

    if (ret < 0)

    if (bdrv_read_unthrottled(bs, 0, buf, 1) < 0) {

        return -1;

    }

    /* test msdos magic */

    if (buf[510] != 0x55 || buf[511] != 0xaa)

        return -1;

block.h

+2 −0
Original line number Diff line number Diff line
@@ -142,6 +142,8 @@ bool bdrv_dev_is_tray_open(BlockDriverState *bs); 
bool bdrv_dev_is_medium_locked(BlockDriverState *bs);

int bdrv_read(BlockDriverState *bs, int64_t sector_num,

              uint8_t *buf, int nb_sectors);

int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,

                          uint8_t *buf, int nb_sectors);

int bdrv_write(BlockDriverState *bs, int64_t sector_num,

               const uint8_t *buf, int nb_sectors);

int bdrv_pread(BlockDriverState *bs, int64_t offset,