Commit dce512de authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Kevin Wolf
Browse files

raw-posix: add discard support 



Add support to discard blocks in a raw image residing on an XFS filesystem
by calling the XFS_IOC_UNRESVSP64 ioctl to punch holes.  Support for other
hole punching mechanisms can be added when they become available.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent edff5db1

block/raw-posix.c

+45 −0
Original line number Diff line number Diff line
@@ -69,6 +69,10 @@ 
#include <sys/diskslice.h>

#endif



#ifdef CONFIG_XFS

#include <xfs/xfs.h>

#endif



//#define DEBUG_FLOPPY



//#define DEBUG_BLOCK
@@ -120,6 +124,9 @@ typedef struct BDRVRawState { 
#endif

    uint8_t *aligned_buf;

    unsigned aligned_buf_size;

#ifdef CONFIG_XFS

    bool is_xfs : 1;

#endif

} BDRVRawState;



static int fd_open(BlockDriverState *bs);
@@ -196,6 +203,12 @@ static int raw_open_common(BlockDriverState *bs, const char *filename, 
#endif

    }



#ifdef CONFIG_XFS

    if (platform_test_xfs_fd(s->fd)) {

        s->is_xfs = 1;

    }

#endif



    return 0;



out_free_buf:
@@ -740,6 +753,37 @@ static int raw_flush(BlockDriverState *bs) 
    return qemu_fdatasync(s->fd);

}



#ifdef CONFIG_XFS

static int xfs_discard(BDRVRawState *s, int64_t sector_num, int nb_sectors)

{

    struct xfs_flock64 fl;



    memset(&fl, 0, sizeof(fl));

    fl.l_whence = SEEK_SET;

    fl.l_start = sector_num << 9;

    fl.l_len = (int64_t)nb_sectors << 9;



    if (xfsctl(NULL, s->fd, XFS_IOC_UNRESVSP64, &fl) < 0) {

        DEBUG_BLOCK_PRINT("cannot punch hole (%s)\n", strerror(errno));

        return -errno;

    }



    return 0;

}

#endif



static int raw_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)

{

#ifdef CONFIG_XFS

    BDRVRawState *s = bs->opaque;



    if (s->is_xfs) {

        return xfs_discard(s, sector_num, nb_sectors);

    }

#endif



    return 0;

}



static QEMUOptionParameter raw_create_options[] = {

    {
@@ -761,6 +805,7 @@ static BlockDriver bdrv_file = { 
    .bdrv_close = raw_close,

    .bdrv_create = raw_create,

    .bdrv_flush = raw_flush,

    .bdrv_discard = raw_discard,



    .bdrv_aio_readv = raw_aio_readv,

    .bdrv_aio_writev = raw_aio_writev,

configure

+26 −0
Original line number Diff line number Diff line
@@ -288,6 +288,7 @@ xen="" 
linux_aio=""

attr=""

vhost_net=""

xfs=""



gprof="no"

debug_tcg="no"
@@ -1398,6 +1399,27 @@ EOF 
  fi

fi



##########################################

# xfsctl() probe, used for raw-posix

if test "$xfs" != "no" ; then

  cat > $TMPC << EOF

#include <xfs/xfs.h>

int main(void)

{

    xfsctl(NULL, 0, 0, NULL);

    return 0;

}

EOF

  if compile_prog "" "" ; then

    xfs="yes"

  else

    if test "$xfs" = "yes" ; then

      feature_not_found "xfs"

    fi

    xfs=no

  fi

fi



##########################################

# vde libraries probe

if test "$vde" != "no" ; then
@@ -2403,6 +2425,7 @@ echo "Trace backend $trace_backend" 
echo "Trace output file $trace_file-<pid>"

echo "spice support     $spice"

echo "rbd support       $rbd"

echo "xfsctl support    $xfs"



if test $sdl_too_old = "yes"; then

echo "-> Your SDL version is too old - please upgrade to have SDL support"
@@ -2548,6 +2571,9 @@ fi 
if test "$uuid" = "yes" ; then

  echo "CONFIG_UUID=y" >> $config_host_mak

fi

if test "$xfs" = "yes" ; then

  echo "CONFIG_XFS=y" >> $config_host_mak

fi

qemu_version=`head $source_path/VERSION`

echo "VERSION=$qemu_version" >>$config_host_mak

echo "PKGVERSION=$pkgversion" >>$config_host_mak