Commit bb8bf76f authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Kevin Wolf
Browse files

block: add discard support 



Add a new bdrv_discard method to free blocks in a mapping image, and a new
drive property to set the granularity for these discard.  If no discard
granularity support is set discard support is disabled.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 61d9d6b0

block.c

+11 −0
Original line number Diff line number Diff line
@@ -1515,6 +1515,17 @@ int bdrv_has_zero_init(BlockDriverState *bs) 
    return 1;

}



int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)

{

    if (!bs->drv) {

        return -ENOMEDIUM;

    }

    if (!bs->drv->bdrv_discard) {

        return 0;

    }

    return bs->drv->bdrv_discard(bs, sector_num, nb_sectors);

}



/*

 * Returns true iff the specified sector is present in the disk image. Drivers

 * not implementing the functionality are assumed to not support backing files,

block.h

+1 −0
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ int bdrv_flush(BlockDriverState *bs); 
void bdrv_flush_all(void);

void bdrv_close_all(void);



int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);

int bdrv_has_zero_init(BlockDriverState *bs);

int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,

	int *pnum);

block/raw.c

+6 −0
Original line number Diff line number Diff line
@@ -65,6 +65,11 @@ static int raw_probe(const uint8_t *buf, int buf_size, const char *filename) 
   return 1; /* everything can be opened as raw image */

}



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

{

    return bdrv_discard(bs->file, sector_num, nb_sectors);

}



static int raw_is_inserted(BlockDriverState *bs)

{

    return bdrv_is_inserted(bs->file);
@@ -130,6 +135,7 @@ static BlockDriver bdrv_raw = { 
    .bdrv_aio_readv     = raw_aio_readv,

    .bdrv_aio_writev    = raw_aio_writev,

    .bdrv_aio_flush     = raw_aio_flush,

    .bdrv_discard       = raw_discard,



    .bdrv_is_inserted   = raw_is_inserted,

    .bdrv_eject         = raw_eject,

block_int.h

+6 −1
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ struct BlockDriver { 
        BlockDriverCompletionFunc *cb, void *opaque);

    BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,

        BlockDriverCompletionFunc *cb, void *opaque);

    int (*bdrv_discard)(BlockDriverState *bs, int64_t sector_num,

                        int nb_sectors);



    int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,

        int num_reqs);
@@ -227,6 +229,7 @@ typedef struct BlockConf { 
    uint16_t min_io_size;

    uint32_t opt_io_size;

    int32_t bootindex;

    uint32_t discard_granularity;

} BlockConf;



static inline unsigned int get_physical_block_exp(BlockConf *conf)
@@ -250,6 +253,8 @@ static inline unsigned int get_physical_block_exp(BlockConf *conf) 
                       _conf.physical_block_size, 512),                 \

    DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 0),  \

    DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 0),    \

    DEFINE_PROP_INT32("bootindex", _state, _conf.bootindex, -1)         \

    DEFINE_PROP_INT32("bootindex", _state, _conf.bootindex, -1),        \

    DEFINE_PROP_UINT32("discard_granularity", _state, \

                       _conf.discard_granularity, 0)



#endif /* BLOCK_INT_H */