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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Christoph Hellwig 2010-12-16 19:36:31 +01:00 committed by Kevin Wolf
parent 61d9d6b091
commit bb8bf76fb1
4 changed files with 24 additions and 1 deletions

View file

@ -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 */