From bb8bf76fb1c4afa116a7f11fee559b3cca671a4a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 16 Dec 2010 19:36:31 +0100 Subject: 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 Signed-off-by: Kevin Wolf --- block.c | 11 +++++++++++ block.h | 1 + block/raw.c | 6 ++++++ block_int.h | 7 ++++++- 4 files changed, 24 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index fe07d0bbfb..9b5e9e11fe 100644 --- a/block.c +++ b/block.c @@ -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, diff --git a/block.h b/block.h index b812172735..f923add60d 100644 --- a/block.h +++ b/block.h @@ -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); diff --git a/block/raw.c b/block/raw.c index 1980debc00..b0f72d6a62 100644 --- a/block/raw.c +++ b/block/raw.c @@ -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, diff --git a/block_int.h b/block_int.h index 6b3b09808b..eb5cd42392 100644 --- a/block_int.h +++ b/block_int.h @@ -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 */ -- cgit v1.2.3