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author | Paolo Bonzini <pbonzini@redhat.com> | 2013-11-22 13:39:55 +0100 |
---|---|---|
committer | Stefan Hajnoczi <stefanha@redhat.com> | 2013-12-03 15:26:49 +0100 |
commit | 260a82e524b7f86c12b8e39d4c3f208af95645f7 (patch) | |
tree | 866cf9e47120f5884e7df2585090201cbed20370 /block | |
parent | fa6252b0565526ec2347e248172f91771e0d9f47 (diff) | |
download | qemu-260a82e524b7f86c12b8e39d4c3f208af95645f7.zip qemu-260a82e524b7f86c12b8e39d4c3f208af95645f7.tar.gz qemu-260a82e524b7f86c12b8e39d4c3f208af95645f7.tar.bz2 |
raw-posix: implement write_zeroes with MAY_UNMAP for files
Writing zeroes to a file can be done by punching a hole if
MAY_UNMAP is set.
Note that in this case ENOTSUP is not ignored, but makes
the block layer fall back to the generic implementation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
-rw-r--r-- | block/raw-posix.c | 66 |
1 files changed, 64 insertions, 2 deletions
diff --git a/block/raw-posix.c b/block/raw-posix.c index cfa3162..7f3f47d 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -139,9 +139,10 @@ typedef struct BDRVRawState { void *aio_ctx; #endif #ifdef CONFIG_XFS - bool is_xfs : 1; + bool is_xfs:1; #endif - bool has_discard : 1; + bool has_discard:1; + bool discard_zeroes:1; } BDRVRawState; typedef struct BDRVRawReopenState { @@ -283,6 +284,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, Error *local_err = NULL; const char *filename; int fd, ret; + struct stat st; opts = qemu_opts_create_nofail(&raw_runtime_opts); qemu_opts_absorb_qdict(opts, options, &local_err); @@ -324,6 +326,15 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, #endif s->has_discard = true; + + if (fstat(s->fd, &st) < 0) { + error_setg_errno(errp, errno, "Could not stat file"); + goto fail; + } + if (S_ISREG(st.st_mode)) { + s->discard_zeroes = true; + } + #ifdef CONFIG_XFS if (platform_test_xfs_fd(s->fd)) { s->is_xfs = true; @@ -787,6 +798,29 @@ static int aio_worker(void *arg) return ret; } +static int paio_submit_co(BlockDriverState *bs, int fd, + int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, + int type) +{ + RawPosixAIOData *acb = g_slice_new(RawPosixAIOData); + ThreadPool *pool; + + acb->bs = bs; + acb->aio_type = type; + acb->aio_fildes = fd; + + if (qiov) { + acb->aio_iov = qiov->iov; + acb->aio_niov = qiov->niov; + } + acb->aio_nbytes = nb_sectors * 512; + acb->aio_offset = sector_num * 512; + + trace_paio_submit_co(sector_num, nb_sectors, type); + pool = aio_get_thread_pool(bdrv_get_aio_context(bs)); + return thread_pool_submit_co(pool, aio_worker, acb); +} + static BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque, int type) @@ -1199,6 +1233,31 @@ static coroutine_fn BlockDriverAIOCB *raw_aio_discard(BlockDriverState *bs, cb, opaque, QEMU_AIO_DISCARD); } +static int coroutine_fn raw_co_write_zeroes( + BlockDriverState *bs, int64_t sector_num, + int nb_sectors, BdrvRequestFlags flags) +{ + BDRVRawState *s = bs->opaque; + + if (!(flags & BDRV_REQ_MAY_UNMAP)) { + return -ENOTSUP; + } + if (!s->discard_zeroes) { + return -ENOTSUP; + } + return paio_submit_co(bs, s->fd, sector_num, NULL, nb_sectors, + QEMU_AIO_DISCARD); +} + +static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) +{ + BDRVRawState *s = bs->opaque; + + bdi->unallocated_blocks_are_zero = s->discard_zeroes; + bdi->can_write_zeroes_with_unmap = s->discard_zeroes; + return 0; +} + static QEMUOptionParameter raw_create_options[] = { { .name = BLOCK_OPT_SIZE, @@ -1222,6 +1281,7 @@ static BlockDriver bdrv_file = { .bdrv_create = raw_create, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_co_get_block_status = raw_co_get_block_status, + .bdrv_co_write_zeroes = raw_co_write_zeroes, .bdrv_aio_readv = raw_aio_readv, .bdrv_aio_writev = raw_aio_writev, @@ -1230,6 +1290,7 @@ static BlockDriver bdrv_file = { .bdrv_truncate = raw_truncate, .bdrv_getlength = raw_getlength, + .bdrv_get_info = raw_get_info, .bdrv_get_allocated_file_size = raw_get_allocated_file_size, @@ -1585,6 +1646,7 @@ static BlockDriver bdrv_host_device = { .bdrv_truncate = raw_truncate, .bdrv_getlength = raw_getlength, + .bdrv_get_info = raw_get_info, .bdrv_get_allocated_file_size = raw_get_allocated_file_size, |