diff options
Diffstat (limited to 'block/quorum.c')
| -rw-r--r-- | block/quorum.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/block/quorum.c b/block/quorum.c index 4b08a199b7..ae62b206c9 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -18,6 +18,7 @@ #include "qemu/module.h" #include "qemu/option.h" #include "block/block_int.h" +#include "block/coroutines.h" #include "block/qdict.h" #include "qapi/error.h" #include "qapi/qapi-events-block.h" @@ -1179,6 +1180,56 @@ static void quorum_child_perm(BlockDriverState *bs, BdrvChild *c, | DEFAULT_PERM_UNCHANGED; } +/* + * Each one of the children can report different status flags even + * when they contain the same data, so what this function does is + * return BDRV_BLOCK_ZERO if *all* children agree that a certain + * region contains zeroes, and BDRV_BLOCK_DATA otherwise. + */ +static int coroutine_fn quorum_co_block_status(BlockDriverState *bs, + bool want_zero, + int64_t offset, int64_t count, + int64_t *pnum, int64_t *map, + BlockDriverState **file) +{ + BDRVQuorumState *s = bs->opaque; + int i, ret; + int64_t pnum_zero = count; + int64_t pnum_data = 0; + + for (i = 0; i < s->num_children; i++) { + int64_t bytes; + ret = bdrv_co_common_block_status_above(s->children[i]->bs, NULL, false, + want_zero, offset, count, + &bytes, NULL, NULL, NULL); + if (ret < 0) { + quorum_report_bad(QUORUM_OP_TYPE_READ, offset, count, + s->children[i]->bs->node_name, ret); + pnum_data = count; + break; + } + /* + * Even if all children agree about whether there are zeroes + * or not at @offset they might disagree on the size, so use + * the smallest when reporting BDRV_BLOCK_ZERO and the largest + * when reporting BDRV_BLOCK_DATA. + */ + if (ret & BDRV_BLOCK_ZERO) { + pnum_zero = MIN(pnum_zero, bytes); + } else { + pnum_data = MAX(pnum_data, bytes); + } + } + + if (pnum_data) { + *pnum = pnum_data; + return BDRV_BLOCK_DATA; + } else { + *pnum = pnum_zero; + return BDRV_BLOCK_ZERO; + } +} + static const char *const quorum_strong_runtime_opts[] = { QUORUM_OPT_VOTE_THRESHOLD, QUORUM_OPT_BLKVERIFY, @@ -1197,6 +1248,7 @@ static BlockDriver bdrv_quorum = { .bdrv_close = quorum_close, .bdrv_gather_child_options = quorum_gather_child_options, .bdrv_dirname = quorum_dirname, + .bdrv_co_block_status = quorum_co_block_status, .bdrv_co_flush_to_disk = quorum_co_flush, |