diff options
| -rw-r--r-- | block/blkdebug.c | 13 | ||||
| -rw-r--r-- | block/io.c | 71 | ||||
| -rw-r--r-- | include/block/block_int.h | 3 |
3 files changed, 59 insertions, 28 deletions
diff --git a/block/blkdebug.c b/block/blkdebug.c index dfdf9b91aa..e21669979d 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -627,6 +627,17 @@ static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs, return bdrv_co_pdiscard(bs->file->bs, offset, bytes); } +static int64_t coroutine_fn blkdebug_co_get_block_status( + BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum, + BlockDriverState **file) +{ + assert(QEMU_IS_ALIGNED(sector_num | nb_sectors, + DIV_ROUND_UP(bs->bl.request_alignment, + BDRV_SECTOR_SIZE))); + return bdrv_co_get_block_status_from_file(bs, sector_num, nb_sectors, + pnum, file); +} + static void blkdebug_close(BlockDriverState *bs) { BDRVBlkdebugState *s = bs->opaque; @@ -896,7 +907,7 @@ static BlockDriver bdrv_blkdebug = { .bdrv_co_flush_to_disk = blkdebug_co_flush, .bdrv_co_pwrite_zeroes = blkdebug_co_pwrite_zeroes, .bdrv_co_pdiscard = blkdebug_co_pdiscard, - .bdrv_co_get_block_status = bdrv_co_get_block_status_from_file, + .bdrv_co_get_block_status = blkdebug_co_get_block_status, .bdrv_debug_event = blkdebug_debug_event, .bdrv_debug_breakpoint = blkdebug_debug_breakpoint, diff --git a/block/io.c b/block/io.c index e64b1cb294..d2cb20d872 100644 --- a/block/io.c +++ b/block/io.c @@ -1839,10 +1839,11 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs, { int64_t total_size; int64_t n; /* bytes */ - int64_t ret; + int ret; int64_t local_map = 0; BlockDriverState *local_file = NULL; - int count; /* sectors */ + int64_t aligned_offset, aligned_bytes; + uint32_t align; assert(pnum); *pnum = 0; @@ -1881,35 +1882,58 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs, } bdrv_inc_in_flight(bs); + + /* Round out to request_alignment boundaries */ + /* TODO: until we have a byte-based driver callback, we also have to + * round out to sectors, even if that is bigger than request_alignment */ + align = MAX(bs->bl.request_alignment, BDRV_SECTOR_SIZE); + aligned_offset = QEMU_ALIGN_DOWN(offset, align); + aligned_bytes = ROUND_UP(offset + bytes, align) - aligned_offset; + + { + int count; /* sectors */ + int64_t longret; + + assert(QEMU_IS_ALIGNED(aligned_offset | aligned_bytes, + BDRV_SECTOR_SIZE)); + /* + * The contract allows us to return pnum smaller than bytes, even + * if the next query would see the same status; we truncate the + * request to avoid overflowing the driver's 32-bit interface. + */ + longret = bs->drv->bdrv_co_get_block_status( + bs, aligned_offset >> BDRV_SECTOR_BITS, + MIN(INT_MAX, aligned_bytes) >> BDRV_SECTOR_BITS, &count, + &local_file); + if (longret < 0) { + assert(INT_MIN <= longret); + ret = longret; + goto out; + } + if (longret & BDRV_BLOCK_OFFSET_VALID) { + local_map = longret & BDRV_BLOCK_OFFSET_MASK; + } + ret = longret & ~BDRV_BLOCK_OFFSET_MASK; + *pnum = count * BDRV_SECTOR_SIZE; + } + /* - * TODO: Rather than require aligned offsets, we could instead - * round to the driver's request_alignment here, then touch up - * count afterwards back to the caller's expectations. - */ - assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE)); - /* - * The contract allows us to return pnum smaller than bytes, even - * if the next query would see the same status; we truncate the - * request to avoid overflowing the driver's 32-bit interface. + * The driver's result must be a multiple of request_alignment. + * Clamp pnum and adjust map to original request. */ - bytes = MIN(bytes, BDRV_REQUEST_MAX_BYTES); - ret = bs->drv->bdrv_co_get_block_status(bs, offset >> BDRV_SECTOR_BITS, - bytes >> BDRV_SECTOR_BITS, &count, - &local_file); - if (ret < 0) { - goto out; + assert(QEMU_IS_ALIGNED(*pnum, align) && align > offset - aligned_offset); + *pnum -= offset - aligned_offset; + if (*pnum > bytes) { + *pnum = bytes; } if (ret & BDRV_BLOCK_OFFSET_VALID) { - local_map = ret & BDRV_BLOCK_OFFSET_MASK; + local_map += offset - aligned_offset; } - *pnum = count * BDRV_SECTOR_SIZE; if (ret & BDRV_BLOCK_RAW) { assert(ret & BDRV_BLOCK_OFFSET_VALID && local_file); ret = bdrv_co_block_status(local_file, want_zero, local_map, *pnum, pnum, &local_map, &local_file); - assert(ret < 0 || - QEMU_IS_ALIGNED(*pnum | local_map, BDRV_SECTOR_SIZE)); goto out; } @@ -1968,11 +1992,6 @@ early_out: if (map) { *map = local_map; } - if (ret >= 0) { - ret &= ~BDRV_BLOCK_OFFSET_MASK; - } else { - assert(INT_MIN <= ret); - } return ret; } diff --git a/include/block/block_int.h b/include/block/block_int.h index 246eee2e82..a5482775ec 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -207,7 +207,8 @@ struct BlockDriver { * according to the current layer, and should not set * BDRV_BLOCK_ALLOCATED, but may set BDRV_BLOCK_RAW. See block.h * for the meaning of _DATA, _ZERO, and _OFFSET_VALID. The block - * layer guarantees non-NULL pnum and file. + * layer guarantees input aligned to request_alignment, as well as + * non-NULL pnum and file. */ int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum, |