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[Qemu-block] [PATCH v3 10/10] block/blklogwrites: Use the block device l
From: |
Ari Sundholm |
Subject: |
[Qemu-block] [PATCH v3 10/10] block/blklogwrites: Use the block device logical sector size when logging writes |
Date: |
Thu, 7 Jun 2018 18:38:14 +0300 |
The guest OS may perform writes which are aligned to the logical
sector size instead of the physical one, so logging at this granularity
records the writes performed on the block device most faithfully.
Signed-off-by: Ari Sundholm <address@hidden>
---
block/blklogwrites.c | 47 ++++++++++++++++++++++++++++++++---------------
1 file changed, 32 insertions(+), 15 deletions(-)
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index 8b09e12..52166f2 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -47,6 +47,8 @@ struct log_write_entry {
typedef struct {
BdrvChild *log_file;
+ uint32_t sectorsize;
+ uint32_t sectorbits;
uint64_t cur_log_sector;
uint64_t nr_entries;
} BDRVBlkLogWritesState;
@@ -67,6 +69,8 @@ static int blk_log_writes_open(BlockDriverState *bs, QDict
*options, int flags,
goto fail;
}
+ s->sectorsize = BDRV_SECTOR_SIZE; /* May be updated later */
+ s->sectorbits = BDRV_SECTOR_BITS;
s->cur_log_sector = 1;
s->nr_entries = 0;
@@ -168,11 +172,20 @@ static void
blk_log_writes_refresh_limits(BlockDriverState *bs, Error **errp)
}
}
+static inline uint32_t blk_log_writes_log2(uint32_t value)
+{
+ assert(value > 0);
+ return 31 - clz32(value);
+}
+
static void blk_log_writes_apply_blkconf(BlockDriverState *bs, BlockConf *conf)
{
- assert(bs && conf && conf->blk);
+ BDRVBlkLogWritesState *s = bs->opaque;
+ assert(bs && conf && conf->blk && s);
- bs->bl.request_alignment = conf->logical_block_size;
+ s->sectorsize = conf->logical_block_size;
+ s->sectorbits = blk_log_writes_log2(s->sectorsize);
+ bs->bl.request_alignment = s->sectorsize;
if (conf->discard_granularity != (uint32_t)-1) {
bs->bl.pdiscard_alignment = conf->discard_granularity;
}
@@ -215,20 +228,20 @@ typedef struct {
static void coroutine_fn blk_log_writes_co_do_log(BlkLogWritesLogReq *lr)
{
BDRVBlkLogWritesState *s = lr->bs->opaque;
- uint64_t cur_log_offset = s->cur_log_sector << BDRV_SECTOR_BITS;
+ uint64_t cur_log_offset = s->cur_log_sector << s->sectorbits;
s->nr_entries++;
s->cur_log_sector +=
- ROUND_UP(lr->qiov->size, BDRV_SECTOR_SIZE) >> BDRV_SECTOR_BITS;
+ ROUND_UP(lr->qiov->size, s->sectorsize) >> s->sectorbits;
lr->log_ret = bdrv_co_pwritev(s->log_file, cur_log_offset, lr->qiov->size,
lr->qiov, 0);
/* Logging for the "write zeroes" operation */
if (lr->log_ret == 0 && lr->zero_size) {
- cur_log_offset = s->cur_log_sector << BDRV_SECTOR_BITS;
+ cur_log_offset = s->cur_log_sector << s->sectorbits;
s->cur_log_sector +=
- ROUND_UP(lr->zero_size, BDRV_SECTOR_SIZE) >> BDRV_SECTOR_BITS;
+ ROUND_UP(lr->zero_size, s->sectorsize) >> s->sectorbits;
lr->log_ret = bdrv_co_pwrite_zeroes(s->log_file, cur_log_offset,
lr->zero_size, 0);
@@ -240,21 +253,22 @@ static void coroutine_fn
blk_log_writes_co_do_log(BlkLogWritesLogReq *lr)
.magic = cpu_to_le64(WRITE_LOG_MAGIC),
.version = cpu_to_le64(WRITE_LOG_VERSION),
.nr_entries = cpu_to_le64(s->nr_entries),
- .sectorsize = cpu_to_le32(1 << BDRV_SECTOR_BITS),
+ .sectorsize = cpu_to_le32(s->sectorsize),
};
- static const char zeroes[BDRV_SECTOR_SIZE - sizeof(super)] = { '\0' };
+ void *zeroes = g_malloc0(s->sectorsize - sizeof(super));
QEMUIOVector qiov;
qemu_iovec_init(&qiov, 2);
qemu_iovec_add(&qiov, &super, sizeof(super));
- qemu_iovec_add(&qiov, (void *)zeroes, sizeof(zeroes));
+ qemu_iovec_add(&qiov, zeroes, s->sectorsize - sizeof(super));
lr->log_ret =
- bdrv_co_pwritev(s->log_file, 0, BDRV_SECTOR_SIZE, &qiov, 0);
+ bdrv_co_pwritev(s->log_file, 0, s->sectorsize, &qiov, 0);
if (lr->log_ret == 0) {
lr->log_ret = bdrv_co_flush(s->log_file->bs);
}
qemu_iovec_destroy(&qiov);
+ g_free(zeroes);
}
}
@@ -271,6 +285,7 @@ blk_log_writes_co_log(BlockDriverState *bs, uint64_t
offset, uint64_t bytes,
{
QEMUIOVector log_qiov;
size_t niov = qiov ? qiov->niov : 0;
+ BDRVBlkLogWritesState *s = bs->opaque;
BlkLogWritesFileReq fr = {
.bs = bs,
.offset = offset,
@@ -283,22 +298,23 @@ blk_log_writes_co_log(BlockDriverState *bs, uint64_t
offset, uint64_t bytes,
.bs = bs,
.qiov = &log_qiov,
.entry = {
- .sector = cpu_to_le64(offset >> BDRV_SECTOR_BITS),
- .nr_sectors = cpu_to_le64(bytes >> BDRV_SECTOR_BITS),
+ .sector = cpu_to_le64(offset >> s->sectorbits),
+ .nr_sectors = cpu_to_le64(bytes >> s->sectorbits),
.flags = cpu_to_le64(entry_flags),
.data_len = 0,
},
.zero_size = is_zero_write ? bytes : 0,
};
- static const char zeroes[BDRV_SECTOR_SIZE - sizeof(struct log_write_entry)]
- = { '\0' };
+ void *zeroes = g_malloc0(s->sectorsize - sizeof(lr.entry));
+ assert((1 << s->sectorbits) == s->sectorsize);
+ assert(bs->bl.request_alignment == s->sectorsize);
assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
qemu_iovec_init(&log_qiov, niov + 2);
qemu_iovec_add(&log_qiov, &lr.entry, sizeof(lr.entry));
- qemu_iovec_add(&log_qiov, (void *)zeroes, sizeof(zeroes));
+ qemu_iovec_add(&log_qiov, zeroes, s->sectorsize - sizeof(lr.entry));
for (size_t i = 0; i < niov; ++i) {
qemu_iovec_add(&log_qiov, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
}
@@ -307,6 +323,7 @@ blk_log_writes_co_log(BlockDriverState *bs, uint64_t
offset, uint64_t bytes,
blk_log_writes_co_do_log(&lr);
qemu_iovec_destroy(&log_qiov);
+ g_free(zeroes);
if (lr.log_ret < 0) {
return lr.log_ret;
--
2.7.4
- [Qemu-block] [PATCH v3 00/10] New block driver: blklogwrites, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 06/10] hw/block/virtio-blk: Always apply block configuration to block driver, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 07/10] hw/block/nvme: Always apply block configuration to block driver, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 10/10] block/blklogwrites: Use the block device logical sector size when logging writes,
Ari Sundholm <=
- [Qemu-block] [PATCH v3 01/10] block: Move two block permission constants to the relevant enum, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 08/10] hw/block/fdc: Always apply block configuration to block driver, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 05/10] hw/ide/qdev: Always apply block configuration to block driver, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 09/10] block/blklogwrites: Use block limits from the backend block configuration, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 02/10] block: Add blklogwrites, Ari Sundholm, 2018/06/07
- [Qemu-block] [PATCH v3 03/10] block: Add a mechanism for passing a block driver a block configuration, Ari Sundholm, 2018/06/07
- Re: [Qemu-block] [Qemu-devel] [PATCH v3 00/10] New block driver: blklogwrites, no-reply, 2018/06/07