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[Qemu-devel] [PATCH v3 05/10] block: Extract common write req handling
From: |
Fam Zheng |
Subject: |
[Qemu-devel] [PATCH v3 05/10] block: Extract common write req handling |
Date: |
Tue, 10 Jul 2018 14:31:19 +0800 |
As a mechanical refactoring patch, this is the first step towards
unified and more correct write code paths. This is helpful because
multiple BlockDriverState fields need to be updated after modifying
image data, and it's hard to maintain in multiple places such as copy
offload, discard and truncate.
Suggested-by: Kevin Wolf <address@hidden>
Signed-off-by: Fam Zheng <address@hidden>
---
block/io.c | 91 ++++++++++++++++++++++++++++++++++--------------------
1 file changed, 57 insertions(+), 34 deletions(-)
diff --git a/block/io.c b/block/io.c
index c56e329bb5..960e1492d0 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1553,6 +1553,61 @@ fail:
return ret;
}
+static inline int coroutine_fn
+bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes,
+ BdrvTrackedRequest *req, int flags)
+{
+ BlockDriverState *bs = child->bs;
+ bool waited;
+ int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
+
+ if (bs->read_only) {
+ return -EPERM;
+ }
+
+ /* BDRV_REQ_NO_SERIALISING is only for read operation */
+ assert(!(flags & BDRV_REQ_NO_SERIALISING));
+ assert(!(bs->open_flags & BDRV_O_INACTIVE));
+ assert((bs->open_flags & BDRV_O_NO_IO) == 0);
+ assert(!(flags & ~BDRV_REQ_MASK));
+
+ if (flags & BDRV_REQ_SERIALISING) {
+ mark_request_serialising(req, bdrv_get_cluster_size(bs));
+ }
+
+ waited = wait_serialising_requests(req);
+
+ assert(!waited || !req->serialising ||
+ is_request_serialising_and_aligned(req));
+ assert(req->overlap_offset <= offset);
+ assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
+
+ if (flags & BDRV_REQ_WRITE_UNCHANGED) {
+ assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE));
+ } else {
+ assert(child->perm & BLK_PERM_WRITE);
+ }
+ assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE);
+ return notifier_with_return_list_notify(&bs->before_write_notifiers, req);
+}
+
+static inline void coroutine_fn
+bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, uint64_t bytes,
+ BdrvTrackedRequest *req, int ret)
+{
+ int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
+ BlockDriverState *bs = child->bs;
+
+ atomic_inc(&bs->write_gen);
+ bdrv_set_dirty(bs, offset, bytes);
+
+ stat64_max(&bs->wr_highest_offset, offset + bytes);
+
+ if (ret == 0) {
+ bs->total_sectors = MAX(bs->total_sectors, end_sector);
+ }
+}
+
/*
* Forwards an already correctly aligned write request to the BlockDriver,
* after possibly fragmenting it.
@@ -1563,10 +1618,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild
*child,
{
BlockDriverState *bs = child->bs;
BlockDriver *drv = bs->drv;
- bool waited;
int ret;
- int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
uint64_t bytes_remaining = bytes;
int max_transfer;
@@ -1582,31 +1635,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild
*child,
assert((offset & (align - 1)) == 0);
assert((bytes & (align - 1)) == 0);
assert(!qiov || bytes == qiov->size);
- assert((bs->open_flags & BDRV_O_NO_IO) == 0);
- assert(!(flags & ~BDRV_REQ_MASK));
max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX),
align);
- /* BDRV_REQ_NO_SERIALISING is only for read operation */
- assert(!(flags & BDRV_REQ_NO_SERIALISING));
-
- if (flags & BDRV_REQ_SERIALISING) {
- mark_request_serialising(req, bdrv_get_cluster_size(bs));
- }
-
- waited = wait_serialising_requests(req);
- assert(!waited || !req->serialising ||
- is_request_serialising_and_aligned(req));
- assert(req->overlap_offset <= offset);
- assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
- if (flags & BDRV_REQ_WRITE_UNCHANGED) {
- assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE));
- } else {
- assert(child->perm & BLK_PERM_WRITE);
- }
- assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE);
-
- ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
+ ret = bdrv_co_write_req_prepare(child, offset, bytes, req, flags);
if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
!(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_pwrite_zeroes &&
@@ -1655,15 +1687,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild
*child,
}
bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
- atomic_inc(&bs->write_gen);
- bdrv_set_dirty(bs, offset, bytes);
-
- stat64_max(&bs->wr_highest_offset, offset + bytes);
-
if (ret >= 0) {
- bs->total_sectors = MAX(bs->total_sectors, end_sector);
ret = 0;
}
+ bdrv_co_write_req_finish(child, offset, bytes, req, ret);
return ret;
}
@@ -1778,10 +1805,6 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
if (!bs->drv) {
return -ENOMEDIUM;
}
- if (bs->read_only) {
- return -EPERM;
- }
- assert(!(bs->open_flags & BDRV_O_INACTIVE));
ret = bdrv_check_byte_request(bs, offset, bytes);
if (ret < 0) {
--
2.17.1
- [Qemu-devel] [PATCH v3 00/10] block: Fix dst reading after tail copy offloading, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 01/10] block: Prefix file driver trace points with "file_", Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 02/10] block: Add copy offloading trace points, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 03/10] block: Use BdrvChild to discard, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 04/10] block: Use uint64_t for BdrvTrackedRequest byte fields, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 05/10] block: Extract common write req handling,
Fam Zheng <=
- [Qemu-devel] [PATCH v3 06/10] block: Fix handling of image enlarging write, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 07/10] block: Use common req handling for discard, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 08/10] block: Use common req handling in copy offloading, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 09/10] block: Fix bdrv_co_truncate overlap check, Fam Zheng, 2018/07/10
- [Qemu-devel] [PATCH v3 10/10] block: Use common write req handling in truncate, Fam Zheng, 2018/07/10
- Re: [Qemu-devel] [PATCH v3 00/10] block: Fix dst reading after tail copy offloading, Kevin Wolf, 2018/07/10