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[PULL 09/20] block: use int64_t as bytes type in tracked requests
From: |
Eric Blake |
Subject: |
[PULL 09/20] block: use int64_t as bytes type in tracked requests |
Date: |
Tue, 2 Feb 2021 16:45:18 -0600 |
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
We are generally moving to int64_t for both offset and bytes parameters
on all io paths.
Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.
We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).
All requests in block/io must not overflow BDRV_MAX_LENGTH, all
external users of BdrvTrackedRequest already have corresponding
assertions, so we are safe. Add some assertions still.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-9-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
include/block/block_int.h | 4 ++--
block/io.c | 14 +++++++----
block/io.c.rej | 50 ++++++++++-----------------------------
3 files changed, 24 insertions(+), 44 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 5bbbf9ee0af9..7f41f0990cc0 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -79,12 +79,12 @@ enum BdrvTrackedRequestType {
typedef struct BdrvTrackedRequest {
BlockDriverState *bs;
int64_t offset;
- uint64_t bytes;
+ int64_t bytes;
enum BdrvTrackedRequestType type;
bool serialising;
int64_t overlap_offset;
- uint64_t overlap_bytes;
+ int64_t overlap_bytes;
QLIST_ENTRY(BdrvTrackedRequest) list;
Coroutine *co; /* owner, used for deadlock detection */
diff --git a/block/io.c b/block/io.c
index b56db913da30..1c23587d18c6 100644
--- a/block/io.c
+++ b/block/io.c
@@ -717,10 +717,10 @@ static void tracked_request_end(BdrvTrackedRequest *req)
static void tracked_request_begin(BdrvTrackedRequest *req,
BlockDriverState *bs,
int64_t offset,
- uint64_t bytes,
+ int64_t bytes,
enum BdrvTrackedRequestType type)
{
- assert(bytes <= INT64_MAX && offset <= INT64_MAX - bytes);
+ bdrv_check_request(offset, bytes, &error_abort);
*req = (BdrvTrackedRequest){
.bs = bs,
@@ -741,8 +741,10 @@ static void tracked_request_begin(BdrvTrackedRequest *req,
}
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
- int64_t offset, uint64_t bytes)
+ int64_t offset, int64_t bytes)
{
+ bdrv_check_request(offset, bytes, &error_abort);
+
/* aaaa bbbb */
if (offset >= req->overlap_offset + req->overlap_bytes) {
return false;
@@ -810,8 +812,10 @@ static void
tracked_request_set_serialising(BdrvTrackedRequest *req,
uint64_t align)
{
int64_t overlap_offset = req->offset & ~(align - 1);
- uint64_t overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
- - overlap_offset;
+ int64_t overlap_bytes =
+ ROUND_UP(req->offset + req->bytes, align) - overlap_offset;
+
+ bdrv_check_request(req->offset, req->bytes, &error_abort);
if (!req->serialising) {
qatomic_inc(&req->bs->serialising_in_flight);
diff --git a/block/io.c.rej b/block/io.c.rej
index f52df016263b..ae2f972d1af9 100644
--- a/block/io.c.rej
+++ b/block/io.c.rej
@@ -1,40 +1,16 @@
diff a/block/io.c b/block/io.c (rejected hunks)
-@@ -2138,20 +2139,32 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
- return 0;
- }
+@@ -798,10 +800,12 @@ bool bdrv_mark_request_serialising(BdrvTrackedRequest
*req, uint64_t align)
+ {
+ BlockDriverState *bs = req->bs;
+ int64_t overlap_offset = req->offset & ~(align - 1);
+- uint64_t overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
+- - overlap_offset;
++ int64_t overlap_bytes =
++ ROUND_UP(req->offset + req->bytes, align) - overlap_offset;
+ bool waited;
-+ if (!(flags & BDRV_REQ_ZERO_WRITE)) {
-+ /*
-+ * Pad request for following read-modify-write cycle.
-+ * bdrv_co_do_zero_pwritev() does aligning by itself, so, we do
-+ * alignment only if there is no ZERO flag.
-+ */
-+ padded = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes,
-+ &pad);
-+ }
++ bdrv_check_request(req->offset, req->bytes, &error_abort);
+
- bdrv_inc_in_flight(bs);
-- /*
-- * Align write if necessary by performing a read-modify-write cycle.
-- * Pad qiov with the read parts and be sure to have a tracked request not
-- * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
-- */
- tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE);
-
- if (flags & BDRV_REQ_ZERO_WRITE) {
-+ assert(!padded);
- ret = bdrv_co_do_zero_pwritev(child, offset, bytes, flags, &req);
- goto out;
- }
-
-- if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) {
-+ if (padded) {
-+ /*
-+ * Request was unaligned to request_alignment and therefore padded.
-+ * We are going to do read-modify-write. User is not prepared to
widened
-+ * request intersections with other requests, so we serialize the
-+ * request.
-+ */
- bdrv_mark_request_serialising(&req, align);
- bdrv_padding_rmw_read(child, &req, &pad, false);
- }
+ qemu_co_mutex_lock(&bs->reqs_lock);
+ if (!req->serialising) {
+ qatomic_inc(&req->bs->serialising_in_flight);
--
2.30.0
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