block/mirror: Pull out mirror_perform()

When converting mirror's I/O to coroutines, we are going to need a point
where these coroutines are created.  mirror_perform() is going to be
that point.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Max Reitz 2018-06-13 20:18:10 +02:00
parent f45280cbf6
commit 4295c5fc61

View File

@ -80,6 +80,12 @@ typedef struct MirrorOp {
uint64_t bytes;
} MirrorOp;
typedef enum MirrorMethod {
MIRROR_METHOD_COPY,
MIRROR_METHOD_ZERO,
MIRROR_METHOD_DISCARD,
} MirrorMethod;
static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read,
int error)
{
@ -319,6 +325,22 @@ static void mirror_do_zero_or_discard(MirrorBlockJob *s,
}
}
static unsigned mirror_perform(MirrorBlockJob *s, int64_t offset,
unsigned bytes, MirrorMethod mirror_method)
{
switch (mirror_method) {
case MIRROR_METHOD_COPY:
return mirror_do_read(s, offset, bytes);
case MIRROR_METHOD_ZERO:
case MIRROR_METHOD_DISCARD:
mirror_do_zero_or_discard(s, offset, bytes,
mirror_method == MIRROR_METHOD_DISCARD);
return bytes;
default:
abort();
}
}
static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
{
BlockDriverState *source = s->source;
@ -385,11 +407,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
int ret;
int64_t io_bytes;
int64_t io_bytes_acct;
enum MirrorMethod {
MIRROR_METHOD_COPY,
MIRROR_METHOD_ZERO,
MIRROR_METHOD_DISCARD
} mirror_method = MIRROR_METHOD_COPY;
MirrorMethod mirror_method = MIRROR_METHOD_COPY;
assert(!(offset % s->granularity));
ret = bdrv_block_status_above(source, NULL, offset,
@ -427,22 +445,11 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
}
io_bytes = mirror_clip_bytes(s, offset, io_bytes);
switch (mirror_method) {
case MIRROR_METHOD_COPY:
io_bytes = io_bytes_acct = mirror_do_read(s, offset, io_bytes);
break;
case MIRROR_METHOD_ZERO:
case MIRROR_METHOD_DISCARD:
mirror_do_zero_or_discard(s, offset, io_bytes,
mirror_method == MIRROR_METHOD_DISCARD);
if (write_zeroes_ok) {
io_bytes_acct = 0;
} else {
io_bytes_acct = io_bytes;
}
break;
default:
abort();
io_bytes = mirror_perform(s, offset, io_bytes, mirror_method);
if (mirror_method != MIRROR_METHOD_COPY && write_zeroes_ok) {
io_bytes_acct = 0;
} else {
io_bytes_acct = io_bytes;
}
assert(io_bytes);
offset += io_bytes;
@ -635,7 +642,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
continue;
}
mirror_do_zero_or_discard(s, offset, bytes, false);
mirror_perform(s, offset, bytes, MIRROR_METHOD_ZERO);
offset += bytes;
}