From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, vsementsov@virtuozzo.com,
qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org,
jsnow@redhat.com
Subject: [PATCH v3 09/10] nbd/server: use bdrv_dirty_bitmap_next_dirty_area
Date: Thu, 19 Dec 2019 13:03:47 +0300 [thread overview]
Message-ID: <20191219100348.24827-10-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20191219100348.24827-1-vsementsov@virtuozzo.com>
Use bdrv_dirty_bitmap_next_dirty_area for bitmap_to_extents. Since
bdrv_dirty_bitmap_next_dirty_area is very accurate in its interface,
we'll never exceed requested region with last chunk. So, we don't need
dont_fragment, and bitmap_to_extents() interface becomes clean enough
to not require any comment.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
nbd/server.c | 59 +++++++++++++++++-----------------------------------
1 file changed, 19 insertions(+), 40 deletions(-)
diff --git a/nbd/server.c b/nbd/server.c
index cc722adc31..461566a051 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2059,57 +2059,36 @@ static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
}
-/*
- * Populate @ea from a dirty bitmap. Unless @dont_fragment, the
- * final extent may exceed the original @length.
- */
+/* Populate @ea from a dirty bitmap. */
static void bitmap_to_extents(BdrvDirtyBitmap *bitmap,
uint64_t offset, uint64_t length,
- NBDExtentArray *ea, bool dont_fragment)
+ NBDExtentArray *es)
{
- uint64_t begin = offset, end = offset;
- uint64_t overall_end = offset + length;
- BdrvDirtyBitmapIter *it;
- bool dirty;
+ int64_t start, dirty_start, dirty_count;
+ int64_t end = offset + length;
+ bool full = false;
bdrv_dirty_bitmap_lock(bitmap);
- it = bdrv_dirty_iter_new(bitmap);
- dirty = bdrv_dirty_bitmap_get_locked(bitmap, offset);
-
- while (begin < overall_end) {
- bool next_dirty = !dirty;
-
- if (dirty) {
- end = bdrv_dirty_bitmap_next_zero(bitmap, begin, INT64_MAX);
- } else {
- bdrv_set_dirty_iter(it, begin);
- end = bdrv_dirty_iter_next(it);
- }
- if (end == -1 || end - begin > UINT32_MAX) {
- /* Cap to an aligned value < 4G beyond begin. */
- end = MIN(bdrv_dirty_bitmap_size(bitmap),
- begin + UINT32_MAX + 1 -
- bdrv_dirty_bitmap_granularity(bitmap));
- next_dirty = dirty;
- }
- if (dont_fragment && end > overall_end) {
- end = overall_end;
- }
-
- if (nbd_extent_array_add(ea, end - begin,
- dirty ? NBD_STATE_DIRTY : 0) < 0) {
+ for (start = offset;
+ bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX,
+ &dirty_start, &dirty_count);
+ start = dirty_start + dirty_count)
+ {
+ if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) ||
+ (nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0))
+ {
+ full = true;
break;
}
- begin = end;
- dirty = next_dirty;
}
- bdrv_dirty_iter_free(it);
+ if (!full) {
+ /* last non dirty extent */
+ nbd_extent_array_add(es, end - start, 0);
+ }
bdrv_dirty_bitmap_unlock(bitmap);
-
- assert(offset < end);
}
static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
@@ -2120,7 +2099,7 @@ static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
- bitmap_to_extents(bitmap, offset, length, ea, dont_fragment);
+ bitmap_to_extents(bitmap, offset, length, ea);
return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
}
--
2.21.0
next prev parent reply other threads:[~2019-12-19 10:06 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 10:03 [PATCH v3 00/10] Further bitmaps improvements Vladimir Sementsov-Ogievskiy
2019-12-19 10:03 ` [PATCH v3 01/10] hbitmap: assert that we don't create bitmap larger than INT64_MAX Vladimir Sementsov-Ogievskiy
2020-01-20 10:51 ` Max Reitz
2019-12-19 10:03 ` [PATCH v3 02/10] hbitmap: move hbitmap_iter_next_word to hbitmap.c Vladimir Sementsov-Ogievskiy
2020-01-20 10:55 ` Max Reitz
2020-01-20 16:14 ` Vladimir Sementsov-Ogievskiy
2019-12-19 10:03 ` [PATCH v3 03/10] hbitmap: unpublish hbitmap_iter_skip_words Vladimir Sementsov-Ogievskiy
2020-01-20 10:59 ` Max Reitz
2019-12-19 10:03 ` [PATCH v3 04/10] hbitmap: drop meta bitmaps as they are unused Vladimir Sementsov-Ogievskiy
2020-01-20 11:13 ` Max Reitz
2020-01-20 16:20 ` Vladimir Sementsov-Ogievskiy
2020-01-20 17:05 ` Max Reitz
2020-01-20 17:28 ` Vladimir Sementsov-Ogievskiy
2020-01-20 19:53 ` Eric Blake
2020-01-21 9:15 ` Vladimir Sementsov-Ogievskiy
2019-12-19 10:03 ` [PATCH v3 05/10] block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_t Vladimir Sementsov-Ogievskiy
2020-01-20 11:59 ` Max Reitz
2020-01-20 12:28 ` Vladimir Sementsov-Ogievskiy
2020-01-20 12:53 ` Max Reitz
2020-01-20 19:56 ` Eric Blake
2019-12-19 10:03 ` [PATCH v3 06/10] block/dirty-bitmap: add _next_dirty API Vladimir Sementsov-Ogievskiy
2020-01-20 13:14 ` Max Reitz
2020-01-20 16:30 ` Vladimir Sementsov-Ogievskiy
2020-01-21 9:35 ` Vladimir Sementsov-Ogievskiy
2019-12-19 10:03 ` [PATCH v3 07/10] block/dirty-bitmap: improve _next_dirty_area API Vladimir Sementsov-Ogievskiy
2020-01-20 13:58 ` Max Reitz
2020-01-20 16:26 ` Vladimir Sementsov-Ogievskiy
2019-12-19 10:03 ` [PATCH v3 08/10] nbd/server: introduce NBDExtentArray Vladimir Sementsov-Ogievskiy
2020-01-20 20:20 ` Eric Blake
2020-01-21 10:25 ` Vladimir Sementsov-Ogievskiy
2019-12-19 10:03 ` Vladimir Sementsov-Ogievskiy [this message]
2020-01-20 20:23 ` [PATCH v3 09/10] nbd/server: use bdrv_dirty_bitmap_next_dirty_area Eric Blake
2019-12-19 10:03 ` [PATCH v3 10/10] block/qcow2-bitmap: use bdrv_dirty_bitmap_next_dirty Vladimir Sementsov-Ogievskiy
2020-01-20 14:18 ` Max Reitz
2020-01-20 16:05 ` Vladimir Sementsov-Ogievskiy
2020-01-20 9:08 ` [PATCH v3 00/10] Further bitmaps improvements Vladimir Sementsov-Ogievskiy
2020-01-20 14:20 ` Max Reitz
2020-01-20 16:33 ` Vladimir Sementsov-Ogievskiy
2020-01-20 20:25 ` Eric Blake
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