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[Qemu-block] [PATCH 05/31] qemu-img: Switch get_block_status() to byte-b
From: |
Eric Blake |
Subject: |
[Qemu-block] [PATCH 05/31] qemu-img: Switch get_block_status() to byte-based |
Date: |
Mon, 17 Apr 2017 20:33:30 -0500 |
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Continue by converting
an internal function (no semantic change), and simplifying its
caller accordingly.
Signed-off-by: Eric Blake <address@hidden>
---
qemu-img.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index d96b4d6..8cb5165 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2662,14 +2662,16 @@ static void dump_map_entry(OutputFormat output_format,
MapEntry *e,
}
}
-static int get_block_status(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, MapEntry *e)
+static int get_block_status(BlockDriverState *bs, int64_t offset,
+ int64_t bytes, MapEntry *e)
{
int64_t ret;
int depth;
BlockDriverState *file;
bool has_offset;
+ int nb_sectors = bytes >> BDRV_SECTOR_BITS;
+ assert(bytes < INT_MAX);
/* As an optimization, we could cache the current range of unallocated
* clusters in each file of the chain, and avoid querying the same
* range repeatedly.
@@ -2677,8 +2679,8 @@ static int get_block_status(BlockDriverState *bs, int64_t
sector_num,
depth = 0;
for (;;) {
- ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors,
- &file);
+ ret = bdrv_get_block_status(bs, offset >> BDRV_SECTOR_BITS, nb_sectors,
+ &nb_sectors, &file);
if (ret < 0) {
return ret;
}
@@ -2698,7 +2700,7 @@ static int get_block_status(BlockDriverState *bs, int64_t
sector_num,
has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID);
*e = (MapEntry) {
- .start = sector_num * BDRV_SECTOR_SIZE,
+ .start = offset,
.length = nb_sectors * BDRV_SECTOR_SIZE,
.data = !!(ret & BDRV_BLOCK_DATA),
.zero = !!(ret & BDRV_BLOCK_ZERO),
@@ -2823,16 +2825,12 @@ static int img_map(int argc, char **argv)
length = blk_getlength(blk);
while (curr.start + curr.length < length) {
- int64_t nsectors_left;
- int64_t sector_num;
- int n;
-
- sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS;
+ int64_t offset = curr.start + curr.length;
+ int64_t n;
/* Probe up to 1 GiB at a time. */
- nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num;
- n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left);
- ret = get_block_status(bs, sector_num, n, &next);
+ n = QEMU_ALIGN_DOWN(MIN(1 << 30, length - offset), BDRV_SECTOR_SIZE);
+ ret = get_block_status(bs, offset, n, &next);
if (ret < 0) {
error_report("Could not read file metadata: %s", strerror(-ret));
--
2.9.3
- [Qemu-block] [PATCH 00/31] make bdrv_get_block_status byte-based, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 01/31] block: Drop unused bdrv_round_sectors_to_clusters(), Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 02/31] block: Make bdrv_round_to_clusters() signature more useful, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 03/31] qcow2: Switch is_zero_sectors() to byte-based, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 05/31] qemu-img: Switch get_block_status() to byte-based,
Eric Blake <=
- [Qemu-block] [PATCH 06/31] block: Convert bdrv_get_block_status() to bytes, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 04/31] block: Switch bdrv_make_zero() to byte-based, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 07/31] block: Switch bdrv_co_get_block_status() to byte-based, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 08/31] block: Switch BdrvCoGetBlockStatusData to byte-based, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 09/31] block: Switch bdrv_co_get_block_status_above() to byte-based, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 10/31] block: Convert bdrv_get_block_status_above() to bytes, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 11/31] block: Add .bdrv_co_block_status() callback, Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 12/31] commit: Switch to .bdrv_co_block_status(), Eric Blake, 2017/04/17
- [Qemu-block] [PATCH 14/31] gluster: Switch to .bdrv_co_block_status(), Eric Blake, 2017/04/17