[Qemu-devel] [PATCH v3 18/44] qemu-img: Switch to byte-based block access

[Eric Blake <eblake@redhat.com>]

Sector-based blk_write() should die; switch to byte-based
blk_pwrite() instead.  Likewise for blk_read().

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 qemu-img.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index 1697762..2e4646e 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1092,7 +1092,8 @@ static int check_empty_sectors(BlockBackend *blk, int64_t sect_num,
                                uint8_t *buffer, bool quiet)
 {
     int pnum, ret = 0;
-    ret = blk_read(blk, sect_num, buffer, sect_count);
+    ret = blk_pread(blk, sect_num << BDRV_SECTOR_BITS, buffer,
+                    sect_count << BDRV_SECTOR_BITS);
     if (ret < 0) {
         error_report("Error while reading offset %" PRId64 " of %s: %s",
                      sectors_to_bytes(sect_num), filename, strerror(-ret));
@@ -1307,7 +1308,8 @@ static int img_compare(int argc, char **argv)
             nb_sectors = MIN(pnum1, pnum2);
         } else if (allocated1 == allocated2) {
             if (allocated1) {
-                ret = blk_read(blk1, sector_num, buf1, nb_sectors);
+                ret = blk_pread(blk1, sector_num << BDRV_SECTOR_BITS, buf1,
+                                nb_sectors << BDRV_SECTOR_BITS);
                 if (ret < 0) {
                     error_report("Error while reading offset %" PRId64 " of %s:"
                                  " %s", sectors_to_bytes(sector_num), filename1,
@@ -1315,7 +1317,8 @@ static int img_compare(int argc, char **argv)
                     ret = 4;
                     goto out;
                 }
-                ret = blk_read(blk2, sector_num, buf2, nb_sectors);
+                ret = blk_pread(blk2, sector_num << BDRV_SECTOR_BITS, buf2,
+                                nb_sectors << BDRV_SECTOR_BITS);
                 if (ret < 0) {
                     error_report("Error while reading offset %" PRId64
                                  " of %s: %s", sectors_to_bytes(sector_num),
@@ -1528,7 +1531,9 @@ static int convert_read(ImgConvertState *s, int64_t sector_num, int nb_sectors,
         bs_sectors = s->src_sectors[s->src_cur];

         n = MIN(nb_sectors, bs_sectors - (sector_num - s->src_cur_offset));
-        ret = blk_read(blk, sector_num - s->src_cur_offset, buf, n);
+        ret = blk_pread(blk,
+                        (sector_num - s->src_cur_offset) << BDRV_SECTOR_BITS,
+                        buf, n << BDRV_SECTOR_BITS);
         if (ret < 0) {
             return ret;
         }
@@ -1583,7 +1588,8 @@ static int convert_write(ImgConvertState *s, int64_t sector_num, int nb_sectors,
             if (!s->min_sparse ||
                 is_allocated_sectors_min(buf, n, &n, s->min_sparse))
             {
-                ret = blk_write(s->target, sector_num, buf, n);
+                ret = blk_pwrite(s->target, sector_num << BDRV_SECTOR_BITS,
+                                 buf, n << BDRV_SECTOR_BITS, 0);
                 if (ret < 0) {
                     return ret;
                 }
@@ -3036,7 +3042,8 @@ static int img_rebase(int argc, char **argv)
                     n = old_backing_num_sectors - sector;
                 }

-                ret = blk_read(blk_old_backing, sector, buf_old, n);
+                ret = blk_pread(blk_old_backing, sector << BDRV_SECTOR_BITS,
+                                buf_old, n << BDRV_SECTOR_BITS);
                 if (ret < 0) {
                     error_report("error while reading from old backing file");
                     goto out;
@@ -3050,7 +3057,8 @@ static int img_rebase(int argc, char **argv)
                     n = new_backing_num_sectors - sector;
                 }

-                ret = blk_read(blk_new_backing, sector, buf_new, n);
+                ret = blk_pread(blk_new_backing, sector << BDRV_SECTOR_BITS,
+                                buf_new, n << BDRV_SECTOR_BITS);
                 if (ret < 0) {
                     error_report("error while reading from new backing file");
                     goto out;
@@ -3066,8 +3074,10 @@ static int img_rebase(int argc, char **argv)
                 if (compare_sectors(buf_old + written * 512,
                     buf_new + written * 512, n - written, &pnum))
                 {
-                    ret = blk_write(blk, sector + written,
-                                    buf_old + written * 512, pnum);
+                    ret = blk_pwrite(blk,
+                                     (sector + written) << BDRV_SECTOR_BITS,
+                                     buf_old + written * 512,
+                                     pnum << BDRV_SECTOR_BITS, 0);
                     if (ret < 0) {
                         error_report("Error while writing to COW image: %s",
                             strerror(-ret));
-- 
2.5.5