[Qemu-devel] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it

[Nir Soffer]

Replace instances of:

    (n & (BDRV_SECTOR_SIZE - 1)) == 0)

With:

    QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)

Which reveals the intent of the code better, and makes it easier to
locate the code checking alignment.

QEMU_IS_ALIGNED is implemented using %, which may be less efficient but
it is used only in assert() except one instance, so it should not
matter.

Signed-off-by: Nir Soffer <address@hidden>
---
 block/bochs.c | 4 ++--
 block/cloop.c | 4 ++--
 block/dmg.c   | 4 ++--
 block/io.c    | 8 ++++----
 block/qcow2.c | 4 ++--
 block/vvfat.c | 8 ++++----
 qemu-img.c    | 2 +-
 7 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/block/bochs.c b/block/bochs.c
index 962f18592d..32bb83b268 100644
--- a/block/bochs.c
+++ b/block/bochs.c
@@ -248,8 +248,8 @@ bochs_co_preadv(BlockDriverState *bs, uint64_t offset, 
uint64_t bytes,
     QEMUIOVector local_qiov;
     int ret;
 
-    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
 
     qemu_iovec_init(&local_qiov, qiov->niov);
     qemu_co_mutex_lock(&s->lock);
diff --git a/block/cloop.c b/block/cloop.c
index 384c9735bb..4de94876d4 100644
--- a/block/cloop.c
+++ b/block/cloop.c
@@ -253,8 +253,8 @@ cloop_co_preadv(BlockDriverState *bs, uint64_t offset, 
uint64_t bytes,
     int nb_sectors = bytes >> BDRV_SECTOR_BITS;
     int ret, i;
 
-    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
 
     qemu_co_mutex_lock(&s->lock);
 
diff --git a/block/dmg.c b/block/dmg.c
index 45f6b28f17..4a045f2b3e 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -697,8 +697,8 @@ dmg_co_preadv(BlockDriverState *bs, uint64_t offset, 
uint64_t bytes,
     int nb_sectors = bytes >> BDRV_SECTOR_BITS;
     int ret, i;
 
-    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
 
     qemu_co_mutex_lock(&s->lock);
 
diff --git a/block/io.c b/block/io.c
index 56bbf195bb..7508703ecd 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1080,8 +1080,8 @@ static int coroutine_fn 
bdrv_driver_preadv(BlockDriverState *bs,
     sector_num = offset >> BDRV_SECTOR_BITS;
     nb_sectors = bytes >> BDRV_SECTOR_BITS;
 
-    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
     assert(bytes <= BDRV_REQUEST_MAX_BYTES);
     assert(drv->bdrv_co_readv);
 
@@ -1133,8 +1133,8 @@ static int coroutine_fn 
bdrv_driver_pwritev(BlockDriverState *bs,
     sector_num = offset >> BDRV_SECTOR_BITS;
     nb_sectors = bytes >> BDRV_SECTOR_BITS;
 
-    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
     assert(bytes <= BDRV_REQUEST_MAX_BYTES);
 
     assert(drv->bdrv_co_writev);
diff --git a/block/qcow2.c b/block/qcow2.c
index 59cff1d4cb..41cab70e1d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2072,8 +2072,8 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState 
*bs, uint64_t offset,
             }
             if (bs->encrypted) {
                 assert(s->crypto);
-                assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-                assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+                assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+                assert(QEMU_IS_ALIGNED(cur_bytes, BDRV_SECTOR_SIZE));
                 if (qcow2_co_decrypt(bs, cluster_offset, offset,
                                      cluster_data, cur_bytes) < 0) {
                     ret = -EIO;
diff --git a/block/vvfat.c b/block/vvfat.c
index f6c28805dd..019b8f1341 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1547,8 +1547,8 @@ vvfat_co_preadv(BlockDriverState *bs, uint64_t offset, 
uint64_t bytes,
     int nb_sectors = bytes >> BDRV_SECTOR_BITS;
     void *buf;
 
-    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
 
     buf = g_try_malloc(bytes);
     if (bytes && buf == NULL) {
@@ -3082,8 +3082,8 @@ vvfat_co_pwritev(BlockDriverState *bs, uint64_t offset, 
uint64_t bytes,
     int nb_sectors = bytes >> BDRV_SECTOR_BITS;
     void *buf;
 
-    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
-    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+    assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
 
     buf = g_try_malloc(bytes);
     if (bytes && buf == NULL) {
diff --git a/qemu-img.c b/qemu-img.c
index c920e3564c..ca3af0c549 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2138,7 +2138,7 @@ static int img_convert(int argc, char **argv)
             int64_t sval;
 
             sval = cvtnum(optarg);
-            if (sval < 0 || sval & (BDRV_SECTOR_SIZE - 1) ||
+            if (sval < 0 || !QEMU_IS_ALIGNED(sval, BDRV_SECTOR_SIZE) ||
                 sval / BDRV_SECTOR_SIZE > MAX_BUF_SECTORS) {
                 error_report("Invalid buffer size for sparse output specified. 
"
                     "Valid sizes are multiples of %llu up to %llu. Select "
-- 
2.20.1