file-posix: Check bs->bl.zoned for zone info

Instead of checking bs->wps or bs->bl.zone_size for whether zone
information is present, check bs->bl.zoned.  That is the flag that
raw_refresh_zoned_limits() reliably sets to indicate zone support.  If
it is set to something other than BLK_Z_NONE, other values and objects
like bs->wps and bs->bl.zone_size must be non-null/zero and valid; if it
is not, we cannot rely on their validity.

Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20230824155345.109765-3-hreitz@redhat.com>
Reviewed-by: Sam Li <faithilikerun@gmail.com>

block/file-posix.c

@@ -2455,9 +2455,10 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
     if (fd_open(bs) < 0)
         return -EIO;
 #if defined(CONFIG_BLKZONED)
-    if ((type & (QEMU_AIO_WRITE | QEMU_AIO_ZONE_APPEND)) && bs->wps) {
+    if ((type & (QEMU_AIO_WRITE | QEMU_AIO_ZONE_APPEND)) &&
+        bs->bl.zoned != BLK_Z_NONE) {
         qemu_co_mutex_lock(&bs->wps->colock);
-        if (type & QEMU_AIO_ZONE_APPEND && bs->bl.zone_size) {
+        if (type & QEMU_AIO_ZONE_APPEND) {
             int index = offset / bs->bl.zone_size;
             offset = bs->wps->wp[index];
         }
@@ -2508,8 +2509,8 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
 {
     BlockZoneWps *wps = bs->wps;
     if (ret == 0) {
-        if ((type & (QEMU_AIO_WRITE | QEMU_AIO_ZONE_APPEND))
-            && wps && bs->bl.zone_size) {
+        if ((type & (QEMU_AIO_WRITE | QEMU_AIO_ZONE_APPEND)) &&
+            bs->bl.zoned != BLK_Z_NONE) {
             uint64_t *wp = &wps->wp[offset / bs->bl.zone_size];
             if (!BDRV_ZT_IS_CONV(*wp)) {
                 if (type & QEMU_AIO_ZONE_APPEND) {
@@ -2529,7 +2530,8 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
         }
     }
 
-    if ((type & (QEMU_AIO_WRITE | QEMU_AIO_ZONE_APPEND)) && wps) {
+    if ((type & (QEMU_AIO_WRITE | QEMU_AIO_ZONE_APPEND)) &&
+        bs->blk.zoned != BLK_Z_NONE) {
         qemu_co_mutex_unlock(&wps->colock);
     }
 }