docs/nvdimm: add example on persistent backend setup

[mirror_qemu.git] / qemu-img.c

diff --git a/qemu-img.c b/qemu-img.c
index 31c72dc746e9782dad997a26e11a39502f106397..4ee436fc948f31c7488a6c905519a7be8132df8f 100644 (file)
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1578,6 +1578,7 @@ typedef struct ImgConvertState {
     bool has_zero_init;
     bool compressed;
     bool unallocated_blocks_are_zero;
+    bool target_is_new;
     bool target_has_backing;
     int64_t target_backing_sectors; /* negative if unknown */
     bool wr_in_order;
@@ -1975,9 +1976,11 @@ static int convert_do_copy(ImgConvertState *s)
     int64_t sector_num = 0;
 
     /* Check whether we have zero initialisation or can get it efficiently */
-    s->has_zero_init = s->min_sparse && !s->target_has_backing
-                     ? bdrv_has_zero_init(blk_bs(s->target))
-                     : false;
+    if (s->target_is_new && s->min_sparse && !s->target_has_backing) {
+        s->has_zero_init = bdrv_has_zero_init(blk_bs(s->target));
+    } else {
+        s->has_zero_init = false;
+    }
 
     if (!s->has_zero_init && !s->target_has_backing &&
         bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)))
@@ -2231,6 +2234,11 @@ static int img_convert(int argc, char **argv)
         goto fail_getopt;
     }
 
+    if (skip_create && options) {
+        warn_report("-o has no effect when skipping image creation");
+        warn_report("This will become an error in future QEMU versions.");
+    }
+
     s.src_num = argc - optind - 1;
     out_filename = s.src_num >= 1 ? argv[argc - 1] : NULL;
 
@@ -2380,7 +2388,7 @@ static int img_convert(int argc, char **argv)
         const char *preallocation =
             qemu_opt_get(opts, BLOCK_OPT_PREALLOC);
 
-        if (drv && !drv->bdrv_co_pwritev_compressed) {
+        if (drv && !block_driver_can_compress(drv)) {
             error_report("Compression not supported for this file format");
             ret = -1;
             goto out;
@@ -2423,6 +2431,8 @@ static int img_convert(int argc, char **argv)
         }
     }
 
+    s.target_is_new = !skip_create;
+
     flags = s.min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
     if (ret < 0) {
@@ -2449,7 +2459,7 @@ static int img_convert(int argc, char **argv)
     }
     out_bs = blk_bs(s.target);
 
-    if (s.compressed && !out_bs->drv->bdrv_co_pwritev_compressed) {
+    if (s.compressed && !block_driver_can_compress(out_bs->drv)) {
         error_report("Compression not supported for this file format");
         ret = -1;
         goto out;