block: Add BDRV_O_RESIZE for blk_new_open()

blk_new_open() is a convenience function that processes flags rather
than QDict options as a simple way to just open an image file.

In order to keep it convenient in the future, it must automatically
request the necessary permissions. This can easily be inferred from the
flags for read and write, but we need another flag that tells us whether
to get the resize permission.

We can't just always request it because that means that no block jobs
can run on the resulting BlockBackend (which is something that e.g.
qemu-img commit wants to do), but we also can't request it never because
most of the .bdrv_create() implementations call blk_truncate().

The solution is to introduce another flag that is passed by all users
that want to resize the image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

diff --git a/block/parallels.c b/block/parallels.c
index 6b0c0a917c39e114e2ea3f1dc9170fe52ade19da..19935e29a9c53484357ba9b4f083061e4651b44a 100644 (file)
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -488,7 +488,8 @@ static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     file = blk_new_open(filename, NULL, NULL,
-                        BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                        BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                        &local_err);
     if (file == NULL) {
         error_propagate(errp, local_err);
         return -EIO;

diff --git a/block/qcow.c b/block/qcow.c
index eb5d54c65a893bab3a3e4231487d3934957b0cf5..9d6ac839593b74674ad8104589999486bd1cc105 100644 (file)
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -823,7 +823,8 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     qcow_blk = blk_new_open(filename, NULL, NULL,
-                            BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                            BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                            &local_err);
     if (qcow_blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;

diff --git a/block/qcow2.c b/block/qcow2.c
index 6f79df85171c486abbbe787b3962225194b52bd5..6a92d2ef3f082cbcef67428d555838d698a083b7 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2202,7 +2202,8 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                       &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         return -EIO;
@@ -2266,7 +2267,8 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     options = qdict_new();
     qdict_put(options, "driver", qstring_from_str("qcow2"));
     blk = blk_new_open(filename, NULL, options,
-                       BDRV_O_RDWR | BDRV_O_NO_FLUSH, &local_err);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH,
+                       &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;

diff --git a/block/qed.c b/block/qed.c
index d8f947aaa3e073283e723f1cc0ffbf34fba4d149..5ec7fd83f25954ac35fdfe7d5f1c7833d58feedb 100644 (file)
--- a/block/qed.c
+++ b/block/qed.c
@@ -625,7 +625,8 @@ static int qed_create(const char *filename, uint32_t cluster_size,
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                       &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         return -EIO;

diff --git a/block/sheepdog.c b/block/sheepdog.c
index 860ba6150247116e8be58d460942f5927973afae..743471043eb55dd3f502150cf4931d772ff287aa 100644 (file)
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -1609,7 +1609,7 @@ static int sd_prealloc(const char *filename, Error **errp)
     int ret;
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_PROTOCOL, errp);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
     if (blk == NULL) {
         ret = -EIO;
         goto out_with_err_set;

diff --git a/block/vdi.c b/block/vdi.c
index fd6e26dfed55998bf17b5d722778d15477cc9f97..9b4f70e97747ae452689ceeba3c6a6610efe3a1b 100644 (file)
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -763,7 +763,8 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                       &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;

diff --git a/block/vhdx.c b/block/vhdx.c
index ab747f639385e0c107db11d498bd9990fc5fd69f..052a753159d6e649cc314da6bd7ccc588b7b4920 100644 (file)
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1859,7 +1859,8 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                       &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;

diff --git a/block/vmdk.c b/block/vmdk.c
index f5e2fb5cf02fc2618ce56fb93d8702fa55c57250..a9bd22bf9353b23000505cc54bea1d19af27f29e 100644 (file)
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1703,7 +1703,8 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                       &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
@@ -2071,7 +2072,8 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     new_blk = blk_new_open(filename, NULL, NULL,
-                           BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                           BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                           &local_err);
     if (new_blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;

diff --git a/block/vpc.c b/block/vpc.c
index b9c98326372fb9be963c218269f6b2aaa1ba76cd..f591d4be38d648e6fbe1c2de057073a86542589a 100644 (file)
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -915,7 +915,8 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
+                       BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+                       &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;

diff --git a/include/block/block.h b/include/block/block.h
index ff951ea772d310b1b5f7f1cbe673e86e7503f87a..07f75618866b167cd02450433ca1a36e6b89266c 100644 (file)
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -82,6 +82,7 @@ typedef struct HDGeometry {
 } HDGeometry;
 
 #define BDRV_O_RDWR        0x0002
+#define BDRV_O_RESIZE      0x0004 /* request permission for resizing the node */
 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */

diff --git a/qemu-img.c b/qemu-img.c
index caa76a7400e9527aa4bc71e999de71258881e1f7..a48a471042649d60cc1a579e2e102bf1bf448c17 100644 (file)
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3419,7 +3419,7 @@ static int img_resize(int argc, char **argv)
     qemu_opts_del(param);
 
     blk = img_open(image_opts, filename, fmt,
-                   BDRV_O_RDWR, false, quiet);
+                   BDRV_O_RDWR | BDRV_O_RESIZE, false, quiet);
     if (!blk) {
         ret = -1;
         goto out;