diff mbox

block: allow resizing of images residing on host devices

Message ID 20110907110245.GA3477@lst.de
State New
Headers show

Commit Message

Christoph Hellwig Sept. 7, 2011, 11:02 a.m. UTC 
Allow to resize images that reside on host devices up to the available
space.  This allows to grow images after resizing the device manually or
vice versa.

Reviewed-by: Christoph Hellwig <hch@lst.de>

Comments

Kevin Wolf Sept. 9, 2011, 9:37 a.m. UTC | #1 
Am 07.09.2011 13:02, schrieb Christoph Hellwig:
> Allow to resize images that reside on host devices up to the available
> space.  This allows to grow images after resizing the device manually or
> vice versa.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

You mean Signed-off-by, no?

> Index: qemu/block/raw-posix.c
> ===================================================================
> --- qemu.orig/block/raw-posix.c	2011-09-01 17:37:42.579651525 +0200
> +++ qemu/block/raw-posix.c	2011-09-01 17:43:28.882967337 +0200
> @@ -645,10 +645,23 @@ static void raw_close(BlockDriverState *
>  static int raw_truncate(BlockDriverState *bs, int64_t offset)
>  {
>      BDRVRawState *s = bs->opaque;
> -    if (s->type != FTYPE_FILE)
> -        return -ENOTSUP;
> -    if (ftruncate(s->fd, offset) < 0)
> +    struct stat st;
> +
> +    if (fstat(s->fd, &st))
>          return -errno;

Coding style requires braces.

> +
> +    if (S_ISREG(st.st_mode)) {
> +        if (ftruncate(s->fd, offset) < 0)
> +            return -errno;

Here as well.

> +    } else if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {
> +       if (offset > raw_getlength(bs)) {
> +           return -EINVAL;
> +       }
> +       return 0;

This return isn't needed and it's not there in the S_ISREG case. It
should be symmetrical at least.

Semantically the patch looks okay.

Kevin
diff mbox

Patch

Index: qemu/block/raw-posix.c
===================================================================
--- qemu.orig/block/raw-posix.c	2011-09-01 17:37:42.579651525 +0200
+++ qemu/block/raw-posix.c	2011-09-01 17:43:28.882967337 +0200
@@ -645,10 +645,23 @@  static void raw_close(BlockDriverState *
 static int raw_truncate(BlockDriverState *bs, int64_t offset)
 {
     BDRVRawState *s = bs->opaque;
-    if (s->type != FTYPE_FILE)
-        return -ENOTSUP;
-    if (ftruncate(s->fd, offset) < 0)
+    struct stat st;
+
+    if (fstat(s->fd, &st))
         return -errno;
+
+    if (S_ISREG(st.st_mode)) {
+        if (ftruncate(s->fd, offset) < 0)
+            return -errno;
+    } else if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {
+       if (offset > raw_getlength(bs)) {
+           return -EINVAL;
+       }
+       return 0;
+
+    } else {
+        return -ENOTSUP;
+    }
     return 0;
 }
 
@@ -1167,6 +1180,7 @@  static BlockDriver bdrv_host_device = {
 
     .bdrv_read          = raw_read,
     .bdrv_write         = raw_write,
+    .bdrv_truncate      = raw_truncate,
     .bdrv_getlength	= raw_getlength,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
@@ -1288,6 +1302,7 @@  static BlockDriver bdrv_host_floppy = {
 
     .bdrv_read          = raw_read,
     .bdrv_write         = raw_write,
+    .bdrv_truncate      = raw_truncate,
     .bdrv_getlength	= raw_getlength,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
@@ -1389,6 +1404,7 @@  static BlockDriver bdrv_host_cdrom = {
 
     .bdrv_read          = raw_read,
     .bdrv_write         = raw_write,
+    .bdrv_truncate      = raw_truncate,
     .bdrv_getlength     = raw_getlength,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
@@ -1510,6 +1526,7 @@  static BlockDriver bdrv_host_cdrom = {
 
     .bdrv_read          = raw_read,
     .bdrv_write         = raw_write,
+    .bdrv_truncate      = raw_truncate,
     .bdrv_getlength     = raw_getlength,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,