Re: [Qemu-devel] [PATCH] block: allow resizing of images residing on host devices

[Kevin Wolf]

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 

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.c2011-09-01 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

[Qemu-devel] [PATCH] block: allow resizing of images residing on host devices

[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 

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,