| Message ID | BANLkTi=GKQo724CK2ULgjych2OP3hr6cyQ@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On Sat, Jun 4, 2011 at 1:44 AM, Fam Zheng <famcool@gmail.com> wrote: > The `qemu-img info` results for mono flat image are no longer > accurate, as the "disk size" was the length of bs->file, which is not > the case for multi file images (such as vmdk images with multiple > files). > The new field disk_size in BlockDriverState can be used by block > driver to tell the exact disk size of block image (only valid if the > field is set to non-zero). > > Signed-off-by: Fam Zheng <famcool@gmail.com> > --- > block/vmdk.c | 1 + > block_int.h | 1 + > qemu-img.c | 6 +++++- > 3 files changed, 7 insertions(+), 1 deletions(-) Instead of introducing a variable please add a new BlockDriver .bdrv_get_allocated_file_size() function pointer and move get_allocated_file_size() from qemu-img.c into block/raw-posix.c and block/raw-win32.c. qemu-img.c should call bdrv_get_allocated_file_size() and bdrv_get_allocated_file_size() could look like this: int bdrv_get_allocated_file_size(BlockDriverState *bs, int64_t *size) { BlockDriver *drv = bs->drv; if (!drv) { return -ENOMEDIUM; } if (drv->bdrv_get_allocated_file_size) { return drv->bdrv_get_allocated_file_size(bs, size); } if (bs->file) { return bdrv_get_allocated_file_size(bs->file, size); } return -ENOTSUP; } > @@ -607,6 +607,7 @@ static int vmdk_open_desc_file(BlockDriverState > *bs, int flags) > extent = s->extents; > vmdk_parse_extents(buf, s->extents, bs->file->filename); > bs->total_sectors = extent->sectors; > + bs->disk_size = bdrv_getlength(bs->file) + bdrv_getlength(extent->file); This should call bdrv_get_allocated_file_size() so add together the actually allocated amount, not what bdrv_getlength() returns. Stefan
Is there any difference between bdrv_getlength and bdrv_get_allocated_file_size for bs-file? If not, I can simplify it by reusing it in two raw devices. On Sun, Jun 19, 2011 at 2:35 AM, Stefan Hajnoczi <stefanha@gmail.com> wrote: > On Sat, Jun 4, 2011 at 1:44 AM, Fam Zheng <famcool@gmail.com> wrote: >> The `qemu-img info` results for mono flat image are no longer >> accurate, as the "disk size" was the length of bs->file, which is not >> the case for multi file images (such as vmdk images with multiple >> files). >> The new field disk_size in BlockDriverState can be used by block >> driver to tell the exact disk size of block image (only valid if the >> field is set to non-zero). >> >> Signed-off-by: Fam Zheng <famcool@gmail.com> >> --- >> block/vmdk.c | 1 + >> block_int.h | 1 + >> qemu-img.c | 6 +++++- >> 3 files changed, 7 insertions(+), 1 deletions(-) > > Instead of introducing a variable please add a new BlockDriver > .bdrv_get_allocated_file_size() function pointer and move > get_allocated_file_size() from qemu-img.c into block/raw-posix.c and > block/raw-win32.c. > > qemu-img.c should call bdrv_get_allocated_file_size() and > bdrv_get_allocated_file_size() could look like this: > > int bdrv_get_allocated_file_size(BlockDriverState *bs, int64_t *size) > { > BlockDriver *drv = bs->drv; > > if (!drv) { > return -ENOMEDIUM; > } > > if (drv->bdrv_get_allocated_file_size) { > return drv->bdrv_get_allocated_file_size(bs, size); > } > > if (bs->file) { > return bdrv_get_allocated_file_size(bs->file, size); > } > return -ENOTSUP; > } > >> @@ -607,6 +607,7 @@ static int vmdk_open_desc_file(BlockDriverState >> *bs, int flags) >> extent = s->extents; >> vmdk_parse_extents(buf, s->extents, bs->file->filename); >> bs->total_sectors = extent->sectors; >> + bs->disk_size = bdrv_getlength(bs->file) + bdrv_getlength(extent->file); > > This should call bdrv_get_allocated_file_size() so add together the > actually allocated amount, not what bdrv_getlength() returns. > > Stefan >
On Mon, Jun 20, 2011 at 6:37 AM, Fam Zheng <famcool@gmail.com> wrote: > Is there any difference between bdrv_getlength and > bdrv_get_allocated_file_size for bs-file? If not, I can simplify it by > reusing it in two raw devices. Yes, the two functions are different: POSIX sparse files (files with holes) take up less space on disk than their file size. For example a 1 GB file where you've only written the last byte and never touched any other blocks will only take up one block - the rest will be unallocated. So bdrv_getlength() == 1 GB and bdrv_get_allocated_file_size() == 4 KB (or whatever the file system block size is). You can look at this using the stat(1) command and dd(1) to only write the last byte of a file. Stefan
diff --git a/block/vmdk.c b/block/vmdk.c index 43b47e2..39c553c 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -607,6 +607,7 @@ static int vmdk_open_desc_file(BlockDriverState *bs, int flags) extent = s->extents; vmdk_parse_extents(buf, s->extents, bs->file->filename); bs->total_sectors = extent->sectors; + bs->disk_size = bdrv_getlength(bs->file) + bdrv_getlength(extent->file); // try to open parent images, if exist if (vmdk_parent_open(bs) != 0) { diff --git a/block_int.h b/block_int.h index dd8f8cb..4c58d6d 100644 --- a/block_int.h +++ b/block_int.h @@ -144,6 +144,7 @@ struct BlockDriver { struct BlockDriverState { int64_t total_sectors; /* if we are reading a disk image, give its size in sectors */ + int64_t disk_size; /* if non-zero, holds the disk size of image */ int read_only; /* if true, the media is read only */ int keep_read_only; /* if true, the media was requested to stay read only */ int open_flags; /* flags used to open the file, re-used for re-open */ diff --git a/qemu-img.c b/qemu-img.c index 4f162d1..7ea8faf 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1067,7 +1067,11 @@ static int img_info(int argc, char **argv) bdrv_get_format(bs, fmt_name, sizeof(fmt_name)); bdrv_get_geometry(bs, &total_sectors); get_human_readable_size(size_buf, sizeof(size_buf), total_sectors * 512); - allocated_size = get_allocated_file_size(filename); + if (bs->disk_size) { + allocated_size = bs->disk_size; + } else { + allocated_size = get_allocated_file_size(filename); + } if (allocated_size < 0) { snprintf(dsize_buf, sizeof(dsize_buf), "unavailable"); } else {
The `qemu-img info` results for mono flat image are no longer accurate, as the "disk size" was the length of bs->file, which is not the case for multi file images (such as vmdk images with multiple files). The new field disk_size in BlockDriverState can be used by block driver to tell the exact disk size of block image (only valid if the field is set to non-zero). Signed-off-by: Fam Zheng <famcool@gmail.com> --- block/vmdk.c | 1 + block_int.h | 1 + qemu-img.c | 6 +++++- 3 files changed, 7 insertions(+), 1 deletions(-)