| Message ID | fce7e61849a1af1b343000b71495482e22f8ed35.1405962961.git.jcody@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 21.07.2014 21:52, Jeff Cody wrote: > Use the block layer to create, and write to, the image file in the > VDI .bdrv_create() operation. > > This has a couple of benefits: Images can now be created over protocols, > and hacks such as NOCOW are not needed in the image format driver, and > the underlying file protocol appropriate for the host OS can be relied This sounds a bit strange to me, but I don't know if it's wrong. > upon. > > Also some minor cleanup for error handling. > > Signed-off-by: Jeff Cody <jcody@redhat.com> > --- > block/vdi.c | 68 ++++++++++++++++++++++++++----------------------------------- > 1 file changed, 29 insertions(+), 39 deletions(-) > > diff --git a/block/vdi.c b/block/vdi.c > index 197bd77..5fd9d5f 100644 > --- a/block/vdi.c > +++ b/block/vdi.c > @@ -681,7 +681,6 @@ static int vdi_co_write(BlockDriverState *bs, > Anyway: Reviewed-by: Max Reitz <mreitz@redhat.com>
On Tue, Jul 22, 2014 at 10:14:58PM +0200, Max Reitz wrote: > On 21.07.2014 21:52, Jeff Cody wrote: > >Use the block layer to create, and write to, the image file in the > >VDI .bdrv_create() operation. > > > >This has a couple of benefits: Images can now be created over protocols, > >and hacks such as NOCOW are not needed in the image format driver, and > >the underlying file protocol appropriate for the host OS can be relied > > This sounds a bit strange to me, but I don't know if it's wrong. > You find the wording strange, or the logic itself? If the latter, the use of the posix calls (open(), write()) means that we cannot create images over protocols such as gluster - so using the qemu block layer operations instead means protocols are now supported. And NOCOW is not needed in the image format driver now, since raw-posix does the same thing (if the bs->file protocol driver is a host file on a posix system). > >upon. > > > >Also some minor cleanup for error handling. > > > >Signed-off-by: Jeff Cody <jcody@redhat.com> > >--- > > block/vdi.c | 68 ++++++++++++++++++++++++++----------------------------------- > > 1 file changed, 29 insertions(+), 39 deletions(-) > > > >diff --git a/block/vdi.c b/block/vdi.c > >index 197bd77..5fd9d5f 100644 > >--- a/block/vdi.c > >+++ b/block/vdi.c > >@@ -681,7 +681,6 @@ static int vdi_co_write(BlockDriverState *bs, > > Anyway: > > Reviewed-by: Max Reitz <mreitz@redhat.com>
On 22.07.2014 22:19, Jeff Cody wrote: > On Tue, Jul 22, 2014 at 10:14:58PM +0200, Max Reitz wrote: >> On 21.07.2014 21:52, Jeff Cody wrote: >>> Use the block layer to create, and write to, the image file in the >>> VDI .bdrv_create() operation. >>> >>> This has a couple of benefits: Images can now be created over protocols, >>> and hacks such as NOCOW are not needed in the image format driver, and >>> the underlying file protocol appropriate for the host OS can be relied >> This sounds a bit strange to me, but I don't know if it's wrong. >> > You find the wording strange, or the logic itself? If the latter, the Just the wording. :-) > use of the posix calls (open(), write()) means that we cannot create > images over protocols such as gluster - so using the qemu block layer > operations instead means protocols are now supported. And NOCOW is > not needed in the image format driver now, since raw-posix does the > same thing (if the bs->file protocol driver is a host file on a posix > system). > >>> upon. >>> >>> Also some minor cleanup for error handling. >>> >>> Signed-off-by: Jeff Cody <jcody@redhat.com> >>> --- >>> block/vdi.c | 68 ++++++++++++++++++++++++++----------------------------------- >>> 1 file changed, 29 insertions(+), 39 deletions(-) >>> >>> diff --git a/block/vdi.c b/block/vdi.c >>> index 197bd77..5fd9d5f 100644 >>> --- a/block/vdi.c >>> +++ b/block/vdi.c >>> @@ -681,7 +681,6 @@ static int vdi_co_write(BlockDriverState *bs, >> Anyway: >> >> Reviewed-by: Max Reitz <mreitz@redhat.com>
diff --git a/block/vdi.c b/block/vdi.c index 197bd77..5fd9d5f 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -681,7 +681,6 @@ static int vdi_co_write(BlockDriverState *bs, static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) { - int fd; int result = 0; uint64_t bytes = 0; uint32_t blocks; @@ -690,7 +689,10 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) VdiHeader header; size_t i; size_t bmap_size; - bool nocow = false; + int64_t offset = 0; + Error *local_err = NULL; + BlockDriverState *bs = NULL; + uint32_t *bmap = NULL; logout("\n"); @@ -707,7 +709,6 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) image_type = VDI_TYPE_STATIC; } #endif - nocow = qemu_opt_get_bool_del(opts, BLOCK_OPT_NOCOW, false); if (bytes > VDI_DISK_SIZE_MAX) { result = -ENOTSUP; @@ -717,27 +718,16 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) goto exit; } - fd = qemu_open(filename, - O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, - 0644); - if (fd < 0) { - result = -errno; + result = bdrv_create_file(filename, opts, &local_err); + if (result < 0) { + error_propagate(errp, local_err); goto exit; } - - if (nocow) { -#ifdef __linux__ - /* Set NOCOW flag to solve performance issue on fs like btrfs. - * This is an optimisation. The FS_IOC_SETFLAGS ioctl return value will - * be ignored since any failure of this operation should not block the - * left work. - */ - int attr; - if (ioctl(fd, FS_IOC_GETFLAGS, &attr) == 0) { - attr |= FS_NOCOW_FL; - ioctl(fd, FS_IOC_SETFLAGS, &attr); - } -#endif + result = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, + NULL, &local_err); + if (result < 0) { + error_propagate(errp, local_err); + goto exit; } /* We need enough blocks to store the given disk size, @@ -769,13 +759,15 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) vdi_header_print(&header); #endif vdi_header_to_le(&header); - if (write(fd, &header, sizeof(header)) < 0) { - result = -errno; - goto close_and_exit; + result = bdrv_pwrite_sync(bs, offset, &header, sizeof(header)); + if (result < 0) { + error_setg(errp, "Error writing header to %s", filename); + goto exit; } + offset += sizeof(header); if (bmap_size > 0) { - uint32_t *bmap = g_malloc0(bmap_size); + bmap = g_malloc0(bmap_size); for (i = 0; i < blocks; i++) { if (image_type == VDI_TYPE_STATIC) { bmap[i] = i; @@ -783,27 +775,25 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) bmap[i] = VDI_UNALLOCATED; } } - if (write(fd, bmap, bmap_size) < 0) { - result = -errno; - g_free(bmap); - goto close_and_exit; + result = bdrv_pwrite_sync(bs, offset, bmap, bmap_size); + if (result < 0) { + error_setg(errp, "Error writing bmap to %s", filename); + goto exit; } - g_free(bmap); + offset += bmap_size; } if (image_type == VDI_TYPE_STATIC) { - if (ftruncate(fd, sizeof(header) + bmap_size + blocks * block_size)) { - result = -errno; - goto close_and_exit; + result = bdrv_truncate(bs, offset + blocks * block_size); + if (result < 0) { + error_setg(errp, "Failed to statically allocate %s", filename); + goto exit; } } -close_and_exit: - if ((close(fd) < 0) && !result) { - result = -errno; - } - exit: + bdrv_unref(bs); + g_free(bmap); return result; }
Use the block layer to create, and write to, the image file in the VDI .bdrv_create() operation. This has a couple of benefits: Images can now be created over protocols, and hacks such as NOCOW are not needed in the image format driver, and the underlying file protocol appropriate for the host OS can be relied upon. Also some minor cleanup for error handling. Signed-off-by: Jeff Cody <jcody@redhat.com> --- block/vdi.c | 68 ++++++++++++++++++++++++++----------------------------------- 1 file changed, 29 insertions(+), 39 deletions(-)