Message ID | 20100111175137.GA7571@lst.de |
---|---|
State | New |
Headers | show |
Am 11.01.2010 18:51, schrieb Christoph Hellwig: > Check the whitelist as early as possible instead of continuing the > setup, and move all the error handling code to the end of the > function. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > > Index: qemu/block.c > =================================================================== > --- qemu.orig/block.c 2010-01-11 17:48:27.811004054 +0100 > +++ qemu/block.c 2010-01-11 17:52:15.578006158 +0100 > @@ -428,10 +428,16 @@ int bdrv_open2(BlockDriverState *bs, con > drv = find_image_format(filename); > } > } > + > if (!drv) { > ret = -ENOENT; > goto unlink_and_fail; > } > + if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) { > + ret = -ENOTSUP; > + goto unlink_and_fail; > + } > + > bs->drv = drv; > bs->opaque = qemu_mallocz(drv->instance_size); > > @@ -452,23 +458,17 @@ int bdrv_open2(BlockDriverState *bs, con > (flags & (BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO)); > else > open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT); > - if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) > - ret = -ENOTSUP; > - else > - ret = drv->bdrv_open(bs, filename, open_flags); > + > + ret = drv->bdrv_open(bs, filename, open_flags); > if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) { > ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR); > bs->read_only = 1; > } > + > if (ret < 0) { > - qemu_free(bs->opaque); > - bs->opaque = NULL; > - bs->drv = NULL; > - unlink_and_fail: > - if (bs->is_temporary) > - unlink(filename); > - return ret; > + goto free_and_fail; > } > + > if (drv->bdrv_getlength) { > bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; > } > @@ -502,6 +502,15 @@ int bdrv_open2(BlockDriverState *bs, con > bs->change_cb(bs->change_opaque); > } > return 0; > + > +free_and_fail: > + qemu_free(bs->opaque); > + bs->opaque = NULL; > + bs->drv = NULL; > +unlink_and_fail: To keep the behaviour as previously you'd need to set at least bs->drv in the unlink_and_fail case, too. I have no clue why it's important to set it to NULL when bs isn't going to be used anyway (probably it is, but I don't know where), but Fabrice committed this in 6b21b973 as a fix. Unfortunately, the commit message looks like most of Fabrice's commit messages, so it's of no use for me... Kevin
On Tue, Jan 12, 2010 at 05:04:00PM +0100, Kevin Wolf wrote: > To keep the behaviour as previously you'd need to set at least bs->drv > in the unlink_and_fail case, too. I have no clue why it's important to > set it to NULL when bs isn't going to be used anyway (probably it is, > but I don't know where), but Fabrice committed this in 6b21b973 as a > fix. Unfortunately, the commit message looks like most of Fabrice's > commit messages, so it's of no use for me... The unlink_and_fail label can only be reached from places where we haven't set bs->drv yet, so it should be fine.
Am 12.01.2010 18:09, schrieb Christoph Hellwig: > On Tue, Jan 12, 2010 at 05:04:00PM +0100, Kevin Wolf wrote: >> To keep the behaviour as previously you'd need to set at least bs->drv >> in the unlink_and_fail case, too. I have no clue why it's important to >> set it to NULL when bs isn't going to be used anyway (probably it is, >> but I don't know where), but Fabrice committed this in 6b21b973 as a >> fix. Unfortunately, the commit message looks like most of Fabrice's >> commit messages, so it's of no use for me... > > The unlink_and_fail label can only be reached from places where we > haven't set bs->drv yet, so it should be fine. Sorry, I confused drv and bs->drv. Looks alright then. Acked-by: Kevin Wolf <kwolf@redhat.com>
Index: qemu/block.c =================================================================== --- qemu.orig/block.c 2010-01-11 17:48:27.811004054 +0100 +++ qemu/block.c 2010-01-11 17:52:15.578006158 +0100 @@ -428,10 +428,16 @@ int bdrv_open2(BlockDriverState *bs, con drv = find_image_format(filename); } } + if (!drv) { ret = -ENOENT; goto unlink_and_fail; } + if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) { + ret = -ENOTSUP; + goto unlink_and_fail; + } + bs->drv = drv; bs->opaque = qemu_mallocz(drv->instance_size); @@ -452,23 +458,17 @@ int bdrv_open2(BlockDriverState *bs, con (flags & (BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO)); else open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT); - if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) - ret = -ENOTSUP; - else - ret = drv->bdrv_open(bs, filename, open_flags); + + ret = drv->bdrv_open(bs, filename, open_flags); if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) { ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR); bs->read_only = 1; } + if (ret < 0) { - qemu_free(bs->opaque); - bs->opaque = NULL; - bs->drv = NULL; - unlink_and_fail: - if (bs->is_temporary) - unlink(filename); - return ret; + goto free_and_fail; } + if (drv->bdrv_getlength) { bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; } @@ -502,6 +502,15 @@ int bdrv_open2(BlockDriverState *bs, con bs->change_cb(bs->change_opaque); } return 0; + +free_and_fail: + qemu_free(bs->opaque); + bs->opaque = NULL; + bs->drv = NULL; +unlink_and_fail: + if (bs->is_temporary) + unlink(filename); + return ret; } void bdrv_close(BlockDriverState *bs)
Check the whitelist as early as possible instead of continuing the setup, and move all the error handling code to the end of the function. Signed-off-by: Christoph Hellwig <hch@lst.de>