Messages in this thread Patch in this message | | | Date | Wed, 7 Oct 2020 00:13:27 -0700 | From | Kees Cook <> | Subject | Re: use case for register_pstore_blk? |
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On Tue, Oct 06, 2020 at 05:52:20PM +0200, Christoph Hellwig wrote: > Hi WeiXiong, hi Kees, > > what is the use case for the code added in commit 17639f67c1d6 > ("pstore/blk: Introduce backend for block devices"). > > This still doesn't have a user, and the API looks really odd to me.
pstore is a beast. :) The API is there so that a blk device can declare its direct support of pstore (specifically, to provide a panic_write handler).
The MTD device does this, but yes, that's a good point, there isn't a blk device user of that entry point yet.
> By our normal kernel rules we should not add new exports without > users and this should probably be reverted for the 5.9 release.
I don't want to revert the entire patch (I'm still using __register_pstore_blk by way of pstore/blk's "best_effort" option), but I wouldn't object to something like this:
diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index fcd5563dde06..e0fe21e2cf34 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -419,27 +419,6 @@ static int __register_pstore_blk(struct pstore_blk_info *info) return ret; } -/** - * register_pstore_blk() - register block device to pstore/blk - * - * @info: details on the desired block device interface - * - * Return: - * * 0 - OK - * * Others - something error. - */ -int register_pstore_blk(struct pstore_blk_info *info) -{ - int ret; - - mutex_lock(&pstore_blk_lock); - ret = __register_pstore_blk(info); - mutex_unlock(&pstore_blk_lock); - - return ret; -} -EXPORT_SYMBOL_GPL(register_pstore_blk); - static void __unregister_pstore_blk(unsigned int major) { struct pstore_device_info dev = { .read = psblk_generic_blk_read }; @@ -454,19 +433,6 @@ static void __unregister_pstore_blk(unsigned int major) } } -/** - * unregister_pstore_blk() - unregister block device from pstore/blk - * - * @major: the major device number of device - */ -void unregister_pstore_blk(unsigned int major) -{ - mutex_lock(&pstore_blk_lock); - __unregister_pstore_blk(major); - mutex_unlock(&pstore_blk_lock); -} -EXPORT_SYMBOL_GPL(unregister_pstore_blk); - /* get information of pstore/blk */ int pstore_blk_get_config(struct pstore_blk_config *info) { diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index 61e914522b01..2bf07d20ce43 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -46,9 +46,6 @@ struct pstore_blk_info { sector_t start_sect; }; -int register_pstore_blk(struct pstore_blk_info *info); -void unregister_pstore_blk(unsigned int major); - /** * struct pstore_device_info - back-end pstore/blk driver structure. * -- Kees Cook
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