Re: [PATCH v2 1/3] badblocks: Add core badblock management code

["Verma, Vishal L" <vishal.l.verma@intel.com>]

On Tue, 2015-12-08 at 13:18 -0800, Dan Williams wrote:
> On Tue, Dec 8, 2015 at 1:08 PM, Verma, Vishal L
> <vishal.l.verma@intel.com> wrote:
> > On Wed, 2015-12-09 at 08:03 +1100, NeilBrown wrote:
> > > On Sat, Dec 05 2015, Verma, Vishal L wrote:
> > > > > 
> > > > > > +int badblocks_clear(struct badblocks *bb, sector_t s, int
> > > > > > sectors)
> > > > > > +{
> > > > > [...]
> > > > > > +#define DO_DEBUG 1
> > > > > 
> > > > > Why have this at all if it's unconditionally defined and
> > > > > always
> > > > > set.
> > > > 
> > > > Neil - any reason or anything you had in mind for this? Or is it
> > > > just an
> > > > artifact and can be removed.
> > > 
> > > Like the comment says:
> > > 
> > >       /* Allow clearing via sysfs *only* for testing/debugging.
> > >        * Normally only a successful write may clear a badblock
> > >        */
> > > 
> > > The DO_DEBUG define and ifdefs are documentation identifying bits
> > > of
> > > code that should be removed when it all seems to be working.
> > > Maybe now is a good time to remove that code.
> > > 
> > Hm, I think it would be nice to continue to have the ability to
> > clear
> > badblocks using sysfs at least for a while more, as we test the
> > various
> > error handling paths for NVDIMMS (Dan, thoughts?).
> > 
> > We could either remove it later or (I'm leaning towards) make it a
> > config option similar to FAIL_MAKE_REQUEST and friends..
> 
> "later" as in before v4.5-rc1?  We can always carry this debug feature
> locally for testing.  We don't want userspace growing ABI attachments
> to this capability now that it's more than just md tooling that will
> see this.


Agreed. The following incremental patch removes sysfs support.
All the latest badblocks patches can also be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/vishal/nvdimm.git gendisk-badblocks


8<-----
From 5f0e7ac31d27a132f314106f1db33af22fde03ed Mon Sep 17 00:00:00 2001
From: Vishal Verma <vishal.l.verma@intel.com>
Date: Tue, 8 Dec 2015 16:28:31 -0700
Subject: [PATCH v4 4/3] badblocks: remove support for clearing via sysfs

sysfs support for clearing badblocks was originally meant for testing
only. With the move to generalize the interface, remove this support so
that userspace doesn't start treating this as an ABI.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 block/badblocks.c | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/block/badblocks.c b/block/badblocks.c
index f0ac279..e5d2a91 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -503,16 +503,6 @@ ssize_t badblocks_store(struct badblocks *bb, const
char *page, size_t len,
 	int length;
 	char newline;
 
-	/* Allow clearing via sysfs *only* for testing/debugging.
-	 * Normally only a successful write may clear a badblock
-	 */
-	int clear = 0;
-
-	if (page[0] == '-') {
-		clear = 1;
-		page++;
-	}
-
 	switch (sscanf(page, "%llu %d%c", &sector, &length, &newline))
{
 	case 3:
 		if (newline != '\n')
@@ -525,11 +515,6 @@ ssize_t badblocks_store(struct badblocks *bb, const
char *page, size_t len,
 		return -EINVAL;
 	}
 
-	if (clear) {
-		badblocks_clear(bb, sector, length);
-		return len;
-	}
-
 	if (badblocks_set(bb, sector, length, !unack))
 		return -ENOSPC;
 	else
-- 
2.5.0