On 2018/5/16 6:46 PM, Kai Krakow wrote:
> Hello Kent!
>
> 2018-05-16 9:58 GMT+02:00 Kent Overstreet <kent.overstreet@xxxxxxxxx>:
>> On Wed, May 02, 2018 at 12:53:17PM +0200, Massimo B. wrote:
>>> Hello,
>>>
>>> have you been able to modprobe bcache on 4.16.x?
>>> I have asked on IRC and it seemed nobody tried before, just me.
>>> So nobody was able to confirm or confirm against...
>>>
>>> https://github.com/dracutdevs/dracut/issues/393
>>> At least here I'm not able to modprobe the bcache module from an initramfs.
>>> So I can't boot with that 4.16.x kernel as my root fs is on bcache.
>>
>> It was busted by 539d39eb27083405b82b9e604e88af01a9a46c63 (bcache: fix wrong
>> return value in bch_debug_init()) - only breaks when CONFIG_DEBUG_FS=n
>>
>> also, that commit has a bunch of other unrelated changes in it...
>
> Thanks for the pointer, this sounds promising. Do you suggest to remove
> the unrelated changes, or do you suggest to revert the change in
> bch_debug_init()?
>
> I'll try to fiddle around with this commit this evening.
Hi Massimo, Kai,
Could you please to have a try with the attached patch ? This is a
rebased version for 4.16.9, I verified it with a kernel has no debugfs
enabled. Hope it works on your kernels.
If the patches works for you all, I will post patches to 4.17 and
4.16-stable both.
Thanks.
Coly Li
From 11543f8f4c002be9450ba3e39a11d007beef0dca Mon Sep 17 00:00:00 2001
From: Coly Li <colyli@xxxxxxx>
Date: Wed, 16 May 2018 20:57:44 +0800
Subject: [PATCH] bcache: return 0 from bch_debug_init() if CONFIG_DEBUG_FS=n
Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
returns the return value of debugfs_create_dir() to bcache_init(). When
CONFIG_DEBUG_FS=n, bch_debug_init() always returns 1 and makes
bcache_init() failedi.
This patch makes bch_debug_init() always returns 0 if CONFIG_DEBUG_FS=n,
so bcache can continue to work for the kernels which don't have debugfs
enanbled.
Fixes: Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Coly Li <colyli@xxxxxxx>
Reported-by: Massimo B. <massimo.b@xxxxxxx>
Reported-by: Kai Krakow <kai@xxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
drivers/md/bcache/bcache.h | 5 +++++
drivers/md/bcache/debug.c | 4 ++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 12e5197f186cd..5787475df9ec0 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -941,8 +941,13 @@ void bch_open_buckets_free(struct cache_set *);
int bch_cache_allocator_start(struct cache *ca);
+#ifdef CONFIG_DEBUG_FS
void bch_debug_exit(void);
int bch_debug_init(struct kobject *);
+#else
+static inline void bch_debug_exit(void) {};
+static inline int bch_debug_init(struct kobject *kobj) { return 0; };
+#endif
void bch_request_exit(void);
int bch_request_init(void);
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index af89408befe84..91c11717ce216 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -241,8 +241,6 @@ void bch_debug_init_cache_set(struct cache_set *c)
}
}
-#endif
-
void bch_debug_exit(void)
{
if (!IS_ERR_OR_NULL(debug))
@@ -255,3 +253,5 @@ int __init bch_debug_init(struct kobject *kobj)
return IS_ERR_OR_NULL(debug);
}
+
+#endif
--
2.16.3
