Patchwork [2/2] UBIFS: add a log overlap assertion

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Submitter hujianyang
Date July 22, 2014, 1:35 a.m.
Message ID <53CDBFDB.6080300@huawei.com>
Download mbox | patch
Permalink /patch/372318/
State New
Headers show

Comments

hujianyang - July 22, 2014, 1:35 a.m.
On 2014/7/16 20:42, Artem Bityutskiy wrote:
> From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
> 
> Add an assertion which checkes that the head of the log never overlaps with the
> tail of the log.
> 
> Suggested-by: hujianyang <hujianyang@huawei.com>
> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
> ---
>  fs/ubifs/misc.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/ubifs/misc.h b/fs/ubifs/misc.h
> index ee7cb5e..81bbf79 100644
> --- a/fs/ubifs/misc.h
> +++ b/fs/ubifs/misc.h
> @@ -297,6 +297,7 @@ static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum)
>  	if (lnum > c->log_last)
>  		lnum = UBIFS_LOG_LNUM;
>  
> +	ubifs_assert(lnum != c->ltail_lnum);
>  	return lnum;
>  }
>  
> 

Hi Artem,

I just come back to work today.

I have to tell you this patch seems wrong. I've tested this patch
and saw lots of 'assert_failed()'. We use ubifs_next_log_lnum()
as an iterator to scan the hole log area and the return value of
this function may equal to c->ltail_lnum.

see:
	fixup_free_space() in fs/ubifs/sb.c line 712
	ubifs_log_post_commit() in fs/ubifs/log.c line 520
and so on.


How about my former patch or a new patch like this?
Artem Bityutskiy - July 28, 2014, 4:18 p.m.
On Tue, 2014-07-22 at 09:35 +0800, hujianyang wrote:
> I have to tell you this patch seems wrong. I've tested this patch
> and saw lots of 'assert_failed()'. We use ubifs_next_log_lnum()
> as an iterator to scan the hole log area and the return value of
> this function may equal to c->ltail_lnum.

OK, thanks. I've reverted my bogus patch.

Would you please re-send your patch with proper commit message, etc, so
that I could 'git am' it. This time I'd like to apply a patch which has
been tested. Thanks!
hujianyang - July 29, 2014, 10:27 a.m.
> 
> Would you please re-send your patch with proper commit message, etc, so
> that I could 'git am' it. This time I'd like to apply a patch which has
> been tested. Thanks!
>

I've tested this patch and resend it.

I don't think you can just am it because you know, I'm not very
good at English. So I think you should change some comments as
before. Sorry for that, and thanks for your help these days.

I'd like to improve my English but it needs some time. -.-

Patch

diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
index 7e818ec..c14628f 100644
--- a/fs/ubifs/log.c
+++ b/fs/ubifs/log.c
@@ -244,6 +244,7 @@  int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)

 	if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
 		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c->lhead_lnum != c->ltail_lnum);
 		c->lhead_offs = 0;
 	}

@@ -408,6 +409,7 @@  int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
 	/* Switch to the next log LEB */
 	if (c->lhead_offs) {
 		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c->lhead_lnum != c->ltail_lnum);
 		c->lhead_offs = 0;
 	}