Re: fs/ocfs2/suballoc.c:2430:2-8: preceding lock on line 2413

From: Julia Lawall
Date: Fri Aug 14 2020 - 15:00:30 EST



On Fri, 14 Aug 2020, Thomas Gleixner wrote:

> On Fri, Aug 14 2020 at 14:11, kernel test robot wrote:
> >
> > coccinelle warnings: (new ones prefixed by >>)
> >
> >>> fs/ocfs2/suballoc.c:2430:2-8: preceding lock on line 2413
> >
> > vim +2430 fs/ocfs2/suballoc.c
> >
> > 415cb800375cc4 Mark Fasheh 2007-09-16 2379
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2380 static int ocfs2_block_group_clear_bits(handle_t *handle,
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2381 struct inode *alloc_inode,
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2382 struct ocfs2_group_desc *bg,
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2383 struct buffer_head *group_bh,
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2384 unsigned int bit_off,
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2385 unsigned int num_bits,
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2386 void (*undo_fn)(unsigned int bit,
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2387 unsigned long *bmap))
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2388 {
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2389 int status;
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2390 unsigned int tmp;
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2391 struct ocfs2_group_desc *undo_bg = NULL;
> > 464170647b5648 Thomas Gleixner 2019-08-09 2392 struct journal_head *jh;
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2393
> > 42035306132802 Joel Becker 2008-11-13 2394 /* The caller got this descriptor from
> > 42035306132802 Joel Becker 2008-11-13 2395 * ocfs2_read_group_descriptor(). Any corruption is a code bug. */
> > 42035306132802 Joel Becker 2008-11-13 2396 BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2397
> > 2f73e135b83c50 Tao Ma 2011-02-22 2398 trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2399
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2400 BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
> > 0cf2f7632b1789 Joel Becker 2009-02-12 2401 status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2402 group_bh,
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2403 undo_fn ?
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2404 OCFS2_JOURNAL_ACCESS_UNDO :
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2405 OCFS2_JOURNAL_ACCESS_WRITE);
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2406 if (status < 0) {
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2407 mlog_errno(status);
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2408 goto bail;
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2409 }
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2410
> > 464170647b5648 Thomas Gleixner 2019-08-09 2411 jh = bh2jh(group_bh);
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2412 if (undo_fn) {
> > 464170647b5648 Thomas Gleixner 2019-08-09 @2413 spin_lock(&jh->b_state_lock);
> > 464170647b5648 Thomas Gleixner 2019-08-09 2414 undo_bg = (struct ocfs2_group_desc *) jh->b_committed_data;
> > 94e41ecfe0f202 Sunil Mushran 2009-06-19 2415 BUG_ON(!undo_bg);
> > 94e41ecfe0f202 Sunil Mushran 2009-06-19 2416 }
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2417
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2418 tmp = num_bits;
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2419 while(tmp--) {
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2420 ocfs2_clear_bit((bit_off + tmp),
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2421 (unsigned long *) bg->bg_bitmap);
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2422 if (undo_fn)
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2423 undo_fn(bit_off + tmp,
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2424 (unsigned long *) undo_bg->bg_bitmap);
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2425 }
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2426 le16_add_cpu(&bg->bg_free_bits_count, num_bits);
> > 9b5cd10e4c14a1 Srinivas Eeda 2010-10-05 2427 if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
> > e75ed71be4f2f7 Changwei Ge 2018-01-31 2428 if (undo_fn)
> > 464170647b5648 Thomas Gleixner 2019-08-09 2429 spin_unlock(&jh->b_state_lock);
> > 7ecef14ab1db96 Joe Perches 2015-09-04 @2430 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
> > 9b5cd10e4c14a1 Srinivas Eeda 2010-10-05 2431 (unsigned long long)le64_to_cpu(bg->bg_blkno),
> > 9b5cd10e4c14a1 Srinivas Eeda 2010-10-05 2432 le16_to_cpu(bg->bg_bits),
> > 7ecef14ab1db96 Joe Perches 2015-09-04 2433 le16_to_cpu(bg->bg_free_bits_count),
> > 7ecef14ab1db96 Joe Perches 2015-09-04 2434 num_bits);
> > 9b5cd10e4c14a1 Srinivas Eeda 2010-10-05 2435 }
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2436
> > b4414eea0e7b9c Mark Fasheh 2010-03-11 2437 if (undo_fn)
> > 464170647b5648 Thomas Gleixner 2019-08-09 2438 spin_unlock(&jh->b_state_lock);
> > 94e41ecfe0f202 Sunil Mushran 2009-06-19 2439
> > ec20cec7a35158 Joel Becker 2010-03-19 2440 ocfs2_journal_dirty(handle, group_bh);
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2441 bail:
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2442 return status;
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2443 }
> > ccd979bdbce9fb Mark Fasheh 2005-12-15 2444
>
> That's clearly a false positive. Is there anything what can be done to
> help that cocci script here?

I have a better version that needs to get pushed.

But normally these pass through me. Did you get it directly from kbuild?

julia