On 21:39 Wed 19 Mar , Eric Sandeen wrote: > Solofo.Ramangalahy@xxxxxxxx wrote: > > Hello, > > > > During stress testing (workload: racer from ltp + fio/iometer), here > > is an error I am encountering: > > 8<------------------------------------------------------------------------------ > > kernel: WARNING: at fs/buffer.c:1680 __block_write_full_page+0xd4/0x2af() > > So this is WARN_ON(bh->b_size != blocksize); > > What is b_size in this case? FS block size, because this page pinned bh (it comes from page_buffers(page)), but not dummy bh which may comes from {write,read}pages or direct_IO. Page's bh i_size must always be equal to fs blocksize. This bh always constructed via following construction if (!page_has_buffers(page)) create_empty_buffers(page, 1<<inode->i_blkbits, flags) So page's bh->b_size was inited with right value from very beginning, but apparently somewhere this size was changed I guess i've localized buggy place, at least it's looks strange. ext4_da_get_block_prep () { ... BUG_ON(create == 0); BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize); ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1, bh_result, 0, 0); #Here ext4_get_block_write called with max_blocks == 1 ^^^^^ ... if (ret > 0) { bh_result->b_size = (ret << inode->i_blkbits); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ## I don't understand this place. I hoped what (ret <= max_blocks) must always ##be true true. But after I've add debug info printing I've got following result. ret = 0; } ... } Some times I've seen following ,message bh= {state=0,size=114688, blknr=18446744073709551615 dev=0000000000000000,count=0}, ret=28 And because it was page-cache's bh later this result in WARNING. > > -Eric > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html