On Thu, 2008-02-14 at 15:13 -0700, Andreas Dilger wrote: > On Feb 14, 2008 17:35 +0100, Valerie Clement wrote: > > From: Valerie Clement <valerie.clement@xxxxxxxx> > > > > With the flex_bg feature enabled, a large file creation oopses the > > kernel. > > The BUG_ON is: > > BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb)); > > > > As the allocation of the bitmaps and the inode table can be done > > outside the block group with flex_bg, this allows to allocate up to > > EXT4_BLOCKS_PER_GROUP blocks in a group. > > Depending on the group size and the block size, extents might be > > larger than BLOCKS_PER_GROUP(); use EXT_INIT_MAX_LEN instead of > > BLOCKS_PER_GROUP(). > > In fact, my earlier review of this patch was incorrect, and Aneesh pointed > out the correct answer. The ext4_mb_mark_free_simple() function is only > called from ext4_mb_generate_buddy() to generate the buddy bitmap from the > on-disk block bitmap, and in that case the @len parameter should always > be <= EXT4_BLOCKS_PER_GROUP(). I think the original patch was correct. > > Sorry about the confusion. I thought at first glance this was for > freeing the blocks from releasing an extent, but that is incorrect. > Ok, I added the revised first patch http://repo.or.cz/w/ext4-patch-queue.git?a=blob;f=ext4_fix_BUGON_at_mballoc.patch;h=c2d11bd2ec46c8103d4fad7c62cd792b7daec202;hb=067598f1a058a05342afee9720a0538b871c61f4 Mingming > Cheers, Andreas > -- > Andreas Dilger > Sr. Staff Engineer, Lustre Group > Sun Microsystems of Canada, Inc. > - 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
