From: Tristan Ye Date: Thu, 12 May 2011 12:47:07 +0000 (+0800) Subject: ocfs2: skip existing hole when removing the last extent_rec in punching-hole codes. X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=9a790ba1ec02bbae0933e7ebd576c0bc329e9796;p=openwrt%2Fstaging%2Fblogic.git ocfs2: skip existing hole when removing the last extent_rec in punching-hole codes. In the case of removing a partial extent record which covers a hole, current punching-hole logic will try to remove more than the length of whole extent record, which leads to the failure of following assert(fs/ocfs2/alloc.c): 5507 BUG_ON(cpos < le32_to_cpu(rec->e_cpos) || trunc_range > rec_range); This patch tries to skip existing hole at the last attempt of removing a partial extent record, what's more, it also adds some necessary comments for better understanding of punching-hole codes. Signed-off-by: Tristan Ye Signed-off-by: Joel Becker --- diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 41565ae52856..89659d6dc206 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1607,6 +1607,9 @@ static void ocfs2_calc_trunc_pos(struct inode *inode, range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec); if (le32_to_cpu(rec->e_cpos) >= trunc_start) { + /* + * remove an entire extent record. + */ *trunc_cpos = le32_to_cpu(rec->e_cpos); /* * Skip holes if any. @@ -1617,7 +1620,16 @@ static void ocfs2_calc_trunc_pos(struct inode *inode, *blkno = le64_to_cpu(rec->e_blkno); *trunc_end = le32_to_cpu(rec->e_cpos); } else if (range > trunc_start) { + /* + * remove a partial extent record, which means we're + * removing the last extent record. + */ *trunc_cpos = trunc_start; + /* + * skip hole if any. + */ + if (range < *trunc_end) + *trunc_end = range; *trunc_len = *trunc_end - trunc_start; coff = trunc_start - le32_to_cpu(rec->e_cpos); *blkno = le64_to_cpu(rec->e_blkno) +