From: Peng Tao Date: Thu, 2 Jul 2009 04:24:15 +0000 (-0400) Subject: filefrag: fix fm_start in filefrag_fiemap loop X-Git-Tag: v1.41.8~20 X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=f97ea10fde6d8bee670d388f02cf9524b8f2d7da;p=tools%2Fe2fsprogs.git filefrag: fix fm_start in filefrag_fiemap loop When used with -v and the targeted file has more than 144 extents(double of the length of fm_extents array provided by buf), filefrag_fiemap loops and calls fiemap ioctl() multiple times to calculate the actual number of extents in a file. Each call to fiemap ioctl() uses fm_start as the starting logical offset. The patch fixes fm_start in each loop( except for the first one) and makes the extent calculation correct for files with more that 144 extents. To produce the problem, first run filefrag -v on a highly fragmented file. Then change the buf size in filefrag_fiemap to make it large enough to have all the extent mapped in a single loop and run filefrag -v after recompiling. The former will produce a much smaller extent count because of the false fm_start used in the loop. And the two will produce different extent output since the 145th extent. Signed-off-by: Peng Tao Signed-off-by: "Theodore Ts'o" --- diff --git a/misc/filefrag.c b/misc/filefrag.c index 7095949..702cb8d 100644 --- a/misc/filefrag.c +++ b/misc/filefrag.c @@ -239,8 +239,8 @@ int filefrag_fiemap(int fd, int blk_shift, int *num_extents) n++; } - fiemap->fm_start += fm_ext[i-1].fe_logical + - fm_ext[i-1].fe_length; + fiemap->fm_start = (fm_ext[i-1].fe_logical + + fm_ext[i-1].fe_length); } while (last == 0); *num_extents = tot_extents;