filefrag on a virtual fs like proc segfaults:
# filefrag /proc/filesystems
Floating point exception
because stat.f_blocks is 0, so the calculation of cylgroups is 0,
which leads to a divide by 0 when calculating expected extents.
Since it's only used for ext2 filesystems anyway, just move
the calculation of expected under "if (is_ext2)" to fix this.
Reported-by: Max Beikirch <redacted>
Signed-off-by: Eric Sandeen <redacted>
---
diff --git a/misc/filefrag.c b/misc/filefrag.c
index 0583e91..b6e7d62 100644
--- a/misc/filefrag.c
+++ b/misc/filefrag.c
@@ -365,11 +366,12 @@ static void frag_report(const char *filename)
else
printf("%s: %d extents found", filename, num_extents);
/* count, and thus expected, only set for indirect FIBMAP'd files */
- expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
- if (is_ext2 && expected && expected < num_extents)
- printf(", perfection would be %d extent%s\n", expected,
- (expected>1) ? "s" : "");
- else
+ if (is_ext2) {
+ expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
+ if (expected && expected < num_extents)
+ printf(", perfection would be %d extent%s\n", expected,
+ (expected>1) ? "s" : "");
+ } else
fputc('\n', stdout);
close(fd);
once = 0;