From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Sun, 17 May 2015 00:22:43 +0000 (-0400)
Subject: filefrag: fix broken extent emulation and uninitialized variables
X-Git-Tag: v1.43-WIP-2015-05-18~12
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=f008143cf5bfb93b5f5a0cb7018091b6f38301f8;p=tools%2Fe2fsprogs.git

filefrag: fix broken extent emulation and uninitialized variables

This started with the fm_ext being uninitialized, but upon closer
analysis I discovered that forcing extent emulation in FIBMAP mode
was reporting an extent for every block in the file.  Fix both
problems.

The Coverity bug was 1297512.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/misc/filefrag.c b/misc/filefrag.c
index c1a8684..3b104c6 100644
--- a/misc/filefrag.c
+++ b/misc/filefrag.c
@@ -287,8 +287,8 @@ static int filefrag_fibmap(int fd, int blk_shift, int *num_extents,
 	const long		bpib = st->st_blksize / 4;
 	int			count;
 
+	memset(&fm_ext, 0, sizeof(fm_ext));
 	if (force_extent) {
-		memset(&fm_ext, 0, sizeof(fm_ext));
 		fm_ext.fe_flags = FIEMAP_EXTENT_MERGED;
 	}
 
@@ -331,15 +331,17 @@ static int filefrag_fibmap(int fd, int blk_shift, int *num_extents,
 					  blk_shift, st);
 			fm_ext.fe_length = 0;
 			(*num_extents)++;
+			fm_ext.fe_logical = logical;
+			fm_ext.fe_physical = block * st->st_blksize;
 		} else if (last_block && (block != last_block + 1)) {
 			if (verbose)
 				printf("Discontinuity: Block %ld is at %lu (was "
 				       "%lu)\n", i, block, last_block + 1);
 			fm_ext.fe_length = 0;
 			(*num_extents)++;
+			fm_ext.fe_logical = logical;
+			fm_ext.fe_physical = block * st->st_blksize;
 		}
-		fm_ext.fe_logical = logical;
-		fm_ext.fe_physical = block * st->st_blksize;
 		fm_ext.fe_length += st->st_blksize;
 		last_block = block;
 	}