diff mbox

misc: Use unsigned long long for file block count in filefrag

Message ID 20140223091251.3545C47E837@yourcmc.ru
State Superseded, archived
Headers show

Commit Message

Vitaliy Filippov Feb. 23, 2014, 9:08 a.m. UTC 
This patch fixes incorrect reporting of file block count on 32-bit platforms.

---
 misc/filefrag.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Theodore Ts'o Feb. 23, 2014, 1:58 p.m. UTC | #1 
On Sun, Feb 23, 2014 at 01:08:47PM +0400, Vitaliy Filippov wrote:
> This patch fixes incorrect reporting of file block count on 32-bit platforms.

Hi Vitaliy,

Thanks for the patch!  Your patch is missing a Signed-Off-By footer.
Also, you note that numblocks gets passed to filefrag_fibmap(), so if
you're going to do this, and we fall back to using fibmap, you should
probably check to see if numblocks would overflow an unsigned long,
and if so, to give an error because fibmap ioctl only supports the use
of a ulong.

Cheers,

					- Ted
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Vitaliy Filippov Feb. 23, 2014, 4:28 p.m. UTC | #2 
> Hi Vitaliy,
>
> Thanks for the patch!  Your patch is missing a Signed-Off-By footer.
> Also, you note that numblocks gets passed to filefrag_fibmap(), so if
> you're going to do this, and we fall back to using fibmap, you should
> probably check to see if numblocks would overflow an unsigned long,
> and if so, to give an error because fibmap ioctl only supports the use
> of a ulong.

OK, I've just resubmitted it :)

In fact, the block count was reported incorrectly for files bigger than  
0xffffffff bytes, not blocks, because filefrag does (numblocks *  
fsinfo.f_bsize >> blk_shift), and this overflows when numblocks is  
32-bit...
diff mbox

Patch

diff --git a/misc/filefrag.c b/misc/filefrag.c
index a050a22..756fad8 100644
--- a/misc/filefrag.c
+++ b/misc/filefrag.c
@@ -337,7 +337,7 @@  static void frag_report(const char *filename)
 	ext2fs_struct_stat st;
 	int		blk_shift;
 	long		fd;
-	unsigned long	numblocks;
+	unsigned long long	numblocks;
 	int		data_blocks_per_cyl = 1;
 	int		num_extents = 1, expected = ~0;
 	int		is_ext2 = 0;
@@ -409,7 +409,7 @@  static void frag_report(const char *filename)
 	if (width > logical_width)
 		logical_width = width;
 	if (verbose)
-		printf("File size of %s is %llu (%lu block%s of %d bytes)\n",
+		printf("File size of %s is %llu (%llu block%s of %d bytes)\n",
 		       filename, (unsigned long long)st.st_size,
 		       numblocks * fsinfo.f_bsize >> blk_shift,
 		       numblocks == 1 ? "" : "s", 1 << blk_shift);