2006-01-05 10:05:41

by Takashi Sato

Subject: [PATCH 3/3] Fix problems on multi-TB filesystem and file

This fix was proposed by Trond Myklebust. He says:
The type "sector_t" is heavily tied in to the block layer interface
as an offset/handle to a block, and is subject to a supposedly
block-specific configuration option: CONFIG_LBD. Despite this, it is
used in struct kstatfs to save a couple of bytes on the stack
whenever we call the filesystems' ->statfs().

So kstatfs's entries related to blocks are invalid on statfs64 for a
network filesystem which has more than 2^32-1 blocks when CONFIG_LBD
is disabled.

The content of the patch attached to this mail is below.
- struct kstatfs
Change the type of following entries from sector_t to u64.
f_blocks
f_bfree
f_bavail
f_files
f_ffree

Any feedback and comments are welcome.

Signed-off-by: Trond Myklebust <[email protected]>
Signed-off-by: Takashi Sato <[email protected]>

diff -uprN -X linux-2.6.15-lsf/Documentation/dontdiff linux-2.6.15-lsf/include/linux/statfs.h
linux-2.6.15-kstatfs/include/linux/statfs.h
--- linux-2.6.15-lsf/include/linux/statfs.h 2006-01-03 12:21:10.000000000 +0900
+++ linux-2.6.15-kstatfs/include/linux/statfs.h 2006-01-04 15:24:38.000000000 +0900
@@ -8,11 +8,11 @@
struct kstatfs {
long f_type;
long f_bsize;
- sector_t f_blocks;
- sector_t f_bfree;
- sector_t f_bavail;
- sector_t f_files;
- sector_t f_ffree;
+ u64 f_blocks;
+ u64 f_bfree;
+ u64 f_bavail;
+ u64 f_files;
+ u64 f_ffree;
__kernel_fsid_t f_fsid;
long f_namelen;
long f_frsize;

-- Takashi Sato

2006-01-13 02:34:19

by Andrew Morton

Subject: Re: [PATCH 3/3] Fix problems on multi-TB filesystem and file

"Takashi Sato" <[email protected]> wrote:
>
> his fix was proposed by Trond Myklebust. He says:
> The type "sector_t" is heavily tied in to the block layer interface
> as an offset/handle to a block, and is subject to a supposedly
> block-specific configuration option: CONFIG_LBD. Despite this, it is
> used in struct kstatfs to save a couple of bytes on the stack
> whenever we call the filesystems' ->statfs().
>
> So kstatfs's entries related to blocks are invalid on statfs64 for a
> network filesystem which has more than 2^32-1 blocks when CONFIG_LBD
> is disabled.
>

That makes sense, thanks.