[PATCH] 2TB files: st_blocks is invalid when calling stat64

This patch series fixes the following problems on 32 bits architecture.

o stat64 returns the lower 32 bits of blocks, although userland st_blocks
  has 64 bits, because i_blocks has only 32 bits.  The ioctl with FIOQSIZE has
  the same problem.

o As Dave Kleikamp said, making >2TB file on JFS results in writing an
  invalid block number to disk inode.  The cause is the same as above too.

o In generic quota code dquot_transfer(), the file usage is calculated from
  i_blocks via inode_get_bytes().  If the file is over 2TB, the change of
  usage is less than expected.  The cause is the same as above too.

o As Trond Myklebust said, statfs64's entries related to blocks are invalid
  on statfs64 for a network filesystem which has more than 2^32-1 blocks with
  CONFIG_LBD disabled.  [PATCH 3/3]

We made patches to fix problems that occur when handling a large filesystem
and a large file.  It was discussed on the mails titled "stat64 for over 2TB
file returned invalid st_blocks".

Signed-off-by: Takashi Sato <sho@tnes.nec.co.jp>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-i386/stat.h

@@ -58,8 +58,7 @@ struct stat64 {
 	long long	st_size;
 	unsigned long	st_blksize;
 
-	unsigned long	st_blocks;	/* Number 512-byte blocks allocated. */
-	unsigned long	__pad4;		/* future possible st_blocks high bits */
+	unsigned long long	st_blocks;	/* Number 512-byte blocks allocated. */
 
 	unsigned long	st_atime;
 	unsigned long	st_atime_nsec;