[PATCH] FS-Cache: Fix bounds check

[David Howells <dhowells@redhat.com>]

__fscache_uncache_all_inode_pages() has a loop that goes through page index
numbers go up to (loff_t)-1.  This is incorrect.  The limit should be
(pgoff_t)-1 as on a 32-bit machine the pgoff_t is smaller than loff_t.

On m68k the following error is observed:

fs/fscache/page.c: In function '__fscache_uncache_all_inode_pages':
fs/fscache/page.c:979: warning: comparison is always false due to
limited range of data type

[Should there be a PGOFF_T_MAX constant defined?]

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/fscache/page.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 60315b3..112359d 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -993,7 +993,7 @@ void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
 
 	pagevec_init(&pvec, 0);
 	next = 0;
-	while (next <= (loff_t)-1 &&
+	while (next <= (pgoff_t)-1 &&
 	       pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)
 	       ) {
 		for (i = 0; i < pagevec_count(&pvec); i++) {