From b307d4655a71749ac3f91c6dbe33d28cc026ceeb Mon Sep 17 00:00:00 2001
From: Jan Beulich <JBeulich@novell.com>
Date: Thu, 21 Jul 2011 15:02:43 +0100
Subject: FS-Cache: Fix __fscache_uncache_all_inode_pages()'s outer loop
The compiler, at least for ix86 and m68k, validly warns that the
comparison:
next <= (loff_t)-1
is always true (and it's always true also for x86-64 and probably all
other arches - as long as pgoff_t isn't wider than loff_t). The
intention appears to be to avoid wrapping of "next", so rather than
eliminating the pointless comparison, fix the loop to indeed get exited
when "next" would otherwise wrap.
On m68k the following warning 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
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Suresh Jayaraman <sjayaraman@suse.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/fscache/page.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 2f343b4d7a7..3f7a59bfa7a 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -976,16 +976,12 @@ void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
pagevec_init(&pvec, 0);
next = 0;
- while (next <= (loff_t)-1 &&
- pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)
- ) {
+ do {
+ if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE))
+ break;
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *page = pvec.pages[i];
- pgoff_t page_index = page->index;
-
- ASSERTCMP(page_index, >=, next);
- next = page_index + 1;
-
+ next = page->index;
if (PageFsCache(page)) {
__fscache_wait_on_page_write(cookie, page);
__fscache_uncache_page(cookie, page);
@@ -993,7 +989,7 @@ void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
}
pagevec_release(&pvec);
cond_resched();
- }
+ } while (++next);
_leave("");
}
--
cgit v1.2.3-18-g5258