From b307d4655a71749ac3f91c6dbe33d28cc026ceeb Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 21 Jul 2011 15:02:43 +0100 Subject: [PATCH] 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 Reported-by: Jan Beulich Signed-off-by: Jan Beulich Signed-off-by: David Howells Cc: Suresh Jayaraman Cc: Geert Uytterhoeven Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- 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 2f343b4d7a7d..3f7a59bfa7ad 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(""); } -- 2.20.1