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authorMichel Lespinasse <walken@google.com>2010-10-26 17:21:56 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-26 19:52:09 -0400
commitb522c94da5d9cbc73f708be5e530ebc3bbd4a031 (patch)
treed29cc4887bca05fde5b86a367f02a3ea70043e11 /mm/filemap.c
parent182fea8f48332de085c0ae936605cb72671db9f2 (diff)
mm: filemap_fault: unique path for locking page
Introduce a single location where filemap_fault() locks the desired page. There used to be two such places, depending if the initial find_get_page() was successful or not. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Ying Han <yinghan@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
-rw-r--r--mm/filemap.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 3d4df44e4221..8ed709a83eb7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1539,25 +1539,27 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1539 * waiting for the lock. 1539 * waiting for the lock.
1540 */ 1540 */
1541 do_async_mmap_readahead(vma, ra, file, page, offset); 1541 do_async_mmap_readahead(vma, ra, file, page, offset);
1542 lock_page(page);
1543
1544 /* Did it get truncated? */
1545 if (unlikely(page->mapping != mapping)) {
1546 unlock_page(page);
1547 put_page(page);
1548 goto no_cached_page;
1549 }
1550 } else { 1542 } else {
1551 /* No page in the page cache at all */ 1543 /* No page in the page cache at all */
1552 do_sync_mmap_readahead(vma, ra, file, offset); 1544 do_sync_mmap_readahead(vma, ra, file, offset);
1553 count_vm_event(PGMAJFAULT); 1545 count_vm_event(PGMAJFAULT);
1554 ret = VM_FAULT_MAJOR; 1546 ret = VM_FAULT_MAJOR;
1555retry_find: 1547retry_find:
1556 page = find_lock_page(mapping, offset); 1548 page = find_get_page(mapping, offset);
1557 if (!page) 1549 if (!page)
1558 goto no_cached_page; 1550 goto no_cached_page;
1559 } 1551 }
1560 1552
1553 lock_page(page);
1554
1555 /* Did it get truncated? */
1556 if (unlikely(page->mapping != mapping)) {
1557 unlock_page(page);
1558 put_page(page);
1559 goto retry_find;
1560 }
1561 VM_BUG_ON(page->index != offset);
1562
1561 /* 1563 /*
1562 * We have a locked page in the page cache, now we need to check 1564 * We have a locked page in the page cache, now we need to check
1563 * that it's up-to-date. If not, it is going to be due to an error. 1565 * that it's up-to-date. If not, it is going to be due to an error.