mm: rename page trylock

Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).

This also facilitates lockdeping of page lock.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

20 files changed, 74 insertions, 59 deletions

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index d3b8ebb83776..3d36270a8b4d 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1747,7 +1747,7 @@ st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
                  */
                 flush_dcache_page(pages[i]);
                 /* ?? Is locking needed? I don't think so */
-                /* if (TestSetPageLocked(pages[i]))
+                /* if (!trylock_page(pages[i]))
                    goto out_unlock; */
         }
 
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 9a849ad3c489..065b4e10681a 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -404,7 +404,7 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
                         page = pages[loop];
                         if (page->index > wb->last)
                                 break;
-                        if (TestSetPageLocked(page))
+                        if (!trylock_page(page))
                                 break;
                         if (!PageDirty(page) ||
                             page_private(page) != (unsigned long) wb) {
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 0aac824371a5..e692c42f24b5 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1280,7 +1280,7 @@ retry:
 
                         if (first < 0)
                                 lock_page(page);
-                        else if (TestSetPageLocked(page))
+                        else if (!trylock_page(page))
                                 break;
 
                         if (unlikely(page->mapping != mapping)) {
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 2eccbfaa1d48..81a9ad7177ca 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -63,7 +63,7 @@ static void release_buffer_page(struct buffer_head *bh)
                 goto nope;
 
         /* OK, it's a truncated page */
-        if (TestSetPageLocked(page))
+        if (!trylock_page(page))
                 goto nope;
 
         page_cache_get(page);
@@ -446,7 +446,7 @@ void journal_commit_transaction(journal_t *journal)
                         spin_lock(&journal->j_list_lock);
                 }
                 if (unlikely(!buffer_uptodate(bh))) {
-                        if (TestSetPageLocked(bh->b_page)) {
+                        if (!trylock_page(bh->b_page)) {
                                 spin_unlock(&journal->j_list_lock);
                                 lock_page(bh->b_page);
                                 spin_lock(&journal->j_list_lock);
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index adf0395f318e..f2ad061e95ec 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -67,7 +67,7 @@ static void release_buffer_page(struct buffer_head *bh)
                 goto nope;
 
         /* OK, it's a truncated page */
-        if (TestSetPageLocked(page))
+        if (!trylock_page(page))
                 goto nope;
 
         page_cache_get(page);
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index c8f60ee183b5..ce2208b27118 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -627,7 +627,7 @@ static int journal_list_still_alive(struct super_block *s,
 static void release_buffer_page(struct buffer_head *bh)
 {
         struct page *page = bh->b_page;
-        if (!page->mapping && !TestSetPageLocked(page)) {
+        if (!page->mapping && trylock_page(page)) {
                 page_cache_get(page);
                 put_bh(bh);
                 if (!page->mapping)
diff --git a/fs/splice.c b/fs/splice.c
index b30311ba8af6..1bbc6f4bb09c 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -371,7 +371,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                          * for an in-flight io page
                          */
                         if (flags & SPLICE_F_NONBLOCK) {
-                                if (TestSetPageLocked(page)) {
+                                if (!trylock_page(page)) {
                                         error = -EAGAIN;
                                         break;
                                 }
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 0b211cba1909..fa73179233ad 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -675,7 +675,7 @@ xfs_probe_cluster(
                         } else
                                 pg_offset = PAGE_CACHE_SIZE;
 
-                        if (page->index == tindex && !TestSetPageLocked(page)) {
+                        if (page->index == tindex && trylock_page(page)) {
                                 pg_len = xfs_probe_page(page, pg_offset, mapped);
                                 unlock_page(page);
                         }
@@ -759,7 +759,7 @@ xfs_convert_page(
 
         if (page->index != tindex)
                 goto fail;
-        if (TestSetPageLocked(page))
+        if (!trylock_page(page))
                 goto fail;
         if (PageWriteback(page))
                 goto fail_unlock_page;
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 25aaccdb2f26..c74d3e875314 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -163,7 +163,7 @@ static inline int Page##uname(struct page *page) 			\
 
 struct page;    /* forward declaration */
 
-PAGEFLAG(Locked, locked) TESTSCFLAG(Locked, locked)
+TESTPAGEFLAG(Locked, locked)
 PAGEFLAG(Error, error)
 PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
 PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 69ed3cb1197a..5da31c12101c 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -250,29 +250,6 @@ static inline struct page *read_mapping_page(struct address_space *mapping,
         return read_cache_page(mapping, index, filler, data);
 }
 
-int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
-                                pgoff_t index, gfp_t gfp_mask);
-int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
-                                pgoff_t index, gfp_t gfp_mask);
-extern void remove_from_page_cache(struct page *page);
-extern void __remove_from_page_cache(struct page *page);
-
-/*
- * Like add_to_page_cache_locked, but used to add newly allocated pages:
- * the page is new, so we can just run SetPageLocked() against it.
- */
-static inline int add_to_page_cache(struct page *page,
-                struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
-{
-        int error;
-
-        SetPageLocked(page);
-        error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
-        if (unlikely(error))
-                ClearPageLocked(page);
-        return error;
-}
-
 /*
  * Return byte-offset into filesystem object for page.
  */
@@ -294,13 +271,28 @@ extern int __lock_page_killable(struct page *page);
 extern void __lock_page_nosync(struct page *page);
 extern void unlock_page(struct page *page);
 
+static inline void set_page_locked(struct page *page)
+{
+        set_bit(PG_locked, &page->flags);
+}
+
+static inline void clear_page_locked(struct page *page)
+{
+        clear_bit(PG_locked, &page->flags);
+}
+
+static inline int trylock_page(struct page *page)
+{
+        return !test_and_set_bit(PG_locked, &page->flags);
+}
+
 /*
  * lock_page may only be called if we have the page's inode pinned.
  */
 static inline void lock_page(struct page *page)
 {
         might_sleep();
-        if (TestSetPageLocked(page))
+        if (!trylock_page(page))
                 __lock_page(page);
 }
 
@@ -312,7 +304,7 @@ static inline void lock_page(struct page *page)
 static inline int lock_page_killable(struct page *page)
 {
         might_sleep();
-        if (TestSetPageLocked(page))
+        if (!trylock_page(page))
                 return __lock_page_killable(page);
         return 0;
 }
@@ -324,7 +316,7 @@ static inline int lock_page_killable(struct page *page)
 static inline void lock_page_nosync(struct page *page)
 {
         might_sleep();
-        if (TestSetPageLocked(page))
+        if (!trylock_page(page))
                 __lock_page_nosync(page);
 }
         
@@ -409,4 +401,27 @@ static inline int fault_in_pages_readable(const char __user *uaddr, int size)
         return ret;
 }
 
+int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
+                                pgoff_t index, gfp_t gfp_mask);
+int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
+                                pgoff_t index, gfp_t gfp_mask);
+extern void remove_from_page_cache(struct page *page);
+extern void __remove_from_page_cache(struct page *page);
+
+/*
+ * Like add_to_page_cache_locked, but used to add newly allocated pages:
+ * the page is new, so we can just run set_page_locked() against it.
+ */
+static inline int add_to_page_cache(struct page *page,
+                struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
+{
+        int error;
+
+        set_page_locked(page);
+        error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
+        if (unlikely(error))
+                clear_page_locked(page);
+        return error;
+}
+
 #endif /* _LINUX_PAGEMAP_H */
diff --git a/mm/filemap.c b/mm/filemap.c
index d97d1ad55473..54e968650855 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -558,14 +558,14 @@ EXPORT_SYMBOL(wait_on_page_bit);
  * But that's OK - sleepers in wait_on_page_writeback() just go back to sleep.
  *
  * The first mb is necessary to safely close the critical section opened by the
- * TestSetPageLocked(), the second mb is necessary to enforce ordering between
- * the clear_bit and the read of the waitqueue (to avoid SMP races with a
- * parallel wait_on_page_locked()).
+ * test_and_set_bit() to lock the page; the second mb is necessary to enforce
+ * ordering between the clear_bit and the read of the waitqueue (to avoid SMP
+ * races with a parallel wait_on_page_locked()).
  */
 void unlock_page(struct page *page)
 {
         smp_mb__before_clear_bit();
-        if (!TestClearPageLocked(page))
+        if (!test_and_clear_bit(PG_locked, &page->flags))
                 BUG();
         smp_mb__after_clear_bit(); 
         wake_up_page(page, PG_locked);
@@ -931,7 +931,7 @@ grab_cache_page_nowait(struct address_space *mapping, pgoff_t index)
         struct page *page = find_get_page(mapping, index);
 
         if (page) {
-                if (!TestSetPageLocked(page))
+                if (trylock_page(page))
                         return page;
                 page_cache_release(page);
                 return NULL;
@@ -1027,7 +1027,7 @@ find_page:
                         if (inode->i_blkbits == PAGE_CACHE_SHIFT ||
                                         !mapping->a_ops->is_partially_uptodate)
                                 goto page_not_up_to_date;
-                        if (TestSetPageLocked(page))
+                        if (!trylock_page(page))
                                 goto page_not_up_to_date;
                         if (!mapping->a_ops->is_partially_uptodate(page,
                                                                 desc, offset))
diff --git a/mm/memory.c b/mm/memory.c
index a472bcd4b061..1002f473f497 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1789,7 +1789,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
          * not dirty accountable.
          */
         if (PageAnon(old_page)) {
-                if (!TestSetPageLocked(old_page)) {
+                if (trylock_page(old_page)) {
                         reuse = can_share_swap_page(old_page);
                         unlock_page(old_page);
                 }
diff --git a/mm/migrate.c b/mm/migrate.c
index 153572fb60b8..2a80136b23bb 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -605,7 +605,7 @@ static int move_to_new_page(struct page *newpage, struct page *page)
          * establishing additional references. We are the only one
          * holding a reference to the new page at this point.
          */
-        if (TestSetPageLocked(newpage))
+        if (!trylock_page(newpage))
                 BUG();
 
         /* Prepare mapping for the new page.*/
@@ -667,7 +667,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
         BUG_ON(charge);
 
         rc = -EAGAIN;
-        if (TestSetPageLocked(page)) {
+        if (!trylock_page(page)) {
                 if (!force)
                         goto move_newpage;
                 lock_page(page);
diff --git a/mm/rmap.c b/mm/rmap.c
index 94a5246a3f98..1ea4e6fcee77 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -422,7 +422,7 @@ int page_referenced(struct page *page, int is_locked,
                         referenced += page_referenced_anon(page, mem_cont);
                 else if (is_locked)
                         referenced += page_referenced_file(page, mem_cont);
-                else if (TestSetPageLocked(page))
+                else if (!trylock_page(page))
                         referenced++;
                 else {
                         if (page->mapping)
diff --git a/mm/shmem.c b/mm/shmem.c
index c1e5a3b4f758..04fb4f1ab88e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1265,7 +1265,7 @@ repeat:
                 }
 
                 /* We have to do this with page locked to prevent races */
-                if (TestSetPageLocked(swappage)) {
+                if (!trylock_page(swappage)) {
                         shmem_swp_unmap(entry);
                         spin_unlock(&info->lock);
                         wait_on_page_locked(swappage);
@@ -1329,7 +1329,7 @@ repeat:
                 shmem_swp_unmap(entry);
                 filepage = find_get_page(mapping, idx);
                 if (filepage &&
-                    (!PageUptodate(filepage) || TestSetPageLocked(filepage))) {
+                    (!PageUptodate(filepage) || !trylock_page(filepage))) {
                         spin_unlock(&info->lock);
                         wait_on_page_locked(filepage);
                         page_cache_release(filepage);
diff --git a/mm/swap.c b/mm/swap.c
index 7417a2adbe50..9e0cb3118079 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -444,7 +444,7 @@ void pagevec_strip(struct pagevec *pvec)
         for (i = 0; i < pagevec_count(pvec); i++) {
                 struct page *page = pvec->pages[i];
 
-                if (PagePrivate(page) && !TestSetPageLocked(page)) {
+                if (PagePrivate(page) && trylock_page(page)) {
                         if (PagePrivate(page))
                                 try_to_release_page(page, 0);
                         unlock_page(page);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index b8035b055129..167cf2dc8a03 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -201,7 +201,7 @@ void delete_from_swap_cache(struct page *page)
  */
 static inline void free_swap_cache(struct page *page)
 {
-        if (PageSwapCache(page) && !TestSetPageLocked(page)) {
+        if (PageSwapCache(page) && trylock_page(page)) {
                 remove_exclusive_swap_page(page);
                 unlock_page(page);
         }
@@ -302,9 +302,9 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
                  * re-using the just freed swap entry for an existing page.
                  * May fail (-ENOMEM) if radix-tree node allocation failed.
                  */
-                SetPageLocked(new_page);
+                set_page_locked(new_page);
                 err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL);
-                if (!err) {
+                if (likely(!err)) {
                         /*
                          * Initiate read into locked page and return.
                          */
@@ -312,7 +312,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
                         swap_readpage(NULL, new_page);
                         return new_page;
                 }
-                ClearPageLocked(new_page);
+                clear_page_locked(new_page);
                 swap_free(entry);
         } while (err != -ENOMEM);
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index bb7f79641f9e..1e330f2998fa 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -403,7 +403,7 @@ void free_swap_and_cache(swp_entry_t entry)
         if (p) {
                 if (swap_entry_free(p, swp_offset(entry)) == 1) {
                         page = find_get_page(&swapper_space, entry.val);
-                        if (page && unlikely(TestSetPageLocked(page))) {
+                        if (page && unlikely(!trylock_page(page))) {
                                 page_cache_release(page);
                                 page = NULL;
                         }
diff --git a/mm/truncate.c b/mm/truncate.c
index 894e9a70699f..250505091d37 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -187,7 +187,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                         if (page_index > next)
                                 next = page_index;
                         next++;
-                        if (TestSetPageLocked(page))
+                        if (!trylock_page(page))
                                 continue;
                         if (PageWriteback(page)) {
                                 unlock_page(page);
@@ -280,7 +280,7 @@ unsigned long __invalidate_mapping_pages(struct address_space *mapping,
                         pgoff_t index;
                         int lock_failed;
 
-                        lock_failed = TestSetPageLocked(page);
+                        lock_failed = !trylock_page(page);
 
                         /*
                          * We really shouldn't be looking at the ->index of an
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 75be453628bf..1ff1a58e7c10 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -496,7 +496,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                 page = lru_to_page(page_list);
                 list_del(&page->lru);
 
-                if (TestSetPageLocked(page))
+                if (!trylock_page(page))
                         goto keep;
 
                 VM_BUG_ON(PageActive(page));
@@ -582,7 +582,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                                  * A synchronous write - probably a ramdisk.  Go
                                  * ahead and try to reclaim the page.
                                  */
-                                if (TestSetPageLocked(page))
+                                if (!trylock_page(page))
                                         goto keep;
                                 if (PageDirty(page) || PageWriteback(page))
                                         goto keep_locked;