Btrfs: use helper to simplify lock/unlock pages

Since we have a helper to set page bits, let lock_delalloc_pages and
__unlock_for_delalloc use it.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 5bb7ced..4a8b119 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1563,29 +1563,15 @@ static noinline void __unlock_for_delalloc(struct inode *inode,
                                           struct page *locked_page,
                                           u64 start, u64 end)
 {
-       int ret;
-       struct page *pages[16];
        unsigned long index = start >> PAGE_SHIFT;
        unsigned long end_index = end >> PAGE_SHIFT;
-       unsigned long nr_pages = end_index - index + 1;
-       int i;
 
+       ASSERT(locked_page);
        if (index == locked_page->index && end_index == index)
                return;
 
-       while (nr_pages > 0) {
-               ret = find_get_pages_contig(inode->i_mapping, index,
-                                    min_t(unsigned long, nr_pages,
-                                    ARRAY_SIZE(pages)), pages);
-               for (i = 0; i < ret; i++) {
-                       if (pages[i] != locked_page)
-                               unlock_page(pages[i]);
-                       put_page(pages[i]);
-               }
-               nr_pages -= ret;
-               index += ret;
-               cond_resched();
-       }
+       __process_pages_contig(inode->i_mapping, locked_page, index, end_index,
+                              PAGE_UNLOCK, NULL);
 }
 
 static noinline int lock_delalloc_pages(struct inode *inode,
@@ -1594,59 +1580,19 @@ static noinline int lock_delalloc_pages(struct inode *inode,
                                        u64 delalloc_end)
 {
        unsigned long index = delalloc_start >> PAGE_SHIFT;
-       unsigned long start_index = index;
+       unsigned long index_ret = index;
        unsigned long end_index = delalloc_end >> PAGE_SHIFT;
-       unsigned long pages_locked = 0;
-       struct page *pages[16];
-       unsigned long nrpages;
        int ret;
-       int i;
 
-       /* the caller is responsible for locking the start index */
+       ASSERT(locked_page);
        if (index == locked_page->index && index == end_index)
                return 0;
 
-       /* skip the page at the start index */
-       nrpages = end_index - index + 1;
-       while (nrpages > 0) {
-               ret = find_get_pages_contig(inode->i_mapping, index,
-                                    min_t(unsigned long,
-                                    nrpages, ARRAY_SIZE(pages)), pages);
-               if (ret == 0) {
-                       ret = -EAGAIN;
-                       goto done;
-               }
-               /* now we have an array of pages, lock them all */
-               for (i = 0; i < ret; i++) {
-                       /*
-                        * the caller is taking responsibility for
-                        * locked_page
-                        */
-                       if (pages[i] != locked_page) {
-                               lock_page(pages[i]);
-                               if (!PageDirty(pages[i]) ||
-                                   pages[i]->mapping != inode->i_mapping) {
-                                       ret = -EAGAIN;
-                                       unlock_page(pages[i]);
-                                       put_page(pages[i]);
-                                       goto done;
-                               }
-                       }
-                       put_page(pages[i]);
-                       pages_locked++;
-               }
-               nrpages -= ret;
-               index += ret;
-               cond_resched();
-       }
-       ret = 0;
-done:
-       if (ret && pages_locked) {
-               __unlock_for_delalloc(inode, locked_page,
-                             delalloc_start,
-                             ((u64)(start_index + pages_locked - 1)) <<
-                             PAGE_SHIFT);
-       }
+       ret = __process_pages_contig(inode->i_mapping, locked_page, index,
+                                    end_index, PAGE_LOCK, &index_ret);
+       if (ret == -EAGAIN)
+               __unlock_for_delalloc(inode, locked_page, delalloc_start,
+                                     (u64)index_ret << PAGE_SHIFT);
        return ret;
 }