btrfs: locking: Add extra check in btrfs_init_new_buffer() to avoid deadlock

[sagit-ice-cold/kernel_xiaomi_msm8998.git] / fs / btrfs / extent_io.c

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 9abe187..88bee67 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2534,7 +2534,7 @@ int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
        if (!uptodate) {
                ClearPageUptodate(page);
                SetPageError(page);
-               ret = ret < 0 ? ret : -EIO;
+               ret = err < 0 ? err : -EIO;
                mapping_set_error(page->mapping, ret);
        }
        return 0;
@@ -2786,12 +2786,6 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
                btrfs_bio->csum = NULL;
                btrfs_bio->csum_allocated = NULL;
                btrfs_bio->end_io = NULL;
-
-#ifdef CONFIG_BLK_CGROUP
-               /* FIXME, put this into bio_clone_bioset */
-               if (bio->bi_css)
-                       bio_associate_blkcg(new, bio->bi_css);
-#endif
        }
        return new;
 }
@@ -5300,11 +5294,20 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
                        lock_page(page);
                }
                locked_pages++;
+       }
+       /*
+        * We need to firstly lock all pages to make sure that
+        * the uptodate bit of our pages won't be affected by
+        * clear_extent_buffer_uptodate().
+        */
+       for (i = start_i; i < num_pages; i++) {
+               page = eb->pages[i];
                if (!PageUptodate(page)) {
                        num_reads++;
                        all_uptodate = 0;
                }
        }
+
        if (all_uptodate) {
                if (start_i == 0)
                        set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);