1 files changed, 30 insertions, 55 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 3e6e410002e5..ca4355ddea06 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1948,28 +1948,6 @@ static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
 }
 
 /*
- * helper function to unlock a page if all the extents in the tree
- * for that page are unlocked
- */
-static void check_page_locked(struct extent_io_tree *tree, struct page *page)
-{
-        u64 start = page_offset(page);
-        u64 end = start + PAGE_CACHE_SIZE - 1;
-        if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
-                unlock_page(page);
-}
-
-/*
- * helper function to end page writeback if all the extents
- * in the tree for that page are done with writeback
- */
-static void check_page_writeback(struct extent_io_tree *tree,
-                                 struct page *page)
-{
-        end_page_writeback(page);
-}
-
-/*
  * When IO fails, either with EIO or csum verification fails, we
  * try other mirrors that might have a good copy of the data.  This
  * io_failure_record is used to record state as we go through all the
@@ -2398,19 +2376,24 @@ static void end_bio_extent_writepage(struct bio *bio, int err)
         struct extent_io_tree *tree;
         u64 start;
         u64 end;
-        int whole_page;
 
         do {
                 struct page *page = bvec->bv_page;
                 tree = &BTRFS_I(page->mapping->host)->io_tree;
 
-                start = page_offset(page) + bvec->bv_offset;
-                end = start + bvec->bv_len - 1;
+                /* We always issue full-page reads, but if some block
+                 * in a page fails to read, blk_update_request() will
+                 * advance bv_offset and adjust bv_len to compensate.
+                 * Print a warning for nonzero offsets, and an error
+                 * if they don't add up to a full page.  */
+                if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
+                        printk("%s page write in btrfs with offset %u and length %u\n",
+                               bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
+                               ? KERN_ERR "partial" : KERN_INFO "incomplete",
+                               bvec->bv_offset, bvec->bv_len);
 
-                if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
-                        whole_page = 1;
-                else
-                        whole_page = 0;
+                start = page_offset(page);
+                end = start + bvec->bv_offset + bvec->bv_len - 1;
 
                 if (--bvec >= bio->bi_io_vec)
                         prefetchw(&bvec->bv_page->flags);
@@ -2418,10 +2401,7 @@ static void end_bio_extent_writepage(struct bio *bio, int err)
                 if (end_extent_writepage(page, err, start, end))
                         continue;
 
-                if (whole_page)
-                        end_page_writeback(page);
-                else
-                        check_page_writeback(tree, page);
+                end_page_writeback(page);
         } while (bvec >= bio->bi_io_vec);
 
         bio_put(bio);
@@ -2446,7 +2426,6 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
         struct extent_io_tree *tree;
         u64 start;
         u64 end;
-        int whole_page;
         int mirror;
         int ret;
 
@@ -2463,13 +2442,19 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                          (long int)bio->bi_bdev);
                 tree = &BTRFS_I(page->mapping->host)->io_tree;
 
-                start = page_offset(page) + bvec->bv_offset;
-                end = start + bvec->bv_len - 1;
+                /* We always issue full-page reads, but if some block
+                 * in a page fails to read, blk_update_request() will
+                 * advance bv_offset and adjust bv_len to compensate.
+                 * Print a warning for nonzero offsets, and an error
+                 * if they don't add up to a full page.  */
+                if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE)
+                        printk("%s page read in btrfs with offset %u and length %u\n",
+                               bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE
+                               ? KERN_ERR "partial" : KERN_INFO "incomplete",
+                               bvec->bv_offset, bvec->bv_len);
 
-                if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
-                        whole_page = 1;
-                else
-                        whole_page = 0;
+                start = page_offset(page);
+                end = start + bvec->bv_offset + bvec->bv_len - 1;
 
                 if (++bvec <= bvec_end)
                         prefetchw(&bvec->bv_page->flags);
@@ -2528,23 +2513,13 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                 }
                 unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
 
-                if (whole_page) {
-                        if (uptodate) {
-                                SetPageUptodate(page);
-                        } else {
-                                ClearPageUptodate(page);
-                                SetPageError(page);
-                        }
-                        unlock_page(page);
+                if (uptodate) {
+                        SetPageUptodate(page);
                 } else {
-                        if (uptodate) {
-                                check_page_uptodate(tree, page);
-                        } else {
-                                ClearPageUptodate(page);
-                                SetPageError(page);
-                        }
-                        check_page_locked(tree, page);
+                        ClearPageUptodate(page);
+                        SetPageError(page);
                 }
+                unlock_page(page);
         } while (bvec <= bvec_end);
 
         bio_put(bio);