btrfs_lookup_bio_sums seems broken, go back to the readpage_io_hook for now

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 70af24aa582bf155a46781a1fc2e1b2801d0097f..51aba8cee7ce3cc7add24c0bfe52e40cde09d12c 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -134,6 +134,7 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
        return ret;
 }
 
+#if 0 /* broken */
 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
                          struct bio *bio)
 {
@@ -200,7 +201,7 @@ int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
                diff = diff * BTRFS_CRC32_SIZE;
 
                read_extent_buffer(path->nodes[0], &sum,
-                                  (unsigned long)item + diff,
+                                  ((unsigned long)item) + diff,
                                   BTRFS_CRC32_SIZE);
 found:
                set_state_private(io_tree, offset, sum);
@@ -210,6 +211,7 @@ found:
        btrfs_free_path(path);
        return 0;
 }
+#endif
 
 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                       struct bio *bio)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8a405a5fa6a31280bb91a5c1f84000ba6f092a13..99121a55ffbef888219c585c33ec9a904a0b821f 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -382,12 +382,6 @@ int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
        BUG_ON(ret);
 
        if (!(rw & (1 << BIO_RW))) {
-               if (!btrfs_test_opt(root, NODATASUM) &&
-                   !btrfs_test_flag(inode, NODATASUM)) {
-                       mutex_lock(&BTRFS_I(inode)->csum_mutex);
-                       btrfs_lookup_bio_sums(root, inode, bio);
-                       mutex_unlock(&BTRFS_I(inode)->csum_mutex);
-               }
                goto mapit;
        }
 
@@ -595,6 +589,58 @@ int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
        return btrfs_finish_ordered_io(page->mapping->host, start, end);
 }
 
+int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
+{
+       int ret = 0;
+       struct inode *inode = page->mapping->host;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+       struct btrfs_csum_item *item;
+       struct btrfs_path *path = NULL;
+       u32 csum;
+
+       if (btrfs_test_opt(root, NODATASUM) ||
+           btrfs_test_flag(inode, NODATASUM))
+               return 0;
+
+       /*
+        * It is possible there is an ordered extent that has
+        * not yet finished for this range in the file.  If so,
+        * that extent will have a csum cached, and it will insert
+        * the sum after all the blocks in the extent are fully
+        * on disk.  So, look for an ordered extent and use the
+        * sum if found.  We have to do this before looking in the
+        * btree because csum items are pre-inserted based on
+        * the file size.  btrfs_lookup_csum might find an item
+        * that still hasn't been fully filled.
+        */
+       ret = btrfs_find_ordered_sum(inode, start, &csum);
+       if (ret == 0)
+               goto found;
+
+       ret = 0;
+       path = btrfs_alloc_path();
+       item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
+       if (IS_ERR(item)) {
+               ret = PTR_ERR(item);
+               /* a csum that isn't present is a preallocated region. */
+               if (ret == -ENOENT || ret == -EFBIG)
+                       ret = 0;
+               csum = 0;
+               printk("no csum found for inode %lu start %Lu\n", inode->i_ino,
+                      start);
+               goto out;
+       }
+       read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
+                          BTRFS_CRC32_SIZE);
+found:
+       set_state_private(io_tree, start, csum);
+out:
+       if (path)
+               btrfs_free_path(path);
+       return ret;
+}
+
 struct io_failure_record {
        struct page *page;
        u64 start;
@@ -3580,6 +3626,7 @@ static struct extent_io_ops btrfs_extent_io_ops = {
        .fill_delalloc = run_delalloc_range,
        .submit_bio_hook = btrfs_submit_bio_hook,
        .merge_bio_hook = btrfs_merge_bio_hook,
+       .readpage_io_hook = btrfs_readpage_io_hook,
        .readpage_end_io_hook = btrfs_readpage_end_io_hook,
        .writepage_end_io_hook = btrfs_writepage_end_io_hook,
        .writepage_start_hook = btrfs_writepage_start_hook,