ocfs2: fix NULL pointer dereference in ocfs2_duplicate_clusters_by_page

[~andy/linux] / fs / ocfs2 / refcounttree.c

diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 9f6b96a09615bcc243b81ebc5cf3c9139c2deec3..a70d604593b61c0ffbce761a92b1207148f3b346 100644 (file)
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -49,7 +49,6 @@
 
 struct ocfs2_cow_context {
        struct inode *inode;
-       struct file *file;
        u32 cow_start;
        u32 cow_len;
        struct ocfs2_extent_tree data_et;
@@ -66,7 +65,7 @@ struct ocfs2_cow_context {
                            u32 *num_clusters,
                            unsigned int *extent_flags);
        int (*cow_duplicate_clusters)(handle_t *handle,
-                                     struct file *file,
+                                     struct inode *inode,
                                      u32 cpos, u32 old_cluster,
                                      u32 new_cluster, u32 new_len);
 };
@@ -2922,14 +2921,12 @@ static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
 }
 
 int ocfs2_duplicate_clusters_by_page(handle_t *handle,
-                                    struct file *file,
+                                    struct inode *inode,
                                     u32 cpos, u32 old_cluster,
                                     u32 new_cluster, u32 new_len)
 {
        int ret = 0, partial;
-       struct inode *inode = file_inode(file);
-       struct ocfs2_caching_info *ci = INODE_CACHE(inode);
-       struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
+       struct super_block *sb = inode->i_sb;
        u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
        struct page *page;
        pgoff_t page_index;
@@ -2978,13 +2975,6 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
                if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
                        BUG_ON(PageDirty(page));
 
-               if (PageReadahead(page)) {
-                       page_cache_async_readahead(mapping,
-                                                  &file->f_ra, file,
-                                                  page, page_index,
-                                                  readahead_pages);
-               }
-
                if (!PageUptodate(page)) {
                        ret = block_read_full_page(page, ocfs2_get_block);
                        if (ret) {
@@ -3004,7 +2994,8 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
                        }
                }
 
-               ocfs2_map_and_dirty_page(inode, handle, from, to,
+               ocfs2_map_and_dirty_page(inode,
+                                        handle, from, to,
                                         page, 0, &new_block);
                mark_page_accessed(page);
 unlock:
@@ -3020,12 +3011,11 @@ unlock:
 }
 
 int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
-                                   struct file *file,
+                                   struct inode *inode,
                                    u32 cpos, u32 old_cluster,
                                    u32 new_cluster, u32 new_len)
 {
        int ret = 0;
-       struct inode *inode = file_inode(file);
        struct super_block *sb = inode->i_sb;
        struct ocfs2_caching_info *ci = INODE_CACHE(inode);
        int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
@@ -3150,7 +3140,7 @@ static int ocfs2_replace_clusters(handle_t *handle,
 
        /*If the old clusters is unwritten, no need to duplicate. */
        if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
-               ret = context->cow_duplicate_clusters(handle, context->file,
+               ret = context->cow_duplicate_clusters(handle, context->inode,
                                                      cpos, old, new, len);
                if (ret) {
                        mlog_errno(ret);
@@ -3428,35 +3418,12 @@ static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
        return ret;
 }
 
-static void ocfs2_readahead_for_cow(struct inode *inode,
-                                   struct file *file,
-                                   u32 start, u32 len)
-{
-       struct address_space *mapping;
-       pgoff_t index;
-       unsigned long num_pages;
-       int cs_bits = OCFS2_SB(inode->i_sb)->s_clustersize_bits;
-
-       if (!file)
-               return;
-
-       mapping = file->f_mapping;
-       num_pages = (len << cs_bits) >> PAGE_CACHE_SHIFT;
-       if (!num_pages)
-               num_pages = 1;
-
-       index = ((loff_t)start << cs_bits) >> PAGE_CACHE_SHIFT;
-       page_cache_sync_readahead(mapping, &file->f_ra, file,
-                                 index, num_pages);
-}
-
 /*
  * Starting at cpos, try to CoW write_len clusters.  Don't CoW
  * past max_cpos.  This will stop when it runs into a hole or an
  * unrefcounted extent.
  */
 static int ocfs2_refcount_cow_hunk(struct inode *inode,
-                                  struct file *file,
                                   struct buffer_head *di_bh,
                                   u32 cpos, u32 write_len, u32 max_cpos)
 {
@@ -3485,8 +3452,6 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
 
        BUG_ON(cow_len == 0);
 
-       ocfs2_readahead_for_cow(inode, file, cow_start, cow_len);
-
        context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
        if (!context) {
                ret = -ENOMEM;
@@ -3508,7 +3473,6 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
        context->ref_root_bh = ref_root_bh;
        context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
        context->get_clusters = ocfs2_di_get_clusters;
-       context->file = file;
 
        ocfs2_init_dinode_extent_tree(&context->data_et,
                                      INODE_CACHE(inode), di_bh);
@@ -3537,7 +3501,6 @@ out:
  * clusters between cpos and cpos+write_len are safe to modify.
  */
 int ocfs2_refcount_cow(struct inode *inode,
-                      struct file *file,
                       struct buffer_head *di_bh,
                       u32 cpos, u32 write_len, u32 max_cpos)
 {
@@ -3557,7 +3520,7 @@ int ocfs2_refcount_cow(struct inode *inode,
                        num_clusters = write_len;
 
                if (ext_flags & OCFS2_EXT_REFCOUNTED) {
-                       ret = ocfs2_refcount_cow_hunk(inode, file, di_bh, cpos,
+                       ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
                                                      num_clusters, max_cpos);
                        if (ret) {
                                mlog_errno(ret);