Btrfs: fix transaction handle leak on failure to create hard link

[firefly-linux-kernel-4.4.55.git] / fs / btrfs / inode.c

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a70c5790f8f5908f08f606d097fe33e6966af36b..52fc1b5e9f0388516517d8fae81a02a4eb3dbce6 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5741,6 +5741,7 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
        char *name_ptr;
        int name_len;
        int is_curr = 0;        /* ctx->pos points to the current index? */
+       bool emitted;
 
        /* FIXME, use a real flag for deciding about the key type */
        if (root->fs_info->tree_root == root)
@@ -5769,6 +5770,7 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
        if (ret < 0)
                goto err;
 
+       emitted = false;
        while (1) {
                leaf = path->nodes[0];
                slot = path->slots[0];
@@ -5848,6 +5850,7 @@ skip:
 
                        if (over)
                                goto nopos;
+                       emitted = true;
                        di_len = btrfs_dir_name_len(leaf, di) +
                                 btrfs_dir_data_len(leaf, di) + sizeof(*di);
                        di_cur += di_len;
@@ -5860,11 +5863,20 @@ next:
        if (key_type == BTRFS_DIR_INDEX_KEY) {
                if (is_curr)
                        ctx->pos++;
-               ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
+               ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
                if (ret)
                        goto nopos;
        }
 
+       /*
+        * If we haven't emitted any dir entry, we must not touch ctx->pos as
+        * it was was set to the termination value in previous call. We assume
+        * that "." and ".." were emitted if we reach this point and set the
+        * termination value as well for an empty directory.
+        */
+       if (ctx->pos > 2 && !emitted)
+               goto nopos;
+
        /* Reached end of directory/root. Bump pos past the last item. */
        ctx->pos++;
 
@@ -6481,7 +6493,7 @@ out_unlock_inode:
 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                      struct dentry *dentry)
 {
-       struct btrfs_trans_handle *trans;
+       struct btrfs_trans_handle *trans = NULL;
        struct btrfs_root *root = BTRFS_I(dir)->root;
        struct inode *inode = d_inode(old_dentry);
        u64 index;
@@ -6507,6 +6519,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
        trans = btrfs_start_transaction(root, 5);
        if (IS_ERR(trans)) {
                err = PTR_ERR(trans);
+               trans = NULL;
                goto fail;
        }
 
@@ -6540,9 +6553,10 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                btrfs_log_new_name(trans, inode, NULL, parent);
        }
 
-       btrfs_end_transaction(trans, root);
        btrfs_balance_delayed_items(root);
 fail:
+       if (trans)
+               btrfs_end_transaction(trans, root);
        if (drop_inode) {
                inode_dec_link_count(inode);
                iput(inode);
@@ -7985,6 +7999,7 @@ static void btrfs_endio_direct_read(struct bio *bio)
 
        kfree(dip);
 
+       dio_bio->bi_error = bio->bi_error;
        dio_end_io(dio_bio, bio->bi_error);
 
        if (io_bio->end_io)
@@ -8030,6 +8045,7 @@ out_test:
 
        kfree(dip);
 
+       dio_bio->bi_error = bio->bi_error;
        dio_end_io(dio_bio, bio->bi_error);
        bio_put(bio);
 }
@@ -8534,15 +8550,28 @@ int btrfs_readpage(struct file *file, struct page *page)
 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
 {
        struct extent_io_tree *tree;
-
+       struct inode *inode = page->mapping->host;
+       int ret;
 
        if (current->flags & PF_MEMALLOC) {
                redirty_page_for_writepage(wbc, page);
                unlock_page(page);
                return 0;
        }
+
+       /*
+        * If we are under memory pressure we will call this directly from the
+        * VM, we need to make sure we have the inode referenced for the ordered
+        * extent.  If not just return like we didn't do anything.
+        */
+       if (!igrab(inode)) {
+               redirty_page_for_writepage(wbc, page);
+               return AOP_WRITEPAGE_ACTIVATE;
+       }
        tree = &BTRFS_I(page->mapping->host)->io_tree;
-       return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
+       ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
+       btrfs_add_delayed_iput(inode);
+       return ret;
 }
 
 static int btrfs_writepages(struct address_space *mapping,
@@ -9636,9 +9665,11 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
        /*
         * 2 items for inode item and ref
         * 2 items for dir items
+        * 1 item for updating parent inode item
+        * 1 item for the inline extent item
         * 1 item for xattr if selinux is on
         */
-       trans = btrfs_start_transaction(root, 5);
+       trans = btrfs_start_transaction(root, 7);
        if (IS_ERR(trans))
                return PTR_ERR(trans);