Btrfs: unlink and delete_inode

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

1 files changed, 114 insertions, 3 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 094a66c267b4..f96bd92155cc 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -187,6 +187,104 @@ static void btrfs_read_locked_inode(struct inode *inode)
         return;
 }
 
+static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+        struct btrfs_path path;
+        struct btrfs_root *root;
+        struct btrfs_trans_handle *trans;
+        const char *name = dentry->d_name.name;
+        int name_len = dentry->d_name.len;
+        int ret;
+        u64 objectid;
+        struct btrfs_dir_item *di;
+
+        btrfs_init_path(&path);
+        root = btrfs_sb(dir->i_sb);
+        mutex_lock(&root->fs_info->fs_mutex);
+        trans = btrfs_start_transaction(root, 1);
+
+        ret = btrfs_lookup_dir_item(trans, root, &path, dir->i_ino,
+                                    name, name_len, -1);
+        if (ret < 0)
+                goto err;
+        if (ret > 0) {
+                ret = -ENOENT;
+                goto err;
+        }
+        di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
+                            struct btrfs_dir_item);
+        objectid = btrfs_dir_objectid(di);
+
+        ret = btrfs_del_item(trans, root, &path);
+        BUG_ON(ret);
+        dentry->d_inode->i_ctime = dir->i_ctime;
+err:
+        btrfs_release_path(root, &path);
+        btrfs_end_transaction(trans, root);
+        mutex_unlock(&root->fs_info->fs_mutex);
+        if (ret == 0)
+                inode_dec_link_count(dentry->d_inode);
+        return ret;
+}
+
+static int btrfs_free_inode(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root,
+                            struct inode *inode)
+{
+        u64 objectid = inode->i_ino;
+        struct btrfs_path path;
+        struct btrfs_inode_map_item *map;
+        struct btrfs_key stat_data_key;
+        int ret;
+        clear_inode(inode);
+        btrfs_init_path(&path);
+        ret = btrfs_lookup_inode_map(trans, root, &path, objectid, -1);
+        if (ret) {
+                if (ret > 0)
+                        ret = -ENOENT;
+                btrfs_release_path(root, &path);
+                goto error;
+        }
+        map = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
+                            struct btrfs_inode_map_item);
+        btrfs_disk_key_to_cpu(&stat_data_key, &map->key);
+        ret = btrfs_del_item(trans, root->fs_info->inode_root, &path);
+        BUG_ON(ret);
+        btrfs_release_path(root, &path);
+        btrfs_init_path(&path);
+
+        ret = btrfs_lookup_inode(trans, root, &path, objectid, -1);
+        BUG_ON(ret);
+        ret = btrfs_del_item(trans, root, &path);
+        BUG_ON(ret);
+        btrfs_release_path(root, &path);
+error:
+        return ret;
+}
+
+static void btrfs_delete_inode(struct inode *inode)
+{
+        struct btrfs_trans_handle *trans;
+        struct btrfs_root *root = btrfs_sb(inode->i_sb);
+        truncate_inode_pages(&inode->i_data, 0);
+        if (is_bad_inode(inode)) {
+                goto no_delete;
+        }
+        inode->i_size = 0;
+        if (inode->i_blocks)
+                WARN_ON(1);
+
+        mutex_lock(&root->fs_info->fs_mutex);
+        trans = btrfs_start_transaction(root, 1);
+        btrfs_free_inode(trans, root, inode);
+        btrfs_end_transaction(trans, root);
+        mutex_unlock(&root->fs_info->fs_mutex);
+        return;
+no_delete:
+        clear_inode(inode);
+}
+
+
 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
                               ino_t *ino)
 {
@@ -272,6 +370,13 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
                                 leaf = btrfs_buffer_leaf(path.nodes[0]);
                                 nritems = btrfs_header_nritems(&leaf->header);
                                 slot = path.slots[0];
+#if 0
+                                page_cache_readahead(
+                                     inode->i_sb->s_bdev->bd_inode->i_mapping,
+                                     &filp->f_ra, filp,
+                                     path.nodes[0]->b_blocknr >>
+                                     (PAGE_CACHE_SHIFT - inode->i_blkbits), 1);
+#endif
                         } else {
                                 slot++;
                                 path.slots[0]++;
@@ -441,8 +546,6 @@ static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
                 d_instantiate(dentry, inode);
                 return 0;
         }
-        inode_dec_link_count(inode);
-        iput(inode);
         return err;
 }
 
@@ -453,6 +556,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
         struct btrfs_root *root = btrfs_sb(dir->i_sb);
         struct inode *inode;
         int err;
+        int drop_inode = 0;
 
         mutex_lock(&root->fs_info->fs_mutex);
         trans = btrfs_start_transaction(root, 1);
@@ -462,10 +566,16 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
                 goto out_unlock;
         // FIXME mark the inode dirty
         err = btrfs_add_nondir(trans, dentry, inode);
+        if (err)
+                drop_inode = 1;
         dir->i_sb->s_dirt = 1;
         btrfs_end_transaction(trans, root);
 out_unlock:
         mutex_unlock(&root->fs_info->fs_mutex);
+        if (drop_inode) {
+                inode_dec_link_count(inode);
+                iput(inode);
+        }
         return err;
 }
 
@@ -516,7 +626,7 @@ static struct file_system_type btrfs_fs_type = {
 
 static struct super_operations btrfs_super_ops = {
         .statfs         = simple_statfs,
-        .drop_inode     = generic_delete_inode,
+        .delete_inode   = btrfs_delete_inode,
         .put_super      = btrfs_put_super,
         .read_inode     = btrfs_read_locked_inode,
         .write_super    = btrfs_write_super,
@@ -526,6 +636,7 @@ static struct super_operations btrfs_super_ops = {
 static struct inode_operations btrfs_dir_inode_operations = {
         .lookup         = btrfs_lookup,
         .create         = btrfs_create,
+        .unlink         = btrfs_unlink,
 };
 
 static struct file_operations btrfs_dir_file_operations = {