Btrfs: deny sys_link across subvolumes.

[linux-beck.git] / fs / btrfs / inode.c

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index dcec42ee8cf22675d6c400ebca4d659e9c36bbdb..da76cad92ecf385e7202d823c3d50463307d05fa 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -88,13 +88,14 @@ static noinline int cow_file_range(struct inode *inode,
                                   u64 start, u64 end, int *page_started,
                                   unsigned long *nr_written, int unlock);
 
-static int btrfs_init_inode_security(struct inode *inode,  struct inode *dir)
+static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
+                                    struct inode *inode,  struct inode *dir)
 {
        int err;
 
-       err = btrfs_init_acl(inode, dir);
+       err = btrfs_init_acl(trans, inode, dir);
        if (!err)
-               err = btrfs_xattr_security_init(inode, dir);
+               err = btrfs_xattr_security_init(trans, inode, dir);
        return err;
 }
 
@@ -2021,6 +2022,54 @@ zeroit:
        return -EIO;
 }
 
+struct delayed_iput {
+       struct list_head list;
+       struct inode *inode;
+};
+
+void btrfs_add_delayed_iput(struct inode *inode)
+{
+       struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
+       struct delayed_iput *delayed;
+
+       if (atomic_add_unless(&inode->i_count, -1, 1))
+               return;
+
+       delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
+       delayed->inode = inode;
+
+       spin_lock(&fs_info->delayed_iput_lock);
+       list_add_tail(&delayed->list, &fs_info->delayed_iputs);
+       spin_unlock(&fs_info->delayed_iput_lock);
+}
+
+void btrfs_run_delayed_iputs(struct btrfs_root *root)
+{
+       LIST_HEAD(list);
+       struct btrfs_fs_info *fs_info = root->fs_info;
+       struct delayed_iput *delayed;
+       int empty;
+
+       spin_lock(&fs_info->delayed_iput_lock);
+       empty = list_empty(&fs_info->delayed_iputs);
+       spin_unlock(&fs_info->delayed_iput_lock);
+       if (empty)
+               return;
+
+       down_read(&root->fs_info->cleanup_work_sem);
+       spin_lock(&fs_info->delayed_iput_lock);
+       list_splice_init(&fs_info->delayed_iputs, &list);
+       spin_unlock(&fs_info->delayed_iput_lock);
+
+       while (!list_empty(&list)) {
+               delayed = list_entry(list.next, struct delayed_iput, list);
+               list_del(&delayed->list);
+               iput(delayed->inode);
+               kfree(delayed);
+       }
+       up_read(&root->fs_info->cleanup_work_sem);
+}
+
 /*
  * This creates an orphan entry for the given inode in case something goes
  * wrong in the middle of an unlink/truncate.
@@ -4296,7 +4345,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
        if (IS_ERR(inode))
                goto out_unlock;
 
-       err = btrfs_init_inode_security(inode, dir);
+       err = btrfs_init_inode_security(trans, inode, dir);
        if (err) {
                drop_inode = 1;
                goto out_unlock;
@@ -4367,7 +4416,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
        if (IS_ERR(inode))
                goto out_unlock;
 
-       err = btrfs_init_inode_security(inode, dir);
+       err = btrfs_init_inode_security(trans, inode, dir);
        if (err) {
                drop_inode = 1;
                goto out_unlock;
@@ -4413,6 +4462,10 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
        if (inode->i_nlink == 0)
                return -ENOENT;
 
+       /* do not allow sys_link's with other subvols of the same device */
+       if (root->objectid != BTRFS_I(inode)->root->objectid)
+               return -EPERM;
+
        /*
         * 1 item for inode ref
         * 2 items for dir items
@@ -4500,7 +4553,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
        drop_on_err = 1;
 
-       err = btrfs_init_inode_security(inode, dir);
+       err = btrfs_init_inode_security(trans, inode, dir);
        if (err)
                goto out_fail;
 
@@ -5567,7 +5620,7 @@ out_fail:
  * some fairly slow code that needs optimization. This walks the list
  * of all the inodes with pending delalloc and forces them to disk.
  */
-int btrfs_start_delalloc_inodes(struct btrfs_root *root)
+int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
 {
        struct list_head *head = &root->fs_info->delalloc_inodes;
        struct btrfs_inode *binode;
@@ -5586,7 +5639,10 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root)
                spin_unlock(&root->fs_info->delalloc_lock);
                if (inode) {
                        filemap_flush(inode->i_mapping);
-                       iput(inode);
+                       if (delay_iput)
+                               btrfs_add_delayed_iput(inode);
+                       else
+                               iput(inode);
                }
                cond_resched();
                spin_lock(&root->fs_info->delalloc_lock);
@@ -5660,7 +5716,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
        if (IS_ERR(inode))
                goto out_unlock;
 
-       err = btrfs_init_inode_security(inode, dir);
+       err = btrfs_init_inode_security(trans, inode, dir);
        if (err) {
                drop_inode = 1;
                goto out_unlock;