btrfs: preparation to fixing mount/umount race

We need fs_info and root to live until the moment when the victim
superblock leaves the list, so we need to postpone free_fs_info()
until after ->put_super().  The call is buried in close_ctree(),
though, so we need to lift it into the callers (including
btrfs_put_super()) first.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-11-17 01:00:31 -05:00
parent 48fa57ac2c
commit 98c7089c76
2 changed files with 6 additions and 3 deletions

View file

@ -2424,6 +2424,7 @@ retry_root_backup:
up_read(&fs_info->cleanup_work_sem);
if (err) {
close_ctree(tree_root);
free_fs_info(fs_info);
return ERR_PTR(err);
}
}
@ -3059,8 +3060,6 @@ int close_ctree(struct btrfs_root *root)
bdi_destroy(&fs_info->bdi);
cleanup_srcu_struct(&fs_info->subvol_srcu);
free_fs_info(fs_info);
return 0;
}

View file

@ -151,6 +151,7 @@ static void btrfs_put_super(struct super_block *sb)
int ret;
ret = close_ctree(root);
free_fs_info(root->fs_info);
sb->s_fs_info = NULL;
(void)ret; /* FIXME: need to fix VFS to return error? */
@ -589,6 +590,7 @@ static int btrfs_fill_super(struct super_block *sb,
struct inode *inode;
struct dentry *root_dentry;
struct btrfs_root *tree_root;
struct btrfs_fs_info *fs_info;
struct btrfs_key key;
int err;
@ -609,12 +611,13 @@ static int btrfs_fill_super(struct super_block *sb,
printk("btrfs: open_ctree failed\n");
return PTR_ERR(tree_root);
}
fs_info = tree_root->fs_info;
sb->s_fs_info = tree_root;
key.objectid = BTRFS_FIRST_FREE_OBJECTID;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto fail_close;
@ -635,6 +638,7 @@ static int btrfs_fill_super(struct super_block *sb,
fail_close:
close_ctree(tree_root);
free_fs_info(fs_info);
return err;
}