diff options
| -rw-r--r-- | kernel/cgroup.c | 73 |
1 files changed, 40 insertions, 33 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index d28cf75f33c1..083b53d79d6f 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1459,21 +1459,22 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, int flags, const char *unused_dev_name, void *data) { + LIST_HEAD(tmp_links); + struct super_block *sb = NULL; + struct inode *inode = NULL; + struct cgroupfs_root *root = NULL; struct cgroup_sb_opts opts; - struct cgroupfs_root *root; - int ret = 0; - struct super_block *sb; struct cgroupfs_root *new_root; - struct list_head tmp_links; - struct inode *inode; const struct cred *cred; + int ret; - /* First find the desired set of subsystems */ + mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); + + /* First find the desired set of subsystems */ ret = parse_cgroupfs_options(data, &opts); - mutex_unlock(&cgroup_mutex); if (ret) - goto out_err; + goto out_unlock; /* * Allocate a new cgroup root. We may not need it if we're @@ -1482,16 +1483,20 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, new_root = cgroup_root_from_opts(&opts); if (IS_ERR(new_root)) { ret = PTR_ERR(new_root); - goto out_err; + goto out_unlock; } opts.new_root = new_root; /* Locate an existing or new sb for this hierarchy */ + mutex_unlock(&cgroup_mutex); + mutex_unlock(&cgroup_tree_mutex); sb = sget(fs_type, cgroup_test_super, cgroup_set_super, 0, &opts); + mutex_lock(&cgroup_tree_mutex); + mutex_lock(&cgroup_mutex); if (IS_ERR(sb)) { ret = PTR_ERR(sb); cgroup_free_root(opts.new_root); - goto out_err; + goto out_unlock; } root = sb->s_fs_info; @@ -1505,9 +1510,12 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, BUG_ON(sb->s_root != NULL); + mutex_unlock(&cgroup_mutex); + mutex_unlock(&cgroup_tree_mutex); + ret = cgroup_get_rootdir(sb); if (ret) - goto drop_new_super; + goto out_unlock; inode = sb->s_root->d_inode; mutex_lock(&inode->i_mutex); @@ -1516,7 +1524,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, ret = idr_alloc(&root->cgroup_idr, root_cgrp, 0, 1, GFP_KERNEL); if (ret < 0) - goto unlock_drop; + goto out_unlock; root_cgrp->id = ret; /* Check for name clashes with existing mounts */ @@ -1524,7 +1532,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, if (strlen(root->name)) for_each_active_root(existing_root) if (!strcmp(existing_root->name, root->name)) - goto unlock_drop; + goto out_unlock; /* * We're accessing css_set_count without locking @@ -1535,12 +1543,12 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, */ ret = allocate_cgrp_cset_links(css_set_count, &tmp_links); if (ret) - goto unlock_drop; + goto out_unlock; /* ID 0 is reserved for dummy root, 1 for unified hierarchy */ ret = cgroup_init_root_id(root, 2, 0); if (ret) - goto unlock_drop; + goto out_unlock; sb->s_root->d_fsdata = root_cgrp; root_cgrp->dentry = sb->s_root; @@ -1580,14 +1588,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, link_css_set(&tmp_links, cset, root_cgrp); write_unlock(&css_set_lock); - free_cgrp_cset_links(&tmp_links); - BUG_ON(!list_empty(&root_cgrp->children)); BUG_ON(root->number_of_cgroups != 1); - - mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); - mutex_unlock(&inode->i_mutex); } else { /* * We re-used an existing hierarchy - the new root (if @@ -1599,32 +1601,37 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, if ((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) { pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n"); ret = -EINVAL; - goto drop_new_super; + goto out_unlock; } else { pr_warning("cgroup: new mount options do not match the existing superblock, will be ignored\n"); } } } - kfree(opts.release_agent); - kfree(opts.name); - return dget(sb->s_root); + ret = 0; + goto out_unlock; - rm_base_files: - free_cgrp_cset_links(&tmp_links); +rm_base_files: cgroup_addrm_files(&root->top_cgroup, cgroup_base_files, false); revert_creds(cred); - unlock_drop: cgroup_exit_root_id(root); +out_unlock: mutex_unlock(&cgroup_mutex); mutex_unlock(&cgroup_tree_mutex); - mutex_unlock(&inode->i_mutex); - drop_new_super: - deactivate_locked_super(sb); - out_err: + if (inode) + mutex_unlock(&inode->i_mutex); + + if (ret && !IS_ERR_OR_NULL(sb)) + deactivate_locked_super(sb); + + free_cgrp_cset_links(&tmp_links); kfree(opts.release_agent); kfree(opts.name); - return ERR_PTR(ret); + + if (!ret) + return dget(sb->s_root); + else + return ERR_PTR(ret); } static void cgroup_kill_sb(struct super_block *sb) |