diff options
Diffstat (limited to 'fs/fsopen.c')
| -rw-r--r-- | fs/fsopen.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/fs/fsopen.c b/fs/fsopen.c index 65cc2f68f994..3bb9c0c8cbcc 100644 --- a/fs/fsopen.c +++ b/fs/fsopen.c @@ -157,6 +157,63 @@ err_fc: } /* + * Pick a superblock into a context for reconfiguration. + */ +SYSCALL_DEFINE3(fspick, int, dfd, const char __user *, path, unsigned int, flags) +{ + struct fs_context *fc; + struct path target; + unsigned int lookup_flags; + int ret; + + if (!ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN)) + return -EPERM; + + if ((flags & ~(FSPICK_CLOEXEC | + FSPICK_SYMLINK_NOFOLLOW | + FSPICK_NO_AUTOMOUNT | + FSPICK_EMPTY_PATH)) != 0) + return -EINVAL; + + lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT; + if (flags & FSPICK_SYMLINK_NOFOLLOW) + lookup_flags &= ~LOOKUP_FOLLOW; + if (flags & FSPICK_NO_AUTOMOUNT) + lookup_flags &= ~LOOKUP_AUTOMOUNT; + if (flags & FSPICK_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + ret = user_path_at(dfd, path, lookup_flags, &target); + if (ret < 0) + goto err; + + ret = -EINVAL; + if (target.mnt->mnt_root != target.dentry) + goto err_path; + + fc = fs_context_for_reconfigure(target.dentry, 0, 0); + if (IS_ERR(fc)) { + ret = PTR_ERR(fc); + goto err_path; + } + + fc->phase = FS_CONTEXT_RECONF_PARAMS; + + ret = fscontext_alloc_log(fc); + if (ret < 0) + goto err_fc; + + path_put(&target); + return fscontext_create_fd(fc, flags & FSPICK_CLOEXEC ? O_CLOEXEC : 0); + +err_fc: + put_fs_context(fc); +err_path: + path_put(&target); +err: + return ret; +} + +/* * Check the state and apply the configuration. Note that this function is * allowed to 'steal' the value by setting param->xxx to NULL before returning. */ |