/* Check a mount point for busyness */ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry) { struct dentry *top = dentry; struct path path = {.mnt = mnt, .dentry = dentry}; int status = 1; DPRINTK("dentry %p %.*s", dentry, (int)dentry->d_name.len, dentry->d_name.name); path_get(&path); if (!follow_down_one(&path)) goto done; if (is_autofs4_dentry(path.dentry)) { struct autofs_sb_info *sbi = autofs4_sbi(path.dentry->d_sb); /* This is an autofs submount, we can't expire it */ if (autofs_type_indirect(sbi->type)) goto done; } /* Update the expiry counter if fs is busy */ if (!may_umount_tree(path.mnt)) { struct autofs_info *ino = autofs4_dentry_ino(top); ino->last_used = jiffies; goto done; } status = 0; done: DPRINTK("returning = %d", status); path_put(&path); return status; }
/* * Check if the given path is a mountpoint. * * If we are supplied with the file descriptor of an autofs * mount we're looking for a specific mount. In this case * the path is considered a mountpoint if it is itself a * mountpoint or contains a mount, such as a multi-mount * without a root mount. In this case we return 1 if the * path is a mount point and the super magic of the covering * mount if there is one or 0 if it isn't a mountpoint. * * If we aren't supplied with a file descriptor then we * lookup the path and check if it is the root of a mount. * If a type is given we are looking for a particular autofs * mount and if we don't find a match we return fail. If the * located path is the root of a mount we return 1 along with * the super magic of the mount or 0 otherwise. * * In both cases the the device number (as returned by * new_encode_dev()) is also returned. */ static int autofs_dev_ioctl_ismountpoint(struct file *fp, struct autofs_sb_info *sbi, struct autofs_dev_ioctl *param) { struct path path; const char *name; unsigned int type; unsigned int devid, magic; int err = -ENOENT; if (param->size <= sizeof(*param)) { err = -EINVAL; goto out; } name = param->path; type = param->ismountpoint.in.type; param->ismountpoint.out.devid = devid = 0; param->ismountpoint.out.magic = magic = 0; if (!fp || param->ioctlfd == -1) { if (autofs_type_any(type)) err = kern_path_mountpoint(AT_FDCWD, name, &path, LOOKUP_FOLLOW); else err = find_autofs_mount(name, &path, test_by_type, &type); if (err) goto out; devid = new_encode_dev(path.dentry->d_sb->s_dev); err = 0; if (path.mnt->mnt_root == path.dentry) { err = 1; magic = path.dentry->d_sb->s_magic; } } else { dev_t dev = sbi->sb->s_dev; err = find_autofs_mount(name, &path, test_by_dev, &dev); if (err) goto out; devid = new_encode_dev(dev); err = path_has_submounts(&path); if (follow_down_one(&path)) magic = path.dentry->d_sb->s_magic; } param->ismountpoint.out.devid = devid; param->ismountpoint.out.magic = magic; path_put(&path); out: return err; }