| /* |
| * Copyright (C) 2010-2013 Junjiro R. Okajima |
| * |
| * This program, aufs is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /* |
| * procfs interfaces |
| */ |
| |
| #include <linux/proc_fs.h> |
| #include "aufs.h" |
| |
| static int au_procfs_plm_release(struct inode *inode, struct file *file) |
| { |
| struct au_sbinfo *sbinfo; |
| |
| sbinfo = file->private_data; |
| if (sbinfo) { |
| au_plink_maint_leave(sbinfo); |
| kobject_put(&sbinfo->si_kobj); |
| } |
| |
| return 0; |
| } |
| |
| static void au_procfs_plm_write_clean(struct file *file) |
| { |
| struct au_sbinfo *sbinfo; |
| |
| sbinfo = file->private_data; |
| if (sbinfo) |
| au_plink_clean(sbinfo->si_sb, /*verbose*/0); |
| } |
| |
| static int au_procfs_plm_write_si(struct file *file, unsigned long id) |
| { |
| int err; |
| struct super_block *sb; |
| struct au_sbinfo *sbinfo; |
| |
| err = -EBUSY; |
| if (unlikely(file->private_data)) |
| goto out; |
| |
| sb = NULL; |
| /* don't use au_sbilist_lock() here */ |
| spin_lock(&au_sbilist.spin); |
| list_for_each_entry(sbinfo, &au_sbilist.head, si_list) |
| if (id == sysaufs_si_id(sbinfo)) { |
| kobject_get(&sbinfo->si_kobj); |
| sb = sbinfo->si_sb; |
| break; |
| } |
| spin_unlock(&au_sbilist.spin); |
| |
| err = -EINVAL; |
| if (unlikely(!sb)) |
| goto out; |
| |
| err = au_plink_maint_enter(sb); |
| if (!err) |
| /* keep kobject_get() */ |
| file->private_data = sbinfo; |
| else |
| kobject_put(&sbinfo->si_kobj); |
| out: |
| return err; |
| } |
| |
| /* |
| * Accept a valid "si=xxxx" only. |
| * Once it is accepted successfully, accept "clean" too. |
| */ |
| static ssize_t au_procfs_plm_write(struct file *file, const char __user *ubuf, |
| size_t count, loff_t *ppos) |
| { |
| ssize_t err; |
| unsigned long id; |
| /* last newline is allowed */ |
| char buf[3 + sizeof(unsigned long) * 2 + 1]; |
| |
| err = -EACCES; |
| if (unlikely(!capable(CAP_SYS_ADMIN))) |
| goto out; |
| |
| err = -EINVAL; |
| if (unlikely(count > sizeof(buf))) |
| goto out; |
| |
| err = copy_from_user(buf, ubuf, count); |
| if (unlikely(err)) { |
| err = -EFAULT; |
| goto out; |
| } |
| buf[count] = 0; |
| |
| err = -EINVAL; |
| if (!strcmp("clean", buf)) { |
| au_procfs_plm_write_clean(file); |
| goto out_success; |
| } else if (unlikely(strncmp("si=", buf, 3))) |
| goto out; |
| |
| err = kstrtoul(buf + 3, 16, &id); |
| if (unlikely(err)) |
| goto out; |
| |
| err = au_procfs_plm_write_si(file, id); |
| if (unlikely(err)) |
| goto out; |
| |
| out_success: |
| err = count; /* success */ |
| out: |
| return err; |
| } |
| |
| static const struct file_operations au_procfs_plm_fop = { |
| .write = au_procfs_plm_write, |
| .release = au_procfs_plm_release, |
| .owner = THIS_MODULE |
| }; |
| |
| /* ---------------------------------------------------------------------- */ |
| |
| static struct proc_dir_entry *au_procfs_dir; |
| |
| void au_procfs_fin(void) |
| { |
| remove_proc_entry(AUFS_PLINK_MAINT_NAME, au_procfs_dir); |
| remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL); |
| } |
| |
| int __init au_procfs_init(void) |
| { |
| int err; |
| struct proc_dir_entry *entry; |
| |
| err = -ENOMEM; |
| au_procfs_dir = proc_mkdir(AUFS_PLINK_MAINT_DIR, NULL); |
| if (unlikely(!au_procfs_dir)) |
| goto out; |
| |
| entry = proc_create(AUFS_PLINK_MAINT_NAME, S_IFREG | S_IWUSR, |
| au_procfs_dir, &au_procfs_plm_fop); |
| if (unlikely(!entry)) |
| goto out_dir; |
| |
| err = 0; |
| goto out; /* success */ |
| |
| |
| out_dir: |
| remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL); |
| out: |
| return err; |
| } |