cifs: add shutdown support

[linux-2.6-microblaze.git] / fs / cifs / ioctl.c

diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
index 08d99fe..ef41fa8 100644 (file)
--- a/fs/cifs/ioctl.c
+++ b/fs/cifs/ioctl.c
@@ -164,6 +164,56 @@ static long smb_mnt_get_fsinfo(unsigned int xid, struct cifs_tcon *tcon,
        return rc;
 }
 
+static int cifs_shutdown(struct super_block *sb, unsigned long arg)
+{
+       struct cifs_sb_info *sbi = CIFS_SB(sb);
+       __u32 flags;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (get_user(flags, (__u32 __user *)arg))
+               return -EFAULT;
+
+       if (flags > CIFS_GOING_FLAGS_NOLOGFLUSH)
+               return -EINVAL;
+
+       if (cifs_forced_shutdown(sbi))
+               return 0;
+
+       cifs_dbg(VFS, "shut down requested (%d)", flags);
+/*     trace_cifs_shutdown(sb, flags);*/
+
+       /*
+        * see:
+        *   https://man7.org/linux/man-pages/man2/ioctl_xfs_goingdown.2.html
+        * for more information and description of original intent of the flags
+        */
+       switch (flags) {
+       /*
+        * We could add support later for default flag which requires:
+        *     "Flush all dirty data and metadata to disk"
+        * would need to call syncfs or equivalent to flush page cache for
+        * the mount and then issue fsync to server (if nostrictsync not set)
+        */
+       case CIFS_GOING_FLAGS_DEFAULT:
+               cifs_dbg(FYI, "shutdown with default flag not supported\n");
+               return -EINVAL;
+       /*
+        * FLAGS_LOGFLUSH is easy since it asks to write out metadata (not
+        * data) but metadata writes are not cached on the client, so can treat
+        * it similarly to NOLOGFLUSH
+        */
+       case CIFS_GOING_FLAGS_LOGFLUSH:
+       case CIFS_GOING_FLAGS_NOLOGFLUSH:
+               sbi->mnt_cifs_flags |= CIFS_MOUNT_SHUTDOWN;
+               return 0;
+       default:
+               return -EINVAL;
+       }
+       return 0;
+}
+
 long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
 {
        struct inode *inode = file_inode(filep);
@@ -325,6 +375,9 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
                                rc = -EOPNOTSUPP;
                        cifs_put_tlink(tlink);
                        break;
+               case CIFS_IOC_SHUTDOWN:
+                       rc = cifs_shutdown(inode->i_sb, arg);
+                       break;
                default:
                        cifs_dbg(FYI, "unsupported ioctl\n");
                        break;