3 files changed, 101 insertions, 0 deletions

diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt
index 06887d46ccf2..8b887ae4e39e 100644
--- a/Documentation/filesystems/nilfs2.txt
+++ b/Documentation/filesystems/nilfs2.txt
@@ -111,6 +111,13 @@ Table of NILFS2 specific ioctls
                                 nilfs_resize utilities and by nilfs_cleanerd
                                 daemon.
 
+ NILFS_IOCTL_SET_SUINFO         Modify segment usage info of requested
+                                segments. This ioctl is used by
+                                nilfs_cleanerd daemon to skip unnecessary
+                                cleaning operation of segments and reduce
+                                performance penalty or wear of flash device
+                                due to redundant move of in-use blocks.
+
  NILFS_IOCTL_GET_SUSTAT         Return segment usage statistics. This ioctl
                                 is used in lssu, nilfs_resize utilities and
                                 by nilfs_cleanerd daemon.
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 2b34021948e4..c19a23158487 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -1163,6 +1163,95 @@ static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
         return ret;
 }
 
+/**
+ * nilfs_ioctl_set_suinfo - set segment usage info
+ * @inode: inode object
+ * @filp: file object
+ * @cmd: ioctl's request code
+ * @argp: pointer on argument from userspace
+ *
+ * Description: Expects an array of nilfs_suinfo_update structures
+ * encapsulated in nilfs_argv and updates the segment usage info
+ * according to the flags in nilfs_suinfo_update.
+ *
+ * Return Value: On success, 0 is returned. On error, one of the
+ * following negative error codes is returned.
+ *
+ * %-EPERM - Not enough permissions
+ *
+ * %-EFAULT - Error copying input data
+ *
+ * %-EIO - I/O error.
+ *
+ * %-ENOMEM - Insufficient amount of memory available.
+ *
+ * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
+ */
+static int nilfs_ioctl_set_suinfo(struct inode *inode, struct file *filp,
+                                unsigned int cmd, void __user *argp)
+{
+        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
+        struct nilfs_transaction_info ti;
+        struct nilfs_argv argv;
+        size_t len;
+        void __user *base;
+        void *kbuf;
+        int ret;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        ret = mnt_want_write_file(filp);
+        if (ret)
+                return ret;
+
+        ret = -EFAULT;
+        if (copy_from_user(&argv, argp, sizeof(argv)))
+                goto out;
+
+        ret = -EINVAL;
+        if (argv.v_size < sizeof(struct nilfs_suinfo_update))
+                goto out;
+
+        if (argv.v_nmembs > nilfs->ns_nsegments)
+                goto out;
+
+        if (argv.v_nmembs >= UINT_MAX / argv.v_size)
+                goto out;
+
+        len = argv.v_size * argv.v_nmembs;
+        if (!len) {
+                ret = 0;
+                goto out;
+        }
+
+        base = (void __user *)(unsigned long)argv.v_base;
+        kbuf = vmalloc(len);
+        if (!kbuf) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        if (copy_from_user(kbuf, base, len)) {
+                ret = -EFAULT;
+                goto out_free;
+        }
+
+        nilfs_transaction_begin(inode->i_sb, &ti, 0);
+        ret = nilfs_sufile_set_suinfo(nilfs->ns_sufile, kbuf, argv.v_size,
+                        argv.v_nmembs);
+        if (unlikely(ret < 0))
+                nilfs_transaction_abort(inode->i_sb);
+        else
+                nilfs_transaction_commit(inode->i_sb); /* never fails */
+
+out_free:
+        vfree(kbuf);
+out:
+        mnt_drop_write_file(filp);
+        return ret;
+}
+
 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
         struct inode *inode = file_inode(filp);
@@ -1189,6 +1278,8 @@ long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
                                             sizeof(struct nilfs_suinfo),
                                             nilfs_ioctl_do_get_suinfo);
+        case NILFS_IOCTL_SET_SUINFO:
+                return nilfs_ioctl_set_suinfo(inode, filp, cmd, argp);
         case NILFS_IOCTL_GET_SUSTAT:
                 return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
         case NILFS_IOCTL_GET_VINFO:
@@ -1228,6 +1319,7 @@ long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
         case NILFS_IOCTL_GET_CPINFO:
         case NILFS_IOCTL_GET_CPSTAT:
         case NILFS_IOCTL_GET_SUINFO:
+        case NILFS_IOCTL_SET_SUINFO:
         case NILFS_IOCTL_GET_SUSTAT:
         case NILFS_IOCTL_GET_VINFO:
         case NILFS_IOCTL_GET_BDESCS:
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 252657874a19..1fb465f9baf2 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -905,5 +905,7 @@ struct nilfs_bdesc {
         _IOW(NILFS_IOCTL_IDENT, 0x8B, __u64)
 #define NILFS_IOCTL_SET_ALLOC_RANGE  \
         _IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2])
+#define NILFS_IOCTL_SET_SUINFO  \
+        _IOW(NILFS_IOCTL_IDENT, 0x8D, struct nilfs_argv)
 
 #endif  /* _LINUX_NILFS_FS_H */