nilfs2: add FITRIM ioctl support for nilfs2

Add support for the FITRIM ioctl, which enables user space tools to
issue TRIM/DISCARD requests to the underlying device.  Every clean
segment within the specified range will be discarded.

Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index c19a23158487..422fb54b7377 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -1072,6 +1072,48 @@ out:
 }
 
 /**
+ * nilfs_ioctl_trim_fs() - trim ioctl handle function
+ * @inode: inode object
+ * @argp: pointer on argument from userspace
+ *
+ * Decription: nilfs_ioctl_trim_fs is the FITRIM ioctl handle function. It
+ * checks the arguments from userspace and calls nilfs_sufile_trim_fs, which
+ * performs the actual trim operation.
+ *
+ * Return Value: On success, 0 is returned or negative error code, otherwise.
+ */
+static int nilfs_ioctl_trim_fs(struct inode *inode, void __user *argp)
+{
+        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
+        struct request_queue *q = bdev_get_queue(nilfs->ns_bdev);
+        struct fstrim_range range;
+        int ret;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        if (!blk_queue_discard(q))
+                return -EOPNOTSUPP;
+
+        if (copy_from_user(&range, argp, sizeof(range)))
+                return -EFAULT;
+
+        range.minlen = max_t(u64, range.minlen, q->limits.discard_granularity);
+
+        down_read(&nilfs->ns_segctor_sem);
+        ret = nilfs_sufile_trim_fs(nilfs->ns_sufile, &range);
+        up_read(&nilfs->ns_segctor_sem);
+
+        if (ret < 0)
+                return ret;
+
+        if (copy_to_user(argp, &range, sizeof(range)))
+                return -EFAULT;
+
+        return 0;
+}
+
+/**
  * nilfs_ioctl_set_alloc_range - limit range of segments to be allocated
  * @inode: inode object
  * @argp: pointer on argument from userspace
@@ -1296,6 +1338,8 @@ long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                 return nilfs_ioctl_resize(inode, filp, argp);
         case NILFS_IOCTL_SET_ALLOC_RANGE:
                 return nilfs_ioctl_set_alloc_range(inode, argp);
+        case FITRIM:
+                return nilfs_ioctl_trim_fs(inode, argp);
         default:
                 return -ENOTTY;
         }
@@ -1327,6 +1371,7 @@ long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
         case NILFS_IOCTL_SYNC:
         case NILFS_IOCTL_RESIZE:
         case NILFS_IOCTL_SET_ALLOC_RANGE:
+        case FITRIM:
                 break;
         default:
                 return -ENOIOCTLCMD;