f2fs: add ioctl to expose current features
This patch adds an ioctl to provide feature information to user.
For exapmle, SQLite can use this ioctl to detect whether f2fs support atomic
write or not.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 75b3fda..0a5faf2 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2401,6 +2401,16 @@
return ret;
}
+static int f2fs_ioc_get_features(struct file *filp, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ u32 sb_feature = le32_to_cpu(F2FS_I_SB(inode)->raw_super->feature);
+
+ /* Must validate to set it with SQLite behavior in Android. */
+ sb_feature |= F2FS_FEATURE_ATOMIC_WRITE;
+
+ return put_user(sb_feature, (u32 __user *)arg);
+}
long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
@@ -2443,6 +2453,8 @@
return f2fs_ioc_move_range(filp, arg);
case F2FS_IOC_FLUSH_DEVICE:
return f2fs_ioc_flush_device(filp, arg);
+ case F2FS_IOC_GET_FEATURES:
+ return f2fs_ioc_get_features(filp, arg);
default:
return -ENOTTY;
}
@@ -2508,6 +2520,7 @@
case F2FS_IOC_DEFRAGMENT:
case F2FS_IOC_MOVE_RANGE:
case F2FS_IOC_FLUSH_DEVICE:
+ case F2FS_IOC_GET_FEATURES:
break;
default:
return -ENOIOCTLCMD;