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/f2fs.h b/fs/f2fs/f2fs.h
index 56a2c73..932e838 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -113,6 +113,7 @@
#define F2FS_FEATURE_ENCRYPT 0x0001
#define F2FS_FEATURE_BLKZONED 0x0002
+#define F2FS_FEATURE_ATOMIC_WRITE 0x0004
#define F2FS_HAS_FEATURE(sb, mask) \
((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)
@@ -309,6 +310,7 @@
struct f2fs_flush_device)
#define F2FS_IOC_GARBAGE_COLLECT_RANGE _IOW(F2FS_IOCTL_MAGIC, 11, \
struct f2fs_gc_range)
+#define F2FS_IOC_GET_FEATURES _IOR(F2FS_IOCTL_MAGIC, 12, __u32)
#define F2FS_IOC_SET_ENCRYPTION_POLICY FS_IOC_SET_ENCRYPTION_POLICY
#define F2FS_IOC_GET_ENCRYPTION_POLICY FS_IOC_GET_ENCRYPTION_POLICY
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 740e203..73b086a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2382,6 +2382,16 @@
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)
{
@@ -2424,6 +2434,8 @@
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;
}
@@ -2489,6 +2501,7 @@
case F2FS_IOC_DEFRAGMENT:
case F2FS_IOC_MOVE_RANGE:
case F2FS_IOC_FLUSH_DEVICE:
+ case F2FS_IOC_GET_FEATURES:
break;
default:
return -ENOIOCTLCMD;