Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e1e8fb6a authored by Li Zefan's avatar Li Zefan Committed by Chris Mason
Browse files

fs: remove FS_COW_FL 



FS_COW_FL and FS_NOCOW_FL were newly introduced to control per file
COW in btrfs, but FS_NOCOW_FL is sufficient.

The fact is we don't have corresponding BTRFS_INODE_COW flag.

COW is default, and FS_NOCOW_FL can be used to switch off COW for
a single file.

If we mount btrfs with nodatacow, a newly created file will be set with
the FS_NOCOW_FL flag. So to turn on COW for it, we can just clear the
FS_NOCOW_FL flag.

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 1aba86d6

fs/btrfs/ioctl.c

+6 −9
Original line number Diff line number Diff line
@@ -144,16 +144,13 @@ static int check_flags(unsigned int flags) 
	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \

		      FS_NOATIME_FL | FS_NODUMP_FL | \

		      FS_SYNC_FL | FS_DIRSYNC_FL | \

		      FS_NOCOMP_FL | FS_COMPR_FL | \

		      FS_NOCOW_FL | FS_COW_FL))

		      FS_NOCOMP_FL | FS_COMPR_FL |

		      FS_NOCOW_FL))

		return -EOPNOTSUPP;



	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))

		return -EINVAL;



	if ((flags & FS_NOCOW_FL) && (flags & FS_COW_FL))

		return -EINVAL;



	return 0;

}
@@ -218,6 +215,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) 
		ip->flags |= BTRFS_INODE_DIRSYNC;

	else

		ip->flags &= ~BTRFS_INODE_DIRSYNC;

	if (flags & FS_NOCOW_FL)

		ip->flags |= BTRFS_INODE_NODATACOW;

	else

		ip->flags &= ~BTRFS_INODE_NODATACOW;



	/*

	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
@@ -231,10 +232,6 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) 
		ip->flags |= BTRFS_INODE_COMPRESS;

		ip->flags &= ~BTRFS_INODE_NOCOMPRESS;

	}

	if (flags & FS_NOCOW_FL)

		ip->flags |= BTRFS_INODE_NODATACOW;

	else if (flags & FS_COW_FL)

		ip->flags &= ~BTRFS_INODE_NODATACOW;



	trans = btrfs_join_transaction(root, 1);

	BUG_ON(IS_ERR(trans));

include/linux/fs.h

+0 −1
Original line number Diff line number Diff line
@@ -365,7 +365,6 @@ struct inodes_stat_t { 
#define FS_EXTENT_FL			0x00080000 /* Extents */

#define FS_DIRECTIO_FL			0x00100000 /* Use direct i/o */

#define FS_NOCOW_FL			0x00800000 /* Do not cow file */

#define FS_COW_FL			0x02000000 /* Cow file */

#define FS_RESERVED_FL			0x80000000 /* reserved for ext2 lib */



#define FS_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */