1 files changed, 37 insertions, 4 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 88d3cb2eaf7..32c980ae0f1 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -138,6 +138,24 @@ static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
         return 0;
 }
 
+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))
+                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;
+}
+
 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 {
         struct inode *inode = file->f_path.dentry->d_inode;
@@ -153,10 +171,9 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
         if (copy_from_user(&flags, arg, sizeof(flags)))
                 return -EFAULT;
 
-        if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
-                      FS_NOATIME_FL | FS_NODUMP_FL | \
-                      FS_SYNC_FL | FS_DIRSYNC_FL))
-                return -EOPNOTSUPP;
+        ret = check_flags(flags);
+        if (ret)
+                return ret;
 
         if (!is_owner_or_cap(inode))
                 return -EACCES;
@@ -201,6 +218,22 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
         else
                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 
+        /*
+         * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
+         * flag may be changed automatically if compression code won't make
+         * things smaller.
+         */
+        if (flags & FS_NOCOMP_FL) {
+                ip->flags &= ~BTRFS_INODE_COMPRESS;
+                ip->flags |= BTRFS_INODE_NOCOMPRESS;
+        } else if (flags & FS_COMPR_FL) {
+                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));