On Fri, Jul 10, 2020 at 10:17:55AM +0000, Johannes Thumshirn wrote:
On 10/07/2020 12:06, David Sterba wrote:
+static int check_fsflags(unsigned int old_flags, unsigned int flags) { if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ FS_NOATIME_FL | FS_NODUMP_FL | \ @@ -174,9 +177,19 @@ static int check_fsflags(unsigned int flags) FS_NOCOW_FL)) return -EOPNOTSUPP;
- /* COMPR and NOCOMP on new/old are valid */ if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL)) return -EINVAL;
- if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
return -EINVAL;- /* NOCOW and compression options are mutually exclusive */
- if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
return -EINVAL;- if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
return -EINVAL;If we'd pass in fs_info to check_fsflags() we could also validate against mount options which are incompatible with inode flags. Like -o nodatacow and FS_COMPR_FL or -o auth_key and FS_NOCOW_FL.
Same question was asked on IRC too, mount options are independent and take lower precedence than the inode attributes. A scenario where user wants to set a nodatacow attribute when the filesystem is mounted with compress= is valid and can be quite common.