On Wed 13-05-20 23:53:13, ira.weiny@xxxxxxxxx wrote: > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > We add 'always', 'never', and 'inode' (default). '-o dax' continue to > operate the same. > > Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set > it and EXT4_MOUNT_DAX_ALWAYS appropriately. > > We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX. > > https://lore.kernel.org/lkml/20200405061945.GA94792@xxxxxxxxxxxxxxxxxxxxxxxxx/ > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > > --- > Changes from RFC: > Combine remount check for DAX_NEVER with DAX_ALWAYS > Update ext4_should_enable_dax() ... > @@ -2076,13 +2079,32 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token, > } > sbi->s_jquota_fmt = m->mount_opt; > #endif > - } else if (token == Opt_dax) { > + } else if (token == Opt_dax || token == Opt_dax_str) { > #ifdef CONFIG_FS_DAX > - ext4_msg(sb, KERN_WARNING, > - "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); > - sbi->s_mount_opt |= m->mount_opt; > + char *tmp = match_strdup(&args[0]); > + > + if (!tmp || !strcmp(tmp, "always")) { > + ext4_msg(sb, KERN_WARNING, > + "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); > + sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS; > + sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER; > + } else if (!strcmp(tmp, "never")) { > + sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER; > + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS; > + } else if (!strcmp(tmp, "inode")) { > + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS; > + sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER; > + } else { > + ext4_msg(sb, KERN_WARNING, "DAX invalid option."); > + kfree(tmp); > + return -1; > + } > + > + kfree(tmp); As I wrote in my reply to previous version of this patch, I'd prefer if we handled this like e.g. 'data=' mount option. I don't think any unification in option parsing with XFS makes sence and I'd rather keep consistent how ext4 handles these 'enum' options. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
