On 05/18/15 17:18, Eric Sandeen wrote: > On 5/18/15 3:21 AM, Karel Zak wrote: >> On Sat, May 16, 2015 at 04:26:33PM +0200, Holger Hoffstätte wrote: >>>> playing with lazytime on 4.0.4-rc1 + yesterday's fencepost patch) I noticed >>>> something odd. Mounting secondary (non-root) partitions with lazytime works >>>> fine, but / does not seem to retain the value from fstab - apparently because >>>> it is remounted rw during boot, and lazytime gets swallowed/undone. >>>> >>>> Same effect when trying to remount manually with lazytime: >>>> >>>> tux>findmnt / >>>> TARGET SOURCE FSTYPE OPTIONS >>>> / /dev/sda1 ext4 rw,noatime >>>> >>>> tux>mount -o lazytime,remount / >>>> >>>> tux>dmesg >>>> [ 5208.482505] EXT4-fs (sda1): re-mounted. Opts: (null) >>>> >>>> tux>findmnt / >>>> TARGET SOURCE FSTYPE OPTIONS >>>> / /dev/sda1 ext4 rw,noatime >>>> >>>> tux>mount --version >>>> mount from util-linux 2.26.2 (libmount 2.26.0: assert, debug) > > And what does /proc/mounts say? That'll tell you what is actually set > on the superblock. Works here, on 4.1.0-rc2: > > # mount /dev/sdb1 /mnt/test > # mount -o remount,lazytime /mnt/test > # grep sdb1 /proc/mounts > /dev/sdb1 /mnt/test ext4 rw,lazytime,seclabel,relatime,data=ordered 0 0 > > # dmesg | tail -n 2 > [516203.450943] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null) > [516211.222020] EXT4-fs (sdb1): re-mounted. Opts: lazytime When I used util-linux 2.26.2 /proc/mounts never contained lazytime for the root device (sda1), despite the fact that it and other partitions explicitly had lazytime in fstab. Secondary drives & partitions *did* get the value right from the start, i.e. anything that didn't go through a ro->remount transition. It all works reliably with 2.25.x since - as Karel mentioned - the bug seems with ext4's remount logic in combination with readonly (as was the case with the root partition) and mount now actually sending the MS_LAZYTIME flag, instead of relying on ext4's builtin extra handling. -h -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
