Re: changing ffs mount between rw and ro while preserving softdep
Op Wed, 27 Aug 2014 20:50:34 +0200 schreef Miod Vallat m...@online.fr: Why not keep the softdep flag when updating rw-ro? E.g. via mount -ur /usr/obj fstab(5) already allows ro+softdep. Because if we were to apply this diff, there would be no way to switch from rw+softdep to rw. That was already broken; rw-rw is not affected as per the enclosing if-block. I just tried this on 5.5 (GENERIC, without my diff): # mount -vu -onosoftdep /usr/obj/ /dev/wd0f on /home type ffs (rw, local, noatime, nodev, nosuid, softdep, ctime=Thu Aug 28 11:04:07 2014) And then after un-mounting and re-mounting without softdep: # mount -vu -osoftdep /usr/obj/ /dev/sd0f on /usr/obj type ffs (rw, local, nodev, nosuid, ctime=Thu Aug 28 11:12:57 2014) So, currently it doesn't seem possible to turn softdep on or off with an rw mount. My diff doesn't change that. -- (Remove the obvious prefix to reply privately.) Gemaakt met Opera's e-mailprogramma: http://www.opera.com/mail/
Re: changing ffs mount between rw and ro while preserving softdep
Because if we were to apply this diff, there would be no way to switch from rw+softdep to rw. That was already broken; rw-rw is not affected as per the enclosing if-block. Which is why the current way to remove softdep from a filesystem is a rw+softdep - ro - rw transition, which would no longer work with your diff. Miod
Re: changing ffs mount between rw and ro while preserving softdep
Op Thu, 28 Aug 2014 11:51:32 +0200 schreef Miod Vallat m...@online.fr: Because if we were to apply this diff, there would be no way to switch from rw+softdep to rw. That was already broken; rw-rw is not affected as per the enclosing if-block. Which is why the current way to remove softdep from a filesystem is a rw+softdep - ro - rw transition, which would no longer work with your diff. It would work, but you'd have to explicitly disable softdep, as one might expect to be required when removing softdep: # mount -vuw /usr/obj /dev/sd0f on /usr/obj type ffs (rw, local, nodev, nosuid, softdep, ctime=Thu Aug 28 11:58:27 2014) # mount -vur -onosoftdep /usr/obj /dev/sd0f on /usr/obj type ffs (local, nodev, nosuid, read-only, ctime=Thu Aug 28 11:58:40 2014) # mount -vuw /usr/obj /dev/sd0f on /usr/obj type ffs (rw, local, nodev, nosuid, ctime=Thu Aug 28 11:58:50 2014) Basically, I made my diff so that (mount -uw;mount -ur) cycles retain softdep. Without my diff, one would have to append -osoftdep depending on the fs-type and what was defined in /etc/fstab. -- (Remove the obvious prefix to reply privately.) Gemaakt met Opera's e-mailprogramma: http://www.opera.com/mail/
Re: changing ffs mount between rw and ro while preserving softdep
Which is why the current way to remove softdep from a filesystem is a rw+softdep - ro - rw transition, which would no longer work with your diff. It would work, but you'd have to explicitly disable softdep, as one might expect to be required when removing softdep: Oh, indeed. Then it's a matter of deciding whether we want mount -u to simply update flags (and then only toggle ro/rw, and leave softdep unchanged) or to update behaviour (and then clear softdep on rw-ro transition as softdep do not apply to read-only filesystems). You're in favour of the former, I am in favour of the latter. Who wants to be the referee? Miod
Re: changing ffs mount between rw and ro while preserving softdep
On Thu, Aug 28, 2014 at 06:27:48PM +, Miod Vallat wrote: | Which is why the current way to remove softdep from a filesystem is a | rw+softdep - ro - rw transition, which would no longer work with your | diff. | | It would work, but you'd have to explicitly disable softdep, as one might | expect to be required when removing softdep: | | Oh, indeed. | | Then it's a matter of deciding whether we want mount -u to simply update | flags (and then only toggle ro/rw, and leave softdep unchanged) or to | update behaviour (and then clear softdep on rw-ro transition as softdep | do not apply to read-only filesystems). You're in favour of the former, | I am in favour of the latter. Who wants to be the referee? I hardly qualify as a referee but I'll add that I think Boudewijn's approach makes more sense to me. Even though I quite often use -ur/-uw to drop softdep from filesystems. Especially given Boudewijn's point that putting ro,softdep in fstab results in a filesystem that would get (still have) softdep after -uw. I don't have very strong feelings on the matter (but, yes, strong enough to write this e-mail ;) Cheers, Paul 'WEiRD' de Weerd -- [++-]+++.+++[---].+++[+ +++-].++[-]+.--.[-] http://www.weirdnet.nl/
Re: changing ffs mount between rw and ro while preserving softdep
On 08/28/14 23:06, Paul de Weerd wrote: On Thu, Aug 28, 2014 at 06:27:48PM +, Miod Vallat wrote: | Which is why the current way to remove softdep from a filesystem is a | rw+softdep - ro - rw transition, which would no longer work with your | diff. | | It would work, but you'd have to explicitly disable softdep, as one might | expect to be required when removing softdep: | | Oh, indeed. | | Then it's a matter of deciding whether we want mount -u to simply update | flags (and then only toggle ro/rw, and leave softdep unchanged) or to | update behaviour (and then clear softdep on rw-ro transition as softdep | do not apply to read-only filesystems). You're in favour of the former, | I am in favour of the latter. Who wants to be the referee? I wouldn't expect any flags to change unless I ask for it, be it noexec, async, softdep or whatever. /Alexander I hardly qualify as a referee but I'll add that I think Boudewijn's approach makes more sense to me. Even though I quite often use -ur/-uw to drop softdep from filesystems. Especially given Boudewijn's point that putting ro,softdep in fstab results in a filesystem that would get (still have) softdep after -uw. I don't have very strong feelings on the matter (but, yes, strong enough to write this e-mail ;) Cheers, Paul 'WEiRD' de Weerd
changing ffs mount between rw and ro while preserving softdep
Why not keep the softdep flag when updating rw-ro?
E.g. via mount -ur /usr/obj
fstab(5) already allows ro+softdep.
--- /usr/src/sys/ufs/ffs/ffs_vfsops.c.orig Wed Aug 27 19:00:31 2014
+++ /usr/src/sys/ufs/ffs/ffs_vfsops.c Wed Aug 27 19:01:19 2014
@@ -218,10 +218,9 @@
flags = WRITECLOSE;
if (mp-mnt_flag MNT_FORCE)
flags |= FORCECLOSE;
- if (fs-fs_flags FS_DOSOFTDEP) {
+ if (fs-fs_flags FS_DOSOFTDEP)
error = softdep_flushfiles(mp, flags, p);
- mp-mnt_flag = ~MNT_SOFTDEP;
- } else
+ else
error = ffs_flushfiles(mp, flags, p);
ronly = 1;
}
--
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Re: changing ffs mount between rw and ro while preserving softdep
Why not keep the softdep flag when updating rw-ro? E.g. via mount -ur /usr/obj fstab(5) already allows ro+softdep. Because if we were to apply this diff, there would be no way to switch from rw+softdep to rw.
Re: changing ffs mount between rw and ro while preserving softdep
On Wed, Aug 27, 2014 at 11:50 AM, Miod Vallat m...@online.fr wrote: Why not keep the softdep flag when updating rw-ro? E.g. via mount -ur /usr/obj fstab(5) already allows ro+softdep. Because if we were to apply this diff, there would be no way to switch from rw+softdep to rw. And what exactly is the operational/behavioral difference between ro and ro+softdep?
Re: changing ffs mount between rw and ro while preserving softdep
On 08/27/14 16:59, Philip Guenther wrote: On Wed, Aug 27, 2014 at 11:50 AM, Miod Vallat m...@online.fr wrote: Why not keep the softdep flag when updating rw-ro? E.g. via mount -ur /usr/obj fstab(5) already allows ro+softdep. Because if we were to apply this diff, there would be no way to switch from rw+softdep to rw. And what exactly is the operational/behavioral difference between ro and ro+softdep? Extra code being executed when it doesn't have to be? --STeve Andre'
