Il 24/08/2012 09:26, Artem Bityutskiy ha scritto:
From: Artem Bityutskiy <artem.bityuts...@linux.intel.com>
Currently the emergency remount (triggered by Sysrq-u) re-mounting only
those file-systems R/O, which have an associated block device (sb->s_bdev).
This does not work for file-systems like UBIFS and JFFS2 which work on top
of MTD devices (character devices) and always have sb->s_bdev = NULL.
This also does not work for tmpfs.
Most probably the intention was to avoid re-mounting R/O file-systems like
procfs, sysfs, cgroup, and debugfs. However, I do not really see why not
to remount them R/O as well in case of emergency.
This patch removes the 'sb->s_bdev != NULL' check from
'do_emergency_remount()', so _all_ file-systems will be re-mounted R/O.
Tested in Fedora - all file-systems (ext4, ubifs, procfs, sysfs, cgroup, and
debugfs) become R/O on Sysrq-u with this patch.
Signed-off-by: Artem Bityutskiy <artem.bityuts...@linux.intel.com>
Does it make sense to remount r/o for example debugfs in this case?
Maybe if there is something wrong I want enable something to catch debug
info. Similar things for other pseudo-fs. Sure, the s_bdev seems a
strong check. We could add a new flag to know if the emergency remount
should be happen. It would give us the fs granularity, and maybe it
could be turned on/off with the mount.
Marco
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