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| author |   Tejun Heo <tj@kernel.org> | 2013-06-27 19:37:26 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-06-27 19:37:26 -0700 |
| commit | 0ce6cba35777cf96a54ce0d5856dc962566b8717 (patch) | |
| tree | c03ee20f1c6deff5494a4ca86802ea053c6d5667 /include/linux/cgroup.h | |
| parent | cgroup: fix deadlock on cgroup_mutex via drop_parsed_module_refcounts() (diff) | |
| download | linux-dev-0ce6cba35777cf96a54ce0d5856dc962566b8717.tar.xz linux-dev-0ce6cba35777cf96a54ce0d5856dc962566b8717.zip | |
cgroup: CGRP_ROOT_SUBSYS_BOUND should be ignored when comparing mount options
1672d04070 ("cgroup: fix cgroupfs_root early destruction path")
introduced CGRP_ROOT_SUBSYS_BOUND which is used to mark completion of
subsys binding on a new root; however, this broke remounts.
cgroup_remount() doesn't allow changing root options via remount and
CGRP_ROOT_SUBSYS_BOUND, which is set on all fully initialized roots,
makes the function reject all remounts.
Fix it by putting the options part in the lower 16 bits of root->flags
and masking the comparions. While at it, make cgroup_remount() emit
an error message explaining why it's rejecting a remount request, so
that it's less of a mystery.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index ad3555bc21f4..8db53974f7b5 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -276,7 +276,11 @@ enum { CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */ CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */ - CGRP_ROOT_SUBSYS_BOUND = (1 << 3), /* subsystems finished binding */ + + /* mount options live below bit 16 */ + CGRP_ROOT_OPTION_MASK = (1 << 16) - 1, + + CGRP_ROOT_SUBSYS_BOUND = (1 << 16), /* subsystems finished binding */ }; /* |