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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-25 16:20:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-25 16:20:55 -0700
commitd4a748a10e50d95992ae67677f1a1a13e2d6ed47 (patch)
tree74bd3b0543be9c1506f9774f188ea36a4105154d
parent03e8f644868f147e021e8660346890e731c2e435 (diff)
parent9badce000e2ce68ba74838a3cd356dde58221c2f (diff)
Merge branch 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull another cgroup fix from Tejun Heo: "The cgroup writeback support got inadvertently enabled for traditional hierarchies revealing two regressions which are currently being worked on. It shouldn't have been enabled on traditional hierarchies, so disable it on them. This is enough to make the regressions go away for people who aren't experimenting with cgroup" * 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup, writeback: don't enable cgroup writeback on traditional hierarchies
-rw-r--r--include/linux/backing-dev.h11
1 files changed, 9 insertions, 2 deletions
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 5a5d79ee256f..d5eb4ad1c534 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -13,6 +13,7 @@
#include <linux/sched.h>
#include <linux/blkdev.h>
#include <linux/writeback.h>
+#include <linux/memcontrol.h>
#include <linux/blk-cgroup.h>
#include <linux/backing-dev-defs.h>
#include <linux/slab.h>
@@ -252,13 +253,19 @@ int inode_congested(struct inode *inode, int cong_bits);
* @inode: inode of interest
*
* cgroup writeback requires support from both the bdi and filesystem.
- * Test whether @inode has both.
+ * Also, both memcg and iocg have to be on the default hierarchy. Test
+ * whether all conditions are met.
+ *
+ * Note that the test result may change dynamically on the same inode
+ * depending on how memcg and iocg are configured.
*/
static inline bool inode_cgwb_enabled(struct inode *inode)
{
struct backing_dev_info *bdi = inode_to_bdi(inode);
- return bdi_cap_account_dirty(bdi) &&
+ return cgroup_on_dfl(mem_cgroup_root_css->cgroup) &&
+ cgroup_on_dfl(blkcg_root_css->cgroup) &&
+ bdi_cap_account_dirty(bdi) &&
(bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
(inode->i_sb->s_iflags & SB_I_CGROUPWB);
}