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authorDennis Zhou <dennis@kernel.org>2018-11-02 00:24:10 +0300
committerJens Axboe <axboe@kernel.dk>2018-11-02 04:59:53 +0300
commitb5f2954d30c77649bce9c27e7a0a94299d9cfdf8 (patch)
treef5dd932dc087c3a60410e82c70be1daf92d350a7 /kernel
parent153fcd5f6d93b8e1e4040b1337f564a10f8d93af (diff)
downloadlinux-b5f2954d30c77649bce9c27e7a0a94299d9cfdf8.tar.xz
blkcg: revert blkcg cleanups series
This reverts a series committed earlier due to null pointer exception bug report in [1]. It seems there are edge case interactions that I did not consider and will need some time to understand what causes the adverse interactions. The original series can be found in [2] with a follow up series in [3]. [1] https://www.spinics.net/lists/cgroups/msg20719.html [2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/ [3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/ This reverts the following commits: d459d853c2ed, b2c3fa546705, 101246ec02b5, b3b9f24f5fcc, e2b0989954ae, f0fcb3ec89f3, c839e7a03f92, bdc2491708c4, 74b7c02a9bc1, 5bf9a1f3b4ef, a7b39b4e961c, 07b05bcc3213, 49f4c2dc2b50, 27e6fa996c53 Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup/cgroup.c48
-rw-r--r--kernel/trace/blktrace.c4
2 files changed, 11 insertions, 41 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 4c1cf0969a80..4a3dae2a8283 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -492,7 +492,7 @@ static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp,
}
/**
- * cgroup_e_css_by_mask - obtain a cgroup's effective css for the specified ss
+ * cgroup_e_css - obtain a cgroup's effective css for the specified subsystem
* @cgrp: the cgroup of interest
* @ss: the subsystem of interest (%NULL returns @cgrp->self)
*
@@ -501,8 +501,8 @@ static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp,
* enabled. If @ss is associated with the hierarchy @cgrp is on, this
* function is guaranteed to return non-NULL css.
*/
-static struct cgroup_subsys_state *cgroup_e_css_by_mask(struct cgroup *cgrp,
- struct cgroup_subsys *ss)
+static struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgrp,
+ struct cgroup_subsys *ss)
{
lockdep_assert_held(&cgroup_mutex);
@@ -523,35 +523,6 @@ static struct cgroup_subsys_state *cgroup_e_css_by_mask(struct cgroup *cgrp,
}
/**
- * cgroup_e_css - obtain a cgroup's effective css for the specified subsystem
- * @cgrp: the cgroup of interest
- * @ss: the subsystem of interest
- *
- * Find and get the effective css of @cgrp for @ss. The effective css is
- * defined as the matching css of the nearest ancestor including self which
- * has @ss enabled. If @ss is not mounted on the hierarchy @cgrp is on,
- * the root css is returned, so this function always returns a valid css.
- *
- * The returned css is not guaranteed to be online, and therefore it is the
- * callers responsiblity to tryget a reference for it.
- */
-struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgrp,
- struct cgroup_subsys *ss)
-{
- struct cgroup_subsys_state *css;
-
- do {
- css = cgroup_css(cgrp, ss);
-
- if (css)
- return css;
- cgrp = cgroup_parent(cgrp);
- } while (cgrp);
-
- return init_css_set.subsys[ss->id];
-}
-
-/**
* cgroup_get_e_css - get a cgroup's effective css for the specified subsystem
* @cgrp: the cgroup of interest
* @ss: the subsystem of interest
@@ -633,11 +604,10 @@ EXPORT_SYMBOL_GPL(of_css);
*
* Should be called under cgroup_[tree_]mutex.
*/
-#define for_each_e_css(css, ssid, cgrp) \
- for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++) \
- if (!((css) = cgroup_e_css_by_mask(cgrp, \
- cgroup_subsys[(ssid)]))) \
- ; \
+#define for_each_e_css(css, ssid, cgrp) \
+ for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++) \
+ if (!((css) = cgroup_e_css(cgrp, cgroup_subsys[(ssid)]))) \
+ ; \
else
/**
@@ -1036,7 +1006,7 @@ static struct css_set *find_existing_css_set(struct css_set *old_cset,
* @ss is in this hierarchy, so we want the
* effective css from @cgrp.
*/
- template[i] = cgroup_e_css_by_mask(cgrp, ss);
+ template[i] = cgroup_e_css(cgrp, ss);
} else {
/*
* @ss is not in this hierarchy, so we don't want
@@ -3053,7 +3023,7 @@ static int cgroup_apply_control(struct cgroup *cgrp)
return ret;
/*
- * At this point, cgroup_e_css_by_mask() results reflect the new csses
+ * At this point, cgroup_e_css() results reflect the new csses
* making the following cgroup_update_dfl_csses() properly update
* css associations of all tasks in the subtree.
*/
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index fac0ddf8a8e2..2868d85f1fb1 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -764,9 +764,9 @@ blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
return NULL;
- if (!bio->bi_blkg)
+ if (!bio->bi_css)
return NULL;
- return cgroup_get_kernfs_id(bio_blkcg(bio)->css.cgroup);
+ return cgroup_get_kernfs_id(bio->bi_css->cgroup);
}
#else
static union kernfs_node_id *