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authorLinus Torvalds <torvalds@linux-foundation.org>2017-03-09 15:53:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-09 15:53:25 -0800
commit34bbce9e344b47e8871273409632f525973afad4 (patch)
tree69bb1c6f4b0d49f5122114d2bc45f4c06c22505d /mm
parentbb61ce54e8986ea18f7eb13cfa4a6fa8eb311bbd (diff)
parent672a2c87c83649fb0167202342ce85af9a3b4f1c (diff)
downloadlinux-34bbce9e344b47e8871273409632f525973afad4.tar.bz2
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe: "Sending this a bit sooner than I otherwise would have, as a fix in the merge window had some unfortunate issues and side effects for some folks. This contains: - Fixes from Jan for the bdi registration/unregistration. These have been tested by the various parties reporting issues, and should be solid at this point. - Also from Jan, fix for axonram gendisk registration. - A stable fix for zram from Johannes. - A small series from Ming, fixing up some long standing issues with blk-mq hardware queue kobject initialization and registration. - A fix for sed opal from Jon, fixing a nonsensical range check and some set-but-not-used variables. - A fix from Neil for a long standing deadlock issue for stacking device drivers. With this in place, dm/md don't have to work around the issue anymore, and can be properly fixed up" * 'for-linus' of git://git.kernel.dk/linux-block: axonram: Fix gendisk handling blk: improve order of bio handling in generic_make_request() Revert "scsi, block: fix duplicate bdi name registration crashes" block: Make del_gendisk() safer for disks without queues bdi: Fix use-after-free in wb_congested_put() block: Allow bdi re-registration block/sed: Fix opal user range check and unused variables zram: set physical queue limits to avoid array out of bounds accesses blk-mq: free hctx->cpumask in release handler of hctx's kobject blk-mq: make lifetime consistent between hctx and its kobject blk-mq: make lifetime consitent between q/ctx and its kobject blk-mq: initialize mq kobjects in blk_mq_init_allocated_queue()
Diffstat (limited to 'mm')
-rw-r--r--mm/backing-dev.c43
1 files changed, 28 insertions, 15 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 6d861d090e9f..c6f2a37028c2 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -683,33 +683,26 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi)
static void cgwb_bdi_destroy(struct backing_dev_info *bdi)
{
struct radix_tree_iter iter;
- struct rb_node *rbn;
void **slot;
WARN_ON(test_bit(WB_registered, &bdi->wb.state));
spin_lock_irq(&cgwb_lock);
-
radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0)
cgwb_kill(*slot);
-
- while ((rbn = rb_first(&bdi->cgwb_congested_tree))) {
- struct bdi_writeback_congested *congested =
- rb_entry(rbn, struct bdi_writeback_congested, rb_node);
-
- rb_erase(rbn, &bdi->cgwb_congested_tree);
- congested->bdi = NULL; /* mark @congested unlinked */
- }
-
spin_unlock_irq(&cgwb_lock);
/*
- * All cgwb's and their congested states must be shutdown and
- * released before returning. Drain the usage counter to wait for
- * all cgwb's and cgwb_congested's ever created on @bdi.
+ * All cgwb's must be shutdown and released before returning. Drain
+ * the usage counter to wait for all cgwb's ever created on @bdi.
*/
atomic_dec(&bdi->usage_cnt);
wait_event(cgwb_release_wait, !atomic_read(&bdi->usage_cnt));
+ /*
+ * Grab back our reference so that we hold it when @bdi gets
+ * re-registered.
+ */
+ atomic_inc(&bdi->usage_cnt);
}
/**
@@ -749,6 +742,21 @@ void wb_blkcg_offline(struct blkcg *blkcg)
spin_unlock_irq(&cgwb_lock);
}
+static void cgwb_bdi_exit(struct backing_dev_info *bdi)
+{
+ struct rb_node *rbn;
+
+ spin_lock_irq(&cgwb_lock);
+ while ((rbn = rb_first(&bdi->cgwb_congested_tree))) {
+ struct bdi_writeback_congested *congested =
+ rb_entry(rbn, struct bdi_writeback_congested, rb_node);
+
+ rb_erase(rbn, &bdi->cgwb_congested_tree);
+ congested->bdi = NULL; /* mark @congested unlinked */
+ }
+ spin_unlock_irq(&cgwb_lock);
+}
+
#else /* CONFIG_CGROUP_WRITEBACK */
static int cgwb_bdi_init(struct backing_dev_info *bdi)
@@ -769,7 +777,9 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi)
return 0;
}
-static void cgwb_bdi_destroy(struct backing_dev_info *bdi)
+static void cgwb_bdi_destroy(struct backing_dev_info *bdi) { }
+
+static void cgwb_bdi_exit(struct backing_dev_info *bdi)
{
wb_congested_put(bdi->wb_congested);
}
@@ -857,6 +867,8 @@ int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner)
MINOR(owner->devt));
if (rc)
return rc;
+ /* Leaking owner reference... */
+ WARN_ON(bdi->owner);
bdi->owner = owner;
get_device(owner);
return 0;
@@ -898,6 +910,7 @@ static void bdi_exit(struct backing_dev_info *bdi)
{
WARN_ON_ONCE(bdi->dev);
wb_exit(&bdi->wb);
+ cgwb_bdi_exit(bdi);
}
static void release_bdi(struct kref *ref)