diff options
| author | Hugh Dickins <hughd@google.com> | 2014-03-04 00:38:23 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-03-04 16:55:47 +0100 |
| commit | 5f30fc94ca985974fd54de454c7a6070388443db (patch) | |
| tree | 61eaa530adadd74be8a5b80d5cbc547505ac0f48 | |
| parent | dma debug: account for cachelines and read-only mappings in overlap tracking (diff) | |
| download | linux-5f30fc94ca985974fd54de454c7a6070388443db.tar.xz linux-5f30fc94ca985974fd54de454c7a6070388443db.zip | |
lib/radix-tree.c: swapoff tmpfs radix_tree: remember to rcu_read_unlock
Running fsx on tmpfs with concurrent memhog-swapoff-swapon, lots of
BUG: sleeping function called from invalid context at kernel/fork.c:606
in_atomic(): 0, irqs_disabled(): 0, pid: 1394, name: swapoff
1 lock held by swapoff/1394:
#0: (rcu_read_lock){.+.+.+}, at: [<ffffffff812520a1>] radix_tree_locate_item+0x1f/0x2b6
followed by
================================================
[ BUG: lock held when returning to user space! ]
3.14.0-rc1 #3 Not tainted
------------------------------------------------
swapoff/1394 is leaving the kernel with locks still held!
1 lock held by swapoff/1394:
#0: (rcu_read_lock){.+.+.+}, at: [<ffffffff812520a1>] radix_tree_locate_item+0x1f/0x2b6
after which the system recovered nicely.
Whoops, I long ago forgot the rcu_read_unlock() on one unlikely branch.
Fixes e504f3fdd63d ("tmpfs radix_tree: locate_item to speed up swapoff")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | lib/radix-tree.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 7811ed3b4e70..bd4a8dfdf0b8 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -1253,8 +1253,10 @@ unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item) node = indirect_to_ptr(node); max_index = radix_tree_maxindex(node->height); - if (cur_index > max_index) + if (cur_index > max_index) { + rcu_read_unlock(); break; + } cur_index = __locate(node, item, cur_index, &found_index); rcu_read_unlock(); |