+ maple_tree-detect-dead-nodes-in-mas_start.patch added to mm-unstable branch

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: maple_tree: detect dead nodes in mas_start()
has been added to the -mm mm-unstable branch.  Its filename is
     maple_tree-detect-dead-nodes-in-mas_start.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-detect-dead-nodes-in-mas_start.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Liam Howlett <Liam.Howlett@xxxxxxxxxx>
Subject: maple_tree: detect dead nodes in mas_start()
Date: Mon, 27 Feb 2023 09:36:01 -0800

When initially starting a search, the root node may already be in the
process of being replaced in RCU mode.  Detect and restart the walk if
this is the case.  This is necessary for RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-3-surenb@xxxxxxxxxx
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---


--- a/lib/maple_tree.c~maple_tree-detect-dead-nodes-in-mas_start
+++ a/lib/maple_tree.c
@@ -1360,12 +1360,16 @@ static inline struct maple_enode *mas_st
 		mas->max = ULONG_MAX;
 		mas->depth = 0;
 
+retry:
 		root = mas_root(mas);
 		/* Tree with nodes */
 		if (likely(xa_is_node(root))) {
 			mas->depth = 1;
 			mas->node = mte_safe_root(root);
 			mas->offset = 0;
+			if (mte_dead_node(mas->node))
+				goto retry;
+
 			return NULL;
 		}
 
_

Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are

mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey.patch
maple_tree-be-more-cautious-about-dead-nodes.patch
maple_tree-detect-dead-nodes-in-mas_start.patch
maple_tree-fix-freeing-of-nodes-in-rcu-mode.patch
maple_tree-remove-extra-smp_wmb-from-mas_dead_leaves.patch
maple_tree-fix-write-memory-barrier-of-nodes-once-dead-for-rcu-mode.patch
maple_tree-add-smp_rmb-to-dead-node-detection.patch
maple_tree-add-rcu-lock-checking-to-rcu-callback-functions.patch
mm-enable-maple-tree-rcu-mode-by-default.patch




[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux