The patch titled
Subject: maple_tree: set the node limit when creating a new root node
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
maple_tree-set-the-node-limit-when-creating-a-new-root-node.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-set-the-node-limit-when-creating-a-new-root-node.patch
This patch will later appear in the mm-hotfixes-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: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Subject: maple_tree: set the node limit when creating a new root node
Date: Tue, 11 Jul 2023 11:54:37 +0800
Set the node limit of the root node so that the last pivot of all nodes is
the node limit (if the node is not full).
This patch also fixes a bug in mas_rev_awalk(). Effectively, always
setting a maximum makes mas_logical_pivot() behave as mas_safe_pivot().
Without this fix, it is possible that very small tasks would fail to find
the correct gap. Although this has not been observed with real tasks, it
has been reported to happen in m68k nommu running the maple tree tests.
Link: https://lkml.kernel.org/r/20230711035444.526-1-zhangpeng.00@xxxxxxxxxxxxx
Link: https://lore.kernel.org/linux-mm/CAMuHMdV4T53fOw7VPoBgPR7fP6RYqf=CBhD_y_vOg53zZX_DnA@xxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20230711035444.526-2-zhangpeng.00@xxxxxxxxxxxxx
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/lib/maple_tree.c~maple_tree-set-the-node-limit-when-creating-a-new-root-node
+++ a/lib/maple_tree.c
@@ -3692,7 +3692,8 @@ static inline int mas_root_expand(struct
mas->offset = slot;
pivots[slot] = mas->last;
if (mas->last != ULONG_MAX)
- slot++;
+ pivots[++slot] = ULONG_MAX;
+
mas->depth = 1;
mas_set_height(mas);
ma_set_meta(node, maple_leaf_64, 0, slot);
_
Patches currently in -mm which might be from zhangpeng.00@xxxxxxxxxxxxx are
maple_tree-set-the-node-limit-when-creating-a-new-root-node.patch
maple_tree-add-test-for-mas_wr_modify-fast-path.patch
maple_tree-add-test-for-expanding-range-in-rcu-mode.patch
maple_tree-optimize-mas_wr_append-also-improve-duplicating-vmas.patch
maple_tree-add-a-fast-path-case-in-mas_wr_slot_store.patch
maple_tree-dont-use-maple_arange64_meta_max-to-indicate-no-gap.patch
maple_tree-make-mas_validate_gaps-to-check-metadata.patch
maple_tree-fix-mas_validate_child_slot-to-check-last-missed-slot.patch
maple_tree-make-mas_validate_limits-check-root-node-and-node-limit.patch
maple_tree-update-mt_validate.patch
maple_tree-replace-mas_logical_pivot-with-mas_safe_pivot.patch
maple_tree-drop-mas_first_entry.patch
