The quilt patch titled Subject: maple_tree: reload mas before the second call for mas_empty_area has been removed from the -mm tree. Its filename was maple_tree-reload-mas-before-the-second-call-for-mas_empty_area.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------ From: Yang Erkun yangerkun@huawei.com Subject: maple_tree: reload mas before the second call for mas_empty_area Date: Sat, 14 Dec 2024 17:30:05 +0800
Change the LONG_MAX in simple_offset_add to 1024, and do latter:
[root@fedora ~]# mkdir /tmp/dir [root@fedora ~]# for i in {1..1024}; do touch /tmp/dir/$i; done touch: cannot touch '/tmp/dir/1024': Device or resource busy [root@fedora ~]# rm /tmp/dir/123 [root@fedora ~]# touch /tmp/dir/1024 [root@fedora ~]# rm /tmp/dir/100 [root@fedora ~]# touch /tmp/dir/1025 touch: cannot touch '/tmp/dir/1025': Device or resource busy
After we delete file 100, actually this is a empty entry, but the latter create failed unexpected.
mas_alloc_cyclic has two chance to find empty entry. First find the entry with range range_lo and range_hi, if no empty entry exist, and range_lo > min, retry find with range min and range_hi. However, the first call mas_empty_area may mark mas as EBUSY, and the second call for mas_empty_area will return false directly. Fix this by reload mas before second call for mas_empty_area.
[Liam.Howlett@Oracle.com: fix mas_alloc_cyclic() second search] Link: https://lore.kernel.org/all/20241216060600.287B4C4CED0@smtp.kernel.org/ Link: https://lkml.kernel.org/r/20241216190113.1226145-2-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20241214093005.72284-1-yangerkun@huaweicloud.com Fixes: 9b6713cc7522 ("maple_tree: Add mtree_alloc_cyclic()") Signed-off-by: Yang Erkun yangerkun@huawei.com Signed-off-by: Liam R. Howlett Liam.Howlett@Oracle.com Cc: Christian Brauner brauner@kernel.org Cc: Chuck Lever chuck.lever@oracle.com says: Cc: Liam R. Howlett Liam.Howlett@Oracle.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
lib/maple_tree.c | 1 + 1 file changed, 1 insertion(+)
--- a/lib/maple_tree.c~maple_tree-reload-mas-before-the-second-call-for-mas_empty_area +++ a/lib/maple_tree.c @@ -4354,6 +4354,7 @@ int mas_alloc_cyclic(struct ma_state *ma ret = 1; } if (ret < 0 && range_lo > min) { + mas_reset(mas); ret = mas_empty_area(mas, min, range_hi, 1); if (ret == 0) ret = 1; _
Patches currently in -mm which might be from yangerkun@huawei.com are