This is a note to let you know that I've just added the patch titled
ext4: no need to generate from free list in mballoc
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-no-need-to-generate-from-free-list-in-mballoc.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ebf6cb7c6e1241984f75f29f1bdbfa2fe7168f88 Mon Sep 17 00:00:00 2001
From: Wang Jianjian <wangjianjian0@xxxxxxxxxxx>
Date: Thu, 24 Aug 2023 23:56:31 +0800
Subject: ext4: no need to generate from free list in mballoc
From: Wang Jianjian <wangjianjian0@xxxxxxxxxxx>
commit ebf6cb7c6e1241984f75f29f1bdbfa2fe7168f88 upstream.
Commit 7a2fcbf7f85 ("ext4: don't use blocks freed but not yet committed in
buddy cache init") added a code to mark as used blocks in the list of not yet
committed freed blocks during initialization of a buddy page. However
ext4_mb_free_metadata() makes sure buddy page is already loaded and takes a
reference to it so it cannot happen that ext4_mb_init_cache() is called
when efd list is non-empty. Just remove the
ext4_mb_generate_from_freelist() call.
Fixes: 7a2fcbf7f85('ext4: don't use blocks freed but not yet committed in buddy cache init')
Signed-off-by: Wang Jianjian <wangjianjian0@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/tencent_53CBCB1668358AE862684E453DF37B722008@xxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/mballoc.c | 39 ++++++---------------------------------
1 file changed, 6 insertions(+), 33 deletions(-)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -417,8 +417,6 @@ static const char * const ext4_groupinfo
static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
ext4_group_t group);
-static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
- ext4_group_t group);
static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
@@ -1361,17 +1359,17 @@ static int ext4_mb_init_cache(struct pag
* We place the buddy block and bitmap block
* close together
*/
+ grinfo = ext4_get_group_info(sb, group);
+ if (!grinfo) {
+ err = -EFSCORRUPTED;
+ goto out;
+ }
if ((first_block + i) & 1) {
/* this is block of buddy */
BUG_ON(incore == NULL);
mb_debug(sb, "put buddy for group %u in page %lu/%x\n",
group, page->index, i * blocksize);
trace_ext4_mb_buddy_bitmap_load(sb, group);
- grinfo = ext4_get_group_info(sb, group);
- if (!grinfo) {
- err = -EFSCORRUPTED;
- goto out;
- }
grinfo->bb_fragments = 0;
memset(grinfo->bb_counters, 0,
sizeof(*grinfo->bb_counters) *
@@ -1398,7 +1396,7 @@ static int ext4_mb_init_cache(struct pag
/* mark all preallocated blks used in in-core bitmap */
ext4_mb_generate_from_pa(sb, data, group);
- ext4_mb_generate_from_freelist(sb, data, group);
+ WARN_ON_ONCE(!RB_EMPTY_ROOT(&grinfo->bb_free_root));
ext4_unlock_group(sb, group);
/* set incore so that the buddy information can be
@@ -4959,31 +4957,6 @@ try_group_pa:
}
/*
- * the function goes through all block freed in the group
- * but not yet committed and marks them used in in-core bitmap.
- * buddy must be generated from this bitmap
- * Need to be called with the ext4 group lock held
- */
-static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
- ext4_group_t group)
-{
- struct rb_node *n;
- struct ext4_group_info *grp;
- struct ext4_free_data *entry;
-
- grp = ext4_get_group_info(sb, group);
- if (!grp)
- return;
- n = rb_first(&(grp->bb_free_root));
-
- while (n) {
- entry = rb_entry(n, struct ext4_free_data, efd_node);
- mb_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count);
- n = rb_next(n);
- }
-}
-
-/*
* the function goes through all preallocation in this group and marks them
* used in in-core bitmap. buddy must be generated from this bitmap
* Need to be called with ext4 group lock held
Patches currently in stable-queue which might be from wangjianjian0@xxxxxxxxxxx are
queue-6.6/ext4-no-need-to-generate-from-free-list-in-mballoc.patch
