The patch below does not apply to the 6.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.5.y git checkout FETCH_HEAD git cherry-pick -x ebf6cb7c6e1241984f75f29f1bdbfa2fe7168f88 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023112415-stabilize-splashy-9350@gregkh' --subject-prefix 'PATCH 6.5.y' HEAD^..

Possible dependencies:

ebf6cb7c6e12 ("ext4: no need to generate from free list in mballoc") ad635507b5b2 ("ext4: remove unnecessary return for void function")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ebf6cb7c6e1241984f75f29f1bdbfa2fe7168f88 Mon Sep 17 00:00:00 2001 From: Wang Jianjian wangjianjian0@foxmail.com Date: Thu, 24 Aug 2023 23:56:31 +0800 Subject: [PATCH] ext4: no need to generate from free list in mballoc

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@foxmail.com Link: https://lore.kernel.org/r/tencent_53CBCB1668358AE862684E453DF37B722008@qq.co... Signed-off-by: Theodore Ts'o tytso@mit.edu Cc: stable@kernel.org

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 1d65c738c4c9..6e304c18d390 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -417,8 +417,6 @@ static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {

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 page *page, char *incore, gfp_t gfp) * 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 page *page, char *incore, gfp_t gfp)

/* 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 @@ -4950,31 +4948,6 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac) return false; }

-/* - * 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