This is a note to let you know that I've just added the patch titled btrfs: add extent allocator hook to decide to allocate chunk or not to the 5.16-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: btrfs-add-extent-allocator-hook-to-decide-to-allocate-chunk-or-not.patch and it can be found in the queue-5.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 50475cd57706359d6cc652be88369dace7a4c2eb Mon Sep 17 00:00:00 2001 From: Naohiro Aota <naohiro.aota@xxxxxxx> Date: Wed, 8 Dec 2021 00:35:48 +0900 Subject: btrfs: add extent allocator hook to decide to allocate chunk or not From: Naohiro Aota <naohiro.aota@xxxxxxx> commit 50475cd57706359d6cc652be88369dace7a4c2eb upstream. Introduce a new hook for an extent allocator policy. With the new hook, a policy can decide to allocate a new block group or not. If not, it will return -ENOSPC, so btrfs_reserve_extent() will cut the allocation size in half and retry the allocation if min_alloc_size is large enough. The hook has a place holder and will be replaced with the real implementation in the next patch. CC: stable@xxxxxxxxxxxxxxx # 5.16 Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/extent-tree.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3947,6 +3947,19 @@ static void found_extent(struct find_fre } } +static bool can_allocate_chunk(struct btrfs_fs_info *fs_info, + struct find_free_extent_ctl *ffe_ctl) +{ + switch (ffe_ctl->policy) { + case BTRFS_EXTENT_ALLOC_CLUSTERED: + return true; + case BTRFS_EXTENT_ALLOC_ZONED: + return true; + default: + BUG(); + } +} + static int chunk_allocation_failed(struct find_free_extent_ctl *ffe_ctl) { switch (ffe_ctl->policy) { @@ -4034,6 +4047,10 @@ static int find_free_extent_update_loop( struct btrfs_trans_handle *trans; int exist = 0; + /*Check if allocation policy allows to create a new chunk */ + if (!can_allocate_chunk(fs_info, ffe_ctl)) + return -ENOSPC; + trans = current->journal_info; if (trans) exist = 1; Patches currently in stable-queue which might be from naohiro.aota@xxxxxxx are queue-5.16/btrfs-zoned-unset-dedicated-block-group-on-allocation-failure.patch queue-5.16/btrfs-add-extent-allocator-hook-to-decide-to-allocate-chunk-or-not.patch queue-5.16/btrfs-zoned-fix-chunk-allocation-condition-for-zoned-allocator.patch queue-5.16/btrfs-zoned-cache-reported-zone-during-mount.patch