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Message-ID: <8d7022f6-8fcc-469c-b43c-64fb30dc0595@huawei.com>
Date: Mon, 15 Apr 2024 09:54:57 +0800
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH] bcachefs: bch_member.btree_allocated_bitmap
Content-Language: en-US
To: Kent Overstreet <kent.overstreet@linux.dev>
CC: <linux-bcachefs@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
References: <20240413215723.1543569-1-kent.overstreet@linux.dev>
 <d7e9f196-c3bd-47ca-87fb-b21f28f1680a@huawei.com>
 <ciib47ljt667csv2m37wj2ci72tps3lvsjwedclpyl7qqoaic2@3tl2vbzh2osg>
From: Hongbo Li <lihongbo22@huawei.com>
In-Reply-To: <ciib47ljt667csv2m37wj2ci72tps3lvsjwedclpyl7qqoaic2@3tl2vbzh2osg>
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On 2024/4/15 9:30, Kent Overstreet wrote:
> On Mon, Apr 15, 2024 at 09:12:11AM +0800, Hongbo Li wrote:
>>
>>
>> On 2024/4/14 5:57, Kent Overstreet wrote:
>>> For those interested, this is a good tour of the facilities for rolling
>>> out new on disk format features.
>>>
>>> -- >8 --
>>>
>>> This adds a small (64 bit) per-device bitmap that tracks ranges that
>>> have btree nodes, for accelerating btree node scan if it is ever needed.
>>>
>>> - New helpers, bch2_dev_btree_bitmap_marked() and
>>>     bch2_dev_bitmap_mark(), for checking and updating the bitmap
>>>
>>> - Interior btree update path updates the bitmaps when required
>>>
>>> - The check_allocations pass has a new fsck_err check,
>>>     btree_bitmap_not_marked
>>>
>>> - New on disk format version, mi_btree_mitmap, which indicates the new
>>>     bitmap is present
>>>
>>> - Upgrade table lists the required recovery pass and expected fsck error
>>>
>>> - Btree node scan uses the bitmap to skip ranges if we're on the new
>>>     version
>>>
>>> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
>>> ---
>>>    fs/bcachefs/bcachefs_format.h       |  7 ++--
>>>    fs/bcachefs/btree_gc.c              | 13 +++++++
>>>    fs/bcachefs/btree_node_scan.c       |  9 +++--
>>>    fs/bcachefs/btree_update_interior.c | 24 +++++++++++++
>>>    fs/bcachefs/sb-downgrade.c          |  5 ++-
>>>    fs/bcachefs/sb-errors_types.h       |  3 +-
>>>    fs/bcachefs/sb-members.c            | 53 +++++++++++++++++++++++++++++
>>>    fs/bcachefs/sb-members.h            | 21 ++++++++++++
>>>    fs/bcachefs/sb-members_types.h      |  2 ++
>>>    9 files changed, 131 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
>>> index 9480f1b44f07..085987435a5e 100644
>>> --- a/fs/bcachefs/bcachefs_format.h
>>> +++ b/fs/bcachefs/bcachefs_format.h
>>> @@ -578,7 +578,8 @@ struct bch_member {
>>>    	__le64			nbuckets;	/* device size */
>>>    	__le16			first_bucket;   /* index of first bucket used */
>>>    	__le16			bucket_size;	/* sectors */
>>> -	__le32			pad;
>>> +	__u8			btree_bitmap_shift;
>>> +	__u8			pad[3];
>>>    	__le64			last_mount;	/* time_t */
>>>    	__le64			flags;
>>> @@ -587,6 +588,7 @@ struct bch_member {
>>>    	__le64			errors_at_reset[BCH_MEMBER_ERROR_NR];
>>>    	__le64			errors_reset_time;
>>>    	__le64			seq;
>>> +	__le64			btree_allocated_bitmap;
>>>    };
>>>    #define BCH_MEMBER_V1_BYTES	56
>>> @@ -876,7 +878,8 @@ struct bch_sb_field_downgrade {
>>>    	x(rebalance_work,		BCH_VERSION(1,  3))		\
>>>    	x(member_seq,			BCH_VERSION(1,  4))		\
>>>    	x(subvolume_fs_parent,		BCH_VERSION(1,  5))		\
>>> -	x(btree_subvolume_children,	BCH_VERSION(1,  6))
>>> +	x(btree_subvolume_children,	BCH_VERSION(1,  6))		\
>>> +	x(mi_btree_bitmap,		BCH_VERSION(1,  7))
>>>    enum bcachefs_metadata_version {
>>>    	bcachefs_metadata_version_min = 9,
>>> diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
>>> index 10c41cf89212..a77c723a9cef 100644
>>> --- a/fs/bcachefs/btree_gc.c
>>> +++ b/fs/bcachefs/btree_gc.c
>>> @@ -822,6 +822,7 @@ static int bch2_gc_mark_key(struct btree_trans *trans, enum btree_id btree_id,
>>>    	struct bch_fs *c = trans->c;
>>>    	struct bkey deleted = KEY(0, 0, 0);
>>>    	struct bkey_s_c old = (struct bkey_s_c) { &deleted, NULL };
>>> +	struct printbuf buf = PRINTBUF;
>>>    	int ret = 0;
>>>    	deleted.p = k->k->p;
>>> @@ -842,11 +843,23 @@ static int bch2_gc_mark_key(struct btree_trans *trans, enum btree_id btree_id,
>>>    	if (ret)
>>>    		goto err;
>>> +	if (mustfix_fsck_err_on(level && !bch2_dev_btree_bitmap_marked(c, *k),
>>> +				c, btree_bitmap_not_marked,
>>> +				"btree ptr not marked in member info btree allocated bitmap\n  %s",
>>> +				(bch2_bkey_val_to_text(&buf, c, *k),
>>> +				 buf.buf))) {
>>> +		mutex_lock(&c->sb_lock);
>>> +		bch2_dev_btree_bitmap_mark(c, *k);
>>> +		bch2_write_super(c);
>>> +		mutex_unlock(&c->sb_lock);
>>> +	}
>>> +
>>>    	ret = commit_do(trans, NULL, NULL, 0,
>>>    			bch2_key_trigger(trans, btree_id, level, old,
>>>    					 unsafe_bkey_s_c_to_s(*k), BTREE_TRIGGER_gc));
>>>    fsck_err:
>>>    err:
>>> +	printbuf_exit(&buf);
>>>    	bch_err_fn(c, ret);
>>>    	return ret;
>>>    }
>>> diff --git a/fs/bcachefs/btree_node_scan.c b/fs/bcachefs/btree_node_scan.c
>>> index 20f2b37c4474..866bd278439f 100644
>>> --- a/fs/bcachefs/btree_node_scan.c
>>> +++ b/fs/bcachefs/btree_node_scan.c
>>> @@ -205,8 +205,13 @@ static int read_btree_nodes_worker(void *p)
>>>    				last_print = jiffies;
>>>    			}
>>> -			try_read_btree_node(w->f, ca, bio, buf,
>>> -					    bucket * ca->mi.bucket_size + bucket_offset);
>>> +			u64 sector = bucket * ca->mi.bucket_size + bucket_offset;
>>> +
>>> +			if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_mi_btree_bitmap &&
>>> +			    !bch2_dev_btree_bitmap_marked_sectors(ca, sector, btree_sectors(c)))
>>> +				continue;
>>> +
>>> +			try_read_btree_node(w->f, ca, bio, buf, sector);
>>>    		}
>>>    err:
>>>    	bio_put(bio);
>>> diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c
>>> index 593241b15aa8..12ce6287416f 100644
>>> --- a/fs/bcachefs/btree_update_interior.c
>>> +++ b/fs/bcachefs/btree_update_interior.c
>>> @@ -21,6 +21,7 @@
>>>    #include "keylist.h"
>>>    #include "recovery_passes.h"
>>>    #include "replicas.h"
>>> +#include "sb-members.h"
>>>    #include "super-io.h"
>>>    #include "trace.h"
>>> @@ -644,6 +645,26 @@ static int btree_update_nodes_written_trans(struct btree_trans *trans,
>>>    	return 0;
>>>    }
>>> +static bool btree_update_new_nodes_marked_sb(struct btree_update *as)
>>> +{
>>> +	for_each_keylist_key(&as->new_keys, k)
>>> +		if (!bch2_dev_btree_bitmap_marked(as->c, bkey_i_to_s_c(k)))
>>> +			return false;
>>> +	return true;
>>> +}
>>> +
>>> +static void btree_update_new_nodes_mark_sb(struct btree_update *as)
>>> +{
>>> +	struct bch_fs *c = as->c;
>>> +
>>> +	mutex_lock(&c->sb_lock);
>>> +	for_each_keylist_key(&as->new_keys, k)
>>> +		bch2_dev_btree_bitmap_mark(c, bkey_i_to_s_c(k));
>>> +
>>> +	bch2_write_super(c);
>>> +	mutex_unlock(&c->sb_lock);
>>> +}
>>> +
>>>    static void btree_update_nodes_written(struct btree_update *as)
>>>    {
>>>    	struct bch_fs *c = as->c;
>>> @@ -664,6 +685,9 @@ static void btree_update_nodes_written(struct btree_update *as)
>>>    	if (ret)
>>>    		goto err;
>>> +	if (!btree_update_new_nodes_marked_sb(as))
>>> +		btree_update_new_nodes_mark_sb(as);
>>> +
>>>    	/*
>>>    	 * Wait for any in flight writes to finish before we free the old nodes
>>>    	 * on disk:
>>> diff --git a/fs/bcachefs/sb-downgrade.c b/fs/bcachefs/sb-downgrade.c
>>> index 56ac8f35cdc3..90b06f8aa1df 100644
>>> --- a/fs/bcachefs/sb-downgrade.c
>>> +++ b/fs/bcachefs/sb-downgrade.c
>>> @@ -51,7 +51,10 @@
>>>    	  BCH_FSCK_ERR_subvol_fs_path_parent_wrong)		\
>>>    	x(btree_subvolume_children,				\
>>>    	  BIT_ULL(BCH_RECOVERY_PASS_check_subvols),		\
>>> -	  BCH_FSCK_ERR_subvol_children_not_set)
>>> +	  BCH_FSCK_ERR_subvol_children_not_set)			\
>>> +	x(mi_btree_bitmap,					\
>>> +	  BIT_ULL(BCH_RECOVERY_PASS_check_allocations),		\
>>> +	  BCH_FSCK_ERR_btree_bitmap_not_marked)
>>>    #define DOWNGRADE_TABLE()
>>> diff --git a/fs/bcachefs/sb-errors_types.h b/fs/bcachefs/sb-errors_types.h
>>> index d7d609131030..5b600c6d7aca 100644
>>> --- a/fs/bcachefs/sb-errors_types.h
>>> +++ b/fs/bcachefs/sb-errors_types.h
>>> @@ -270,7 +270,8 @@
>>>    	x(btree_ptr_v2_min_key_bad,				262)	\
>>>    	x(btree_root_unreadable_and_scan_found_nothing,		263)	\
>>>    	x(snapshot_node_missing,				264)	\
>>> -	x(dup_backpointer_to_bad_csum_extent,			265)
>>> +	x(dup_backpointer_to_bad_csum_extent,			265)	\
>>> +	x(btree_bitmap_not_marked,				266)
>>>    enum bch_sb_error_id {
>>>    #define x(t, n) BCH_FSCK_ERR_##t = n,
>>> diff --git a/fs/bcachefs/sb-members.c b/fs/bcachefs/sb-members.c
>>> index 9b7a2f300182..d5937aba0910 100644
>>> --- a/fs/bcachefs/sb-members.c
>>> +++ b/fs/bcachefs/sb-members.c
>>> @@ -1,6 +1,7 @@
>>>    // SPDX-License-Identifier: GPL-2.0
>>>    #include "bcachefs.h"
>>> +#include "btree_cache.h"
>>>    #include "disk_groups.h"
>>>    #include "opts.h"
>>>    #include "replicas.h"
>>> @@ -378,3 +379,55 @@ void bch2_dev_errors_reset(struct bch_dev *ca)
>>>    	bch2_write_super(c);
>>>    	mutex_unlock(&c->sb_lock);
>>>    }
>>> +
>>> +/*
>>> + * Per member "range has btree nodes" bitmap:
>>> + *
>>> + * This is so that if we ever have to run the btree node scan to repair we don't
>>> + * have to scan full devices:
>>> + */
>>> +
>>> +bool bch2_dev_btree_bitmap_marked(struct bch_fs *c, struct bkey_s_c k)
>>> +{
>>> +	bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr)
>>> +		if (!bch2_dev_btree_bitmap_marked_sectors(bch2_dev_bkey_exists(c, ptr->dev),
>>> +							  ptr->offset, btree_sectors(c)))
>>> +			return false;
>>> +	return true;
>>> +}
>>> +
>>> +static void __bch2_dev_btree_bitmap_mark(struct bch_sb_field_members_v2 *mi, unsigned dev,
>>> +				u64 start, unsigned sectors)
>>> +{
>>> +	struct bch_member *m = __bch2_members_v2_get_mut(mi, dev);
>>> +	u64 bitmap = le64_to_cpu(m->btree_allocated_bitmap);
>>> +
>>> +	u64 end = start + sectors;
>>> +
>>> +	int resize = ilog2(roundup_pow_of_two(end)) - (m->btree_bitmap_shift + 6);
>>> +	if (resize > 0) {
>>> +		u64 new_bitmap = 0;
>>> +
>>> +		for (unsigned i = 0; i < 64; i++)
>>> +			if (bitmap & BIT_ULL(i))
>>> +				new_bitmap |= BIT_ULL(i >> resize);
>>> +		bitmap = new_bitmap;
>>> +		m->btree_bitmap_shift += resize;
>>> +	}
>>> +
>>> +	for (unsigned bit = sectors >> m->btree_bitmap_shift;
>>> +	     bit << m->btree_bitmap_shift < end;
>>> +	     bit++)
>>> +		bitmap |= BIT_ULL(bit);
>>> +
>>> +	m->btree_allocated_bitmap = cpu_to_le64(bitmap);
>>> +}
>>> +
>>> +void bch2_dev_btree_bitmap_mark(struct bch_fs *c, struct bkey_s_c k)
>>> +{
>>> +	lockdep_assert_held(&c->sb_lock);
>>> +
>>> +	struct bch_sb_field_members_v2 *mi = bch2_sb_field_get(c->disk_sb.sb, members_v2);
>>> +	bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr)
>>> +		__bch2_dev_btree_bitmap_mark(mi, ptr->dev, ptr->offset, btree_sectors(c));
>>> +}
>>> diff --git a/fs/bcachefs/sb-members.h b/fs/bcachefs/sb-members.h
>>> index bc3bcfef7b3a..8bbad30a4370 100644
>>> --- a/fs/bcachefs/sb-members.h
>>> +++ b/fs/bcachefs/sb-members.h
>>> @@ -3,6 +3,7 @@
>>>    #define _BCACHEFS_SB_MEMBERS_H
>>>    #include "darray.h"
>>> +#include "bkey_types.h"
>>>    extern char * const bch2_member_error_strs[];
>>> @@ -234,6 +235,8 @@ static inline struct bch_member_cpu bch2_mi_to_cpu(struct bch_member *mi)
>>>    			: 1,
>>>    		.freespace_initialized = BCH_MEMBER_FREESPACE_INITIALIZED(mi),
>>>    		.valid		= bch2_member_alive(mi),
>>> +		.btree_bitmap_shift	= mi->btree_bitmap_shift,
>>> +		.btree_allocated_bitmap = le64_to_cpu(mi->btree_allocated_bitmap),
>>>    	};
>>>    }
>>> @@ -242,4 +245,22 @@ void bch2_sb_members_from_cpu(struct bch_fs *);
>>>    void bch2_dev_io_errors_to_text(struct printbuf *, struct bch_dev *);
>>>    void bch2_dev_errors_reset(struct bch_dev *);
>>> +static inline bool bch2_dev_btree_bitmap_marked_sectors(struct bch_dev *ca, u64 start, unsigned sectors)
>>> +{
>>> +	u64 end = start + sectors;
>>> +
>>> +	if (end > 64 << ca->mi.btree_bitmap_shift)
>>> +		return false;
>>> +
>>> +	for (unsigned bit = sectors >> ca->mi.btree_bitmap_shift;
>>> +	     bit << ca->mi.btree_bitmap_shift < end;
>>> +	     bit++)
>>> +		if (!(ca->mi.btree_allocated_bitmap & BIT_ULL(bit)))
>> Should it be transferred by le64_to_cpu?
> 
> no, ca->mi is bch_member_cpu, a different type that has everything in
> native byte order

Sorry, I made a mistake in reading it.

```c
struct bch_dev {
..
     struct bch_member_cpu   mi;
..
```