bcachefs: BCH_MEMBER_RESIZE_ON_MOUNT

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/recovery.c

@@ -734,11 +734,6 @@ int bch2_fs_recovery(struct bch_fs *c)
 		c->opts.read_only = true;
 	}
 
-	if (c->sb.features & BIT_ULL(BCH_FEATURE_small_image)) {
-		bch_info(c, "filesystem is an unresized image file, mounting ro");
-		c->opts.read_only = true;
-	}
-
 	mutex_lock(&c->sb_lock);
 	struct bch_sb_field_ext *ext = bch2_sb_field_get(c->disk_sb.sb, ext);
 	bool write_sb = false;
@@ -892,6 +887,17 @@ int bch2_fs_recovery(struct bch_fs *c)
 	if (ret)
 		goto err;
 
+	ret = bch2_fs_resize_on_mount(c);
+	if (ret) {
+		up_write(&c->state_lock);
+		goto err;
+	}
+
+	if (c->sb.features & BIT_ULL(BCH_FEATURE_small_image)) {
+		bch_info(c, "filesystem is an unresized image file, mounting ro");
+		c->opts.read_only = true;
+	}
+
 	if (!c->opts.read_only &&
 	    (c->sb.features & BIT_ULL(BCH_FEATURE_no_alloc_info))) {
 		bch_info(c, "mounting a filesystem with no alloc info read-write; will recreate");
@@ -954,6 +960,8 @@ int bch2_fs_recovery(struct bch_fs *c)
 	set_bit(BCH_FS_btree_running, &c->flags);
 
 	ret = bch2_sb_set_upgrade_extra(c);
+	if (ret)
+		goto err;
 
 	ret = bch2_run_recovery_passes(c);
 	if (ret)

fs/bcachefs/sb-members.c

@@ -294,6 +294,7 @@ static void member_to_text(struct printbuf *out,
 
 	prt_printf(out, "Discard:\t%llu\n", BCH_MEMBER_DISCARD(&m));
 	prt_printf(out, "Freespace initialized:\t%llu\n", BCH_MEMBER_FREESPACE_INITIALIZED(&m));
+	prt_printf(out, "Resize on mount:\t%llu\n", BCH_MEMBER_RESIZE_ON_MOUNT(&m));
 
 	printbuf_indent_sub(out, 2);
 }

fs/bcachefs/sb-members.h

@@ -353,6 +353,7 @@ static inline struct bch_member_cpu bch2_mi_to_cpu(struct bch_member *mi)
 			? BCH_MEMBER_DURABILITY(mi) - 1
 			: 1,
 		.freespace_initialized = BCH_MEMBER_FREESPACE_INITIALIZED(mi),
+		.resize_on_mount	= BCH_MEMBER_RESIZE_ON_MOUNT(mi),
 		.valid		= bch2_member_alive(mi),
 		.btree_bitmap_shift	= mi->btree_bitmap_shift,
 		.btree_allocated_bitmap = le64_to_cpu(mi->btree_allocated_bitmap),

fs/bcachefs/sb-members_format.h

@@ -88,6 +88,8 @@ LE64_BITMASK(BCH_MEMBER_GROUP,		struct bch_member, flags, 20, 28)
 LE64_BITMASK(BCH_MEMBER_DURABILITY,	struct bch_member, flags, 28, 30)
 LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
 					struct bch_member, flags, 30, 31)
+LE64_BITMASK(BCH_MEMBER_RESIZE_ON_MOUNT,
+					struct bch_member, flags, 31, 32)
 
 #if 0
 LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS,	struct bch_member, flags[1], 0,  20);

fs/bcachefs/sb-members_types.h

@@ -13,6 +13,7 @@ struct bch_member_cpu {
 	u8			data_allowed;
 	u8			durability;
 	u8			freespace_initialized;
+	u8			resize_on_mount;
 	u8			valid;
 	u8			btree_bitmap_shift;
 	u64			btree_allocated_bitmap;

fs/bcachefs/super.c

@@ -1141,6 +1141,9 @@ int bch2_fs_start(struct bch_fs *c)
 	for_each_online_member(c, ca)
 		bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx)->last_mount = cpu_to_le64(now);
 
+	/*
+	 * Dno't write superblock yet: recovery might have to downgrade
+	 */
 	mutex_unlock(&c->sb_lock);
 
 	for_each_rw_member(c, ca)
@@ -2039,6 +2042,18 @@ int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
 	return 0;
 }
 
+static int __bch2_dev_resize_alloc(struct bch_dev *ca, u64 old_nbuckets, u64 new_nbuckets)
+{
+	struct bch_fs *c = ca->fs;
+	u64 v[3] = { new_nbuckets - old_nbuckets, 0, 0 };
+
+	return bch2_trans_commit_do(ca->fs, NULL, NULL, 0,
+			bch2_disk_accounting_mod2(trans, false, v, dev_data_type,
+						  .dev = ca->dev_idx,
+						  .data_type = BCH_DATA_free)) ?:
+		bch2_dev_freespace_init(c, ca, old_nbuckets, new_nbuckets);
+}
+
 int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 {
 	struct bch_member *m;
@@ -2086,13 +2101,7 @@ int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 	mutex_unlock(&c->sb_lock);
 
 	if (ca->mi.freespace_initialized) {
-		u64 v[3] = { nbuckets - old_nbuckets, 0, 0 };
-
-		ret   = bch2_trans_commit_do(ca->fs, NULL, NULL, 0,
-				bch2_disk_accounting_mod2(trans, false, v, dev_data_type,
-							  .dev = ca->dev_idx,
-							  .data_type = BCH_DATA_free)) ?:
-			bch2_dev_freespace_init(c, ca, old_nbuckets, nbuckets);
+		ret = __bch2_dev_resize_alloc(ca, old_nbuckets, nbuckets);
 		if (ret)
 			goto err;
 	}
@@ -2103,6 +2112,47 @@ int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 	return ret;
 }
 
+int bch2_fs_resize_on_mount(struct bch_fs *c)
+{
+	for_each_online_member(c, ca) {
+		u64 old_nbuckets = ca->mi.nbuckets;
+		u64 new_nbuckets = div64_u64(get_capacity(ca->disk_sb.bdev->bd_disk),
+					 ca->mi.bucket_size);
+
+		if (ca->mi.resize_on_mount &&
+		    new_nbuckets > ca->mi.nbuckets) {
+			bch_info(ca, "resizing to size %llu", new_nbuckets * ca->mi.bucket_size);
+			int ret = bch2_dev_buckets_resize(c, ca, new_nbuckets);
+			bch_err_fn(ca, ret);
+			if (ret) {
+				percpu_ref_put(&ca->io_ref[READ]);
+				up_write(&c->state_lock);
+				return ret;
+			}
+
+			mutex_lock(&c->sb_lock);
+			struct bch_member *m =
+				bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
+			m->nbuckets = cpu_to_le64(new_nbuckets);
+			SET_BCH_MEMBER_RESIZE_ON_MOUNT(m, false);
+
+			c->disk_sb.sb->features[0] &= ~cpu_to_le64(BIT_ULL(BCH_FEATURE_small_image));
+			bch2_write_super(c);
+			mutex_unlock(&c->sb_lock);
+
+			if (ca->mi.freespace_initialized) {
+				ret = __bch2_dev_resize_alloc(ca, old_nbuckets, new_nbuckets);
+				if (ret) {
+					percpu_ref_put(&ca->io_ref[READ]);
+					up_write(&c->state_lock);
+					return ret;
+				}
+			}
+		}
+	}
+	return 0;
+}
+
 /* return with ref on ca->ref: */
 struct bch_dev *bch2_dev_lookup(struct bch_fs *c, const char *name)
 {

fs/bcachefs/super.h

@@ -35,6 +35,8 @@ void bch2_fs_read_only(struct bch_fs *);
 int bch2_fs_read_write(struct bch_fs *);
 int bch2_fs_read_write_early(struct bch_fs *);
 
+int bch2_fs_resize_on_mount(struct bch_fs *);
+
 void __bch2_fs_stop(struct bch_fs *);
 void bch2_fs_free(struct bch_fs *);
 void bch2_fs_stop(struct bch_fs *);