bcachefs: Some fixes for building in userspace

userspace allocators don't align allocations as nicely as kernel
allocators, which meant that in some cases we weren't allocating big
enough bvec arrays - just make the calculations more rigorous and
explicit to fix it.

5 files changed, 25 insertions, 7 deletions

diff --git a/fs/bcachefs/bset.c b/fs/bcachefs/bset.c
index 2b1460f55aae..c631e30aca53 100644
--- a/fs/bcachefs/bset.c
+++ b/fs/bcachefs/bset.c
@@ -1689,7 +1689,7 @@ struct bkey_packed *bch2_btree_node_iter_prev_filter(struct btree_node_iter *ite
 	struct bkey_packed *orig_pos = bch2_btree_node_iter_peek_all(iter, b);
 	struct btree_node_iter_set *set;
 	struct bset_tree *t;
-	unsigned end;
+	unsigned end = 0;
 
 	bch2_btree_node_iter_verify(iter, b);
 
diff --git a/fs/bcachefs/btree_io.c b/fs/bcachefs/btree_io.c
index aee5dba0e1db..beab463b51e1 100644
--- a/fs/bcachefs/btree_io.c
+++ b/fs/bcachefs/btree_io.c
@@ -1424,7 +1424,9 @@ void bch2_btree_node_read(struct bch_fs *c, struct btree *b,
 
 	ca = bch_dev_bkey_exists(c, pick.ptr.dev);
 
-	bio = bio_alloc_bioset(GFP_NOIO, btree_pages(c), &c->btree_bio);
+	bio = bio_alloc_bioset(GFP_NOIO, buf_pages(b->data,
+						   btree_bytes(c)),
+			       &c->btree_bio);
 	rb = container_of(bio, struct btree_read_bio, bio);
 	rb->c			= c;
 	rb->start_time		= local_clock();
@@ -1879,7 +1881,9 @@ void __bch2_btree_node_write(struct bch_fs *c, struct btree *b,
 
 	trace_btree_write(b, bytes_to_write, sectors_to_write);
 
-	wbio = container_of(bio_alloc_bioset(GFP_NOIO, 1 << order, &c->btree_bio),
+	wbio = container_of(bio_alloc_bioset(GFP_NOIO,
+				buf_pages(data, sectors_to_write << 9),
+				&c->btree_bio),
 			    struct btree_write_bio, wbio.bio);
 	wbio_init(&wbio->wbio.bio);
 	wbio->data			= data;
diff --git a/fs/bcachefs/debug.c b/fs/bcachefs/debug.c
index 50aac3a4a818..f69d76ec1e78 100644
--- a/fs/bcachefs/debug.c
+++ b/fs/bcachefs/debug.c
@@ -62,7 +62,9 @@ void __bch2_btree_verify(struct bch_fs *c, struct btree *b)
 	if (!bch2_dev_get_ioref(ca, READ))
 		return;
 
-	bio = bio_alloc_bioset(GFP_NOIO, btree_pages(c), &c->btree_bio);
+	bio = bio_alloc_bioset(GFP_NOIO,
+			buf_pages(n_sorted, btree_bytes(c)),
+			&c->btree_bio);
 	bio_set_dev(bio, ca->disk_sb.bdev);
 	bio->bi_opf		= REQ_OP_READ|REQ_META;
 	bio->bi_iter.bi_sector	= pick.ptr.offset;
diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c
index acf7db721fad..0cb1bc3c0df7 100644
--- a/fs/bcachefs/journal_io.c
+++ b/fs/bcachefs/journal_io.c
@@ -429,7 +429,6 @@ static int journal_read_bucket(struct bch_dev *ca,
 {
 	struct bch_fs *c = ca->fs;
 	struct journal_device *ja = &ca->journal;
-	struct bio *bio = ja->bio;
 	struct jset *j = NULL;
 	unsigned sectors, sectors_read = 0;
 	u64 offset = bucket_to_sector(ca, ja->buckets[bucket]),
@@ -441,10 +440,14 @@ static int journal_read_bucket(struct bch_dev *ca,
 
 	while (offset < end) {
 		if (!sectors_read) {
-reread:			sectors_read = min_t(unsigned,
+			struct bio *bio;
+reread:
+			sectors_read = min_t(unsigned,
 				end - offset, buf->size >> 9);
 
-			bio_reset(bio);
+			bio = bio_kmalloc(GFP_KERNEL,
+					  buf_pages(buf->data,
+						    sectors_read << 9));
 			bio_set_dev(bio, ca->disk_sb.bdev);
 			bio->bi_iter.bi_sector	= offset;
 			bio->bi_iter.bi_size	= sectors_read << 9;
@@ -452,6 +455,7 @@ reread:			sectors_read = min_t(unsigned,
 			bch2_bio_map(bio, buf->data);
 
 			ret = submit_bio_wait(bio);
+			bio_put(bio);
 
 			if (bch2_dev_io_err_on(ret, ca,
 					       "journal read from sector %llu",
diff --git a/fs/bcachefs/util.h b/fs/bcachefs/util.h
index 66febaea031a..433ba9c14dcb 100644
--- a/fs/bcachefs/util.h
+++ b/fs/bcachefs/util.h
@@ -83,6 +83,14 @@ struct closure;
 	(__builtin_types_compatible_p(typeof(_val), _type) ||		\
 	 __builtin_types_compatible_p(typeof(_val), const _type))
 
+/* Userspace doesn't align allocations as nicely as the kernel allocators: */
+static inline size_t buf_pages(void *p, size_t len)
+{
+	return DIV_ROUND_UP(len +
+			    ((unsigned long) p & (PAGE_SIZE - 1)),
+			    PAGE_SIZE);
+}
+
 static inline void vpfree(void *p, size_t size)
 {
 	if (is_vmalloc_addr(p))