bcachefs: Initial commit

Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.

Website: https://bcachefs.org

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

1 files changed, 517 insertions, 0 deletions

diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
new file mode 100644
index 000000000000..2d635555bffb
--- /dev/null
+++ b/fs/bcachefs/inode.c
@@ -0,0 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "bkey_methods.h"
+#include "btree_update.h"
+#include "error.h"
+#include "extents.h"
+#include "inode.h"
+#include "io.h"
+#include "keylist.h"
+
+#include <linux/random.h>
+
+#include <asm/unaligned.h>
+
+#define FIELD_BYTES()						\
+
+static const u8 byte_table[8] = { 1, 2, 3, 4, 6, 8, 10, 13 };
+static const u8 bits_table[8] = {
+	1  * 8 - 1,
+	2  * 8 - 2,
+	3  * 8 - 3,
+	4  * 8 - 4,
+	6  * 8 - 5,
+	8  * 8 - 6,
+	10 * 8 - 7,
+	13 * 8 - 8,
+};
+
+static int inode_encode_field(u8 *out, u8 *end, u64 hi, u64 lo)
+{
+	__be64 in[2] = { cpu_to_be64(hi), cpu_to_be64(lo), };
+	unsigned shift, bytes, bits = likely(!hi)
+		? fls64(lo)
+		: fls64(hi) + 64;
+
+	for (shift = 1; shift <= 8; shift++)
+		if (bits < bits_table[shift - 1])
+			goto got_shift;
+
+	BUG();
+got_shift:
+	bytes = byte_table[shift - 1];
+
+	BUG_ON(out + bytes > end);
+
+	memcpy(out, (u8 *) in + 16 - bytes, bytes);
+	*out |= (1 << 8) >> shift;
+
+	return bytes;
+}
+
+static int inode_decode_field(const u8 *in, const u8 *end,
+			      u64 out[2], unsigned *out_bits)
+{
+	__be64 be[2] = { 0, 0 };
+	unsigned bytes, shift;
+	u8 *p;
+
+	if (in >= end)
+		return -1;
+
+	if (!*in)
+		return -1;
+
+	/*
+	 * position of highest set bit indicates number of bytes:
+	 * shift = number of bits to remove in high byte:
+	 */
+	shift	= 8 - __fls(*in); /* 1 <= shift <= 8 */
+	bytes	= byte_table[shift - 1];
+
+	if (in + bytes > end)
+		return -1;
+
+	p = (u8 *) be + 16 - bytes;
+	memcpy(p, in, bytes);
+	*p ^= (1 << 8) >> shift;
+
+	out[0] = be64_to_cpu(be[0]);
+	out[1] = be64_to_cpu(be[1]);
+	*out_bits = out[0] ? 64 + fls64(out[0]) : fls64(out[1]);
+
+	return bytes;
+}
+
+void bch2_inode_pack(struct bkey_inode_buf *packed,
+		     const struct bch_inode_unpacked *inode)
+{
+	u8 *out = packed->inode.v.fields;
+	u8 *end = (void *) &packed[1];
+	u8 *last_nonzero_field = out;
+	unsigned nr_fields = 0, last_nonzero_fieldnr = 0;
+
+	bkey_inode_init(&packed->inode.k_i);
+	packed->inode.k.p.inode		= inode->bi_inum;
+	packed->inode.v.bi_hash_seed	= inode->bi_hash_seed;
+	packed->inode.v.bi_flags	= cpu_to_le32(inode->bi_flags);
+	packed->inode.v.bi_mode		= cpu_to_le16(inode->bi_mode);
+
+#define BCH_INODE_FIELD(_name, _bits)					\
+	out += inode_encode_field(out, end, 0, inode->_name);		\
+	nr_fields++;							\
+									\
+	if (inode->_name) {						\
+		last_nonzero_field = out;				\
+		last_nonzero_fieldnr = nr_fields;			\
+	}
+
+	BCH_INODE_FIELDS()
+#undef  BCH_INODE_FIELD
+
+	out = last_nonzero_field;
+	nr_fields = last_nonzero_fieldnr;
+
+	set_bkey_val_bytes(&packed->inode.k, out - (u8 *) &packed->inode.v);
+	memset(out, 0,
+	       (u8 *) &packed->inode.v +
+	       bkey_val_bytes(&packed->inode.k) - out);
+
+	SET_INODE_NR_FIELDS(&packed->inode.v, nr_fields);
+
+	if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
+		struct bch_inode_unpacked unpacked;
+
+		int ret = bch2_inode_unpack(inode_i_to_s_c(&packed->inode),
+					   &unpacked);
+		BUG_ON(ret);
+		BUG_ON(unpacked.bi_inum		!= inode->bi_inum);
+		BUG_ON(unpacked.bi_hash_seed	!= inode->bi_hash_seed);
+		BUG_ON(unpacked.bi_mode		!= inode->bi_mode);
+
+#define BCH_INODE_FIELD(_name, _bits)	BUG_ON(unpacked._name != inode->_name);
+		BCH_INODE_FIELDS()
+#undef  BCH_INODE_FIELD
+	}
+}
+
+int bch2_inode_unpack(struct bkey_s_c_inode inode,
+		      struct bch_inode_unpacked *unpacked)
+{
+	const u8 *in = inode.v->fields;
+	const u8 *end = (void *) inode.v + bkey_val_bytes(inode.k);
+	u64 field[2];
+	unsigned fieldnr = 0, field_bits;
+	int ret;
+
+	unpacked->bi_inum	= inode.k->p.inode;
+	unpacked->bi_hash_seed	= inode.v->bi_hash_seed;
+	unpacked->bi_flags	= le32_to_cpu(inode.v->bi_flags);
+	unpacked->bi_mode	= le16_to_cpu(inode.v->bi_mode);
+
+#define BCH_INODE_FIELD(_name, _bits)					\
+	if (fieldnr++ == INODE_NR_FIELDS(inode.v)) {			\
+		unsigned offset = offsetof(struct bch_inode_unpacked, _name);\
+		memset((void *) unpacked + offset, 0,			\
+		       sizeof(*unpacked) - offset);			\
+		return 0;						\
+	}								\
+									\
+	ret = inode_decode_field(in, end, field, &field_bits);		\
+	if (ret < 0)							\
+		return ret;						\
+									\
+	if (field_bits > sizeof(unpacked->_name) * 8)			\
+		return -1;						\
+									\
+	unpacked->_name = field[1];					\
+	in += ret;
+
+	BCH_INODE_FIELDS()
+#undef  BCH_INODE_FIELD
+
+	/* XXX: signal if there were more fields than expected? */
+
+	return 0;
+}
+
+const char *bch2_inode_invalid(const struct bch_fs *c, struct bkey_s_c k)
+{
+	if (k.k->p.offset)
+		return "nonzero offset";
+
+	switch (k.k->type) {
+	case BCH_INODE_FS: {
+		struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
+		struct bch_inode_unpacked unpacked;
+
+		if (bkey_val_bytes(k.k) < sizeof(struct bch_inode))
+			return "incorrect value size";
+
+		if (k.k->p.inode < BLOCKDEV_INODE_MAX)
+			return "fs inode in blockdev range";
+
+		if (INODE_STR_HASH(inode.v) >= BCH_STR_HASH_NR)
+			return "invalid str hash type";
+
+		if (bch2_inode_unpack(inode, &unpacked))
+			return "invalid variable length fields";
+
+		if (unpacked.bi_data_checksum >= BCH_CSUM_OPT_NR + 1)
+			return "invalid data checksum type";
+
+		if (unpacked.bi_compression >= BCH_COMPRESSION_OPT_NR + 1)
+			return "invalid data checksum type";
+
+		if ((unpacked.bi_flags & BCH_INODE_UNLINKED) &&
+		    unpacked.bi_nlink != 0)
+			return "flagged as unlinked but bi_nlink != 0";
+
+		return NULL;
+	}
+	case BCH_INODE_BLOCKDEV:
+		if (bkey_val_bytes(k.k) != sizeof(struct bch_inode_blockdev))
+			return "incorrect value size";
+
+		if (k.k->p.inode >= BLOCKDEV_INODE_MAX)
+			return "blockdev inode in fs range";
+
+		return NULL;
+	case BCH_INODE_GENERATION:
+		if (bkey_val_bytes(k.k) != sizeof(struct bch_inode_generation))
+			return "incorrect value size";
+
+		return NULL;
+	default:
+		return "invalid type";
+	}
+}
+
+void bch2_inode_to_text(struct bch_fs *c, char *buf,
+			size_t size, struct bkey_s_c k)
+{
+	char *out = buf, *end = out + size;
+	struct bkey_s_c_inode inode;
+	struct bch_inode_unpacked unpacked;
+
+	switch (k.k->type) {
+	case BCH_INODE_FS:
+		inode = bkey_s_c_to_inode(k);
+		if (bch2_inode_unpack(inode, &unpacked)) {
+			out += scnprintf(out, end - out, "(unpack error)");
+			break;
+		}
+
+#define BCH_INODE_FIELD(_name, _bits)						\
+		out += scnprintf(out, end - out, #_name ": %llu ", (u64) unpacked._name);
+		BCH_INODE_FIELDS()
+#undef  BCH_INODE_FIELD
+		break;
+	}
+}
+
+void bch2_inode_init(struct bch_fs *c, struct bch_inode_unpacked *inode_u,
+		     uid_t uid, gid_t gid, umode_t mode, dev_t rdev,
+		     struct bch_inode_unpacked *parent)
+{
+	s64 now = bch2_current_time(c);
+
+	memset(inode_u, 0, sizeof(*inode_u));
+
+	/* ick */
+	inode_u->bi_flags |= c->opts.str_hash << INODE_STR_HASH_OFFSET;
+	get_random_bytes(&inode_u->bi_hash_seed, sizeof(inode_u->bi_hash_seed));
+
+	inode_u->bi_mode	= mode;
+	inode_u->bi_uid		= uid;
+	inode_u->bi_gid		= gid;
+	inode_u->bi_dev		= rdev;
+	inode_u->bi_atime	= now;
+	inode_u->bi_mtime	= now;
+	inode_u->bi_ctime	= now;
+	inode_u->bi_otime	= now;
+
+	if (parent) {
+#define BCH_INODE_FIELD(_name)	inode_u->_name = parent->_name;
+		BCH_INODE_FIELDS_INHERIT()
+#undef BCH_INODE_FIELD
+	}
+}
+
+static inline u32 bkey_generation(struct bkey_s_c k)
+{
+	switch (k.k->type) {
+	case BCH_INODE_BLOCKDEV:
+	case BCH_INODE_FS:
+		BUG();
+	case BCH_INODE_GENERATION:
+		return le32_to_cpu(bkey_s_c_to_inode_generation(k).v->bi_generation);
+	default:
+		return 0;
+	}
+}
+
+int __bch2_inode_create(struct btree_trans *trans,
+			struct bch_inode_unpacked *inode_u,
+			u64 min, u64 max, u64 *hint)
+{
+	struct bch_fs *c = trans->c;
+	struct bkey_inode_buf *inode_p;
+	struct btree_iter *iter;
+	u64 start;
+	int ret;
+
+	if (!max)
+		max = ULLONG_MAX;
+
+	if (c->opts.inodes_32bit)
+		max = min_t(u64, max, U32_MAX);
+
+	start = READ_ONCE(*hint);
+
+	if (start >= max || start < min)
+		start = min;
+
+	inode_p = bch2_trans_kmalloc(trans, sizeof(*inode_p));
+	if (IS_ERR(inode_p))
+		return PTR_ERR(inode_p);
+
+	iter = bch2_trans_get_iter(trans,
+			BTREE_ID_INODES, POS(start, 0),
+			BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+again:
+	while (1) {
+		struct bkey_s_c k = bch2_btree_iter_peek_slot(iter);
+
+		ret = btree_iter_err(k);
+		if (ret)
+			return ret;
+
+		switch (k.k->type) {
+		case BCH_INODE_BLOCKDEV:
+		case BCH_INODE_FS:
+			/* slot used */
+			if (iter->pos.inode >= max)
+				goto out;
+
+			bch2_btree_iter_next_slot(iter);
+			break;
+
+		default:
+			*hint			= k.k->p.inode;
+			inode_u->bi_inum	= k.k->p.inode;
+			inode_u->bi_generation	= bkey_generation(k);
+
+			bch2_inode_pack(inode_p, inode_u);
+			bch2_trans_update(trans, iter, &inode_p->inode.k_i, 0);
+			return 0;
+		}
+	}
+out:
+	if (start != min) {
+		/* Retry from start */
+		start = min;
+		bch2_btree_iter_set_pos(iter, POS(start, 0));
+		goto again;
+	}
+
+	return -ENOSPC;
+}
+
+int bch2_inode_create(struct bch_fs *c, struct bch_inode_unpacked *inode_u,
+		      u64 min, u64 max, u64 *hint)
+{
+	return bch2_trans_do(c, NULL, BTREE_INSERT_ATOMIC,
+			__bch2_inode_create(&trans, inode_u, min, max, hint));
+}
+
+int bch2_inode_truncate(struct bch_fs *c, u64 inode_nr, u64 new_size,
+			struct extent_insert_hook *hook, u64 *journal_seq)
+{
+	return bch2_btree_delete_range(c, BTREE_ID_EXTENTS,
+				       POS(inode_nr, new_size),
+				       POS(inode_nr + 1, 0),
+				       ZERO_VERSION, NULL, hook,
+				       journal_seq);
+}
+
+int bch2_inode_rm(struct bch_fs *c, u64 inode_nr)
+{
+	struct btree_iter iter;
+	struct bkey_i_inode_generation delete;
+	int ret;
+
+	ret = bch2_inode_truncate(c, inode_nr, 0, NULL, NULL);
+	if (ret < 0)
+		return ret;
+
+	ret = bch2_btree_delete_range(c, BTREE_ID_XATTRS,
+				     POS(inode_nr, 0),
+				     POS(inode_nr + 1, 0),
+				     ZERO_VERSION, NULL, NULL, NULL);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * If this was a directory, there shouldn't be any real dirents left -
+	 * but there could be whiteouts (from hash collisions) that we should
+	 * delete:
+	 *
+	 * XXX: the dirent could ideally would delete whiteouts when they're no
+	 * longer needed
+	 */
+	ret = bch2_btree_delete_range(c, BTREE_ID_DIRENTS,
+				     POS(inode_nr, 0),
+				     POS(inode_nr + 1, 0),
+				     ZERO_VERSION, NULL, NULL, NULL);
+	if (ret < 0)
+		return ret;
+
+	bch2_btree_iter_init(&iter, c, BTREE_ID_INODES, POS(inode_nr, 0),
+			     BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+	do {
+		struct bkey_s_c k = bch2_btree_iter_peek_slot(&iter);
+		u32 bi_generation = 0;
+
+		ret = btree_iter_err(k);
+		if (ret) {
+			bch2_btree_iter_unlock(&iter);
+			return ret;
+		}
+
+		bch2_fs_inconsistent_on(k.k->type != BCH_INODE_FS, c,
+					"inode %llu not found when deleting",
+					inode_nr);
+
+		switch (k.k->type) {
+		case BCH_INODE_FS: {
+			struct bch_inode_unpacked inode_u;
+
+			if (!bch2_inode_unpack(bkey_s_c_to_inode(k), &inode_u))
+				bi_generation = inode_u.bi_generation + 1;
+			break;
+		}
+		case BCH_INODE_GENERATION: {
+			struct bkey_s_c_inode_generation g =
+				bkey_s_c_to_inode_generation(k);
+			bi_generation = le32_to_cpu(g.v->bi_generation);
+			break;
+		}
+		}
+
+		if (!bi_generation) {
+			bkey_init(&delete.k);
+			delete.k.p.inode = inode_nr;
+		} else {
+			bkey_inode_generation_init(&delete.k_i);
+			delete.k.p.inode = inode_nr;
+			delete.v.bi_generation = cpu_to_le32(bi_generation);
+		}
+
+		ret = bch2_btree_insert_at(c, NULL, NULL, NULL,
+				BTREE_INSERT_ATOMIC|
+				BTREE_INSERT_NOFAIL,
+				BTREE_INSERT_ENTRY(&iter, &delete.k_i));
+	} while (ret == -EINTR);
+
+	bch2_btree_iter_unlock(&iter);
+	return ret;
+}
+
+int bch2_inode_find_by_inum(struct bch_fs *c, u64 inode_nr,
+			    struct bch_inode_unpacked *inode)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int ret = -ENOENT;
+
+	for_each_btree_key(&iter, c, BTREE_ID_INODES,
+			   POS(inode_nr, 0),
+			   BTREE_ITER_SLOTS, k) {
+		switch (k.k->type) {
+		case BCH_INODE_FS:
+			ret = bch2_inode_unpack(bkey_s_c_to_inode(k), inode);
+			break;
+		default:
+			/* hole, not found */
+			break;
+		}
+
+		break;
+
+	}
+
+	return bch2_btree_iter_unlock(&iter) ?: ret;
+}
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+void bch2_inode_pack_test(void)
+{
+	struct bch_inode_unpacked *u, test_inodes[] = {
+		{
+			.bi_atime	= U64_MAX,
+			.bi_ctime	= U64_MAX,
+			.bi_mtime	= U64_MAX,
+			.bi_otime	= U64_MAX,
+			.bi_size	= U64_MAX,
+			.bi_sectors	= U64_MAX,
+			.bi_uid		= U32_MAX,
+			.bi_gid		= U32_MAX,
+			.bi_nlink	= U32_MAX,
+			.bi_generation	= U32_MAX,
+			.bi_dev		= U32_MAX,
+		},
+	};
+
+	for (u = test_inodes;
+	     u < test_inodes + ARRAY_SIZE(test_inodes);
+	     u++) {
+		struct bkey_inode_buf p;
+
+		bch2_inode_pack(&p, u);
+	}
+}
+#endif