Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1205 insertions, 0 deletions

diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
new file mode 100644
index 0000000000..9309cfeecd
--- /dev/null
+++ b/fs/bcachefs/inode.c
@@ -0,0 +1,1205 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "btree_key_cache.h"
+#include "btree_write_buffer.h"
+#include "bkey_methods.h"
+#include "btree_update.h"
+#include "buckets.h"
+#include "compress.h"
+#include "dirent.h"
+#include "error.h"
+#include "extents.h"
+#include "extent_update.h"
+#include "inode.h"
+#include "str_hash.h"
+#include "snapshot.h"
+#include "subvolume.h"
+#include "varint.h"
+
+#include <linux/random.h>
+
+#include <asm/unaligned.h>
+
+#define x(name, ...)	#name,
+const char * const bch2_inode_opts[] = {
+	BCH_INODE_OPTS()
+	NULL,
+};
+
+static const char * const bch2_inode_flag_strs[] = {
+	BCH_INODE_FLAGS()
+	NULL
+};
+#undef  x
+
+static const u8 byte_table[8] = { 1, 2, 3, 4, 6, 8, 10, 13 };
+
+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;
+}
+
+static inline void bch2_inode_pack_inlined(struct bkey_inode_buf *packed,
+					   const struct bch_inode_unpacked *inode)
+{
+	struct bkey_i_inode_v3 *k = &packed->inode;
+	u8 *out = k->v.fields;
+	u8 *end = (void *) &packed[1];
+	u8 *last_nonzero_field = out;
+	unsigned nr_fields = 0, last_nonzero_fieldnr = 0;
+	unsigned bytes;
+	int ret;
+
+	bkey_inode_v3_init(&packed->inode.k_i);
+	packed->inode.k.p.offset	= inode->bi_inum;
+	packed->inode.v.bi_journal_seq	= cpu_to_le64(inode->bi_journal_seq);
+	packed->inode.v.bi_hash_seed	= inode->bi_hash_seed;
+	packed->inode.v.bi_flags	= cpu_to_le64(inode->bi_flags);
+	packed->inode.v.bi_sectors	= cpu_to_le64(inode->bi_sectors);
+	packed->inode.v.bi_size		= cpu_to_le64(inode->bi_size);
+	packed->inode.v.bi_version	= cpu_to_le64(inode->bi_version);
+	SET_INODEv3_MODE(&packed->inode.v, inode->bi_mode);
+	SET_INODEv3_FIELDS_START(&packed->inode.v, INODEv3_FIELDS_START_CUR);
+
+
+#define x(_name, _bits)							\
+	nr_fields++;							\
+									\
+	if (inode->_name) {						\
+		ret = bch2_varint_encode_fast(out, inode->_name);	\
+		out += ret;						\
+									\
+		if (_bits > 64)						\
+			*out++ = 0;					\
+									\
+		last_nonzero_field = out;				\
+		last_nonzero_fieldnr = nr_fields;			\
+	} else {							\
+		*out++ = 0;						\
+									\
+		if (_bits > 64)						\
+			*out++ = 0;					\
+	}
+
+	BCH_INODE_FIELDS_v3()
+#undef  x
+	BUG_ON(out > end);
+
+	out = last_nonzero_field;
+	nr_fields = last_nonzero_fieldnr;
+
+	bytes = out - (u8 *) &packed->inode.v;
+	set_bkey_val_bytes(&packed->inode.k, bytes);
+	memset_u64s_tail(&packed->inode.v, 0, bytes);
+
+	SET_INODEv3_NR_FIELDS(&k->v, nr_fields);
+
+	if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
+		struct bch_inode_unpacked unpacked;
+
+		ret = bch2_inode_unpack(bkey_i_to_s_c(&packed->inode.k_i), &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_sectors	!= inode->bi_sectors);
+		BUG_ON(unpacked.bi_size		!= inode->bi_size);
+		BUG_ON(unpacked.bi_version	!= inode->bi_version);
+		BUG_ON(unpacked.bi_mode		!= inode->bi_mode);
+
+#define x(_name, _bits)	if (unpacked._name != inode->_name)		\
+			panic("unpacked %llu should be %llu",		\
+			      (u64) unpacked._name, (u64) inode->_name);
+		BCH_INODE_FIELDS_v3()
+#undef  x
+	}
+}
+
+void bch2_inode_pack(struct bkey_inode_buf *packed,
+		     const struct bch_inode_unpacked *inode)
+{
+	bch2_inode_pack_inlined(packed, inode);
+}
+
+static noinline int bch2_inode_unpack_v1(struct bkey_s_c_inode inode,
+				struct bch_inode_unpacked *unpacked)
+{
+	const u8 *in = inode.v->fields;
+	const u8 *end = bkey_val_end(inode);
+	u64 field[2];
+	unsigned fieldnr = 0, field_bits;
+	int ret;
+
+#define x(_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_v2()
+#undef  x
+
+	/* XXX: signal if there were more fields than expected? */
+	return 0;
+}
+
+static int bch2_inode_unpack_v2(struct bch_inode_unpacked *unpacked,
+				const u8 *in, const u8 *end,
+				unsigned nr_fields)
+{
+	unsigned fieldnr = 0;
+	int ret;
+	u64 v[2];
+
+#define x(_name, _bits)							\
+	if (fieldnr < nr_fields) {					\
+		ret = bch2_varint_decode_fast(in, end, &v[0]);		\
+		if (ret < 0)						\
+			return ret;					\
+		in += ret;						\
+									\
+		if (_bits > 64) {					\
+			ret = bch2_varint_decode_fast(in, end, &v[1]);	\
+			if (ret < 0)					\
+				return ret;				\
+			in += ret;					\
+		} else {						\
+			v[1] = 0;					\
+		}							\
+	} else {							\
+		v[0] = v[1] = 0;					\
+	}								\
+									\
+	unpacked->_name = v[0];						\
+	if (v[1] || v[0] != unpacked->_name)				\
+		return -1;						\
+	fieldnr++;
+
+	BCH_INODE_FIELDS_v2()
+#undef  x
+
+	/* XXX: signal if there were more fields than expected? */
+	return 0;
+}
+
+static int bch2_inode_unpack_v3(struct bkey_s_c k,
+				struct bch_inode_unpacked *unpacked)
+{
+	struct bkey_s_c_inode_v3 inode = bkey_s_c_to_inode_v3(k);
+	const u8 *in = inode.v->fields;
+	const u8 *end = bkey_val_end(inode);
+	unsigned nr_fields = INODEv3_NR_FIELDS(inode.v);
+	unsigned fieldnr = 0;
+	int ret;
+	u64 v[2];
+
+	unpacked->bi_inum	= inode.k->p.offset;
+	unpacked->bi_journal_seq= le64_to_cpu(inode.v->bi_journal_seq);
+	unpacked->bi_hash_seed	= inode.v->bi_hash_seed;
+	unpacked->bi_flags	= le64_to_cpu(inode.v->bi_flags);
+	unpacked->bi_sectors	= le64_to_cpu(inode.v->bi_sectors);
+	unpacked->bi_size	= le64_to_cpu(inode.v->bi_size);
+	unpacked->bi_version	= le64_to_cpu(inode.v->bi_version);
+	unpacked->bi_mode	= INODEv3_MODE(inode.v);
+
+#define x(_name, _bits)							\
+	if (fieldnr < nr_fields) {					\
+		ret = bch2_varint_decode_fast(in, end, &v[0]);		\
+		if (ret < 0)						\
+			return ret;					\
+		in += ret;						\
+									\
+		if (_bits > 64) {					\
+			ret = bch2_varint_decode_fast(in, end, &v[1]);	\
+			if (ret < 0)					\
+				return ret;				\
+			in += ret;					\
+		} else {						\
+			v[1] = 0;					\
+		}							\
+	} else {							\
+		v[0] = v[1] = 0;					\
+	}								\
+									\
+	unpacked->_name = v[0];						\
+	if (v[1] || v[0] != unpacked->_name)				\
+		return -1;						\
+	fieldnr++;
+
+	BCH_INODE_FIELDS_v3()
+#undef  x
+
+	/* XXX: signal if there were more fields than expected? */
+	return 0;
+}
+
+static noinline int bch2_inode_unpack_slowpath(struct bkey_s_c k,
+					       struct bch_inode_unpacked *unpacked)
+{
+	memset(unpacked, 0, sizeof(*unpacked));
+
+	switch (k.k->type) {
+	case KEY_TYPE_inode: {
+		struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
+
+		unpacked->bi_inum	= inode.k->p.offset;
+		unpacked->bi_journal_seq= 0;
+		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);
+
+		if (INODE_NEW_VARINT(inode.v)) {
+			return bch2_inode_unpack_v2(unpacked, inode.v->fields,
+						    bkey_val_end(inode),
+						    INODE_NR_FIELDS(inode.v));
+		} else {
+			return bch2_inode_unpack_v1(inode, unpacked);
+		}
+		break;
+	}
+	case KEY_TYPE_inode_v2: {
+		struct bkey_s_c_inode_v2 inode = bkey_s_c_to_inode_v2(k);
+
+		unpacked->bi_inum	= inode.k->p.offset;
+		unpacked->bi_journal_seq= le64_to_cpu(inode.v->bi_journal_seq);
+		unpacked->bi_hash_seed	= inode.v->bi_hash_seed;
+		unpacked->bi_flags	= le64_to_cpu(inode.v->bi_flags);
+		unpacked->bi_mode	= le16_to_cpu(inode.v->bi_mode);
+
+		return bch2_inode_unpack_v2(unpacked, inode.v->fields,
+					    bkey_val_end(inode),
+					    INODEv2_NR_FIELDS(inode.v));
+	}
+	default:
+		BUG();
+	}
+}
+
+int bch2_inode_unpack(struct bkey_s_c k,
+		      struct bch_inode_unpacked *unpacked)
+{
+	if (likely(k.k->type == KEY_TYPE_inode_v3))
+		return bch2_inode_unpack_v3(k, unpacked);
+	return bch2_inode_unpack_slowpath(k, unpacked);
+}
+
+static int bch2_inode_peek_nowarn(struct btree_trans *trans,
+		    struct btree_iter *iter,
+		    struct bch_inode_unpacked *inode,
+		    subvol_inum inum, unsigned flags)
+{
+	struct bkey_s_c k;
+	u32 snapshot;
+	int ret;
+
+	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		return ret;
+
+	k = bch2_bkey_get_iter(trans, iter, BTREE_ID_inodes,
+			       SPOS(0, inum.inum, snapshot),
+			       flags|BTREE_ITER_CACHED);
+	ret = bkey_err(k);
+	if (ret)
+		return ret;
+
+	ret = bkey_is_inode(k.k) ? 0 : -BCH_ERR_ENOENT_inode;
+	if (ret)
+		goto err;
+
+	ret = bch2_inode_unpack(k, inode);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	bch2_trans_iter_exit(trans, iter);
+	return ret;
+}
+
+int bch2_inode_peek(struct btree_trans *trans,
+		    struct btree_iter *iter,
+		    struct bch_inode_unpacked *inode,
+		    subvol_inum inum, unsigned flags)
+{
+	int ret = bch2_inode_peek_nowarn(trans, iter, inode, inum, flags);
+	bch_err_msg(trans->c, ret, "looking up inum %u:%llu:", inum.subvol, inum.inum);
+	return ret;
+}
+
+int bch2_inode_write_flags(struct btree_trans *trans,
+		     struct btree_iter *iter,
+		     struct bch_inode_unpacked *inode,
+		     enum btree_update_flags flags)
+{
+	struct bkey_inode_buf *inode_p;
+
+	inode_p = bch2_trans_kmalloc(trans, sizeof(*inode_p));
+	if (IS_ERR(inode_p))
+		return PTR_ERR(inode_p);
+
+	bch2_inode_pack_inlined(inode_p, inode);
+	inode_p->inode.k.p.snapshot = iter->snapshot;
+	return bch2_trans_update(trans, iter, &inode_p->inode.k_i, flags);
+}
+
+struct bkey_i *bch2_inode_to_v3(struct btree_trans *trans, struct bkey_i *k)
+{
+	struct bch_inode_unpacked u;
+	struct bkey_inode_buf *inode_p;
+	int ret;
+
+	if (!bkey_is_inode(&k->k))
+		return ERR_PTR(-ENOENT);
+
+	inode_p = bch2_trans_kmalloc(trans, sizeof(*inode_p));
+	if (IS_ERR(inode_p))
+		return ERR_CAST(inode_p);
+
+	ret = bch2_inode_unpack(bkey_i_to_s_c(k), &u);
+	if (ret)
+		return ERR_PTR(ret);
+
+	bch2_inode_pack(inode_p, &u);
+	return &inode_p->inode.k_i;
+}
+
+static int __bch2_inode_invalid(struct bch_fs *c, struct bkey_s_c k, struct printbuf *err)
+{
+	struct bch_inode_unpacked unpacked;
+	int ret = 0;
+
+	bkey_fsck_err_on(k.k->p.inode, c, err,
+			 inode_pos_inode_nonzero,
+			 "nonzero k.p.inode");
+
+	bkey_fsck_err_on(k.k->p.offset < BLOCKDEV_INODE_MAX, c, err,
+			 inode_pos_blockdev_range,
+			 "fs inode in blockdev range");
+
+	bkey_fsck_err_on(bch2_inode_unpack(k, &unpacked), c, err,
+			 inode_unpack_error,
+			 "invalid variable length fields");
+
+	bkey_fsck_err_on(unpacked.bi_data_checksum >= BCH_CSUM_OPT_NR + 1, c, err,
+			 inode_checksum_type_invalid,
+			 "invalid data checksum type (%u >= %u",
+			 unpacked.bi_data_checksum, BCH_CSUM_OPT_NR + 1);
+
+	bkey_fsck_err_on(unpacked.bi_compression &&
+			 !bch2_compression_opt_valid(unpacked.bi_compression - 1), c, err,
+			 inode_compression_type_invalid,
+			 "invalid compression opt %u", unpacked.bi_compression - 1);
+
+	bkey_fsck_err_on((unpacked.bi_flags & BCH_INODE_unlinked) &&
+			 unpacked.bi_nlink != 0, c, err,
+			 inode_unlinked_but_nlink_nonzero,
+			 "flagged as unlinked but bi_nlink != 0");
+
+	bkey_fsck_err_on(unpacked.bi_subvol && !S_ISDIR(unpacked.bi_mode), c, err,
+			 inode_subvol_root_but_not_dir,
+			 "subvolume root but not a directory");
+fsck_err:
+	return ret;
+}
+
+int bch2_inode_invalid(struct bch_fs *c, struct bkey_s_c k,
+		       enum bkey_invalid_flags flags,
+		       struct printbuf *err)
+{
+	struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
+	int ret = 0;
+
+	bkey_fsck_err_on(INODE_STR_HASH(inode.v) >= BCH_STR_HASH_NR, c, err,
+			 inode_str_hash_invalid,
+			 "invalid str hash type (%llu >= %u)",
+			 INODE_STR_HASH(inode.v), BCH_STR_HASH_NR);
+
+	ret = __bch2_inode_invalid(c, k, err);
+fsck_err:
+	return ret;
+}
+
+int bch2_inode_v2_invalid(struct bch_fs *c, struct bkey_s_c k,
+			  enum bkey_invalid_flags flags,
+			  struct printbuf *err)
+{
+	struct bkey_s_c_inode_v2 inode = bkey_s_c_to_inode_v2(k);
+	int ret = 0;
+
+	bkey_fsck_err_on(INODEv2_STR_HASH(inode.v) >= BCH_STR_HASH_NR, c, err,
+			 inode_str_hash_invalid,
+			 "invalid str hash type (%llu >= %u)",
+			 INODEv2_STR_HASH(inode.v), BCH_STR_HASH_NR);
+
+	ret = __bch2_inode_invalid(c, k, err);
+fsck_err:
+	return ret;
+}
+
+int bch2_inode_v3_invalid(struct bch_fs *c, struct bkey_s_c k,
+			  enum bkey_invalid_flags flags,
+			  struct printbuf *err)
+{
+	struct bkey_s_c_inode_v3 inode = bkey_s_c_to_inode_v3(k);
+	int ret = 0;
+
+	bkey_fsck_err_on(INODEv3_FIELDS_START(inode.v) < INODEv3_FIELDS_START_INITIAL ||
+			 INODEv3_FIELDS_START(inode.v) > bkey_val_u64s(inode.k), c, err,
+			 inode_v3_fields_start_bad,
+			 "invalid fields_start (got %llu, min %u max %zu)",
+			 INODEv3_FIELDS_START(inode.v),
+			 INODEv3_FIELDS_START_INITIAL,
+			 bkey_val_u64s(inode.k));
+
+	bkey_fsck_err_on(INODEv3_STR_HASH(inode.v) >= BCH_STR_HASH_NR, c, err,
+			 inode_str_hash_invalid,
+			 "invalid str hash type (%llu >= %u)",
+			 INODEv3_STR_HASH(inode.v), BCH_STR_HASH_NR);
+
+	ret = __bch2_inode_invalid(c, k, err);
+fsck_err:
+	return ret;
+}
+
+static void __bch2_inode_unpacked_to_text(struct printbuf *out,
+					  struct bch_inode_unpacked *inode)
+{
+	prt_printf(out, "mode=%o ", inode->bi_mode);
+
+	prt_str(out, "flags=");
+	prt_bitflags(out, bch2_inode_flag_strs, inode->bi_flags & ((1U << 20) - 1));
+	prt_printf(out, " (%x)", inode->bi_flags);
+
+	prt_printf(out, " journal_seq=%llu bi_size=%llu bi_sectors=%llu bi_version=%llu",
+	       inode->bi_journal_seq,
+	       inode->bi_size,
+	       inode->bi_sectors,
+	       inode->bi_version);
+
+#define x(_name, _bits)						\
+	prt_printf(out, " "#_name "=%llu", (u64) inode->_name);
+	BCH_INODE_FIELDS_v3()
+#undef  x
+}
+
+void bch2_inode_unpacked_to_text(struct printbuf *out, struct bch_inode_unpacked *inode)
+{
+	prt_printf(out, "inum: %llu ", inode->bi_inum);
+	__bch2_inode_unpacked_to_text(out, inode);
+}
+
+void bch2_inode_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
+{
+	struct bch_inode_unpacked inode;
+
+	if (bch2_inode_unpack(k, &inode)) {
+		prt_printf(out, "(unpack error)");
+		return;
+	}
+
+	__bch2_inode_unpacked_to_text(out, &inode);
+}
+
+static inline u64 bkey_inode_flags(struct bkey_s_c k)
+{
+	switch (k.k->type) {
+	case KEY_TYPE_inode:
+		return le32_to_cpu(bkey_s_c_to_inode(k).v->bi_flags);
+	case KEY_TYPE_inode_v2:
+		return le64_to_cpu(bkey_s_c_to_inode_v2(k).v->bi_flags);
+	case KEY_TYPE_inode_v3:
+		return le64_to_cpu(bkey_s_c_to_inode_v3(k).v->bi_flags);
+	default:
+		return 0;
+	}
+}
+
+static inline bool bkey_is_deleted_inode(struct bkey_s_c k)
+{
+	return bkey_inode_flags(k) & BCH_INODE_unlinked;
+}
+
+int bch2_trans_mark_inode(struct btree_trans *trans,
+			  enum btree_id btree_id, unsigned level,
+			  struct bkey_s_c old,
+			  struct bkey_i *new,
+			  unsigned flags)
+{
+	int nr = bkey_is_inode(&new->k) - bkey_is_inode(old.k);
+	bool old_deleted = bkey_is_deleted_inode(old);
+	bool new_deleted = bkey_is_deleted_inode(bkey_i_to_s_c(new));
+
+	if (nr) {
+		int ret = bch2_replicas_deltas_realloc(trans, 0);
+		struct replicas_delta_list *d = trans->fs_usage_deltas;
+
+		if (ret)
+			return ret;
+
+		d->nr_inodes += nr;
+	}
+
+	if (old_deleted != new_deleted) {
+		int ret = bch2_btree_bit_mod(trans, BTREE_ID_deleted_inodes, new->k.p, new_deleted);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+int bch2_mark_inode(struct btree_trans *trans,
+		    enum btree_id btree_id, unsigned level,
+		    struct bkey_s_c old, struct bkey_s_c new,
+		    unsigned flags)
+{
+	struct bch_fs *c = trans->c;
+	struct bch_fs_usage *fs_usage;
+	u64 journal_seq = trans->journal_res.seq;
+
+	if (flags & BTREE_TRIGGER_INSERT) {
+		struct bch_inode_v3 *v = (struct bch_inode_v3 *) new.v;
+
+		BUG_ON(!journal_seq);
+		BUG_ON(new.k->type != KEY_TYPE_inode_v3);
+
+		v->bi_journal_seq = cpu_to_le64(journal_seq);
+	}
+
+	if (flags & BTREE_TRIGGER_GC) {
+		percpu_down_read(&c->mark_lock);
+		preempt_disable();
+
+		fs_usage = fs_usage_ptr(c, journal_seq, flags & BTREE_TRIGGER_GC);
+		fs_usage->nr_inodes += bkey_is_inode(new.k);
+		fs_usage->nr_inodes -= bkey_is_inode(old.k);
+
+		preempt_enable();
+		percpu_up_read(&c->mark_lock);
+	}
+	return 0;
+}
+
+int bch2_inode_generation_invalid(struct bch_fs *c, struct bkey_s_c k,
+				  enum bkey_invalid_flags flags,
+				  struct printbuf *err)
+{
+	int ret = 0;
+
+	bkey_fsck_err_on(k.k->p.inode, c, err,
+			 inode_pos_inode_nonzero,
+			 "nonzero k.p.inode");
+fsck_err:
+	return ret;
+}
+
+void bch2_inode_generation_to_text(struct printbuf *out, struct bch_fs *c,
+				   struct bkey_s_c k)
+{
+	struct bkey_s_c_inode_generation gen = bkey_s_c_to_inode_generation(k);
+
+	prt_printf(out, "generation: %u", le32_to_cpu(gen.v->bi_generation));
+}
+
+void bch2_inode_init_early(struct bch_fs *c,
+			   struct bch_inode_unpacked *inode_u)
+{
+	enum bch_str_hash_type str_hash =
+		bch2_str_hash_opt_to_type(c, c->opts.str_hash);
+
+	memset(inode_u, 0, sizeof(*inode_u));
+
+	/* ick */
+	inode_u->bi_flags |= str_hash << INODE_STR_HASH_OFFSET;
+	get_random_bytes(&inode_u->bi_hash_seed,
+			 sizeof(inode_u->bi_hash_seed));
+}
+
+void bch2_inode_init_late(struct bch_inode_unpacked *inode_u, u64 now,
+			  uid_t uid, gid_t gid, umode_t mode, dev_t rdev,
+			  struct bch_inode_unpacked *parent)
+{
+	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 && parent->bi_mode & S_ISGID) {
+		inode_u->bi_gid = parent->bi_gid;
+		if (S_ISDIR(mode))
+			inode_u->bi_mode |= S_ISGID;
+	}
+
+	if (parent) {
+#define x(_name, ...)	inode_u->bi_##_name = parent->bi_##_name;
+		BCH_INODE_OPTS()
+#undef x
+	}
+}
+
+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)
+{
+	bch2_inode_init_early(c, inode_u);
+	bch2_inode_init_late(inode_u, bch2_current_time(c),
+			     uid, gid, mode, rdev, parent);
+}
+
+static inline u32 bkey_generation(struct bkey_s_c k)
+{
+	switch (k.k->type) {
+	case KEY_TYPE_inode:
+	case KEY_TYPE_inode_v2:
+		BUG();
+	case KEY_TYPE_inode_generation:
+		return le32_to_cpu(bkey_s_c_to_inode_generation(k).v->bi_generation);
+	default:
+		return 0;
+	}
+}
+
+/*
+ * This just finds an empty slot:
+ */
+int bch2_inode_create(struct btree_trans *trans,
+		      struct btree_iter *iter,
+		      struct bch_inode_unpacked *inode_u,
+		      u32 snapshot, u64 cpu)
+{
+	struct bch_fs *c = trans->c;
+	struct bkey_s_c k;
+	u64 min, max, start, pos, *hint;
+	int ret = 0;
+	unsigned bits = (c->opts.inodes_32bit ? 31 : 63);
+
+	if (c->opts.shard_inode_numbers) {
+		bits -= c->inode_shard_bits;
+
+		min = (cpu << bits);
+		max = (cpu << bits) | ~(ULLONG_MAX << bits);
+
+		min = max_t(u64, min, BLOCKDEV_INODE_MAX);
+		hint = c->unused_inode_hints + cpu;
+	} else {
+		min = BLOCKDEV_INODE_MAX;
+		max = ~(ULLONG_MAX << bits);
+		hint = c->unused_inode_hints;
+	}
+
+	start = READ_ONCE(*hint);
+
+	if (start >= max || start < min)
+		start = min;
+
+	pos = start;
+	bch2_trans_iter_init(trans, iter, BTREE_ID_inodes, POS(0, pos),
+			     BTREE_ITER_ALL_SNAPSHOTS|
+			     BTREE_ITER_INTENT);
+again:
+	while ((k = bch2_btree_iter_peek(iter)).k &&
+	       !(ret = bkey_err(k)) &&
+	       bkey_lt(k.k->p, POS(0, max))) {
+		if (pos < iter->pos.offset)
+			goto found_slot;
+
+		/*
+		 * We don't need to iterate over keys in every snapshot once
+		 * we've found just one:
+		 */
+		pos = iter->pos.offset + 1;
+		bch2_btree_iter_set_pos(iter, POS(0, pos));
+	}
+
+	if (!ret && pos < max)
+		goto found_slot;
+
+	if (!ret && start == min)
+		ret = -BCH_ERR_ENOSPC_inode_create;
+
+	if (ret) {
+		bch2_trans_iter_exit(trans, iter);
+		return ret;
+	}
+
+	/* Retry from start */
+	pos = start = min;
+	bch2_btree_iter_set_pos(iter, POS(0, pos));
+	goto again;
+found_slot:
+	bch2_btree_iter_set_pos(iter, SPOS(0, pos, snapshot));
+	k = bch2_btree_iter_peek_slot(iter);
+	ret = bkey_err(k);
+	if (ret) {
+		bch2_trans_iter_exit(trans, iter);
+		return ret;
+	}
+
+	*hint			= k.k->p.offset;
+	inode_u->bi_inum	= k.k->p.offset;
+	inode_u->bi_generation	= bkey_generation(k);
+	return 0;
+}
+
+static int bch2_inode_delete_keys(struct btree_trans *trans,
+				  subvol_inum inum, enum btree_id id)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	struct bkey_i delete;
+	struct bpos end = POS(inum.inum, U64_MAX);
+	u32 snapshot;
+	int ret = 0;
+
+	/*
+	 * We're never going to be deleting partial extents, no need to use an
+	 * extent iterator:
+	 */
+	bch2_trans_iter_init(trans, &iter, id, POS(inum.inum, 0),
+			     BTREE_ITER_INTENT);
+
+	while (1) {
+		bch2_trans_begin(trans);
+
+		ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+		if (ret)
+			goto err;
+
+		bch2_btree_iter_set_snapshot(&iter, snapshot);
+
+		k = bch2_btree_iter_peek_upto(&iter, end);
+		ret = bkey_err(k);
+		if (ret)
+			goto err;
+
+		if (!k.k)
+			break;
+
+		bkey_init(&delete.k);
+		delete.k.p = iter.pos;
+
+		if (iter.flags & BTREE_ITER_IS_EXTENTS)
+			bch2_key_resize(&delete.k,
+					bpos_min(end, k.k->p).offset -
+					iter.pos.offset);
+
+		ret = bch2_trans_update(trans, &iter, &delete, 0) ?:
+		      bch2_trans_commit(trans, NULL, NULL,
+					BTREE_INSERT_NOFAIL);
+err:
+		if (ret && !bch2_err_matches(ret, BCH_ERR_transaction_restart))
+			break;
+	}
+
+	bch2_trans_iter_exit(trans, &iter);
+	return ret;
+}
+
+int bch2_inode_rm(struct bch_fs *c, subvol_inum inum)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter = { NULL };
+	struct bkey_i_inode_generation delete;
+	struct bch_inode_unpacked inode_u;
+	struct bkey_s_c k;
+	u32 snapshot;
+	int 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_inode_delete_keys(trans, inum, BTREE_ID_extents) ?:
+		bch2_inode_delete_keys(trans, inum, BTREE_ID_xattrs) ?:
+		bch2_inode_delete_keys(trans, inum, BTREE_ID_dirents);
+	if (ret)
+		goto err;
+retry:
+	bch2_trans_begin(trans);
+
+	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		goto err;
+
+	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
+			       SPOS(0, inum.inum, snapshot),
+			       BTREE_ITER_INTENT|BTREE_ITER_CACHED);
+	ret = bkey_err(k);
+	if (ret)
+		goto err;
+
+	if (!bkey_is_inode(k.k)) {
+		bch2_fs_inconsistent(c,
+				     "inode %llu:%u not found when deleting",
+				     inum.inum, snapshot);
+		ret = -EIO;
+		goto err;
+	}
+
+	bch2_inode_unpack(k, &inode_u);
+
+	bkey_inode_generation_init(&delete.k_i);
+	delete.k.p = iter.pos;
+	delete.v.bi_generation = cpu_to_le32(inode_u.bi_generation + 1);
+
+	ret   = bch2_trans_update(trans, &iter, &delete.k_i, 0) ?:
+		bch2_trans_commit(trans, NULL, NULL,
+				BTREE_INSERT_NOFAIL);
+err:
+	bch2_trans_iter_exit(trans, &iter);
+	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		goto retry;
+
+	bch2_trans_put(trans);
+	return ret;
+}
+
+int bch2_inode_find_by_inum_nowarn_trans(struct btree_trans *trans,
+				  subvol_inum inum,
+				  struct bch_inode_unpacked *inode)
+{
+	struct btree_iter iter;
+	int ret;
+
+	ret = bch2_inode_peek_nowarn(trans, &iter, inode, inum, 0);
+	if (!ret)
+		bch2_trans_iter_exit(trans, &iter);
+	return ret;
+}
+
+int bch2_inode_find_by_inum_trans(struct btree_trans *trans,
+				  subvol_inum inum,
+				  struct bch_inode_unpacked *inode)
+{
+	struct btree_iter iter;
+	int ret;
+
+	ret = bch2_inode_peek(trans, &iter, inode, inum, 0);
+	if (!ret)
+		bch2_trans_iter_exit(trans, &iter);
+	return ret;
+}
+
+int bch2_inode_find_by_inum(struct bch_fs *c, subvol_inum inum,
+			    struct bch_inode_unpacked *inode)
+{
+	return bch2_trans_do(c, NULL, NULL, 0,
+		bch2_inode_find_by_inum_trans(trans, inum, inode));
+}
+
+int bch2_inode_nlink_inc(struct bch_inode_unpacked *bi)
+{
+	if (bi->bi_flags & BCH_INODE_unlinked)
+		bi->bi_flags &= ~BCH_INODE_unlinked;
+	else {
+		if (bi->bi_nlink == U32_MAX)
+			return -EINVAL;
+
+		bi->bi_nlink++;
+	}
+
+	return 0;
+}
+
+void bch2_inode_nlink_dec(struct btree_trans *trans, struct bch_inode_unpacked *bi)
+{
+	if (bi->bi_nlink && (bi->bi_flags & BCH_INODE_unlinked)) {
+		bch2_trans_inconsistent(trans, "inode %llu unlinked but link count nonzero",
+					bi->bi_inum);
+		return;
+	}
+
+	if (bi->bi_flags & BCH_INODE_unlinked) {
+		bch2_trans_inconsistent(trans, "inode %llu link count underflow", bi->bi_inum);
+		return;
+	}
+
+	if (bi->bi_nlink)
+		bi->bi_nlink--;
+	else
+		bi->bi_flags |= BCH_INODE_unlinked;
+}
+
+struct bch_opts bch2_inode_opts_to_opts(struct bch_inode_unpacked *inode)
+{
+	struct bch_opts ret = { 0 };
+#define x(_name, _bits)							\
+	if (inode->bi_##_name)						\
+		opt_set(ret, _name, inode->bi_##_name - 1);
+	BCH_INODE_OPTS()
+#undef x
+	return ret;
+}
+
+void bch2_inode_opts_get(struct bch_io_opts *opts, struct bch_fs *c,
+			 struct bch_inode_unpacked *inode)
+{
+#define x(_name, _bits)		opts->_name = inode_opt_get(c, inode, _name);
+	BCH_INODE_OPTS()
+#undef x
+
+	if (opts->nocow)
+		opts->compression = opts->background_compression = opts->data_checksum = opts->erasure_code = 0;
+}
+
+int bch2_inum_opts_get(struct btree_trans *trans, subvol_inum inum, struct bch_io_opts *opts)
+{
+	struct bch_inode_unpacked inode;
+	int ret = lockrestart_do(trans, bch2_inode_find_by_inum_trans(trans, inum, &inode));
+
+	if (ret)
+		return ret;
+
+	bch2_inode_opts_get(opts, trans->c, &inode);
+	return 0;
+}
+
+int bch2_inode_rm_snapshot(struct btree_trans *trans, u64 inum, u32 snapshot)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter iter = { NULL };
+	struct bkey_i_inode_generation delete;
+	struct bch_inode_unpacked inode_u;
+	struct bkey_s_c k;
+	int ret;
+
+	do {
+		ret   = bch2_btree_delete_range_trans(trans, BTREE_ID_extents,
+						      SPOS(inum, 0, snapshot),
+						      SPOS(inum, U64_MAX, snapshot),
+						      0, NULL) ?:
+			bch2_btree_delete_range_trans(trans, BTREE_ID_dirents,
+						      SPOS(inum, 0, snapshot),
+						      SPOS(inum, U64_MAX, snapshot),
+						      0, NULL) ?:
+			bch2_btree_delete_range_trans(trans, BTREE_ID_xattrs,
+						      SPOS(inum, 0, snapshot),
+						      SPOS(inum, U64_MAX, snapshot),
+						      0, NULL);
+	} while (ret == -BCH_ERR_transaction_restart_nested);
+	if (ret)
+		goto err;
+retry:
+	bch2_trans_begin(trans);
+
+	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
+			       SPOS(0, inum, snapshot), BTREE_ITER_INTENT);
+	ret = bkey_err(k);
+	if (ret)
+		goto err;
+
+	if (!bkey_is_inode(k.k)) {
+		bch2_fs_inconsistent(c,
+				     "inode %llu:%u not found when deleting",
+				     inum, snapshot);
+		ret = -EIO;
+		goto err;
+	}
+
+	bch2_inode_unpack(k, &inode_u);
+
+	/* Subvolume root? */
+	if (inode_u.bi_subvol)
+		bch_warn(c, "deleting inode %llu marked as unlinked, but also a subvolume root!?", inode_u.bi_inum);
+
+	bkey_inode_generation_init(&delete.k_i);
+	delete.k.p = iter.pos;
+	delete.v.bi_generation = cpu_to_le32(inode_u.bi_generation + 1);
+
+	ret   = bch2_trans_update(trans, &iter, &delete.k_i, 0) ?:
+		bch2_trans_commit(trans, NULL, NULL,
+				BTREE_INSERT_NOFAIL);
+err:
+	bch2_trans_iter_exit(trans, &iter);
+	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		goto retry;
+
+	return ret ?: -BCH_ERR_transaction_restart_nested;
+}
+
+static int may_delete_deleted_inode(struct btree_trans *trans,
+				    struct btree_iter *iter,
+				    struct bpos pos,
+				    bool *need_another_pass)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter inode_iter;
+	struct bkey_s_c k;
+	struct bch_inode_unpacked inode;
+	int ret;
+
+	k = bch2_bkey_get_iter(trans, &inode_iter, BTREE_ID_inodes, pos, BTREE_ITER_CACHED);
+	ret = bkey_err(k);
+	if (ret)
+		return ret;
+
+	ret = bkey_is_inode(k.k) ? 0 : -BCH_ERR_ENOENT_inode;
+	if (fsck_err_on(!bkey_is_inode(k.k), c,
+			deleted_inode_missing,
+			"nonexistent inode %llu:%u in deleted_inodes btree",
+			pos.offset, pos.snapshot))
+		goto delete;
+
+	ret = bch2_inode_unpack(k, &inode);
+	if (ret)
+		goto out;
+
+	if (S_ISDIR(inode.bi_mode)) {
+		ret = bch2_empty_dir_snapshot(trans, pos.offset, pos.snapshot);
+		if (fsck_err_on(ret == -ENOTEMPTY, c, deleted_inode_is_dir,
+				"non empty directory %llu:%u in deleted_inodes btree",
+				pos.offset, pos.snapshot))
+			goto delete;
+		if (ret)
+			goto out;
+	}
+
+	if (fsck_err_on(!(inode.bi_flags & BCH_INODE_unlinked), c,
+			deleted_inode_not_unlinked,
+			"non-deleted inode %llu:%u in deleted_inodes btree",
+			pos.offset, pos.snapshot))
+		goto delete;
+
+	if (c->sb.clean &&
+	    !fsck_err(c,
+		      deleted_inode_but_clean,
+		      "filesystem marked as clean but have deleted inode %llu:%u",
+		      pos.offset, pos.snapshot)) {
+		ret = 0;
+		goto out;
+	}
+
+	if (bch2_snapshot_is_internal_node(c, pos.snapshot)) {
+		struct bpos new_min_pos;
+
+		ret = bch2_propagate_key_to_snapshot_leaves(trans, inode_iter.btree_id, k, &new_min_pos);
+		if (ret)
+			goto out;
+
+		inode.bi_flags &= ~BCH_INODE_unlinked;
+
+		ret = bch2_inode_write_flags(trans, &inode_iter, &inode,
+					     BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+		bch_err_msg(c, ret, "clearing inode unlinked flag");
+		if (ret)
+			goto out;
+
+		/*
+		 * We'll need another write buffer flush to pick up the new
+		 * unlinked inodes in the snapshot leaves:
+		 */
+		*need_another_pass = true;
+		goto out;
+	}
+
+	ret = 1;
+out:
+fsck_err:
+	bch2_trans_iter_exit(trans, &inode_iter);
+	return ret;
+delete:
+	ret = bch2_btree_bit_mod(trans, BTREE_ID_deleted_inodes, pos, false);
+	goto out;
+}
+
+int bch2_delete_dead_inodes(struct bch_fs *c)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	bool need_another_pass;
+	int ret;
+again:
+	need_another_pass = false;
+
+	ret = bch2_btree_write_buffer_flush_sync(trans);
+	if (ret)
+		goto err;
+
+	/*
+	 * Weird transaction restart handling here because on successful delete,
+	 * bch2_inode_rm_snapshot() will return a nested transaction restart,
+	 * but we can't retry because the btree write buffer won't have been
+	 * flushed and we'd spin:
+	 */
+	for_each_btree_key(trans, iter, BTREE_ID_deleted_inodes, POS_MIN,
+			   BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k, ret) {
+		ret = commit_do(trans, NULL, NULL,
+				BTREE_INSERT_NOFAIL|
+				BTREE_INSERT_LAZY_RW,
+			may_delete_deleted_inode(trans, &iter, k.k->p, &need_another_pass));
+		if (ret < 0)
+			break;
+
+		if (ret) {
+			if (!test_bit(BCH_FS_RW, &c->flags)) {
+				bch2_trans_unlock(trans);
+				bch2_fs_lazy_rw(c);
+			}
+
+			bch_verbose(c, "deleting unlinked inode %llu:%u", k.k->p.offset, k.k->p.snapshot);
+
+			ret = bch2_inode_rm_snapshot(trans, k.k->p.offset, k.k->p.snapshot);
+			if (ret && !bch2_err_matches(ret, BCH_ERR_transaction_restart))
+				break;
+		}
+	}
+	bch2_trans_iter_exit(trans, &iter);
+
+	if (!ret && need_another_pass)
+		goto again;
+err:
+	bch2_trans_put(trans);
+
+	return ret;
+}