]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/inode.c
Move c_src dirs back to toplevel
[bcachefs-tools-debian] / libbcachefs / inode.c
diff --git a/libbcachefs/inode.c b/libbcachefs/inode.c
new file mode 100644 (file)
index 0000000..37dce96
--- /dev/null
@@ -0,0 +1,1184 @@
+// 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_trigger_inode(struct btree_trans *trans,
+                      enum btree_id btree_id, unsigned level,
+                      struct bkey_s_c old,
+                      struct bkey_s new,
+                      unsigned flags)
+{
+       s64 nr = bkey_is_inode(new.k) - bkey_is_inode(old.k);
+
+       if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+               if (nr) {
+                       int ret = bch2_replicas_deltas_realloc(trans, 0);
+                       if (ret)
+                               return ret;
+
+                       trans->fs_usage_deltas->nr_inodes += nr;
+               }
+
+               bool old_deleted = bkey_is_deleted_inode(old);
+               bool new_deleted = bkey_is_deleted_inode(new.s_c);
+               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;
+               }
+       }
+
+       if (!(flags & BTREE_TRIGGER_TRANSACTIONAL) && (flags & BTREE_TRIGGER_INSERT)) {
+               BUG_ON(!trans->journal_res.seq);
+
+               bkey_s_to_inode_v3(new).v->bi_journal_seq = cpu_to_le64(trans->journal_res.seq);
+       }
+
+       if (flags & BTREE_TRIGGER_GC) {
+               struct bch_fs *c = trans->c;
+
+               percpu_down_read(&c->mark_lock);
+               this_cpu_add(c->usage_gc->nr_inodes, nr);
+               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,
+                                       BCH_TRANS_COMMIT_no_enospc);
+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,
+                               BCH_TRANS_COMMIT_no_enospc);
+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,
+                               BCH_TRANS_COMMIT_no_enospc);
+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);
+       bool need_another_pass;
+       int ret;
+again:
+       need_another_pass = false;
+
+       /*
+        * 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:
+        */
+       ret = for_each_btree_key_commit(trans, iter, BTREE_ID_deleted_inodes, POS_MIN,
+                                       BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+                                       NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
+               ret = may_delete_deleted_inode(trans, &iter, k.k->p, &need_another_pass);
+               if (ret > 0) {
+                       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);
+                       /*
+                        * We don't want to loop here: a transaction restart
+                        * error here means we handled a transaction restart and
+                        * we're actually done, but if we loop we'll retry the
+                        * same key because the write buffer hasn't been flushed
+                        * yet
+                        */
+                       if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
+                               ret = 0;
+                               continue;
+                       }
+               }
+
+               ret;
+       }));
+
+       if (!ret && need_another_pass) {
+               ret = bch2_btree_write_buffer_flush_sync(trans);
+               if (ret)
+                       goto err;
+               goto again;
+       }
+err:
+       bch2_trans_put(trans);
+       return ret;
+}