path: root/fs/bcachefs/inode.c

// 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;