--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 LG Electronics.
+ *
+ * Author(s): Hyunchul Lee <hyc.lee@gmail.com>
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <time.h>
+
+#include "exfat_ondisk.h"
+#include "libexfat.h"
+#include "exfat_fs.h"
+#include "exfat_dir.h"
+
+static struct path_resolve_ctx path_resolve_ctx;
+
+#define fsck_err(parent, inode, fmt, ...) \
+({ \
+ exfat_resolve_path_parent(&path_resolve_ctx, \
+ parent, inode); \
+ exfat_err("ERROR: %s: " fmt, \
+ path_resolve_ctx.local_path, \
+ ##__VA_ARGS__); \
+})
+
+static ssize_t write_block(struct exfat_de_iter *iter, unsigned int block)
+{
+ off_t device_offset;
+ struct exfat *exfat = iter->exfat;
+ struct buffer_desc *desc;
+ unsigned int i;
+
+ desc = &iter->buffer_desc[block & 0x01];
+ device_offset = exfat_c2o(exfat, desc->p_clus) + desc->offset;
+
+ for (i = 0; i < iter->read_size / iter->write_size; i++) {
+ if (desc->dirty[i]) {
+ if (exfat_write(exfat->blk_dev->dev_fd,
+ desc->buffer + i * iter->write_size,
+ iter->write_size,
+ device_offset + i * iter->write_size)
+ != (ssize_t)iter->write_size)
+ return -EIO;
+ desc->dirty[i] = 0;
+ }
+ }
+ return 0;
+}
+
+static int read_ahead_first_blocks(struct exfat_de_iter *iter)
+{
+#ifdef POSIX_FADV_WILLNEED
+ struct exfat *exfat = iter->exfat;
+ clus_t clus_count;
+ unsigned int size;
+
+ clus_count = iter->parent->size / exfat->clus_size;
+
+ if (clus_count > 1) {
+ iter->ra_begin_offset = 0;
+ iter->ra_next_clus = 1;
+ size = exfat->clus_size;
+ } else {
+ iter->ra_begin_offset = 0;
+ iter->ra_next_clus = 0;
+ size = iter->ra_partial_size;
+ }
+ return posix_fadvise(exfat->blk_dev->dev_fd,
+ exfat_c2o(exfat, iter->parent->first_clus), size,
+ POSIX_FADV_WILLNEED);
+#else
+ return -ENOTSUP;
+#endif
+}
+
+/**
+ * read the next fragment in advance, and assume the fragment
+ * which covers @clus is already read.
+ */
+static int read_ahead_next_blocks(struct exfat_de_iter *iter,
+ clus_t clus, unsigned int offset, clus_t p_clus)
+{
+#ifdef POSIX_FADV_WILLNEED
+ struct exfat *exfat = iter->exfat;
+ off_t device_offset;
+ clus_t clus_count, ra_clus, ra_p_clus;
+ unsigned int size;
+ int ret = 0;
+
+ clus_count = iter->parent->size / exfat->clus_size;
+ if (clus + 1 < clus_count) {
+ ra_clus = clus + 1;
+ if (ra_clus == iter->ra_next_clus &&
+ offset >= iter->ra_begin_offset) {
+ ret = exfat_get_inode_next_clus(exfat, iter->parent,
+ p_clus, &ra_p_clus);
+ if (ret)
+ return ret;
+
+ if (ra_p_clus == EXFAT_EOF_CLUSTER)
+ return -EIO;
+
+ device_offset = exfat_c2o(exfat, ra_p_clus);
+ size = ra_clus + 1 < clus_count ?
+ exfat->clus_size : iter->ra_partial_size;
+ ret = posix_fadvise(exfat->blk_dev->dev_fd,
+ device_offset, size,
+ POSIX_FADV_WILLNEED);
+ iter->ra_next_clus = ra_clus + 1;
+ iter->ra_begin_offset = 0;
+ }
+ } else {
+ if (offset >= iter->ra_begin_offset &&
+ offset + iter->ra_partial_size <=
+ exfat->clus_size) {
+ device_offset = exfat_c2o(exfat, p_clus) +
+ offset + iter->ra_partial_size;
+ ret = posix_fadvise(exfat->blk_dev->dev_fd,
+ device_offset, iter->ra_partial_size,
+ POSIX_FADV_WILLNEED);
+ iter->ra_begin_offset =
+ offset + iter->ra_partial_size;
+ }
+ }
+
+ return ret;
+#else
+ return -ENOTSUP;
+#endif
+}
+
+static int read_ahead_next_dir_blocks(struct exfat_de_iter *iter)
+{
+#ifdef POSIX_FADV_WILLNEED
+ struct exfat *exfat = iter->exfat;
+ struct list_head *current;
+ struct exfat_inode *next_inode;
+ off_t offset;
+
+ if (list_empty(&exfat->dir_list))
+ return -EINVAL;
+
+ current = exfat->dir_list.next;
+ if (iter->parent == list_entry(current, struct exfat_inode, list) &&
+ current->next != &exfat->dir_list) {
+ next_inode = list_entry(current->next, struct exfat_inode,
+ list);
+ offset = exfat_c2o(exfat, next_inode->first_clus);
+ return posix_fadvise(exfat->blk_dev->dev_fd, offset,
+ iter->ra_partial_size,
+ POSIX_FADV_WILLNEED);
+ }
+
+ return 0;
+#else
+ return -ENOTSUP;
+#endif
+}
+
+static ssize_t read_block(struct exfat_de_iter *iter, unsigned int block)
+{
+ struct exfat *exfat = iter->exfat;
+ struct buffer_desc *desc, *prev_desc;
+ off_t device_offset;
+ ssize_t ret;
+
+ desc = &iter->buffer_desc[block & 0x01];
+ if (block == 0) {
+ desc->p_clus = iter->parent->first_clus;
+ desc->offset = 0;
+ }
+
+ /* if the buffer already contains dirty dentries, write it */
+ if (write_block(iter, block))
+ return -EIO;
+
+ if (block > 0) {
+ if (block > iter->parent->size / iter->read_size)
+ return EOF;
+
+ prev_desc = &iter->buffer_desc[(block-1) & 0x01];
+ if (prev_desc->offset + 2 * iter->read_size <=
+ exfat->clus_size) {
+ desc->p_clus = prev_desc->p_clus;
+ desc->offset = prev_desc->offset + iter->read_size;
+ } else {
+ ret = exfat_get_inode_next_clus(exfat, iter->parent,
+ prev_desc->p_clus, &desc->p_clus);
+ desc->offset = 0;
+ if (ret)
+ return ret;
+ else if (desc->p_clus == EXFAT_EOF_CLUSTER)
+ return EOF;
+ }
+ }
+
+ device_offset = exfat_c2o(exfat, desc->p_clus) + desc->offset;
+ ret = exfat_read(exfat->blk_dev->dev_fd, desc->buffer,
+ iter->read_size, device_offset);
+ if (ret <= 0)
+ return ret;
+
+ /*
+ * if a buffer is filled with dentries, read blocks ahead of time,
+ * otherwise read blocks of the next directory in advance.
+ */
+ if (desc->buffer[iter->read_size - 32] != EXFAT_LAST)
+ read_ahead_next_blocks(iter,
+ (block * iter->read_size) / exfat->clus_size,
+ (block * iter->read_size) % exfat->clus_size,
+ desc->p_clus);
+ else
+ read_ahead_next_dir_blocks(iter);
+ return ret;
+}
+
+int exfat_de_iter_init(struct exfat_de_iter *iter, struct exfat *exfat,
+ struct exfat_inode *dir, struct buffer_desc *bd)
+{
+ iter->exfat = exfat;
+ iter->parent = dir;
+ iter->write_size = exfat->sect_size;
+ iter->read_size = exfat->clus_size <= 4*KB ? exfat->clus_size : 4*KB;
+ if (exfat->clus_size <= 32 * KB)
+ iter->ra_partial_size = MAX(4 * KB, exfat->clus_size / 2);
+ else
+ iter->ra_partial_size = exfat->clus_size / 4;
+ iter->ra_partial_size = MIN(iter->ra_partial_size, 8 * KB);
+
+ iter->buffer_desc = bd;
+
+ iter->de_file_offset = 0;
+ iter->next_read_offset = iter->read_size;
+ iter->max_skip_dentries = 0;
+ iter->dot_name_num = 0;
+
+ if (iter->parent->size == 0)
+ return EOF;
+
+ read_ahead_first_blocks(iter);
+ if (read_block(iter, 0) != (ssize_t)iter->read_size) {
+ exfat_err("failed to read directory entries.\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+int exfat_de_iter_get(struct exfat_de_iter *iter,
+ int ith, struct exfat_dentry **dentry)
+{
+ off_t next_de_file_offset;
+ ssize_t ret;
+ unsigned int block;
+
+ next_de_file_offset = iter->de_file_offset +
+ ith * sizeof(struct exfat_dentry);
+ block = (unsigned int)(next_de_file_offset / iter->read_size);
+
+ if (next_de_file_offset + sizeof(struct exfat_dentry) >
+ iter->parent->size)
+ return EOF;
+ /* the dentry must be in current, or next block which will be read */
+ if (block > iter->de_file_offset / iter->read_size + 1)
+ return -ERANGE;
+
+ /* read next cluster if needed */
+ if (next_de_file_offset >= iter->next_read_offset) {
+ ret = read_block(iter, block);
+ if (ret != (ssize_t)iter->read_size)
+ return ret;
+ iter->next_read_offset += iter->read_size;
+ }
+
+ if (ith + 1 > iter->max_skip_dentries)
+ iter->max_skip_dentries = ith + 1;
+
+ *dentry = (struct exfat_dentry *)
+ (iter->buffer_desc[block & 0x01].buffer +
+ next_de_file_offset % iter->read_size);
+ return 0;
+}
+
+int exfat_de_iter_get_dirty(struct exfat_de_iter *iter,
+ int ith, struct exfat_dentry **dentry)
+{
+ off_t next_file_offset;
+ unsigned int block;
+ int ret, sect_idx;
+
+ ret = exfat_de_iter_get(iter, ith, dentry);
+ if (!ret) {
+ next_file_offset = iter->de_file_offset +
+ ith * sizeof(struct exfat_dentry);
+ block = (unsigned int)(next_file_offset / iter->read_size);
+ sect_idx = (int)((next_file_offset % iter->read_size) /
+ iter->write_size);
+ iter->buffer_desc[block & 0x01].dirty[sect_idx] = 1;
+ }
+
+ return ret;
+}
+
+int exfat_de_iter_flush(struct exfat_de_iter *iter)
+{
+ if (write_block(iter, 0) || write_block(iter, 1))
+ return -EIO;
+ return 0;
+}
+
+int exfat_de_iter_advance(struct exfat_de_iter *iter, int skip_dentries)
+{
+ if (skip_dentries > iter->max_skip_dentries)
+ return -EINVAL;
+
+ iter->max_skip_dentries = 0;
+ iter->de_file_offset = iter->de_file_offset +
+ skip_dentries * sizeof(struct exfat_dentry);
+ return 0;
+}
+
+off_t exfat_de_iter_device_offset(struct exfat_de_iter *iter)
+{
+ struct buffer_desc *bd;
+ unsigned int block;
+
+ if ((uint64_t)iter->de_file_offset >= iter->parent->size)
+ return EOF;
+
+ block = iter->de_file_offset / iter->read_size;
+ bd = &iter->buffer_desc[block & 0x01];
+ return exfat_c2o(iter->exfat, bd->p_clus) + bd->offset +
+ iter->de_file_offset % iter->read_size;
+}
+
+off_t exfat_de_iter_file_offset(struct exfat_de_iter *iter)
+{
+ return iter->de_file_offset;
+}
+
+/*
+ * try to find the dentry set matched with @filter. this function
+ * doesn't verify the dentry set.
+ *
+ * if found, return 0. if not found, return EOF. otherwise return errno.
+ */
+int exfat_lookup_dentry_set(struct exfat *exfat, struct exfat_inode *parent,
+ struct exfat_lookup_filter *filter)
+{
+ struct buffer_desc *bd = NULL;
+ struct exfat_dentry *dentry = NULL;
+ off_t free_file_offset = 0, free_dev_offset = 0;
+ struct exfat_de_iter de_iter;
+ int dentry_count;
+ int retval;
+ bool last_is_free = false;
+
+ bd = exfat_alloc_buffer(2, exfat->clus_size, exfat->sect_size);
+ if (!bd)
+ return -ENOMEM;
+
+ retval = exfat_de_iter_init(&de_iter, exfat, parent, bd);
+ if (retval == EOF || retval)
+ goto out;
+
+ filter->out.dentry_set = NULL;
+ while (1) {
+ retval = exfat_de_iter_get(&de_iter, 0, &dentry);
+ if (retval == EOF) {
+ break;
+ } else if (retval) {
+ fsck_err(parent->parent, parent,
+ "failed to get a dentry. %d\n", retval);
+ goto out;
+ }
+
+ dentry_count = 1;
+ if (dentry->type == filter->in.type) {
+ retval = 0;
+ if (filter->in.filter)
+ retval = filter->in.filter(&de_iter,
+ filter->in.param,
+ &dentry_count);
+
+ if (retval == 0) {
+ struct exfat_dentry *d;
+ int i;
+
+ filter->out.dentry_set = calloc(dentry_count,
+ sizeof(struct exfat_dentry));
+ if (!filter->out.dentry_set) {
+ retval = -ENOMEM;
+ goto out;
+ }
+ for (i = 0; i < dentry_count; i++) {
+ exfat_de_iter_get(&de_iter, i, &d);
+ memcpy(filter->out.dentry_set + i, d,
+ sizeof(struct exfat_dentry));
+ }
+ filter->out.dentry_count = dentry_count;
+ goto out;
+ } else if (retval < 0) {
+ goto out;
+ }
+ last_is_free = false;
+ } else if ((dentry->type == EXFAT_LAST ||
+ IS_EXFAT_DELETED(dentry->type))) {
+ if (!last_is_free) {
+ free_file_offset =
+ exfat_de_iter_file_offset(&de_iter);
+ free_dev_offset =
+ exfat_de_iter_device_offset(&de_iter);
+ last_is_free = true;
+ }
+ } else {
+ last_is_free = false;
+ }
+
+ exfat_de_iter_advance(&de_iter, dentry_count);
+ }
+
+out:
+ if (retval == 0) {
+ filter->out.file_offset =
+ exfat_de_iter_file_offset(&de_iter);
+ filter->out.dev_offset =
+ exfat_de_iter_device_offset(&de_iter);
+ } else if (retval == EOF && last_is_free) {
+ filter->out.file_offset = free_file_offset;
+ filter->out.dev_offset = free_dev_offset;
+ } else {
+ filter->out.file_offset = exfat_de_iter_file_offset(&de_iter);
+ filter->out.dev_offset = EOF;
+ }
+ if (bd)
+ exfat_free_buffer(bd, 2);
+ return retval;
+}
+
+static int filter_lookup_file(struct exfat_de_iter *de_iter,
+ void *param, int *dentry_count)
+{
+ struct exfat_dentry *file_de, *stream_de, *name_de;
+ __le16 *name;
+ int retval, name_len;
+ int i;
+
+ retval = exfat_de_iter_get(de_iter, 0, &file_de);
+ if (retval || file_de->type != EXFAT_FILE)
+ return 1;
+
+ retval = exfat_de_iter_get(de_iter, 1, &stream_de);
+ if (retval || stream_de->type != EXFAT_STREAM)
+ return 1;
+
+ name = (__le16 *)param;
+ name_len = (int)exfat_utf16_len(name, PATH_MAX);
+
+ if (file_de->dentry.file.num_ext <
+ 1 + (name_len + ENTRY_NAME_MAX - 1) / ENTRY_NAME_MAX)
+ return 1;
+
+ for (i = 2; i <= file_de->dentry.file.num_ext && name_len > 0; i++) {
+ int len;
+
+ retval = exfat_de_iter_get(de_iter, i, &name_de);
+ if (retval || name_de->type != EXFAT_NAME)
+ return 1;
+
+ len = MIN(name_len, ENTRY_NAME_MAX);
+ if (memcmp(name_de->dentry.name.unicode_0_14,
+ name, len * 2) != 0)
+ return 1;
+
+ name += len;
+ name_len -= len;
+ }
+
+ *dentry_count = i;
+ return 0;
+}
+
+int exfat_lookup_file(struct exfat *exfat, struct exfat_inode *parent,
+ const char *name, struct exfat_lookup_filter *filter_out)
+{
+ int retval;
+ __le16 utf16_name[PATH_MAX + 2] = {0, };
+
+ retval = (int)exfat_utf16_enc(name, utf16_name, sizeof(utf16_name));
+ if (retval < 0)
+ return retval;
+
+ filter_out->in.type = EXFAT_FILE;
+ filter_out->in.filter = filter_lookup_file;
+ filter_out->in.param = utf16_name;
+
+ retval = exfat_lookup_dentry_set(exfat, parent, filter_out);
+ if (retval < 0)
+ return retval;
+
+ return 0;
+}
+
+void exfat_calc_dentry_checksum(struct exfat_dentry *dentry,
+ uint16_t *checksum, bool primary)
+{
+ unsigned int i;
+ uint8_t *bytes;
+
+ bytes = (uint8_t *)dentry;
+
+ *checksum = ((*checksum << 15) | (*checksum >> 1)) + bytes[0];
+ *checksum = ((*checksum << 15) | (*checksum >> 1)) + bytes[1];
+
+ i = primary ? 4 : 2;
+ for (; i < sizeof(*dentry); i++)
+ *checksum = ((*checksum << 15) | (*checksum >> 1)) + bytes[i];
+}
+
+static uint16_t calc_dentry_set_checksum(struct exfat_dentry *dset, int dcount)
+{
+ uint16_t checksum;
+ int i;
+
+ if (dcount < MIN_FILE_DENTRIES)
+ return 0;
+
+ checksum = 0;
+ exfat_calc_dentry_checksum(&dset[0], &checksum, true);
+ for (i = 1; i < dcount; i++)
+ exfat_calc_dentry_checksum(&dset[i], &checksum, false);
+ return checksum;
+}
+
+uint16_t exfat_calc_name_hash(struct exfat *exfat,
+ __le16 *name, int len)
+{
+ int i;
+ __le16 ch;
+ uint16_t chksum = 0;
+
+ for (i = 0; i < len; i++) {
+ ch = exfat->upcase_table[le16_to_cpu(name[i])];
+ ch = cpu_to_le16(ch);
+
+ chksum = ((chksum << 15) | (chksum >> 1)) + (ch & 0xFF);
+ chksum = ((chksum << 15) | (chksum >> 1)) + (ch >> 8);
+ }
+ return chksum;
+}
+
+static void unix_time_to_exfat_time(time_t unix_time, __u8 *tz, __le16 *date,
+ __le16 *time, __u8 *time_ms)
+{
+ struct tm tm;
+ __u16 t, d;
+
+ gmtime_r(&unix_time, &tm);
+ d = ((tm.tm_year - 80) << 9) | ((tm.tm_mon + 1) << 5) | tm.tm_mday;
+ t = (tm.tm_hour << 11) | (tm.tm_min << 5) | (tm.tm_sec >> 1);
+
+ *tz = 0x80;
+ *date = cpu_to_le16(d);
+ *time = cpu_to_le16(t);
+ if (time_ms)
+ *time_ms = (tm.tm_sec & 1) * 100;
+}
+
+int exfat_build_file_dentry_set(struct exfat *exfat, const char *name,
+ unsigned short attr, struct exfat_dentry **dentry_set,
+ int *dentry_count)
+{
+ struct exfat_dentry *dset;
+ __le16 utf16_name[PATH_MAX + 2];
+ int retval;
+ int dcount, name_len, i;
+ __le16 e_date, e_time;
+ __u8 tz, e_time_ms;
+
+ memset(utf16_name, 0, sizeof(utf16_name));
+ retval = exfat_utf16_enc(name, utf16_name, sizeof(utf16_name));
+ if (retval < 0)
+ return retval;
+
+ name_len = retval / 2;
+ dcount = 2 + DIV_ROUND_UP(name_len, ENTRY_NAME_MAX);
+ dset = calloc(1, dcount * DENTRY_SIZE);
+ if (!dset)
+ return -ENOMEM;
+
+ dset[0].type = EXFAT_FILE;
+ dset[0].dentry.file.num_ext = dcount - 1;
+ dset[0].dentry.file.attr = cpu_to_le16(attr);
+
+ unix_time_to_exfat_time(time(NULL), &tz,
+ &e_date, &e_time, &e_time_ms);
+
+ dset[0].dentry.file.create_date = e_date;
+ dset[0].dentry.file.create_time = e_time;
+ dset[0].dentry.file.create_time_ms = e_time_ms;
+ dset[0].dentry.file.create_tz = tz;
+
+ dset[0].dentry.file.modify_date = e_date;
+ dset[0].dentry.file.modify_time = e_time;
+ dset[0].dentry.file.modify_time_ms = e_time_ms;
+ dset[0].dentry.file.modify_tz = tz;
+
+ dset[0].dentry.file.access_date = e_date;
+ dset[0].dentry.file.access_time = e_time;
+ dset[0].dentry.file.access_tz = tz;
+
+ dset[1].type = EXFAT_STREAM;
+ dset[1].dentry.stream.flags = 0x01;
+ dset[1].dentry.stream.name_len = (__u8)name_len;
+ dset[1].dentry.stream.name_hash =
+ cpu_to_le16(exfat_calc_name_hash(exfat, utf16_name, name_len));
+
+ for (i = 2; i < dcount; i++) {
+ dset[i].type = EXFAT_NAME;
+ memcpy(dset[i].dentry.name.unicode_0_14,
+ utf16_name + (i - 2) * ENTRY_NAME_MAX,
+ ENTRY_NAME_MAX * 2);
+ }
+
+ dset[0].dentry.file.checksum =
+ cpu_to_le16(calc_dentry_set_checksum(dset, dcount));
+
+ *dentry_set = dset;
+ *dentry_count = dcount;
+ return 0;
+}
+
+int exfat_update_file_dentry_set(struct exfat *exfat,
+ struct exfat_dentry *dset, int dcount,
+ const char *name,
+ clus_t start_clu, clus_t ccount)
+{
+ int i, name_len;
+ __le16 utf16_name[PATH_MAX + 2];
+
+ if (dset[0].type != EXFAT_FILE || dcount < MIN_FILE_DENTRIES)
+ return -EINVAL;
+
+ if (name) {
+ name_len = (int)exfat_utf16_enc(name,
+ utf16_name, sizeof(utf16_name));
+ if (name_len < 0)
+ return name_len;
+
+ name_len /= 2;
+ if (dcount != 2 + DIV_ROUND_UP(name_len, ENTRY_NAME_MAX))
+ return -EINVAL;
+
+ dset[1].dentry.stream.name_len = (__u8)name_len;
+ dset[1].dentry.stream.name_hash =
+ exfat_calc_name_hash(exfat, utf16_name, name_len);
+
+ for (i = 2; i < dcount; i++) {
+ dset[i].type = EXFAT_NAME;
+ memcpy(dset[i].dentry.name.unicode_0_14,
+ utf16_name + (i - 2) * ENTRY_NAME_MAX,
+ ENTRY_NAME_MAX * 2);
+ }
+ }
+
+ dset[1].dentry.stream.valid_size = cpu_to_le64(ccount * exfat->clus_size);
+ dset[1].dentry.stream.size = cpu_to_le64(ccount * exfat->clus_size);
+ if (start_clu)
+ dset[1].dentry.stream.start_clu = cpu_to_le32(start_clu);
+
+ dset[0].dentry.file.checksum =
+ cpu_to_le16(calc_dentry_set_checksum(dset, dcount));
+ return 0;
+}
+
+static int find_free_cluster(struct exfat *exfat,
+ clus_t start, clus_t *new_clu)
+{
+ clus_t end = le32_to_cpu(exfat->bs->bsx.clu_count) +
+ EXFAT_FIRST_CLUSTER;
+
+ if (!exfat_heap_clus(exfat, start))
+ return -EINVAL;
+
+ while (start < end) {
+ if (exfat_bitmap_find_zero(exfat, exfat->alloc_bitmap,
+ start, new_clu))
+ break;
+ if (!exfat_bitmap_get(exfat->disk_bitmap, *new_clu))
+ return 0;
+ start = *new_clu + 1;
+ }
+
+ end = start;
+ start = EXFAT_FIRST_CLUSTER;
+ while (start < end) {
+ if (exfat_bitmap_find_zero(exfat, exfat->alloc_bitmap,
+ start, new_clu))
+ goto out_nospc;
+ if (!exfat_bitmap_get(exfat->disk_bitmap, *new_clu))
+ return 0;
+ start = *new_clu + 1;
+ }
+
+out_nospc:
+ *new_clu = EXFAT_EOF_CLUSTER;
+ return -ENOSPC;
+}
+
+static int exfat_map_cluster(struct exfat *exfat, struct exfat_inode *inode,
+ off_t file_off, clus_t *mapped_clu)
+{
+ clus_t clu, next, count, last_count;
+
+ if (!exfat_heap_clus(exfat, inode->first_clus))
+ return -EINVAL;
+
+ clu = inode->first_clus;
+ next = EXFAT_EOF_CLUSTER;
+ count = 1;
+ if (file_off == EOF)
+ last_count = DIV_ROUND_UP(inode->size, exfat->clus_size);
+ else
+ last_count = file_off / exfat->clus_size + 1;
+
+ while (true) {
+ if (count * exfat->clus_size > inode->size)
+ return -EINVAL;
+
+ if (count == last_count) {
+ *mapped_clu = clu;
+ return 0;
+ }
+
+ if (exfat_get_inode_next_clus(exfat, inode, clu, &next))
+ return -EINVAL;
+
+ if (!exfat_heap_clus(exfat, clu))
+ return -EINVAL;
+
+ clu = next;
+ count++;
+ }
+ return -EINVAL;
+}
+
+static int exfat_write_dentry_set(struct exfat *exfat,
+ struct exfat_dentry *dset, int dcount,
+ off_t dev_off, off_t *next_dev_off)
+{
+ clus_t clus;
+ unsigned int clus_off, dent_len, first_half_len, sec_half_len;
+ off_t first_half_off, sec_half_off = 0;
+
+ if (exfat_o2c(exfat, dev_off, &clus, &clus_off))
+ return -ERANGE;
+
+ dent_len = dcount * DENTRY_SIZE;
+ first_half_len = MIN(dent_len, exfat->clus_size - clus_off);
+ sec_half_len = dent_len - first_half_len;
+
+ first_half_off = dev_off;
+ if (sec_half_len) {
+ clus_t next_clus;
+
+ if (exfat_get_next_clus(exfat, clus, &next_clus))
+ return -EIO;
+ if (!exfat_heap_clus(exfat, next_clus))
+ return -EINVAL;
+ sec_half_off = exfat_c2o(exfat, next_clus);
+ }
+
+ if (exfat_write(exfat->blk_dev->dev_fd, dset, first_half_len,
+ first_half_off) != (ssize_t)first_half_len)
+ return -EIO;
+
+ if (sec_half_len) {
+ dset = (struct exfat_dentry *)((char *)dset + first_half_len);
+ if (exfat_write(exfat->blk_dev->dev_fd, dset, sec_half_len,
+ sec_half_off) != (ssize_t)sec_half_len)
+ return -EIO;
+ }
+
+ if (next_dev_off) {
+ if (sec_half_len)
+ *next_dev_off = sec_half_off + sec_half_len;
+ else
+ *next_dev_off = first_half_off + first_half_len;
+ }
+ return 0;
+}
+
+static int exfat_alloc_cluster(struct exfat *exfat, struct exfat_inode *inode,
+ clus_t *new_clu)
+{
+ clus_t last_clu;
+ int err;
+ bool need_dset = inode != exfat->root;
+
+ if ((need_dset && !inode->dentry_set) || inode->is_contiguous)
+ return -EINVAL;
+
+ err = find_free_cluster(exfat, exfat->start_clu, new_clu);
+ if (err) {
+ exfat->start_clu = EXFAT_FIRST_CLUSTER;
+ exfat_err("failed to find an free cluster\n");
+ return -ENOSPC;
+ }
+ exfat->start_clu = *new_clu;
+
+ if (exfat_set_fat(exfat, *new_clu, EXFAT_EOF_CLUSTER))
+ return -EIO;
+
+ /* zero out the new cluster */
+ if (exfat_write(exfat->blk_dev->dev_fd, exfat->zero_cluster,
+ exfat->clus_size, exfat_c2o(exfat, *new_clu)) !=
+ (ssize_t)exfat->clus_size) {
+ exfat_err("failed to fill new cluster with zeroes\n");
+ return -EIO;
+ }
+
+ if (inode->size) {
+ err = exfat_map_cluster(exfat, inode, EOF, &last_clu);
+ if (err) {
+ exfat_err("failed to get the last cluster\n");
+ return err;
+ }
+
+ if (exfat_set_fat(exfat, last_clu, *new_clu))
+ return -EIO;
+
+ if (need_dset) {
+ err = exfat_update_file_dentry_set(exfat,
+ inode->dentry_set,
+ inode->dentry_count,
+ NULL, 0,
+ DIV_ROUND_UP(inode->size,
+ exfat->clus_size) + 1);
+ if (err)
+ return -EINVAL;
+ }
+ } else {
+ if (need_dset) {
+ err = exfat_update_file_dentry_set(exfat,
+ inode->dentry_set,
+ inode->dentry_count,
+ NULL, *new_clu, 1);
+ if (err)
+ return -EINVAL;
+ }
+ }
+
+ if (need_dset && exfat_write_dentry_set(exfat, inode->dentry_set,
+ inode->dentry_count,
+ inode->dev_offset, NULL))
+ return -EIO;
+
+ exfat_bitmap_set(exfat->alloc_bitmap, *new_clu);
+ if (inode->size == 0)
+ inode->first_clus = *new_clu;
+ inode->size += exfat->clus_size;
+ return 0;
+}
+
+int exfat_add_dentry_set(struct exfat *exfat, struct exfat_dentry_loc *loc,
+ struct exfat_dentry *dset, int dcount,
+ bool need_next_loc)
+{
+ struct exfat_inode *parent = loc->parent;
+ off_t dev_off, next_dev_off;
+
+ if (parent->is_contiguous ||
+ (uint64_t)loc->file_offset > parent->size ||
+ (unsigned int)dcount * DENTRY_SIZE > exfat->clus_size)
+ return -EINVAL;
+
+ dev_off = loc->dev_offset;
+ if ((uint64_t)loc->file_offset + dcount * DENTRY_SIZE > parent->size) {
+ clus_t new_clus;
+
+ if (exfat_alloc_cluster(exfat, parent, &new_clus))
+ return -EIO;
+ if ((uint64_t)loc->file_offset == parent->size - exfat->clus_size)
+ dev_off = exfat_c2o(exfat, new_clus);
+ }
+
+ if (exfat_write_dentry_set(exfat, dset, dcount, dev_off, &next_dev_off))
+ return -EIO;
+
+ if (need_next_loc) {
+ loc->file_offset += dcount * DENTRY_SIZE;
+ loc->dev_offset = next_dev_off;
+ }
+ return 0;
+}
+
+int exfat_create_file(struct exfat *exfat, struct exfat_inode *parent,
+ const char *name, unsigned short attr)
+{
+ struct exfat_dentry *dset;
+ int err, dcount;
+ struct exfat_lookup_filter filter;
+ struct exfat_dentry_loc loc;
+
+ err = exfat_lookup_file(exfat, parent, name, &filter);
+ if (err == 0) {
+ dset = filter.out.dentry_set;
+ dcount = filter.out.dentry_count;
+ if ((le16_to_cpu(dset->dentry.file.attr) & attr) != attr)
+ err = -EEXIST;
+ goto out;
+ }
+
+ err = exfat_build_file_dentry_set(exfat, name, attr,
+ &dset, &dcount);
+ if (err)
+ return err;
+
+ loc.parent = parent;
+ loc.file_offset = filter.out.file_offset;
+ loc.dev_offset = filter.out.dev_offset;
+ err = exfat_add_dentry_set(exfat, &loc, dset, dcount, false);
+out:
+ free(dset);
+ return err;
+}
projects / sven / exfatprogs.git / blobdiff