123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205 |
- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * Written 1992,1993 by Werner Almesberger
- * 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
- * and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
- * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
- */
- #include <linux/time.h>
- #include <linux/fs.h>
- #include <linux/slab.h>
- #include <linux/buffer_head.h>
- #include "exfat_raw.h"
- #include "exfat_fs.h"
- /*
- * exfat_fs_error reports a file system problem that might indicate fa data
- * corruption/inconsistency. Depending on 'errors' mount option the
- * panic() is called, or error message is printed FAT and nothing is done,
- * or filesystem is remounted read-only (default behavior).
- * In case the file system is remounted read-only, it can be made writable
- * again by remounting it.
- */
- void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
- {
- struct exfat_mount_options *opts = &EXFAT_SB(sb)->options;
- va_list args;
- struct va_format vaf;
- if (report) {
- va_start(args, fmt);
- vaf.fmt = fmt;
- vaf.va = &args;
- exfat_err(sb, "error, %pV", &vaf);
- va_end(args);
- }
- if (opts->errors == EXFAT_ERRORS_PANIC) {
- panic("exFAT-fs (%s): fs panic from previous error\n",
- sb->s_id);
- } else if (opts->errors == EXFAT_ERRORS_RO && !sb_rdonly(sb)) {
- sb->s_flags |= SB_RDONLY;
- exfat_err(sb, "Filesystem has been set read-only");
- }
- }
- /*
- * exfat_msg() - print preformated EXFAT specific messages.
- * All logs except what uses exfat_fs_error() should be written by exfat_msg()
- */
- void exfat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
- {
- struct va_format vaf;
- va_list args;
- va_start(args, fmt);
- vaf.fmt = fmt;
- vaf.va = &args;
- /* level means KERN_ pacility level */
- printk("%sexFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
- va_end(args);
- }
- #define SECS_PER_MIN (60)
- #define TIMEZONE_SEC(x) ((x) * 15 * SECS_PER_MIN)
- static void exfat_adjust_tz(struct timespec64 *ts, u8 tz_off)
- {
- if (tz_off <= 0x3F)
- ts->tv_sec -= TIMEZONE_SEC(tz_off);
- else /* 0x40 <= (tz_off & 0x7F) <=0x7F */
- ts->tv_sec += TIMEZONE_SEC(0x80 - tz_off);
- }
- /* Convert a EXFAT time/date pair to a UNIX date (seconds since 1 1 70). */
- void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
- u8 tz, __le16 time, __le16 date, u8 time_cs)
- {
- u16 t = le16_to_cpu(time);
- u16 d = le16_to_cpu(date);
- ts->tv_sec = mktime64(1980 + (d >> 9), d >> 5 & 0x000F, d & 0x001F,
- t >> 11, (t >> 5) & 0x003F, (t & 0x001F) << 1);
- /* time_cs field represent 0 ~ 199cs(1990 ms) */
- if (time_cs) {
- ts->tv_sec += time_cs / 100;
- ts->tv_nsec = (time_cs % 100) * 10 * NSEC_PER_MSEC;
- } else
- ts->tv_nsec = 0;
- if (tz & EXFAT_TZ_VALID)
- /* Adjust timezone to UTC0. */
- exfat_adjust_tz(ts, tz & ~EXFAT_TZ_VALID);
- else
- /* Convert from local time to UTC using time_offset. */
- ts->tv_sec -= sbi->options.time_offset * SECS_PER_MIN;
- }
- /* Convert linear UNIX date to a EXFAT time/date pair. */
- void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
- u8 *tz, __le16 *time, __le16 *date, u8 *time_cs)
- {
- struct tm tm;
- u16 t, d;
- time64_to_tm(ts->tv_sec, 0, &tm);
- t = (tm.tm_hour << 11) | (tm.tm_min << 5) | (tm.tm_sec >> 1);
- d = ((tm.tm_year - 80) << 9) | ((tm.tm_mon + 1) << 5) | tm.tm_mday;
- *time = cpu_to_le16(t);
- *date = cpu_to_le16(d);
- /* time_cs field represent 0 ~ 199cs(1990 ms) */
- if (time_cs)
- *time_cs = (tm.tm_sec & 1) * 100 +
- ts->tv_nsec / (10 * NSEC_PER_MSEC);
- /*
- * Record 00h value for OffsetFromUtc field and 1 value for OffsetValid
- * to indicate that local time and UTC are the same.
- */
- *tz = EXFAT_TZ_VALID;
- }
- /*
- * The timestamp for access_time has double seconds granularity.
- * (There is no 10msIncrement field for access_time unlike create/modify_time)
- * atime also has only a 2-second resolution.
- */
- void exfat_truncate_atime(struct timespec64 *ts)
- {
- ts->tv_sec = round_down(ts->tv_sec, 2);
- ts->tv_nsec = 0;
- }
- u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type)
- {
- int i;
- u8 *c = (u8 *)data;
- for (i = 0; i < len; i++, c++) {
- if (unlikely(type == CS_DIR_ENTRY && (i == 2 || i == 3)))
- continue;
- chksum = ((chksum << 15) | (chksum >> 1)) + *c;
- }
- return chksum;
- }
- u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type)
- {
- int i;
- u8 *c = (u8 *)data;
- for (i = 0; i < len; i++, c++) {
- if (unlikely(type == CS_BOOT_SECTOR &&
- (i == 106 || i == 107 || i == 112)))
- continue;
- chksum = ((chksum << 31) | (chksum >> 1)) + *c;
- }
- return chksum;
- }
- void exfat_update_bh(struct buffer_head *bh, int sync)
- {
- set_buffer_uptodate(bh);
- mark_buffer_dirty(bh);
- if (sync)
- sync_dirty_buffer(bh);
- }
- int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync)
- {
- int i, err = 0;
- for (i = 0; i < nr_bhs; i++) {
- set_buffer_uptodate(bhs[i]);
- mark_buffer_dirty(bhs[i]);
- if (sync)
- write_dirty_buffer(bhs[i], 0);
- }
- for (i = 0; i < nr_bhs && sync; i++) {
- wait_on_buffer(bhs[i]);
- if (!err && !buffer_uptodate(bhs[i]))
- err = -EIO;
- }
- return err;
- }
- void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
- unsigned int size, unsigned char flags)
- {
- ec->dir = dir;
- ec->size = size;
- ec->flags = flags;
- }
- void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec)
- {
- return exfat_chain_set(dup, ec->dir, ec->size, ec->flags);
- }
|