[v9,09/13] exfat: add misc operations

Message ID	20200102082036.29643-10-namjae.jeon@samsung.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=gSOW=2X=vger.kernel.org=linux-fsdevel-owner@kernel.org> From: Namjae Jeon <namjae.jeon@samsung.com> To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: gregkh@linuxfoundation.org, valdis.kletnieks@vt.edu, hch@lst.de, sj1557.seo@samsung.com, linkinjeon@gmail.com, pali.rohar@gmail.com, Namjae Jeon <namjae.jeon@samsung.com> Subject: [PATCH v9 09/13] exfat: add misc operations Date: Thu, 2 Jan 2020 16:20:32 +0800 Message-Id: <20200102082036.29643-10-namjae.jeon@samsung.com> In-Reply-To: <20200102082036.29643-1-namjae.jeon@samsung.com> Content-Type: text/plain; charset="utf-8" CMS-TYPE: 101P DLP-Filter: Pass References: <20200102082036.29643-1-namjae.jeon@samsung.com> <CGME20200102082406epcas1p268f260d90213bdaabee25a7518f86625@epcas1p2.samsung.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk
Series	add the latest exfat driver \| expand [v9,00/13] add the latest exfat driver [v9,01/13] exfat: add in-memory and on-disk structures and headers [v9,02/13] exfat: add super block operations [v9,03/13] exfat: add inode operations [v9,04/13] exfat: add directory operations [v9,05/13] exfat: add file operations [v9,06/13] exfat: add exfat entry operations [v9,07/13] exfat: add bitmap operations [v9,08/13] exfat: add exfat cache [v9,09/13] exfat: add misc operations [v9,10/13] exfat: add nls operations [v9,11/13] exfat: add Kconfig and Makefile [v9,12/13] exfat: add exfat in fs/Kconfig and fs/Makefile [v9,13/13] MAINTAINERS: add exfat filesystem

diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c new file mode 100644 index 000000000000..7f533bcb3b3f --- /dev/null +++ b/fs/exfat/misc.c @@ -0,0 +1,253 @@ +// 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_msg(sb, KERN_ERR, "error, %pV\n", &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_msg(sb, KERN_ERR, "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); +} + +/* <linux/time.h> externs sys_tz + * extern struct timezone sys_tz; + */ +#define UNIX_SECS_1980 315532800L + +#if BITS_PER_LONG == 64 +#define UNIX_SECS_2108 4354819200L +#endif + +/* days between 1970/01/01 and 1980/01/01 (2 leap days) */ +#define DAYS_DELTA_DECADE (365 * 10 + 2) +/* 120 (2100 - 1980) isn't leap year */ +#define NO_LEAP_YEAR_2100 (120) +#define IS_LEAP_YEAR(y) (!((y) & 0x3) && (y) != NO_LEAP_YEAR_2100) + +#define SECS_PER_MIN (60) +#define SECS_PER_HOUR (60 * SECS_PER_MIN) +#define SECS_PER_DAY (24 * SECS_PER_HOUR) + +#define MAKE_LEAP_YEAR(leap_year, year) \ + do { \ + /* 2100 isn't leap year */ \ + if (unlikely(year > NO_LEAP_YEAR_2100)) \ + leap_year = ((year + 3) / 4) - 1; \ + else \ + leap_year = ((year + 3) / 4); \ + } while (0) + +/* Linear day numbers of the respective 1sts in non-leap years. */ +static time_t accum_days_in_year[] = { + /* Month : N 01 02 03 04 05 06 07 08 09 10 11 12 */ + 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, +}; + +#define TIMEZONE_SEC(x) ((x) * 15 * SECS_PER_MIN) +/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */ +void exfat_time_fat2unix(struct exfat_sb_info *sbi, struct timespec64 *ts, + struct exfat_date_time *tp) +{ + time_t year = tp->year; + time_t ld; /* leap day */ + + MAKE_LEAP_YEAR(ld, year); + + if (IS_LEAP_YEAR(year) && (tp->month) > 2) + ld++; + + ts->tv_sec = tp->second + tp->minute * SECS_PER_MIN + + tp->hour * SECS_PER_HOUR + + (year * 365 + ld + accum_days_in_year[tp->month] + + (tp->day - 1) + DAYS_DELTA_DECADE) * SECS_PER_DAY; + + ts->tv_nsec = 0; + + /* Treat as local time */ + if (!tp->timezone.valid) { + ts->tv_sec += sys_tz.tz_minuteswest * SECS_PER_MIN; + return; + } + + /* Treat as UTC time, but need to adjust timezone to UTC0 */ + if (tp->timezone.off <= 0x3F) + ts->tv_sec -= TIMEZONE_SEC(tp->timezone.off); + else /* 0x40 <= (tp->timezone & 0x7F) <=0x7F */ + ts->tv_sec += TIMEZONE_SEC(0x80 - tp->timezone.off); +} + +#define TIMEZONE_CUR_OFFSET() ((sys_tz.tz_minuteswest / (-15)) & 0x7F) +/* Convert linear UNIX date to a FAT time/date pair. */ +void exfat_time_unix2fat(struct exfat_sb_info *sbi, struct timespec64 *ts, + struct exfat_date_time *tp) +{ + time_t second = ts->tv_sec; + time_t day, month, year; + time_t ld; /* leap day */ + + /* Treats as local time with proper time */ + second -= sys_tz.tz_minuteswest * SECS_PER_MIN; + tp->timezone.valid = 1; + tp->timezone.off = TIMEZONE_CUR_OFFSET(); + + /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */ + if (second < UNIX_SECS_1980) { + tp->second = 0; + tp->minute = 0; + tp->hour = 0; + tp->day = 1; + tp->month = 1; + tp->year = 0; + return; + } + + if (second >= UNIX_SECS_2108) { + tp->second = 59; + tp->minute = 59; + tp->hour = 23; + tp->day = 31; + tp->month = 12; + tp->year = 127; + return; + } + + day = second / SECS_PER_DAY - DAYS_DELTA_DECADE; + year = day / 365; + + MAKE_LEAP_YEAR(ld, year); + if (year * 365 + ld > day) + year--; + + MAKE_LEAP_YEAR(ld, year); + day -= year * 365 + ld; + + if (IS_LEAP_YEAR(year) && day == accum_days_in_year[3]) { + month = 2; + } else { + if (IS_LEAP_YEAR(year) && day > accum_days_in_year[3]) + day--; + for (month = 1; month < 12; month++) { + if (accum_days_in_year[month + 1] > day) + break; + } + } + day -= accum_days_in_year[month]; + + tp->second = second % SECS_PER_MIN; + tp->minute = (second / SECS_PER_MIN) % 60; + tp->hour = (second / SECS_PER_HOUR) % 24; + tp->day = day + 1; + tp->month = month; + tp->year = year; +} + +struct exfat_timestamp *exfat_tm_now(struct exfat_sb_info *sbi, + struct exfat_timestamp *tp) +{ + struct timespec64 ts; + struct exfat_date_time dt; + + ktime_get_real_ts64(&ts); + exfat_time_unix2fat(sbi, &ts, &dt); + + tp->year = dt.year; + tp->mon = dt.month; + tp->day = dt.day; + tp->hour = dt.hour; + tp->min = dt.minute; + tp->sec = dt.second; + tp->tz.value = dt.timezone.value; + + return tp; +} + +unsigned short exfat_calc_chksum_2byte(void *data, int len, + unsigned short chksum, int type) +{ + int i; + unsigned char *c = (unsigned char *)data; + + for (i = 0; i < len; i++, c++) { + if (((i == 2) || (i == 3)) && (type == CS_DIR_ENTRY)) + continue; + chksum = (((chksum & 1) << 15) | ((chksum & 0xFFFE) >> 1)) + + (unsigned short)*c; + } + return chksum; +} + +void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync) +{ + set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(sb)->s_state); + set_buffer_uptodate(bh); + mark_buffer_dirty(bh); + + if (sync) + sync_dirty_buffer(bh); +} + +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); +}

[v9,09/13] exfat: add misc operations

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