From 58156c8fbf43e71dd091848d4dbfd780d04016e6 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 17 Dec 2012 16:02:58 -0800 Subject: fat: provide option for setting timezone offset So far FAT either offsets time stamps by sys_tz.minuteswest or leaves them as they are (when tz=UTC mount option is used). However in some cases it is useful if one can specify time stamp offset on his own (e.g. when time zone of the camera connected is different from time zone of the computer, or when HW clock is in UTC and thus sys_tz.minuteswest == 0). So provide a mount option time_offset= which allows user to specify offset in minutes that should be applied to time stamps on the filesystem. akpm: this code would work incorrectly when used via `mount -o remount', because cached inodes would not be updated. But fatfs's fat_remount() is basically a no-op anyway. Signed-off-by: Jan Kara Acked-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fat/inode.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) (limited to 'fs/fat/inode.c') diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 7b186a5d51b1..59ac83be2d5b 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -778,8 +778,12 @@ static int fat_show_options(struct seq_file *m, struct dentry *root) } if (opts->flush) seq_puts(m, ",flush"); - if (opts->tz_utc) - seq_puts(m, ",tz=UTC"); + if (opts->tz_set) { + if (opts->time_offset) + seq_printf(m, ",time_offset=%d", opts->time_offset); + else + seq_puts(m, ",tz=UTC"); + } if (opts->errors == FAT_ERRORS_CONT) seq_puts(m, ",errors=continue"); else if (opts->errors == FAT_ERRORS_PANIC) @@ -801,7 +805,8 @@ enum { Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, - Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_err, + Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, + Opt_err, }; static const match_table_t fat_tokens = { @@ -826,6 +831,7 @@ static const match_table_t fat_tokens = { {Opt_immutable, "sys_immutable"}, {Opt_flush, "flush"}, {Opt_tz_utc, "tz=UTC"}, + {Opt_time_offset, "time_offset=%d"}, {Opt_err_cont, "errors=continue"}, {Opt_err_panic, "errors=panic"}, {Opt_err_ro, "errors=remount-ro"}, @@ -910,7 +916,7 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, opts->utf8 = opts->unicode_xlate = 0; opts->numtail = 1; opts->usefree = opts->nocase = 0; - opts->tz_utc = 0; + opts->tz_set = 0; opts->nfs = 0; opts->errors = FAT_ERRORS_RO; *debug = 0; @@ -1006,8 +1012,17 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, case Opt_flush: opts->flush = 1; break; + case Opt_time_offset: + if (match_int(&args[0], &option)) + return 0; + if (option < -12 * 60 || option > 12 * 60) + return 0; + opts->tz_set = 1; + opts->time_offset = option; + break; case Opt_tz_utc: - opts->tz_utc = 1; + opts->tz_set = 1; + opts->time_offset = 0; break; case Opt_err_cont: opts->errors = FAT_ERRORS_CONT; -- cgit v1.2.3