• J
    fatfs: add UTC timestamp option · b271e067
    Joe Peterson 提交于
    Provide a new mount option ("tz=UTC") for DOS (vfat/msdos) filesystems,
    allowing timestamps to be in coordinated universal time (UTC) rather than
    local time in applications where doing this is advantageous.
    
    In particular, portable devices that use fat/vfat (such as digital
    cameras) can benefit from using UTC in their internal clocks, thus
    avoiding daylight saving time errors and general time ambiguity issues.
    The user of the device does not have to worry about changing the time when
    moving from place or when daylight saving changes.
    
    The new mount option, when set, disables the counter-adjustment that Linux
    currently makes to FAT timestamp info in anticipation of the normal
    userspace time zone correction.  When used in this new mode, all daylight
    saving time and time zone handling is done in userspace as is normal for
    many other filesystems (like ext3).  The default mode, which remains
    unchanged, is still appropriate when mounting volumes written in Windows
    (because of its use of local time).
    
    I originally based this patch on one submitted last year by Paul Collins,
    but I updated it to work with current source and changed variable/option
    naming.  Ogawa Hirofumi (who maintains these filesystems) and I discussed
    this patch at length on lkml, and he suggested using the option name in
    the attached version of the patch.  Barry Bouwsma pointed out a good
    addition to the patch as well.
    Signed-off-by: NJoe Peterson <joe@skyrush.com>
    Signed-off-by: NPaul Collins <paul@ondioline.org>
    Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
    Cc: Barry Bouwsma <free_beer_for_all@yahoo.com>
    Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    b271e067
misc.c 5.5 KB