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author | Frank Sorenson <sorenson@redhat.com> | 2018-10-31 01:06:53 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-31 18:54:14 +0300 |
commit | 6bb885ecd746752aa70d146b58f2f83e5e21813d (patch) | |
tree | f32ed7a4fda8e9fc8317adf2b024cd87d05fcc5a /fs/fat/misc.c | |
parent | d9f4d94261d52a5fe31ad2ec00a06824a150af6f (diff) | |
download | linux-6bb885ecd746752aa70d146b58f2f83e5e21813d.tar.xz |
fat: add functions to update and truncate timestamps appropriately
Add the fat-specific inode_operation ->update_time() and
fat_truncate_time() function to truncate the inode timestamps from 1
nanosecond to the appropriate granularity.
Link: http://lkml.kernel.org/r/38af1ba3c3cf0d7381ce7b63077ef8af75901532.1538363961.git.sorenson@redhat.com
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/fat/misc.c')
-rw-r--r-- | fs/fat/misc.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/fs/fat/misc.c b/fs/fat/misc.c index 2eca073fe785..fce0a76f3f1e 100644 --- a/fs/fat/misc.c +++ b/fs/fat/misc.c @@ -7,6 +7,7 @@ */ #include "fat.h" +#include <linux/iversion.h> /* * fat_fs_error reports a file system problem that might indicate fa data @@ -265,6 +266,80 @@ void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec64 *ts, } EXPORT_SYMBOL_GPL(fat_time_unix2fat); +static inline struct timespec64 fat_timespec64_trunc_2secs(struct timespec64 ts) +{ + return (struct timespec64){ ts.tv_sec & ~1ULL, 0 }; +} +/* + * truncate the various times with appropriate granularity: + * root inode: + * all times always 0 + * all other inodes: + * mtime - 2 seconds + * ctime + * msdos - 2 seconds + * vfat - 10 milliseconds + * atime - 24 hours (00:00:00 in local timezone) + */ +int fat_truncate_time(struct inode *inode, struct timespec64 *now, int flags) +{ + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + struct timespec64 ts; + + if (inode->i_ino == MSDOS_ROOT_INO) + return 0; + + if (now == NULL) { + now = &ts; + ts = current_time(inode); + } + + if (flags & S_ATIME) { + /* to localtime */ + time64_t seconds = now->tv_sec - fat_tz_offset(sbi); + s32 remainder; + + div_s64_rem(seconds, SECS_PER_DAY, &remainder); + /* to day boundary, and back to unix time */ + seconds = seconds + fat_tz_offset(sbi) - remainder; + + inode->i_atime = (struct timespec64){ seconds, 0 }; + } + if (flags & S_CTIME) { + if (sbi->options.isvfat) + inode->i_ctime = timespec64_trunc(*now, 10000000); + else + inode->i_ctime = fat_timespec64_trunc_2secs(*now); + } + if (flags & S_MTIME) + inode->i_mtime = fat_timespec64_trunc_2secs(*now); + + return 0; +} +EXPORT_SYMBOL_GPL(fat_truncate_time); + +int fat_update_time(struct inode *inode, struct timespec64 *now, int flags) +{ + int iflags = I_DIRTY_TIME; + bool dirty = false; + + if (inode->i_ino == MSDOS_ROOT_INO) + return 0; + + fat_truncate_time(inode, now, flags); + if (flags & S_VERSION) + dirty = inode_maybe_inc_iversion(inode, false); + if ((flags & (S_ATIME | S_CTIME | S_MTIME)) && + !(inode->i_sb->s_flags & SB_LAZYTIME)) + dirty = true; + + if (dirty) + iflags |= I_DIRTY_SYNC; + __mark_inode_dirty(inode, iflags); + return 0; +} +EXPORT_SYMBOL_GPL(fat_update_time); + int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs) { int i, err = 0; |