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authorFrank Sorenson <sorenson@redhat.com>2018-10-31 01:06:53 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-31 18:54:14 +0300
commit6bb885ecd746752aa70d146b58f2f83e5e21813d (patch)
treef32ed7a4fda8e9fc8317adf2b024cd87d05fcc5a /fs/fat/misc.c
parentd9f4d94261d52a5fe31ad2ec00a06824a150af6f (diff)
downloadlinux-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.c75
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;