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.
Signed-off-by: Frank Sorenson <sorenson@xxxxxxxxxx>
---
fs/fat/fat.h | 4 +++
fs/fat/file.c | 1 +
fs/fat/inode.c | 5 ++++
fs/fat/misc.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/fat/namei_msdos.c | 1 +
fs/fat/namei_vfat.c | 1 +
6 files changed, 87 insertions(+)
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 9d7d2d5da28b..4e1b2f6df5e6 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -416,6 +416,10 @@ extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec64 *ts,
__le16 __time, __le16 __date, u8 time_cs);
extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec64 *ts,
__le16 *time, __le16 *date, u8 *time_cs);
+extern int fat_truncate_time(struct inode *inode, struct timespec64 *now,
+ int flags);
+extern int fat_update_time(struct inode *inode, struct timespec64 *now,
+ int flags);
extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
int fat_cache_init(void);
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 4f3d72fb1e60..19b6b0566411 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -552,4 +552,5 @@ EXPORT_SYMBOL_GPL(fat_setattr);
const struct inode_operations fat_file_inode_operations = {
.setattr = fat_setattr,
.getattr = fat_getattr,
+ .update_time = fat_update_time,
};
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index d6b81e31f9f5..3bf60f19b6d3 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1626,6 +1626,11 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
sb->s_magic = MSDOS_SUPER_MAGIC;
sb->s_op = &fat_sops;
sb->s_export_op = &fat_export_ops;
+ /*
+ * fat timestamps are complex and truncated by fat itself, so
+ * we set 1 here to be fast
+ */
+ sb->s_time_gran = 1;
mutex_init(&sbi->nfs_build_inode_lock);
ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
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;
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index efb8c40c9d27..effbdd5fbf6e 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -637,6 +637,7 @@ static const struct inode_operations msdos_dir_inode_operations = {
.rename = msdos_rename,
.setattr = fat_setattr,
.getattr = fat_getattr,
+ .update_time = fat_update_time,
};
static void setup(struct super_block *sb)
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 82cd1e69cbdf..1daa57cf4bf3 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -1032,6 +1032,7 @@ static const struct inode_operations vfat_dir_inode_operations = {
.rename = vfat_rename,
.setattr = fat_setattr,
.getattr = fat_getattr,
+ .update_time = fat_update_time,
};
static void setup(struct super_block *sb)
--
2.13.6
