[PATCH] fat: set s_time_gran for msdos or vfat mounts

[Frank Sorenson <sorenson@xxxxxxxxxx>]

Author: Frank Sorenson <sorenson@xxxxxxxxxx>
Date:   2018-01-23 15:51:37 -0600

    fat: set the s_time_gran for msdos or vfat mounts
    
    For vfat, ctime granularity is 10ms; set the
    super_block's s_time_gran to 10ms for vfat and
    1 second for msdos mounts.
    
    Signed-off-by: Frank Sorenson <sorenson@xxxxxxxxxx>

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 20a0a89eaca5..ff10cdf07a93 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1612,6 +1612,7 @@ 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;
+	sb->s_time_gran = isvfat ? 10000000 : 1000000000;
 	mutex_init(&sbi->nfs_build_inode_lock);
 	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
 			     DEFAULT_RATELIMIT_BURST);