fs: Replace CURRENT_TIME with current_time() for inode timestamps

CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hugetlbfs/inode.c

@@ -657,7 +657,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 
 	if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size)
 		i_size_write(inode, offset + len);
-	inode->i_ctime = CURRENT_TIME;
+	inode->i_ctime = current_time(inode);
 out:
 	inode_unlock(inode);
 	return error;
@@ -702,7 +702,7 @@ static struct inode *hugetlbfs_get_root(struct super_block *sb,
 		inode->i_mode = S_IFDIR | config->mode;
 		inode->i_uid = config->uid;
 		inode->i_gid = config->gid;
-		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 		info = HUGETLBFS_I(inode);
 		mpol_shared_policy_init(&info->policy, NULL);
 		inode->i_op = &hugetlbfs_dir_inode_operations;
@@ -741,7 +741,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 		lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
 				&hugetlbfs_i_mmap_rwsem_key);
 		inode->i_mapping->a_ops = &hugetlbfs_aops;
-		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 		inode->i_mapping->private_data = resv_map;
 		info = HUGETLBFS_I(inode);
 		/*
@@ -790,7 +790,7 @@ static int hugetlbfs_mknod(struct inode *dir,
 
 	inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
 	if (inode) {
-		dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+		dir->i_ctime = dir->i_mtime = current_time(dir);
 		d_instantiate(dentry, inode);
 		dget(dentry);	/* Extra count - pin the dentry in core */
 		error = 0;
@@ -827,7 +827,7 @@ static int hugetlbfs_symlink(struct inode *dir,
 		} else
 			iput(inode);
 	}
-	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+	dir->i_ctime = dir->i_mtime = current_time(dir);
 
 	return error;
 }