fuse: allow ctime flushing to userspace

The patch extends fuse_setattr_in, and extends the flush procedure
(fuse_flush_times()) called on ->write_inode() to send the ctime as well as
mtime.
Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

fs/fuse/dir.c

@@ -1597,7 +1597,7 @@ static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_req *req,
 /*
  * Flush inode->i_mtime to the server
  */
-int fuse_flush_mtime(struct inode *inode, struct fuse_file *ff)
+int fuse_flush_times(struct inode *inode, struct fuse_file *ff)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_req *req;
@@ -1612,9 +1612,14 @@ int fuse_flush_mtime(struct inode *inode, struct fuse_file *ff)
 	memset(&inarg, 0, sizeof(inarg));
 	memset(&outarg, 0, sizeof(outarg));
 
-	inarg.valid |= FATTR_MTIME;
+	inarg.valid = FATTR_MTIME;
 	inarg.mtime = inode->i_mtime.tv_sec;
 	inarg.mtimensec = inode->i_mtime.tv_nsec;
+	if (fc->minor >= 23) {
+		inarg.valid |= FATTR_CTIME;
+		inarg.ctime = inode->i_ctime.tv_sec;
+		inarg.ctimensec = inode->i_ctime.tv_nsec;
+	}
 	if (ff) {
 		inarg.valid |= FATTR_FH;
 		inarg.fh = ff->fh;

fs/fuse/file.c

@@ -1691,7 +1691,7 @@ int fuse_write_inode(struct inode *inode, struct writeback_control *wbc)
 	int err;
 
 	ff = __fuse_write_file_get(fc, fi);
-	err = fuse_flush_mtime(inode, ff);
+	err = fuse_flush_times(inode, ff);
 	if (ff)
 		fuse_file_put(ff, 0);
 

fs/fuse/fuse_i.h

@@ -889,7 +889,7 @@ int fuse_dev_release(struct inode *inode, struct file *file);
 
 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 
-int fuse_flush_mtime(struct inode *inode, struct fuse_file *ff);
+int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 
 int fuse_do_setattr(struct inode *inode, struct iattr *attr,

include/uapi/linux/fuse.h

@@ -98,6 +98,8 @@
  *  - add FUSE_WRITEBACK_CACHE
  *  - add time_gran to fuse_init_out
  *  - add reserved space to fuse_init_out
+ *  - add FATTR_CTIME
+ *  - add ctime and ctimensec to fuse_setattr_in
  */
 
 #ifndef _LINUX_FUSE_H
@@ -193,6 +195,7 @@ struct fuse_file_lock {
 #define FATTR_ATIME_NOW	(1 << 7)
 #define FATTR_MTIME_NOW	(1 << 8)
 #define FATTR_LOCKOWNER	(1 << 9)
+#define FATTR_CTIME	(1 << 10)
 
 /**
  * Flags returned by the OPEN request
@@ -440,10 +443,10 @@ struct fuse_setattr_in {
 	uint64_t	lock_owner;
 	uint64_t	atime;
 	uint64_t	mtime;
-	uint64_t	unused2;
+	uint64_t	ctime;
 	uint32_t	atimensec;
 	uint32_t	mtimensec;
-	uint32_t	unused3;
+	uint32_t	ctimensec;
 	uint32_t	mode;
 	uint32_t	unused4;
 	uint32_t	uid;