Add 'flag_utime_omit_ok' flag to fuse_operations

If the filesystem sets this flag then ->utimens() will receive UTIME_OMIT and
UTIME_NOW values as specified in utimensat(2).

4 files changed, 41 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index fab6ee1..c8d9323 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,10 @@
 	* Check protocol version before sending notifications and return
 	-ENOSYS if a particular notification is not supported.
 
+	* Add 'flag_utime_omit_ok' flag to fuse_operations.  If the
+	filesystem sets this flag then ->utimens() will receive UTIME_OMIT
+	and UTIME_NOW values as specified in utimensat(2).
+
 2012-01-27  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Interpret octal escape codes in options.  Requested by Jan
diff --git a/example/fusexmp_fh.c b/example/fusexmp_fh.c
index 57053ca..e9524c6 100644
--- a/example/fusexmp_fh.c
+++ b/example/fusexmp_fh.c
@@ -539,6 +539,9 @@ static struct fuse_operations xmp_oper = {
 	.flock		= xmp_flock,
 
 	.flag_nullpath_ok = 1,
+#if HAVE_UTIMENSAT
+	.flag_utime_omit_ok = 1,
+#endif
 };
 
 int main(int argc, char *argv[])
diff --git a/include/fuse.h b/include/fuse.h
index b05152d..36b168c 100644
--- a/include/fuse.h
+++ b/include/fuse.h
@@ -480,9 +480,15 @@ struct fuse_operations {
 	unsigned int flag_nopath:1;
 
 	/**
+	 * Flag indicating that the filesystem accepts special
+	 * UTIME_NOW and UTIME_OMIT values in its utimens operation.
+	 */
+	unsigned int flag_utime_omit_ok:1;
+
+	/**
 	 * Reserved flags, don't set
 	 */
-	unsigned int flag_reserved:30;
+	unsigned int flag_reserved:29;
 
 	/**
 	 * Ioctl
diff --git a/lib/fuse.c b/lib/fuse.c
index e01f450..4922361 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -132,6 +132,7 @@ struct fuse {
 	int intr_installed;
 	struct fuse_fs *fs;
 	int nullpath_ok;
+	int utime_omit_ok;
 	int curr_ticket;
 	struct lock_queue_element *lockq;
 	int pagesize;
@@ -2720,6 +2721,29 @@ static void fuse_lib_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
 				err = fuse_fs_truncate(f->fs, path,
 						       attr->st_size);
 		}
+#ifdef HAVE_UTIMENSAT
+		if (!err && f->utime_omit_ok &&
+		    (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME))) {
+			struct timespec tv[2];
+
+			tv[0].tv_sec = 0;
+			tv[1].tv_sec = 0;
+			tv[0].tv_nsec = UTIME_OMIT;
+			tv[1].tv_nsec = UTIME_OMIT;
+
+			if (valid & FUSE_SET_ATTR_ATIME_NOW)
+				tv[0].tv_nsec = UTIME_NOW;
+			else if (valid & FUSE_SET_ATTR_ATIME)
+				tv[0] = attr->st_atim;
+
+			if (valid & FUSE_SET_ATTR_MTIME_NOW)
+				tv[1].tv_nsec = UTIME_NOW;
+			else if (valid & FUSE_SET_ATTR_MTIME)
+				tv[1] = attr->st_mtim;
+
+			err = fuse_fs_utimens(f->fs, path, tv);
+		} else
+#endif
 		if (!err &&
 		    (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) ==
 		    (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) {
@@ -4401,6 +4425,7 @@ static int fuse_push_module(struct fuse *f, const char *module,
 	f->fs = newfs;
 	f->nullpath_ok = newfs->op.flag_nullpath_ok && f->nullpath_ok;
 	f->conf.nopath = newfs->op.flag_nopath && f->conf.nopath;
+	f->utime_omit_ok = newfs->op.flag_utime_omit_ok && f->utime_omit_ok;
 	return 0;
 }
 
@@ -4496,6 +4521,7 @@ struct fuse *fuse_new_common(struct fuse_chan *ch, struct fuse_args *args,
 	f->fs = fs;
 	f->nullpath_ok = fs->op.flag_nullpath_ok;
 	f->conf.nopath = fs->op.flag_nopath;
+	f->utime_omit_ok = fs->op.flag_utime_omit_ok;
 
 	/* Oh f**k, this is ugly! */
 	if (!fs->op.lock) {
@@ -4560,6 +4586,7 @@ struct fuse *fuse_new_common(struct fuse_chan *ch, struct fuse_args *args,
 	if (f->conf.debug) {
 		fprintf(stderr, "nullpath_ok: %i\n", f->nullpath_ok);
 		fprintf(stderr, "nopath: %i\n", f->conf.nopath);
+		fprintf(stderr, "utime_omit_ok: %i\n", f->utime_omit_ok);
 	}
 
 	/* Trace topmost layer by default */