GFS2: Clean up freeze code

The freeze code has not been looked at a lot recently. Upstream has
moved on, and this is an attempt to catch us back up again. There
is a vfs level interface for the freeze code which can be called
from our (obsolete, but kept for backward compatibility purposes)
sysfs freeze interface. This means freezing this way vs. doing it
from the ioctl should now work in identical fashion.

As a result of this, the freeze function is only called once
and we can drop our own special purpose code for counting the
number of freezes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 11 insertions, 13 deletions

diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 8056b7b7238e..462e84142759 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -91,19 +91,15 @@ static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
 
 static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
 {
-	unsigned int count;
-
-	mutex_lock(&sdp->sd_freeze_lock);
-	count = sdp->sd_freeze_count;
-	mutex_unlock(&sdp->sd_freeze_lock);
+	struct super_block *sb = sdp->sd_vfs;
+	int frozen = (sb->s_writers.frozen == SB_UNFROZEN) ? 0 : 1;
 
-	return snprintf(buf, PAGE_SIZE, "%u\n", count);
+	return snprintf(buf, PAGE_SIZE, "%u\n", frozen);
 }
 
 static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
 {
-	ssize_t ret = len;
-	int error = 0;
+	int error;
 	int n = simple_strtol(buf, NULL, 0);
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -111,19 +107,21 @@ static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
 
 	switch (n) {
 	case 0:
-		gfs2_unfreeze_fs(sdp);
+		error = thaw_super(sdp->sd_vfs);
 		break;
 	case 1:
-		error = gfs2_freeze_fs(sdp);
+		error = freeze_super(sdp->sd_vfs);
 		break;
 	default:
-		ret = -EINVAL;
+		return -EINVAL;
 	}
 
-	if (error)
+	if (error) {
 		fs_warn(sdp, "freeze %d error %d", n, error);
+		return error;
+	}
 
-	return ret;
+	return len;
 }
 
 static ssize_t withdraw_show(struct gfs2_sbd *sdp, char *buf)