mountd: optimize libblkid usagenfs-utils-1-3-0-rc2nfs-utils-1-2-10-rc2

 * use get_uuid_blkdev() only first time for the path (it means
   that uuid_by_path() is called with type==0)

 * don't use libblkid for btrfs, network or pseudo filesystems

Note that the patch defines the fs type ID rather than include
<linux/magic.h> as this file seems incomplete and libc specific).

Signed-off-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

1 files changed, 35 insertions, 3 deletions

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index e04b86e..ca35de2 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -266,6 +266,27 @@ static int get_uuid(const char *val, size_t uuidlen, char *u)
 	return 1;
 }
 
+
+/*
+ * Don't ask libblkid for these filesystems. Note that BTRF is ignored, because
+ * we generate the identifier from statfs->f_fsid. The rest are network or
+ * pseudo filesystems. (See <linux/magic.h> for the basic IDs.)
+ */
+static const long int nonblkid_filesystems[] = {
+    0x2fc12fc1,    /* ZFS_SUPER_MAGIC */
+    0x9123683E,    /* BTRFS_SUPER_MAGIC */
+    0xFF534D42,    /* CIFS_MAGIC_NUMBER */
+    0x1373,        /* DEVFS_SUPER_MAGIC */
+    0x73757245,    /* CODA_SUPER_MAGIC */
+    0x564C,        /* NCP_SUPER_MAGIC */
+    0x6969,        /* NFS_SUPER_MAGIC */
+    0x9FA0,        /* PROC_SUPER_MAGIC */
+    0x62656572,    /* SYSFS_MAGIC */
+    0x517B,        /* SMB_SUPER_MAGIC */
+    0x01021994,    /* TMPFS_SUPER_MAGIC */
+    0        /* last */
+};
+
 static int uuid_by_path(char *path, int type, size_t uuidlen, char *uuid)
 {
 	/* get a uuid for the filesystem found at 'path'.
@@ -297,12 +318,23 @@ static int uuid_by_path(char *path, int type, size_t uuidlen, char *uuid)
 	 */
 	struct statfs64 st;
 	char fsid_val[17];
-	const char *blkid_val;
+	const char *blkid_val = NULL;
 	const char *val;
+	int rc;
 
-	blkid_val = get_uuid_blkdev(path);
+	rc = statfs64(path, &st);
+
+	if (type == 0 && rc == 0) {
+		const long int *bad;
+		for (bad = nonblkid_filesystems; *bad; bad++) {
+			if (*bad == st.f_type)
+				break;
+		}
+		if (*bad == 0)
+			blkid_val = get_uuid_blkdev(path);
+	}
 
-	if (statfs64(path, &st) == 0 &&
+	if (rc == 0 &&
 	    (st.f_fsid.__val[0] || st.f_fsid.__val[1]))
 		snprintf(fsid_val, 17, "%08x%08x",
 			 st.f_fsid.__val[0], st.f_fsid.__val[1]);