0001-libhammer-Add-a-function-to-calculate-PFS-paths.diff

From 025c7794f89c68e80fe75c041b74b475388b1e2e Mon Sep 17 00:00:00 2001
From: Antonio Huete Jimenez <[email protected]>
Date: Sun, 29 Dec 2013 21:45:34 +0100
Subject: [PATCH] libhammer - Add a function to calculate PFS paths.

---
 lib/libhammer/libhammer.h |  1 +
 lib/libhammer/misc.c      | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/libhammer/libhammer.h b/lib/libhammer/libhammer.h
index 712abc0..5271466 100644
--- a/lib/libhammer/libhammer.h
+++ b/lib/libhammer/libhammer.h
@@ -168,6 +168,7 @@ int libhammer_io_stats(struct libhammer_io_stats *);
 
 char *libhammer_find_pfs_mount(int, uuid_t, int);
 void *_libhammer_malloc(size_t);
+void libhammer_get_pfspath(libhammer_pfsinfo_t, char *);
 __END_DECLS
 
 static __inline libhammer_pfsinfo_t
diff --git a/lib/libhammer/misc.c b/lib/libhammer/misc.c
index 03751ab..6b7fec6 100644
--- a/lib/libhammer/misc.c
+++ b/lib/libhammer/misc.c
@@ -140,3 +140,23 @@ _libhammer_malloc(size_t len)
 
 	return (m);
 }
+
+/*
+ * Identify the type of PFS (slave, master) and determine a
+ * valid path to open(2).
+ * Useful when trying to get a file-descriptor to issue an
+ * ioctl(2) on a specific PFS.
+ */
+void
+libhammer_get_pfspath(libhammer_pfsinfo_t pfi, char *path)
+{
+
+	/* In the case beg_tid and end_tid is 1 it means it's
+	 * a manually created PFS and it's unlikely the calculated
+	 * path below will be resolved by the VFS code.
+	 */
+	if (pfi->ismaster)
+		sprintf(path, "@@-1:%05d", pfi->pfs_id);
+	else
+		sprintf(path, "@@0x%016jx:%05d", pfi->end_tid, pfi->pfs_id);
+}
-- 
1.8.4.1