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yaml --- r: 43313 b: refs/heads/master c: aac1a3c h: refs/heads/master i: 43311: 4354a45 v: v3
git-mirror · Nov 30, 2006 · ae18686 · ae18686
1 parent 5ec4def
commit ae18686
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0da3585e1ef650d3224b4d6f9799558d1d99fa1e
+refs/heads/master: aac1a3c77a46c2d06f297641760dd740ac2a84af
diff --git a/trunk/fs/gfs2/super.c b/trunk/fs/gfs2/super.c
@@ -180,6 +180,24 @@ static int end_bio_io_page(struct bio *bio, unsigned int bytes_done, int error)
 	return 0;
 }
 
+/**
+ * gfs2_read_super - Read the gfs2 super block from disk
+ * @sb: The VFS super block
+ * @sector: The location of the super block
+ *
+ * This uses the bio functions to read the super block from disk
+ * because we want to be 100% sure that we never read cached data.
+ * A super block is read twice only during each GFS2 mount and is
+ * never written to by the filesystem. The first time its read no
+ * locks are held, and the only details which are looked at are those
+ * relating to the locking protocol. Once locking is up and working,
+ * the sb is read again under the lock to establish the location of
+ * the master directory (contains pointers to journals etc) and the
+ * root directory.
+ *
+ * Returns: A page containing the sb or NULL
+ */
+
 struct page *gfs2_read_super(struct super_block *sb, sector_t sector)
 {
 	struct page *page;