From 426c85303bfb03fa8e343182f30d266dad621fcc Mon Sep 17 00:00:00 2001
From: plougher <plougher>
Date: Tue, 14 Oct 2008 05:34:55 +0000
Subject: More comments

---
 kernel/fs/squashfs/export.c   | 16 ++++++++++++++--
 kernel/fs/squashfs/fragment.c |  6 +++---
 kernel/fs/squashfs/id.c       |  4 ++--
 3 files changed, 19 insertions(+), 7 deletions(-)

(limited to 'kernel')

diff --git a/kernel/fs/squashfs/export.c b/kernel/fs/squashfs/export.c
index 9c8cc2d..b59bfeb 100644
--- a/kernel/fs/squashfs/export.c
+++ b/kernel/fs/squashfs/export.c
@@ -21,6 +21,20 @@
  * export.c
  */
 
+/*
+ * This file implements code to make Squashfs filesystems exportable (NFS etc.)
+ *
+ * The export code uses an inode lookup table to map inode numbers passed in
+ * filehandles to an inode location on disk.  This table is stored compressed
+ * into metadata blocks.  A second index table is used to locate these.  This
+ * second index table for speed of access (and because it is small) is read at
+ * mount time and cached in memory.
+ *
+ * The inode lookup table is used only by the export code, inode disk
+ * locations are directly encoded in directories, enabling direct access
+ * without an intermediate lookup for all operations except the export ops.
+ */
+
 #include <linux/fs.h>
 #include <linux/vfs.h>
 #include <linux/dcache.h>
@@ -92,8 +106,6 @@ static struct dentry *squashfs_get_parent(struct dentry *child)
 {
 	struct inode *i = child->d_inode;
 
-	TRACE("Entered squashfs_get_parent\n");
-
 	return squashfs_export_iget(i->i_sb, SQUASHFS_I(i)->parent_inode);
 }
 
diff --git a/kernel/fs/squashfs/fragment.c b/kernel/fs/squashfs/fragment.c
index 2ebbbae..f0f3e51 100644
--- a/kernel/fs/squashfs/fragment.c
+++ b/kernel/fs/squashfs/fragment.c
@@ -26,11 +26,11 @@
  * datablocks).
  *
  * Regular files contain a fragment index which is mapped to a fragment
- * location on disk and compressed size using a fragment lookup table. 
+ * location on disk and compressed size using a fragment lookup table.
  * Like everything in Squashfs this fragment lookup table is itself stored
  * compressed into metadata blocks.  A second index table is used to locate
- * these compressed metadata blocks.  This index table for speed of access
- * (and because it is small) is read at mount time and cached in memory.
+ * these.  This second index table for speed of access (and because it
+ * is small) is read at mount time and cached in memory.
  */
 
 #include <linux/fs.h>
diff --git a/kernel/fs/squashfs/id.c b/kernel/fs/squashfs/id.c
index 044547e..d2920c9 100644
--- a/kernel/fs/squashfs/id.c
+++ b/kernel/fs/squashfs/id.c
@@ -27,8 +27,8 @@
  * For space efficiency regular files store uid and gid indexes, which are
  * converted to 32-bit uids/gids using an id look up table.  This table is
  * stored compressed into metadata blocks.  A second index table is used to
- * locate these.  This index table for speed of access (and because it is
- * small) is read at mount time and cached in memory.
+ * locate these.  This second index table for speed of access (and because it
+ * is small) is read at mount time and cached in memory.
  */
 
 #include <linux/fs.h>
-- 
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