make offline logfs image and some BUG()
Tristan Lelong
tristan.lelong at blunderer.org
Mon Nov 19 14:31:32 EST 2012
Hi,
I am trying to use logfs for a project I am currently working on. The
kernel version I used is 2.6.37 with some patch from TI DM8168.
I search on the internet for an offline way to create a logfs image from
a directory (like mkfs.jffs2), and the only way seems to be using the
block2mtd kernel module. Does anybody confirm that?
Also I encountered two BUG():
- The first is already documented on some mailing lists: it is the one
that it appears when doing umount -> call to map_invalidatepage.
I was able to apply the attached patch1 to fix this, but I still see
call to this function. I guess I might miss something.
- The other one is when mounting a filesystem that detects a previous
incomplete write: it BUG() because it cannot find any free segment.
Trying to understand what is happening, I realized that during the
mount, the function that adds segment to the free list is called after
the function that check the filesystem. I modified this like in the
following patch2 and it seems to work fine.
Does anybody have any thoughts about that?
Thanks a lo
---
618FE3EF
-------------- next part --------------
Index: super.c
===================================================================
--- super.c (revision 24035)
+++ super.c (working copy)
@@ -511,6 +510,7 @@
/* Alias entries slow down mount, so evict as many as possible */
sync_filesystem(sb);
logfs_write_anchor(sb);
+ free_areas(sb);
/*
* From this point on alias entries are simply dropped - and any
Index: segment.c
===================================================================
--- segment.c (revision 24035)
+++ segment.c (working copy)
@@ -841,6 +841,16 @@
kfree(area);
}
+void free_areas(struct super_block *sb)
+{
+ struct logfs_super *super = logfs_super(sb);
+ int i;
+
+ for_each_area(i)
+ free_area(super->s_area[i]);
+ free_area(super->s_journal_area);
+}
+
static struct logfs_area *alloc_area(struct super_block *sb)
{
struct logfs_area *area;
@@ -923,10 +933,6 @@
void logfs_cleanup_areas(struct super_block *sb)
{
struct logfs_super *super = logfs_super(sb);
- int i;
btree_grim_visitor128(&super->s_object_alias_tree, 0, kill_alias);
- for_each_area(i)
- free_area(super->s_area[i]);
- free_area(super->s_journal_area);
}
Index: logfs.h
===================================================================
--- logfs.h (revision 24035)
+++ logfs.h (working copy)
@@ -594,6 +594,7 @@
void logfs_sync_area(struct logfs_area *area);
void logfs_sync_segments(struct super_block *sb);
void freeseg(struct super_block *sb, u32 segno);
+void free_areas(struct super_block *sb);
/* area handling */
int logfs_init_areas(struct super_block *sb);
-------------- next part --------------
Index: super.c
===================================================================
--- super.c (revision 24035)
+++ super.c (working copy)
@@ -308,14 +308,13 @@
if (err)
return err;
+ /* Do one GC pass before any data gets dirtied */
+ logfs_gc_pass(sb);
+
/* Check areas for trailing unaccounted data */
err = logfs_check_areas(sb);
if (err)
return err;
-
- /* Do one GC pass before any data gets dirtied */
- logfs_gc_pass(sb);
-
/* after all initializations are done, replay the journal
* for rw-mounts, if necessary */
err = logfs_replay_journal(sb);
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