GFS2: Clean up journal extent mapping

This patch fixes a long standing issue in mapping the journal
extents. Most journals will consist of only a single extent,
and although the cache took account of that by merging extents,
it did not actually map large extents, but instead was doing a
block by block mapping. Since the journal was only being mapped
on mount, this was not normally noticeable.

With the updated code, it is now possible to use the same extent
mapping system during journal recovery (which will be added in a
later patch). This will allow checking of the integrity of the
journal before any reply of the journal content is attempted. For
this reason the code is moving to bmap.c, since it will be used
more widely in due course.

An exercise left for the reader is to compare the new function
gfs2_map_journal_extents() with gfs2_write_alloc_required()

Additionally, should there be a failure, the error reporting is
also updated to show more detail about what went wrong.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 2 insertions, 10 deletions

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 60f60f6181f3..25747440ebbb 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -295,9 +295,8 @@ int gfs2_mount_args(struct gfs2_args *args, char *options)
 
 void gfs2_jindex_free(struct gfs2_sbd *sdp)
 {
-        struct list_head list, *head;
+        struct list_head list;
         struct gfs2_jdesc *jd;
-        struct gfs2_journal_extent *jext;
 
         spin_lock(&sdp->sd_jindex_spin);
         list_add(&list, &sdp->sd_jindex_list);
@@ -307,14 +306,7 @@ void gfs2_jindex_free(struct gfs2_sbd *sdp)
 
         while (!list_empty(&list)) {
                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
-                head = &jd->extent_list;
-                while (!list_empty(head)) {
-                        jext = list_entry(head->next,
-                                          struct gfs2_journal_extent,
-                                          extent_list);
-                        list_del(&jext->extent_list);
-                        kfree(jext);
-                }
+                gfs2_free_journal_extents(jd);
                 list_del(&jd->jd_list);
                 iput(jd->jd_inode);
                 kfree(jd);