[GFS2] Fix bug in directory code and tidy up

Due to a typo, the dir leaf split operation was (for the first
split in a directory) writing the new hash vaules at the
wrong offset. This is now fixed.

Also some other tidy ups are included:

 - We use GFS2's hash function for dentries (see ops_dentry.c) so that
   we don't have to keep recalculating the hash values.
 - A lot of common code is eliminated between the various directory
   lookup routines.
 - Better error checking on directory lookup (previously different
   routines checked for different errors)
 - The leaf split operation has a couple of redundant operations
   removed from it, so it should be faster.

There is still further scope for further clean ups in the directory
code, and readdir in particular could do with slimming down a bit.

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

1 files changed, 13 insertions, 8 deletions

diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
index 7f6139288519..b54608f9df50 100644
--- a/fs/gfs2/ops_dentry.c
+++ b/fs/gfs2/ops_dentry.c
@@ -38,25 +38,26 @@
 static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
 {
         struct dentry *parent = dget_parent(dentry);
+        struct gfs2_sbd *sdp = parent->d_inode->i_sb->s_fs_info;
         struct gfs2_inode *dip = parent->d_inode->u.generic_ip;
-        struct inode *inode;
+        struct inode *inode = dentry->d_inode;
         struct gfs2_holder d_gh;
         struct gfs2_inode *ip;
         struct gfs2_inum inum;
         unsigned int type;
         int error;
 
-        lock_kernel();
-
-        inode = dentry->d_inode;
         if (inode && is_bad_inode(inode))
                 goto invalid;
 
+        if (sdp->sd_args.ar_localcaching)
+                goto valid;
+
         error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
         if (error)
                 goto fail;
 
-        error = gfs2_dir_search(dip, &dentry->d_name, &inum, &type);
+        error = gfs2_dir_search(parent->d_inode, &dentry->d_name, &inum, &type);
         switch (error) {
         case 0:
                 if (!inode)
@@ -84,7 +85,6 @@ static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
         gfs2_glock_dq_uninit(&d_gh);
 
  valid:
-        unlock_kernel();
         dput(parent);
         return 1;
 
@@ -99,7 +99,6 @@ static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
         }
         d_drop(dentry);
 
-        unlock_kernel();
         dput(parent);
         return 0;
 
@@ -107,12 +106,18 @@ static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
         gfs2_glock_dq_uninit(&d_gh);
 
  fail:
-        unlock_kernel();
         dput(parent);
         return 0;
 }
 
+static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
+{
+        str->hash = gfs2_disk_hash(str->name, str->len);
+        return 0;
+}
+
 struct dentry_operations gfs2_dops = {
         .d_revalidate = gfs2_drevalidate,
+        .d_hash = gfs2_dhash,
 };