JFFS2: Speed up and fix comparison functions

[karo-tx-uboot.git] / fs / jffs2 / jffs2_1pass.c

diff --git a/fs/jffs2/jffs2_1pass.c b/fs/jffs2/jffs2_1pass.c
index 2e569ff59bb30a1d2b0594ba09a5e9d09c1979e4..aaeb522a31b88d8c4b86ccfcf051d5ec35680bf2 100644 (file)
--- a/fs/jffs2/jffs2_1pass.c
+++ b/fs/jffs2/jffs2_1pass.c
@@ -598,14 +598,18 @@ insert_node(struct b_list *list, u32 offset)
  */
 static int compare_inodes(struct b_node *new, struct b_node *old)
 {
-       struct jffs2_raw_inode ojNew;
-       struct jffs2_raw_inode ojOld;
-       struct jffs2_raw_inode *jNew =
-               (struct jffs2_raw_inode *)get_fl_mem(new->offset, sizeof(ojNew), &ojNew);
-       struct jffs2_raw_inode *jOld =
-               (struct jffs2_raw_inode *)get_fl_mem(old->offset, sizeof(ojOld), &ojOld);
-
-       return jNew->version > jOld->version;
+       /*
+        * Only read in the version info from flash, not the entire inode.
+        * This can make a big difference to speed if flash is slow.
+        */
+       u32 new_version;
+       u32 old_version;
+       get_fl_mem(new->offset + offsetof(struct jffs2_raw_inode, version),
+                  sizeof(new_version), &new_version);
+       get_fl_mem(old->offset + offsetof(struct jffs2_raw_inode, version),
+                  sizeof(old_version), &old_version);
+
+       return new_version > old_version;
 }
 
 /* Sort directory entries so all entries in the same directory
@@ -615,42 +619,45 @@ static int compare_inodes(struct b_node *new, struct b_node *old)
  */
 static int compare_dirents(struct b_node *new, struct b_node *old)
 {
-       struct jffs2_raw_dirent ojNew;
-       struct jffs2_raw_dirent ojOld;
-       struct jffs2_raw_dirent *jNew =
-               (struct jffs2_raw_dirent *)get_fl_mem(new->offset, sizeof(ojNew), &ojNew);
-       struct jffs2_raw_dirent *jOld =
-               (struct jffs2_raw_dirent *)get_fl_mem(old->offset, sizeof(ojOld), &ojOld);
-       int cmp;
-
-       /* ascending sort by pino */
-       if (jNew->pino != jOld->pino)
-               return jNew->pino > jOld->pino;
-
-       /* pino is the same, so use ascending sort by nsize, so
-        * we don't do strncmp unless we really must.
-        */
-       if (jNew->nsize != jOld->nsize)
-               return jNew->nsize > jOld->nsize;
-
-       /* length is also the same, so use ascending sort by name
-        */
-       cmp = strncmp((char *)jNew->name, (char *)jOld->name, jNew->nsize);
-       if (cmp != 0)
-               return cmp > 0;
-
-       /* we have duplicate names in this directory, so use ascending
-        * sort by version
+       /*
+        * Using NULL as the buffer for NOR flash prevents the entire node
+        * being read. This makes most comparisons much quicker as only one
+        * or two entries from the node will be used most of the time.
         */
-       if (jNew->version > jOld->version) {
-               /* since jNew is newer, we know jOld is not valid, so
-                * mark it with inode 0 and it will not be used
+       struct jffs2_raw_dirent *jNew = get_node_mem(new->offset, NULL);
+       struct jffs2_raw_dirent *jOld = get_node_mem(old->offset, NULL);
+       int cmp;
+       int ret;
+
+       if (jNew->pino != jOld->pino) {
+               /* ascending sort by pino */
+               ret = jNew->pino > jOld->pino;
+       } else if (jNew->nsize != jOld->nsize) {
+               /*
+                * pino is the same, so use ascending sort by nsize,
+                * so we don't do strncmp unless we really must.
                 */
-               jOld->ino = 0;
-               return 1;
+               ret = jNew->nsize > jOld->nsize;
+       } else {
+               /*
+                * length is also the same, so use ascending sort by name
+                */
+               cmp = strncmp((char *)jNew->name, (char *)jOld->name,
+                       jNew->nsize);
+               if (cmp != 0) {
+                       ret = cmp > 0;
+               } else {
+                       /*
+                        * we have duplicate names in this directory,
+                        * so use ascending sort by version
+                        */
+                       ret = jNew->version > jOld->version;
+               }
        }
+       put_fl_mem(jNew, NULL);
+       put_fl_mem(jOld, NULL);
 
-       return 0;
+       return ret;
 }
 #endif