[JFFS2] Add symlink caching support.

Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 48 insertions, 6 deletions

diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c
index a1980a9da531..ef552477c813 100644
--- a/fs/jffs2/readinode.c
+++ b/fs/jffs2/readinode.c
@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: readinode.c,v 1.118 2005/02/27 23:01:33 dwmw2 Exp $
+ * $Id: readinode.c,v 1.119 2005/03/01 10:34:03 dedekind Exp $
  *
  */
 
@@ -623,6 +623,40 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
                    case. */
                 if (!je32_to_cpu(latest_node->isize))
                         latest_node->isize = latest_node->dsize;
+
+                if (f->inocache->state != INO_STATE_CHECKING) {
+                        /* Symlink's inode data is the target path. Read it and
+                         * keep in RAM to facilitate quick follow symlink operation.
+                         * We use f->dents field to store the target path, which
+                         * is somewhat ugly. */
+                        f->dents = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL);
+                        if (!f->dents) {
+                                printk(KERN_WARNING "Can't allocate %d bytes of memory "
+                                                "for the symlink target path cache\n",
+                                                je32_to_cpu(latest_node->csize));
+                                up(&f->sem);
+                                jffs2_do_clear_inode(c, f);
+                                return -ENOMEM;
+                        }
+                        
+                        ret = jffs2_flash_read(c, ref_offset(fn->raw) + sizeof(*latest_node),
+                                                je32_to_cpu(latest_node->csize), &retlen, (char *)f->dents);
+                        
+                        if (ret  || retlen != je32_to_cpu(latest_node->csize)) {
+                                if (retlen != je32_to_cpu(latest_node->csize))
+                                        ret = -EIO;
+                                kfree(f->dents);
+                                f->dents = NULL;
+                                up(&f->sem);
+                                jffs2_do_clear_inode(c, f);
+                                return -ret;
+                        }
+
+                        ((char *)f->dents)[je32_to_cpu(latest_node->csize)] = '\0';
+                        D1(printk(KERN_DEBUG "jffs2_do_read_inode(): symlink's target '%s' cached\n",
+                                                (char *)f->dents));
+                }
+                
                 /* fall through... */
 
         case S_IFBLK:
@@ -683,12 +717,20 @@ void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f)
 
         jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL);
 
-        fds = f->dents;
+        /* For symlink inodes we us f->dents to store the target path name */
+        if (S_ISLNK(OFNI_EDONI_2SFFJ(f)->i_mode)) {
+                if (f->dents) {
+                        kfree(f->dents);
+                        f->dents = NULL;
+                }
+        } else {
+                fds = f->dents;
 
-        while(fds) {
-                fd = fds;
-                fds = fd->next;
-                jffs2_free_full_dirent(fd);
+                while(fds) {
+                        fd = fds;
+                        fds = fd->next;
+                        jffs2_free_full_dirent(fd);
+                }
         }
 
         if (f->inocache && f->inocache->state != INO_STATE_CHECKING) {