1 files changed, 29 insertions, 4 deletions

diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index b4957c7d9fe2..edaded48e7e9 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -40,6 +40,14 @@
 #include "inode.h"
 #include "super.h"
 
+void ocfs2_dentry_attach_gen(struct dentry *dentry)
+{
+        unsigned long gen =
+                OCFS2_I(dentry->d_parent->d_inode)->ip_dir_lock_gen;
+        BUG_ON(dentry->d_inode);
+        dentry->d_fsdata = (void *)gen;
+}
+
 
 static int ocfs2_dentry_revalidate(struct dentry *dentry,
                                    struct nameidata *nd)
@@ -51,11 +59,20 @@ static int ocfs2_dentry_revalidate(struct dentry *dentry,
         mlog_entry("(0x%p, '%.*s')\n", dentry,
                    dentry->d_name.len, dentry->d_name.name);
 
-        /* Never trust a negative dentry - force a new lookup. */
+        /* For a negative dentry -
+         * check the generation number of the parent and compare with the
+         * one stored in the inode.
+         */
         if (inode == NULL) {
-                mlog(0, "negative dentry: %.*s\n", dentry->d_name.len,
-                     dentry->d_name.name);
-                goto bail;
+                unsigned long gen = (unsigned long) dentry->d_fsdata;
+                unsigned long pgen =
+                        OCFS2_I(dentry->d_parent->d_inode)->ip_dir_lock_gen;
+                mlog(0, "negative dentry: %.*s parent gen: %lu "
+                        "dentry gen: %lu\n",
+                        dentry->d_name.len, dentry->d_name.name, pgen, gen);
+                if (gen != pgen)
+                        goto bail;
+                goto valid;
         }
 
         BUG_ON(!osb);
@@ -96,6 +113,7 @@ static int ocfs2_dentry_revalidate(struct dentry *dentry,
                 goto bail;
         }
 
+valid:
         ret = 1;
 
 bail:
@@ -227,6 +245,12 @@ int ocfs2_dentry_attach_lock(struct dentry *dentry,
         if (!inode)
                 return 0;
 
+        if (!dentry->d_inode && dentry->d_fsdata) {
+                /* Converting a negative dentry to positive
+                   Clear dentry->d_fsdata */
+                dentry->d_fsdata = dl = NULL;
+        }
+
         if (dl) {
                 mlog_bug_on_msg(dl->dl_parent_blkno != parent_blkno,
                                 " \"%.*s\": old parent: %llu, new: %llu\n",
@@ -452,6 +476,7 @@ static void ocfs2_dentry_iput(struct dentry *dentry, struct inode *inode)
 
 out:
         iput(inode);
+        ocfs2_dentry_attach_gen(dentry);
 }
 
 /*