add workaround for race in dcache with patchless client.

Branch b1_8_gate
b=15975
i=johann
i=adilger

diff --git a/lustre/llite/namei.c b/lustre/llite/namei.c
index a49b9ab..9206791 100644 (file)
--- a/lustre/llite/namei.c
+++ b/lustre/llite/namei.c
@@ -148,6 +148,7 @@ static void ll_drop_negative_dentry(struct inode *dir)
 { 
         struct dentry *dentry, *tmp_alias, *tmp_subdir;
 
+        spin_lock(&ll_lookup_lock);
         spin_lock(&dcache_lock);
 restart:
         list_for_each_entry_safe(dentry, tmp_alias,
@@ -168,6 +169,7 @@ restart:
                 }
         }
         spin_unlock(&dcache_lock);
+        spin_unlock(&ll_lookup_lock);
 }
 
 int ll_mdc_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
@@ -376,6 +378,7 @@ static struct dentry *ll_find_alias(struct inode *inode, struct dentry *de)
         struct dentry *dentry;
         struct dentry *last_discon = NULL;
 
+        spin_lock(&ll_lookup_lock);
         spin_lock(&dcache_lock);
         list_for_each(tmp, &inode->i_dentry) {
                 dentry = list_entry(tmp, struct dentry, d_alias);
@@ -414,6 +417,7 @@ static struct dentry *ll_find_alias(struct inode *inode, struct dentry *de)
                 unlock_dentry(dentry);
                 d_rehash_cond(dentry, 0); /* avoid taking dcache_lock inside */
                 spin_unlock(&dcache_lock);
+                spin_unlock(&ll_lookup_lock);
                 iput(inode);
                 CDEBUG(D_DENTRY, "alias dentry %.*s (%p) parent %p inode %p "
                        "refc %d\n", de->d_name.len, de->d_name.name, de,
@@ -428,6 +432,8 @@ static struct dentry *ll_find_alias(struct inode *inode, struct dentry *de)
                  spin_unlock(&dcache_lock);
                  d_rehash(de);
                  d_move(last_discon, de);
+                 spin_unlock(&ll_lookup_lock);
+
                  iput(inode);
                  return last_discon;
         }
@@ -435,6 +441,7 @@ static struct dentry *ll_find_alias(struct inode *inode, struct dentry *de)
         ll_d_add(de, inode);
 
         spin_unlock(&dcache_lock);
+        spin_unlock(&ll_lookup_lock);
 
         return de;
 }