land lustre part of b_hd_sec on HEAD.

[fs/lustre-release.git] / lustre / kernel_patches / patches / vfs-dcache_locking-vanilla-2.6.patch

diff --git a/lustre/kernel_patches/patches/vfs-dcache_locking-vanilla-2.6.patch b/lustre/kernel_patches/patches/vfs-dcache_locking-vanilla-2.6.patch
new file mode 100644 (file)
index 0000000..f99ff70
--- /dev/null
+++ b/lustre/kernel_patches/patches/vfs-dcache_locking-vanilla-2.6.patch
@@ -0,0 +1,85 @@
+Introduce lock-free versions of d_rehash and d_move.
+
+ fs/dcache.c            |   22 ++++++++++++++++++----
+ include/linux/dcache.h |    2 ++
+ 2 files changed, 20 insertions(+), 4 deletions(-)
+
+Index: linus-2.6.7-bk5/fs/dcache.c
+===================================================================
+--- linus-2.6.7-bk5.orig/fs/dcache.c   2004-06-24 10:39:11.232154728 +0300
++++ linus-2.6.7-bk5/fs/dcache.c        2004-06-24 10:56:01.043640048 +0300
+@@ -1115,16 +1115,23 @@
+  * Adds a dentry to the hash according to its name.
+  */
+  
+-void d_rehash(struct dentry * entry)
++void __d_rehash(struct dentry * entry)
+ {
+       struct hlist_head *list = d_hash(entry->d_parent, entry->d_name.hash);
+ 
+-      spin_lock(&dcache_lock);
+       spin_lock(&entry->d_lock);
+       entry->d_flags &= ~DCACHE_UNHASHED;
+       spin_unlock(&entry->d_lock);
+       entry->d_bucket = list;
+       hlist_add_head_rcu(&entry->d_hash, list);
++}
++
++EXPORT_SYMBOL(__d_rehash);
++ 
++void d_rehash(struct dentry * entry)
++{
++      spin_lock(&dcache_lock);
++      __d_rehash(entry);
+       spin_unlock(&dcache_lock);
+ }
+ 
+@@ -1200,12 +1207,11 @@
+  * dcache entries should not be moved in this way.
+  */
+ 
+-void d_move(struct dentry * dentry, struct dentry * target)
++void __d_move(struct dentry * dentry, struct dentry * target)
+ {
+       if (!dentry->d_inode)
+               printk(KERN_WARNING "VFS: moving negative dcache entry\n");
+ 
+-      spin_lock(&dcache_lock);
+       write_seqlock(&rename_lock);
+       /*
+        * XXXX: do we really need to take target->d_lock?
+@@ -1257,6 +1263,14 @@
+       spin_unlock(&target->d_lock);
+       spin_unlock(&dentry->d_lock);
+       write_sequnlock(&rename_lock);
++}
++
++EXPORT_SYMBOL(__d_move);
++
++void d_move(struct dentry *dentry, struct dentry *target)
++{
++      spin_lock(&dcache_lock);
++      __d_move(dentry, target);
+       spin_unlock(&dcache_lock);
+ }
+ 
+Index: linus-2.6.7-bk5/include/linux/dcache.h
+===================================================================
+--- linus-2.6.7-bk5.orig/include/linux/dcache.h        2004-06-24 10:39:29.534372368 +0300
++++ linus-2.6.7-bk5/include/linux/dcache.h     2004-06-24 10:53:10.319594048 +0300
+@@ -227,6 +227,7 @@
+  * This adds the entry to the hash queues.
+  */
+ extern void d_rehash(struct dentry *);
++extern void __d_rehash(struct dentry *);
+ 
+ /**
+  * d_add - add dentry to hash queues
+@@ -245,6 +246,7 @@
+ 
+ /* used for rename() and baskets */
+ extern void d_move(struct dentry *, struct dentry *);
++extern void __d_move(struct dentry *, struct dentry *);
+ 
+ /* appendix may either be NULL or be used for transname suffixes */
+ extern struct dentry * d_lookup(struct dentry *, struct qstr *);