1 files changed, 403 insertions, 143 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 4e97dcceaf8..3867244fb14 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -55,7 +55,6 @@
 #include "slot_map.h"
 #include "super.h"
 #include "uptodate.h"
-#include "vote.h"
 
 #include "buffer_head_io.h"
 
@@ -69,6 +68,7 @@ struct ocfs2_mask_waiter {
 
 static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
 static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
 
 /*
  * Return value from ->downconvert_worker functions.
@@ -153,10 +153,10 @@ struct ocfs2_lock_res_ops {
 	struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
 
 	/*
-	 * Optionally called in the downconvert (or "vote") thread
-	 * after a successful downconvert. The lockres will not be
-	 * referenced after this callback is called, so it is safe to
-	 * free memory, etc.
+	 * Optionally called in the downconvert thread after a
+	 * successful downconvert. The lockres will not be referenced
+	 * after this callback is called, so it is safe to free
+	 * memory, etc.
 	 *
 	 * The exact semantics of when this is called are controlled
 	 * by ->downconvert_worker()
@@ -225,17 +225,12 @@ static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
 	.flags		= 0,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = {
+static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
 	.get_osb	= ocfs2_get_inode_osb,
 	.check_downconvert = ocfs2_check_meta_downconvert,
 	.set_lvb	= ocfs2_set_meta_lvb,
-	.flags		= LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
-};
-
-static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = {
-	.get_osb	= ocfs2_get_inode_osb,
 	.downconvert_worker = ocfs2_data_convert_worker,
-	.flags		= 0,
+	.flags		= LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
 };
 
 static struct ocfs2_lock_res_ops ocfs2_super_lops = {
@@ -258,10 +253,14 @@ static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
 	.flags		= 0,
 };
 
+static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
+	.get_osb	= ocfs2_get_file_osb,
+	.flags		= 0,
+};
+
 static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
 {
 	return lockres->l_type == OCFS2_LOCK_TYPE_META ||
-		lockres->l_type == OCFS2_LOCK_TYPE_DATA ||
 		lockres->l_type == OCFS2_LOCK_TYPE_RW ||
 		lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
 }
@@ -310,12 +309,24 @@ static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
 		"resource %s: %s\n", dlm_errname(_stat), _func,	\
 		_lockres->l_name, dlm_errmsg(_stat));		\
 } while (0)
-static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
-				 struct ocfs2_lock_res *lockres);
-static int ocfs2_meta_lock_update(struct inode *inode,
+static int ocfs2_downconvert_thread(void *arg);
+static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
+					struct ocfs2_lock_res *lockres);
+static int ocfs2_inode_lock_update(struct inode *inode,
 				  struct buffer_head **bh);
 static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
 static inline int ocfs2_highest_compat_lock_level(int level);
+static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
+				      int new_level);
+static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
+				  struct ocfs2_lock_res *lockres,
+				  int new_level,
+				  int lvb);
+static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
+				        struct ocfs2_lock_res *lockres);
+static int ocfs2_cancel_convert(struct ocfs2_super *osb,
+				struct ocfs2_lock_res *lockres);
+
 
 static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
 				  u64 blkno,
@@ -402,10 +413,7 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
 			ops = &ocfs2_inode_rw_lops;
 			break;
 		case OCFS2_LOCK_TYPE_META:
-			ops = &ocfs2_inode_meta_lops;
-			break;
-		case OCFS2_LOCK_TYPE_DATA:
-			ops = &ocfs2_inode_data_lops;
+			ops = &ocfs2_inode_inode_lops;
 			break;
 		case OCFS2_LOCK_TYPE_OPEN:
 			ops = &ocfs2_inode_open_lops;
@@ -428,6 +436,13 @@ static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
 	return OCFS2_SB(inode->i_sb);
 }
 
+static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
+{
+	struct ocfs2_file_private *fp = lockres->l_priv;
+
+	return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
+}
+
 static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
 {
 	__be64 inode_blkno_be;
@@ -508,6 +523,21 @@ static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
 				   &ocfs2_rename_lops, osb);
 }
 
+void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
+			      struct ocfs2_file_private *fp)
+{
+	struct inode *inode = fp->fp_file->f_mapping->host;
+	struct ocfs2_inode_info *oi = OCFS2_I(inode);
+
+	ocfs2_lock_res_init_once(lockres);
+	ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
+			      inode->i_generation, lockres->l_name);
+	ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
+				   OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
+				   fp);
+	lockres->l_flags |= OCFS2_LOCK_NOCACHE;
+}
+
 void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
 {
 	mlog_entry_void();
@@ -724,6 +754,13 @@ static void ocfs2_blocking_ast(void *opaque, int level)
 	     lockres->l_name, level, lockres->l_level,
 	     ocfs2_lock_type_string(lockres->l_type));
 
+	/*
+	 * We can skip the bast for locks which don't enable caching -
+	 * they'll be dropped at the earliest possible time anyway.
+	 */
+	if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
+		return;
+
 	spin_lock_irqsave(&lockres->l_lock, flags);
 	needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
 	if (needs_downconvert)
@@ -732,7 +769,7 @@ static void ocfs2_blocking_ast(void *opaque, int level)
 
 	wake_up(&lockres->l_event);
 
-	ocfs2_kick_vote_thread(osb);
+	ocfs2_wake_downconvert_thread(osb);
 }
 
 static void ocfs2_locking_ast(void *opaque)
@@ -935,6 +972,21 @@ static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
 
 }
 
+static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
+					     struct ocfs2_lock_res *lockres)
+{
+	int ret;
+
+	ret = wait_for_completion_interruptible(&mw->mw_complete);
+	if (ret)
+		lockres_remove_mask_waiter(lockres, mw);
+	else
+		ret = mw->mw_status;
+	/* Re-arm the completion in case we want to wait on it again */
+	INIT_COMPLETION(mw->mw_complete);
+	return ret;
+}
+
 static int ocfs2_cluster_lock(struct ocfs2_super *osb,
 			      struct ocfs2_lock_res *lockres,
 			      int level,
@@ -1089,7 +1141,7 @@ static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
 	mlog_entry_void();
 	spin_lock_irqsave(&lockres->l_lock, flags);
 	ocfs2_dec_holders(lockres, level);
-	ocfs2_vote_on_unlock(osb, lockres);
+	ocfs2_downconvert_on_unlock(osb, lockres);
 	spin_unlock_irqrestore(&lockres->l_lock, flags);
 	mlog_exit_void();
 }
@@ -1147,13 +1199,7 @@ int ocfs2_create_new_inode_locks(struct inode *inode)
 	 * We don't want to use LKM_LOCAL on a meta data lock as they
 	 * don't use a generation in their lock names.
 	 */
-	ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0);
-	if (ret) {
-		mlog_errno(ret);
-		goto bail;
-	}
-
-	ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1);
+	ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
 	if (ret) {
 		mlog_errno(ret);
 		goto bail;
@@ -1311,76 +1357,221 @@ out:
 	mlog_exit_void();
 }
 
-int ocfs2_data_lock_full(struct inode *inode,
-			 int write,
-			 int arg_flags)
+static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
+				     int level)
 {
-	int status = 0, level;
-	struct ocfs2_lock_res *lockres;
-	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	int ret;
+	struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
+	unsigned long flags;
+	struct ocfs2_mask_waiter mw;
 
-	BUG_ON(!inode);
+	ocfs2_init_mask_waiter(&mw);
 
-	mlog_entry_void();
+retry_cancel:
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	if (lockres->l_flags & OCFS2_LOCK_BUSY) {
+		ret = ocfs2_prepare_cancel_convert(osb, lockres);
+		if (ret) {
+			spin_unlock_irqrestore(&lockres->l_lock, flags);
+			ret = ocfs2_cancel_convert(osb, lockres);
+			if (ret < 0) {
+				mlog_errno(ret);
+				goto out;
+			}
+			goto retry_cancel;
+		}
+		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-	mlog(0, "inode %llu take %s DATA lock\n",
-	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
-	     write ? "EXMODE" : "PRMODE");
+		ocfs2_wait_for_mask(&mw);
+		goto retry_cancel;
+	}
 
-	/* We'll allow faking a readonly data lock for
-	 * rodevices. */
-	if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) {
-		if (write) {
-			status = -EROFS;
-			mlog_errno(status);
+	ret = -ERESTARTSYS;
+	/*
+	 * We may still have gotten the lock, in which case there's no
+	 * point to restarting the syscall.
+	 */
+	if (lockres->l_level == level)
+		ret = 0;
+
+	mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
+	     lockres->l_flags, lockres->l_level, lockres->l_action);
+
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+out:
+	return ret;
+}
+
+/*
+ * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
+ * flock() calls. The locking approach this requires is sufficiently
+ * different from all other cluster lock types that we implement a
+ * seperate path to the "low-level" dlm calls. In particular:
+ *
+ * - No optimization of lock levels is done - we take at exactly
+ *   what's been requested.
+ *
+ * - No lock caching is employed. We immediately downconvert to
+ *   no-lock at unlock time. This also means flock locks never go on
+ *   the blocking list).
+ *
+ * - Since userspace can trivially deadlock itself with flock, we make
+ *   sure to allow cancellation of a misbehaving applications flock()
+ *   request.
+ *
+ * - Access to any flock lockres doesn't require concurrency, so we
+ *   can simplify the code by requiring the caller to guarantee
+ *   serialization of dlmglue flock calls.
+ */
+int ocfs2_file_lock(struct file *file, int ex, int trylock)
+{
+	int ret, level = ex ? LKM_EXMODE : LKM_PRMODE;
+	unsigned int lkm_flags = trylock ? LKM_NOQUEUE : 0;
+	unsigned long flags;
+	struct ocfs2_file_private *fp = file->private_data;
+	struct ocfs2_lock_res *lockres = &fp->fp_flock;
+	struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
+	struct ocfs2_mask_waiter mw;
+
+	ocfs2_init_mask_waiter(&mw);
+
+	if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
+	    (lockres->l_level > LKM_NLMODE)) {
+		mlog(ML_ERROR,
+		     "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
+		     "level: %u\n", lockres->l_name, lockres->l_flags,
+		     lockres->l_level);
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
+		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+		/*
+		 * Get the lock at NLMODE to start - that way we
+		 * can cancel the upconvert request if need be.
+		 */
+		ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out;
 		}
-		goto out;
+
+		ret = ocfs2_wait_for_mask(&mw);
+		if (ret) {
+			mlog_errno(ret);
+			goto out;
+		}
+		spin_lock_irqsave(&lockres->l_lock, flags);
 	}
 
-	if (ocfs2_mount_local(osb))
-		goto out;
+	lockres->l_action = OCFS2_AST_CONVERT;
+	lkm_flags |= LKM_CONVERT;
+	lockres->l_requested = level;
+	lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
 
-	lockres = &OCFS2_I(inode)->ip_data_lockres;
+	lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-	level = write ? LKM_EXMODE : LKM_PRMODE;
+	ret = dlmlock(osb->dlm, level, &lockres->l_lksb, lkm_flags,
+		      lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1,
+		      ocfs2_locking_ast, lockres, ocfs2_blocking_ast);
+	if (ret != DLM_NORMAL) {
+		if (trylock && ret == DLM_NOTQUEUED)
+			ret = -EAGAIN;
+		else {
+			ocfs2_log_dlm_error("dlmlock", ret, lockres);
+			ret = -EINVAL;
+		}
 
-	status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level,
-				    0, arg_flags);
-	if (status < 0 && status != -EAGAIN)
-		mlog_errno(status);
+		ocfs2_recover_from_dlm_error(lockres, 1);
+		lockres_remove_mask_waiter(lockres, &mw);
+		goto out;
+	}
+
+	ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
+	if (ret == -ERESTARTSYS) {
+		/*
+		 * Userspace can cause deadlock itself with
+		 * flock(). Current behavior locally is to allow the
+		 * deadlock, but abort the system call if a signal is
+		 * received. We follow this example, otherwise a
+		 * poorly written program could sit in kernel until
+		 * reboot.
+		 *
+		 * Handling this is a bit more complicated for Ocfs2
+		 * though. We can't exit this function with an
+		 * outstanding lock request, so a cancel convert is
+		 * required. We intentionally overwrite 'ret' - if the
+		 * cancel fails and the lock was granted, it's easier
+		 * to just bubble sucess back up to the user.
+		 */
+		ret = ocfs2_flock_handle_signal(lockres, level);
+	}
 
 out:
-	mlog_exit(status);
-	return status;
+
+	mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
+	     lockres->l_name, ex, trylock, ret);
+	return ret;
 }
 
-/* see ocfs2_meta_lock_with_page() */
-int ocfs2_data_lock_with_page(struct inode *inode,
-			      int write,
-			      struct page *page)
+void ocfs2_file_unlock(struct file *file)
 {
 	int ret;
+	unsigned long flags;
+	struct ocfs2_file_private *fp = file->private_data;
+	struct ocfs2_lock_res *lockres = &fp->fp_flock;
+	struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
+	struct ocfs2_mask_waiter mw;
 
-	ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK);
-	if (ret == -EAGAIN) {
-		unlock_page(page);
-		if (ocfs2_data_lock(inode, write) == 0)
-			ocfs2_data_unlock(inode, write);
-		ret = AOP_TRUNCATED_PAGE;
+	ocfs2_init_mask_waiter(&mw);
+
+	if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
+		return;
+
+	if (lockres->l_level == LKM_NLMODE)
+		return;
+
+	mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
+	     lockres->l_name, lockres->l_flags, lockres->l_level,
+	     lockres->l_action);
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	/*
+	 * Fake a blocking ast for the downconvert code.
+	 */
+	lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
+	lockres->l_blocking = LKM_EXMODE;
+
+	ocfs2_prepare_downconvert(lockres, LKM_NLMODE);
+	lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	ret = ocfs2_downconvert_lock(osb, lockres, LKM_NLMODE, 0);
+	if (ret) {
+		mlog_errno(ret);
+		return;
 	}
 
-	return ret;
+	ret = ocfs2_wait_for_mask(&mw);
+	if (ret)
+		mlog_errno(ret);
 }
 
-static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
-				 struct ocfs2_lock_res *lockres)
+static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
+					struct ocfs2_lock_res *lockres)
 {
 	int kick = 0;
 
 	mlog_entry_void();
 
 	/* If we know that another node is waiting on our lock, kick
-	 * the vote thread * pre-emptively when we reach a release
+	 * the downconvert thread * pre-emptively when we reach a release
 	 * condition. */
 	if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
 		switch(lockres->l_blocking) {
@@ -1398,27 +1589,7 @@ static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
 	}
 
 	if (kick)
-		ocfs2_kick_vote_thread(osb);
-
-	mlog_exit_void();
-}
-
-void ocfs2_data_unlock(struct inode *inode,
-		       int write)
-{
-	int level = write ? LKM_EXMODE : LKM_PRMODE;
-	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres;
-	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
-
-	mlog_entry_void();
-
-	mlog(0, "inode %llu drop %s DATA lock\n",
-	     (unsigned long long)OCFS2_I(inode)->ip_blkno,
-	     write ? "EXMODE" : "PRMODE");
-
-	if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)) &&
-	    !ocfs2_mount_local(osb))
-		ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
+		ocfs2_wake_downconvert_thread(osb);
 
 	mlog_exit_void();
 }
@@ -1442,11 +1613,11 @@ static u64 ocfs2_pack_timespec(struct timespec *spec)
 
 /* Call this with the lockres locked. I am reasonably sure we don't
  * need ip_lock in this function as anyone who would be changing those
- * values is supposed to be blocked in ocfs2_meta_lock right now. */
+ * values is supposed to be blocked in ocfs2_inode_lock right now. */
 static void __ocfs2_stuff_meta_lvb(struct inode *inode)
 {
 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
-	struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+	struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
 	struct ocfs2_meta_lvb *lvb;
 
 	mlog_entry_void();
@@ -1496,7 +1667,7 @@ static void ocfs2_unpack_timespec(struct timespec *spec,
 static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
 {
 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
-	struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+	struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
 	struct ocfs2_meta_lvb *lvb;
 
 	mlog_entry_void();
@@ -1604,12 +1775,12 @@ static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockre
 }
 
 /* may or may not return a bh if it went to disk. */
-static int ocfs2_meta_lock_update(struct inode *inode,
+static int ocfs2_inode_lock_update(struct inode *inode,
 				  struct buffer_head **bh)
 {
 	int status = 0;
 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
-	struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+	struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
 	struct ocfs2_dinode *fe;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
@@ -1721,7 +1892,7 @@ static int ocfs2_assign_bh(struct inode *inode,
  * returns < 0 error if the callback will never be called, otherwise
  * the result of the lock will be communicated via the callback.
  */
-int ocfs2_meta_lock_full(struct inode *inode,
+int ocfs2_inode_lock_full(struct inode *inode,
 			 struct buffer_head **ret_bh,
 			 int ex,
 			 int arg_flags)
@@ -1756,7 +1927,7 @@ int ocfs2_meta_lock_full(struct inode *inode,
 		wait_event(osb->recovery_event,
 			   ocfs2_node_map_is_empty(osb, &osb->recovery_map));
 
-	lockres = &OCFS2_I(inode)->ip_meta_lockres;
+	lockres = &OCFS2_I(inode)->ip_inode_lockres;
 	level = ex ? LKM_EXMODE : LKM_PRMODE;
 	dlm_flags = 0;
 	if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
@@ -1795,11 +1966,11 @@ local:
 	}
 
 	/* This is fun. The caller may want a bh back, or it may
-	 * not. ocfs2_meta_lock_update definitely wants one in, but
+	 * not. ocfs2_inode_lock_update definitely wants one in, but
 	 * may or may not read one, depending on what's in the
 	 * LVB. The result of all of this is that we've *only* gone to
 	 * disk if we have to, so the complexity is worthwhile. */
-	status = ocfs2_meta_lock_update(inode, &local_bh);
+	status = ocfs2_inode_lock_update(inode, &local_bh);
 	if (status < 0) {
 		if (status != -ENOENT)
 			mlog_errno(status);
@@ -1821,7 +1992,7 @@ bail:
 			*ret_bh = NULL;
 		}
 		if (acquired)
-			ocfs2_meta_unlock(inode, ex);
+			ocfs2_inode_unlock(inode, ex);
 	}
 
 	if (local_bh)
@@ -1832,19 +2003,20 @@ bail:
 }
 
 /*
- * This is working around a lock inversion between tasks acquiring DLM locks
- * while holding a page lock and the vote thread which blocks dlm lock acquiry
- * while acquiring page locks.
+ * This is working around a lock inversion between tasks acquiring DLM
+ * locks while holding a page lock and the downconvert thread which
+ * blocks dlm lock acquiry while acquiring page locks.
  *
  * ** These _with_page variantes are only intended to be called from aop
  * methods that hold page locks and return a very specific *positive* error
  * code that aop methods pass up to the VFS -- test for errors with != 0. **
  *
- * The DLM is called such that it returns -EAGAIN if it would have blocked
- * waiting for the vote thread.  In that case we unlock our page so the vote
- * thread can make progress.  Once we've done this we have to return
- * AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up
- * into the VFS who will then immediately retry the aop call.
+ * The DLM is called such that it returns -EAGAIN if it would have
+ * blocked waiting for the downconvert thread.  In that case we unlock
+ * our page so the downconvert thread can make progress.  Once we've
+ * done this we have to return AOP_TRUNCATED_PAGE so the aop method
+ * that called us can bubble that back up into the VFS who will then
+ * immediately retry the aop call.
  *
  * We do a blocking lock and immediate unlock before returning, though, so that
  * the lock has a great chance of being cached on this node by the time the VFS
@@ -1852,32 +2024,32 @@ bail:
  * ping locks back and forth, but that's a risk we're willing to take to avoid
  * the lock inversion simply.
  */
-int ocfs2_meta_lock_with_page(struct inode *inode,
+int ocfs2_inode_lock_with_page(struct inode *inode,
 			      struct buffer_head **ret_bh,
 			      int ex,
 			      struct page *page)
 {
 	int ret;
 
-	ret = ocfs2_meta_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
+	ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
 	if (ret == -EAGAIN) {
 		unlock_page(page);
-		if (ocfs2_meta_lock(inode, ret_bh, ex) == 0)
-			ocfs2_meta_unlock(inode, ex);
+		if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
+			ocfs2_inode_unlock(inode, ex);
 		ret = AOP_TRUNCATED_PAGE;
 	}
 
 	return ret;
 }
 
-int ocfs2_meta_lock_atime(struct inode *inode,
+int ocfs2_inode_lock_atime(struct inode *inode,
 			  struct vfsmount *vfsmnt,
 			  int *level)
 {
 	int ret;
 
 	mlog_entry_void();
-	ret = ocfs2_meta_lock(inode, NULL, 0);
+	ret = ocfs2_inode_lock(inode, NULL, 0);
 	if (ret < 0) {
 		mlog_errno(ret);
 		return ret;
@@ -1890,8 +2062,8 @@ int ocfs2_meta_lock_atime(struct inode *inode,
 	if (ocfs2_should_update_atime(inode, vfsmnt)) {
 		struct buffer_head *bh = NULL;
 
-		ocfs2_meta_unlock(inode, 0);
-		ret = ocfs2_meta_lock(inode, &bh, 1);
+		ocfs2_inode_unlock(inode, 0);
+		ret = ocfs2_inode_lock(inode, &bh, 1);
 		if (ret < 0) {
 			mlog_errno(ret);
 			return ret;
@@ -1908,11 +2080,11 @@ int ocfs2_meta_lock_atime(struct inode *inode,
 	return ret;
 }
 
-void ocfs2_meta_unlock(struct inode *inode,
+void ocfs2_inode_unlock(struct inode *inode,
 		       int ex)
 {
 	int level = ex ? LKM_EXMODE : LKM_PRMODE;
-	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
+	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
 	mlog_entry_void();
@@ -2320,11 +2492,11 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
 		goto bail;
 	}
 
-	/* launch vote thread */
-	osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote");
-	if (IS_ERR(osb->vote_task)) {
-		status = PTR_ERR(osb->vote_task);
-		osb->vote_task = NULL;
+	/* launch downconvert thread */
+	osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc");
+	if (IS_ERR(osb->dc_task)) {
+		status = PTR_ERR(osb->dc_task);
+		osb->dc_task = NULL;
 		mlog_errno(status);
 		goto bail;
 	}
@@ -2353,8 +2525,8 @@ local:
 bail:
 	if (status < 0) {
 		ocfs2_dlm_shutdown_debug(osb);
-		if (osb->vote_task)
-			kthread_stop(osb->vote_task);
+		if (osb->dc_task)
+			kthread_stop(osb->dc_task);
 	}
 
 	mlog_exit(status);
@@ -2369,9 +2541,9 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
 
 	ocfs2_drop_osb_locks(osb);
 
-	if (osb->vote_task) {
-		kthread_stop(osb->vote_task);
-		osb->vote_task = NULL;
+	if (osb->dc_task) {
+		kthread_stop(osb->dc_task);
+		osb->dc_task = NULL;
 	}
 
 	ocfs2_lock_res_free(&osb->osb_super_lockres);
@@ -2527,7 +2699,7 @@ out:
 
 /* Mark the lockres as being dropped. It will no longer be
  * queued if blocking, but we still may have to wait on it
- * being dequeued from the vote thread before we can consider
+ * being dequeued from the downconvert thread before we can consider
  * it safe to drop. 
  *
  * You can *not* attempt to call cluster_lock on this lockres anymore. */
@@ -2590,14 +2762,7 @@ int ocfs2_drop_inode_locks(struct inode *inode)
 	status = err;
 
 	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
-			      &OCFS2_I(inode)->ip_data_lockres);
-	if (err < 0)
-		mlog_errno(err);
-	if (err < 0 && !status)
-		status = err;
-
-	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
-			      &OCFS2_I(inode)->ip_meta_lockres);
+			      &OCFS2_I(inode)->ip_inode_lockres);
 	if (err < 0)
 		mlog_errno(err);
 	if (err < 0 && !status)
@@ -2850,6 +3015,9 @@ static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
        	inode = ocfs2_lock_res_inode(lockres);
 	mapping = inode->i_mapping;
 
+	if (S_ISREG(inode->i_mode))
+		goto out;
+
 	/*
 	 * We need this before the filemap_fdatawrite() so that it can
 	 * transfer the dirty bit from the PTE to the
@@ -2875,6 +3043,7 @@ static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
 		filemap_fdatawait(mapping);
 	}
 
+out:
 	return UNBLOCK_CONTINUE;
 }
 
@@ -2903,7 +3072,7 @@ static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
 
 /*
  * Does the final reference drop on our dentry lock. Right now this
- * happens in the vote thread, but we could choose to simplify the
+ * happens in the downconvert thread, but we could choose to simplify the
  * dlmglue API and push these off to the ocfs2_wq in the future.
  */
 static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
@@ -3042,7 +3211,7 @@ void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
 	mlog(0, "lockres %s blocked.\n", lockres->l_name);
 
 	/* Detect whether a lock has been marked as going away while
-	 * the vote thread was processing other things. A lock can
+	 * the downconvert thread was processing other things. A lock can
 	 * still be marked with OCFS2_LOCK_FREEING after this check,
 	 * but short circuiting here will still save us some
 	 * performance. */
@@ -3091,13 +3260,104 @@ static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
 
 	lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
 
-	spin_lock(&osb->vote_task_lock);
+	spin_lock(&osb->dc_task_lock);
 	if (list_empty(&lockres->l_blocked_list)) {
 		list_add_tail(&lockres->l_blocked_list,
 			      &osb->blocked_lock_list);
 		osb->blocked_lock_count++;
 	}
-	spin_unlock(&osb->vote_task_lock);
+	spin_unlock(&osb->dc_task_lock);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
+{
+	unsigned long processed;
+	struct ocfs2_lock_res *lockres;
+
+	mlog_entry_void();
+
+	spin_lock(&osb->dc_task_lock);
+	/* grab this early so we know to try again if a state change and
+	 * wake happens part-way through our work  */
+	osb->dc_work_sequence = osb->dc_wake_sequence;
+
+	processed = osb->blocked_lock_count;
+	while (processed) {
+		BUG_ON(list_empty(&osb->blocked_lock_list));
+
+		lockres = list_entry(osb->blocked_lock_list.next,
+				     struct ocfs2_lock_res, l_blocked_list);
+		list_del_init(&lockres->l_blocked_list);
+		osb->blocked_lock_count--;
+		spin_unlock(&osb->dc_task_lock);
+
+		BUG_ON(!processed);
+		processed--;
+
+		ocfs2_process_blocked_lock(osb, lockres);
+
+		spin_lock(&osb->dc_task_lock);
+	}
+	spin_unlock(&osb->dc_task_lock);
 
 	mlog_exit_void();
 }
+
+static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
+{
+	int empty = 0;
+
+	spin_lock(&osb->dc_task_lock);
+	if (list_empty(&osb->blocked_lock_list))
+		empty = 1;
+
+	spin_unlock(&osb->dc_task_lock);
+	return empty;
+}
+
+static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
+{
+	int should_wake = 0;
+
+	spin_lock(&osb->dc_task_lock);
+	if (osb->dc_work_sequence != osb->dc_wake_sequence)
+		should_wake = 1;
+	spin_unlock(&osb->dc_task_lock);
+
+	return should_wake;
+}
+
+int ocfs2_downconvert_thread(void *arg)
+{
+	int status = 0;
+	struct ocfs2_super *osb = arg;
+
+	/* only quit once we've been asked to stop and there is no more
+	 * work available */
+	while (!(kthread_should_stop() &&
+		ocfs2_downconvert_thread_lists_empty(osb))) {
+
+		wait_event_interruptible(osb->dc_event,
+					 ocfs2_downconvert_thread_should_wake(osb) ||
+					 kthread_should_stop());
+
+		mlog(0, "downconvert_thread: awoken\n");
+
+		ocfs2_downconvert_thread_do_work(osb);
+	}
+
+	osb->dc_task = NULL;
+	return status;
+}
+
+void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
+{
+	spin_lock(&osb->dc_task_lock);
+	/* make sure the voting thread gets a swipe at whatever changes
+	 * the caller may have made to the voting state */
+	osb->dc_wake_sequence++;
+	spin_unlock(&osb->dc_task_lock);
+	wake_up(&osb->dc_event);
+}