1 files changed, 232 insertions, 96 deletions

diff --git a/fs/locks.c b/fs/locks.c
index cb424a4fed71..b27a3005d78d 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -126,6 +126,9 @@
 #include <linux/time.h>
 #include <linux/rcupdate.h>
 #include <linux/pid_namespace.h>
+#include <linux/hashtable.h>
+#include <linux/percpu.h>
+#include <linux/lglock.h>
 
 #include <asm/uaccess.h>
 
@@ -153,30 +156,53 @@ int lease_break_time = 45;
 #define for_each_lock(inode, lockp) \
         for (lockp = &inode->i_flock; *lockp != NULL; lockp = &(*lockp)->fl_next)
 
-static LIST_HEAD(file_lock_list);
-static LIST_HEAD(blocked_list);
-static DEFINE_SPINLOCK(file_lock_lock);
+/*
+ * The global file_lock_list is only used for displaying /proc/locks, so we
+ * keep a list on each CPU, with each list protected by its own spinlock via
+ * the file_lock_lglock. Note that alterations to the list also require that
+ * the relevant i_lock is held.
+ */
+DEFINE_STATIC_LGLOCK(file_lock_lglock);
+static DEFINE_PER_CPU(struct hlist_head, file_lock_list);
 
 /*
- * Protects the two list heads above, plus the inode->i_flock list
+ * The blocked_hash is used to find POSIX lock loops for deadlock detection.
+ * It is protected by blocked_lock_lock.
+ *
+ * We hash locks by lockowner in order to optimize searching for the lock a
+ * particular lockowner is waiting on.
+ *
+ * FIXME: make this value scale via some heuristic? We generally will want more
+ * buckets when we have more lockowners holding locks, but that's a little
+ * difficult to determine without knowing what the workload will look like.
  */
-void lock_flocks(void)
-{
-        spin_lock(&file_lock_lock);
-}
-EXPORT_SYMBOL_GPL(lock_flocks);
+#define BLOCKED_HASH_BITS       7
+static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS);
 
-void unlock_flocks(void)
-{
-        spin_unlock(&file_lock_lock);
-}
-EXPORT_SYMBOL_GPL(unlock_flocks);
+/*
+ * This lock protects the blocked_hash. Generally, if you're accessing it, you
+ * want to be holding this lock.
+ *
+ * In addition, it also protects the fl->fl_block list, and the fl->fl_next
+ * pointer for file_lock structures that are acting as lock requests (in
+ * contrast to those that are acting as records of acquired locks).
+ *
+ * Note that when we acquire this lock in order to change the above fields,
+ * we often hold the i_lock as well. In certain cases, when reading the fields
+ * protected by this lock, we can skip acquiring it iff we already hold the
+ * i_lock.
+ *
+ * In particular, adding an entry to the fl_block list requires that you hold
+ * both the i_lock and the blocked_lock_lock (acquired in that order). Deleting
+ * an entry from the list however only requires the file_lock_lock.
+ */
+static DEFINE_SPINLOCK(blocked_lock_lock);
 
 static struct kmem_cache *filelock_cache __read_mostly;
 
 static void locks_init_lock_heads(struct file_lock *fl)
 {
-        INIT_LIST_HEAD(&fl->fl_link);
+        INIT_HLIST_NODE(&fl->fl_link);
         INIT_LIST_HEAD(&fl->fl_block);
         init_waitqueue_head(&fl->fl_wait);
 }
@@ -210,7 +236,7 @@ void locks_free_lock(struct file_lock *fl)
 {
         BUG_ON(waitqueue_active(&fl->fl_wait));
         BUG_ON(!list_empty(&fl->fl_block));
-        BUG_ON(!list_empty(&fl->fl_link));
+        BUG_ON(!hlist_unhashed(&fl->fl_link));
 
         locks_release_private(fl);
         kmem_cache_free(filelock_cache, fl);
@@ -484,47 +510,118 @@ static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
         return fl1->fl_owner == fl2->fl_owner;
 }
 
+/* Must be called with the i_lock held! */
+static inline void
+locks_insert_global_locks(struct file_lock *fl)
+{
+        lg_local_lock(&file_lock_lglock);
+        fl->fl_link_cpu = smp_processor_id();
+        hlist_add_head(&fl->fl_link, this_cpu_ptr(&file_lock_list));
+        lg_local_unlock(&file_lock_lglock);
+}
+
+/* Must be called with the i_lock held! */
+static inline void
+locks_delete_global_locks(struct file_lock *fl)
+{
+        /*
+         * Avoid taking lock if already unhashed. This is safe since this check
+         * is done while holding the i_lock, and new insertions into the list
+         * also require that it be held.
+         */
+        if (hlist_unhashed(&fl->fl_link))
+                return;
+        lg_local_lock_cpu(&file_lock_lglock, fl->fl_link_cpu);
+        hlist_del_init(&fl->fl_link);
+        lg_local_unlock_cpu(&file_lock_lglock, fl->fl_link_cpu);
+}
+
+static unsigned long
+posix_owner_key(struct file_lock *fl)
+{
+        if (fl->fl_lmops && fl->fl_lmops->lm_owner_key)
+                return fl->fl_lmops->lm_owner_key(fl);
+        return (unsigned long)fl->fl_owner;
+}
+
+static inline void
+locks_insert_global_blocked(struct file_lock *waiter)
+{
+        hash_add(blocked_hash, &waiter->fl_link, posix_owner_key(waiter));
+}
+
+static inline void
+locks_delete_global_blocked(struct file_lock *waiter)
+{
+        hash_del(&waiter->fl_link);
+}
+
 /* Remove waiter from blocker's block list.
  * When blocker ends up pointing to itself then the list is empty.
+ *
+ * Must be called with blocked_lock_lock held.
  */
 static void __locks_delete_block(struct file_lock *waiter)
 {
+        locks_delete_global_blocked(waiter);
         list_del_init(&waiter->fl_block);
-        list_del_init(&waiter->fl_link);
         waiter->fl_next = NULL;
 }
 
-/*
- */
-void locks_delete_block(struct file_lock *waiter)
+static void locks_delete_block(struct file_lock *waiter)
 {
-        lock_flocks();
+        spin_lock(&blocked_lock_lock);
         __locks_delete_block(waiter);
-        unlock_flocks();
+        spin_unlock(&blocked_lock_lock);
 }
-EXPORT_SYMBOL(locks_delete_block);
 
 /* Insert waiter into blocker's block list.
  * We use a circular list so that processes can be easily woken up in
  * the order they blocked. The documentation doesn't require this but
  * it seems like the reasonable thing to do.
+ *
+ * Must be called with both the i_lock and blocked_lock_lock held. The fl_block
+ * list itself is protected by the file_lock_list, but by ensuring that the
+ * i_lock is also held on insertions we can avoid taking the blocked_lock_lock
+ * in some cases when we see that the fl_block list is empty.
  */
-static void locks_insert_block(struct file_lock *blocker, 
-                               struct file_lock *waiter)
+static void __locks_insert_block(struct file_lock *blocker,
+                                        struct file_lock *waiter)
 {
         BUG_ON(!list_empty(&waiter->fl_block));
-        list_add_tail(&waiter->fl_block, &blocker->fl_block);
         waiter->fl_next = blocker;
+        list_add_tail(&waiter->fl_block, &blocker->fl_block);
         if (IS_POSIX(blocker))
-                list_add(&waiter->fl_link, &blocked_list);
+                locks_insert_global_blocked(waiter);
 }
 
-/* Wake up processes blocked waiting for blocker.
- * If told to wait then schedule the processes until the block list
- * is empty, otherwise empty the block list ourselves.
+/* Must be called with i_lock held. */
+static void locks_insert_block(struct file_lock *blocker,
+                                        struct file_lock *waiter)
+{
+        spin_lock(&blocked_lock_lock);
+        __locks_insert_block(blocker, waiter);
+        spin_unlock(&blocked_lock_lock);
+}
+
+/*
+ * Wake up processes blocked waiting for blocker.
+ *
+ * Must be called with the inode->i_lock held!
  */
 static void locks_wake_up_blocks(struct file_lock *blocker)
 {
+        /*
+         * Avoid taking global lock if list is empty. This is safe since new
+         * blocked requests are only added to the list under the i_lock, and
+         * the i_lock is always held here. Note that removal from the fl_block
+         * list does not require the i_lock, so we must recheck list_empty()
+         * after acquiring the blocked_lock_lock.
+         */
+        if (list_empty(&blocker->fl_block))
+                return;
+
+        spin_lock(&blocked_lock_lock);
         while (!list_empty(&blocker->fl_block)) {
                 struct file_lock *waiter;
 
@@ -536,20 +633,23 @@ static void locks_wake_up_blocks(struct file_lock *blocker)
                 else
                         wake_up(&waiter->fl_wait);
         }
+        spin_unlock(&blocked_lock_lock);
 }
 
 /* Insert file lock fl into an inode's lock list at the position indicated
  * by pos. At the same time add the lock to the global file lock list.
+ *
+ * Must be called with the i_lock held!
  */
 static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
 {
-        list_add(&fl->fl_link, &file_lock_list);
-
         fl->fl_nspid = get_pid(task_tgid(current));
 
         /* insert into file's list */
         fl->fl_next = *pos;
         *pos = fl;
+
+        locks_insert_global_locks(fl);
 }
 
 /*
@@ -557,14 +657,17 @@ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
  * Wake up processes that are blocked waiting for this lock,
  * notify the FS that the lock has been cleared and
  * finally free the lock.
+ *
+ * Must be called with the i_lock held!
  */
 static void locks_delete_lock(struct file_lock **thisfl_p)
 {
         struct file_lock *fl = *thisfl_p;
 
+        locks_delete_global_locks(fl);
+
         *thisfl_p = fl->fl_next;
         fl->fl_next = NULL;
-        list_del_init(&fl->fl_link);
 
         if (fl->fl_nspid) {
                 put_pid(fl->fl_nspid);
@@ -625,8 +728,9 @@ void
 posix_test_lock(struct file *filp, struct file_lock *fl)
 {
         struct file_lock *cfl;
+        struct inode *inode = file_inode(filp);
 
-        lock_flocks();
+        spin_lock(&inode->i_lock);
         for (cfl = file_inode(filp)->i_flock; cfl; cfl = cfl->fl_next) {
                 if (!IS_POSIX(cfl))
                         continue;
@@ -639,7 +743,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
                         fl->fl_pid = pid_vnr(cfl->fl_nspid);
         } else
                 fl->fl_type = F_UNLCK;
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         return;
 }
 EXPORT_SYMBOL(posix_test_lock);
@@ -676,13 +780,14 @@ static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl)
 {
         struct file_lock *fl;
 
-        list_for_each_entry(fl, &blocked_list, fl_link) {
+        hash_for_each_possible(blocked_hash, fl, fl_link, posix_owner_key(block_fl)) {
                 if (posix_same_owner(fl, block_fl))
                         return fl->fl_next;
         }
         return NULL;
 }
 
+/* Must be called with the blocked_lock_lock held! */
 static int posix_locks_deadlock(struct file_lock *caller_fl,
                                 struct file_lock *block_fl)
 {
@@ -718,7 +823,7 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
                         return -ENOMEM;
         }
 
-        lock_flocks();
+        spin_lock(&inode->i_lock);
         if (request->fl_flags & FL_ACCESS)
                 goto find_conflict;
 
@@ -748,9 +853,9 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
          * give it the opportunity to lock the file.
          */
         if (found) {
-                unlock_flocks();
+                spin_unlock(&inode->i_lock);
                 cond_resched();
-                lock_flocks();
+                spin_lock(&inode->i_lock);
         }
 
 find_conflict:
@@ -777,7 +882,7 @@ find_conflict:
         error = 0;
 
 out:
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         if (new_fl)
                 locks_free_lock(new_fl);
         return error;
@@ -791,7 +896,8 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
         struct file_lock *left = NULL;
         struct file_lock *right = NULL;
         struct file_lock **before;
-        int error, added = 0;
+        int error;
+        bool added = false;
 
         /*
          * We may need two file_lock structures for this operation,
@@ -806,7 +912,12 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                 new_fl2 = locks_alloc_lock();
         }
 
-        lock_flocks();
+        spin_lock(&inode->i_lock);
+        /*
+         * New lock request. Walk all POSIX locks and look for conflicts. If
+         * there are any, either return error or put the request on the
+         * blocker's list of waiters and the global blocked_hash.
+         */
         if (request->fl_type != F_UNLCK) {
                 for_each_lock(inode, before) {
                         fl = *before;
@@ -819,11 +930,17 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                         error = -EAGAIN;
                         if (!(request->fl_flags & FL_SLEEP))
                                 goto out;
+                        /*
+                         * Deadlock detection and insertion into the blocked
+                         * locks list must be done while holding the same lock!
+                         */
                         error = -EDEADLK;
-                        if (posix_locks_deadlock(request, fl))
-                                goto out;
-                        error = FILE_LOCK_DEFERRED;
-                        locks_insert_block(fl, request);
+                        spin_lock(&blocked_lock_lock);
+                        if (likely(!posix_locks_deadlock(request, fl))) {
+                                error = FILE_LOCK_DEFERRED;
+                                __locks_insert_block(fl, request);
+                        }
+                        spin_unlock(&blocked_lock_lock);
                         goto out;
                 }
         }
@@ -845,7 +962,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                 before = &fl->fl_next;
         }
 
-        /* Process locks with this owner.  */
+        /* Process locks with this owner. */
         while ((fl = *before) && posix_same_owner(request, fl)) {
                 /* Detect adjacent or overlapping regions (if same lock type)
                  */
@@ -880,7 +997,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                                 continue;
                         }
                         request = fl;
-                        added = 1;
+                        added = true;
                 }
                 else {
                         /* Processing for different lock types is a bit
@@ -891,7 +1008,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                         if (fl->fl_start > request->fl_end)
                                 break;
                         if (request->fl_type == F_UNLCK)
-                                added = 1;
+                                added = true;
                         if (fl->fl_start < request->fl_start)
                                 left = fl;
                         /* If the next lock in the list has a higher end
@@ -921,7 +1038,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                                 locks_release_private(fl);
                                 locks_copy_private(fl, request);
                                 request = fl;
-                                added = 1;
+                                added = true;
                         }
                 }
                 /* Go on to next lock.
@@ -931,10 +1048,9 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
         }
 
         /*
-         * The above code only modifies existing locks in case of
-         * merging or replacing.  If new lock(s) need to be inserted
-         * all modifications are done bellow this, so it's safe yet to
-         * bail out.
+         * The above code only modifies existing locks in case of merging or
+         * replacing. If new lock(s) need to be inserted all modifications are
+         * done below this, so it's safe yet to bail out.
          */
         error = -ENOLCK; /* "no luck" */
         if (right && left == right && !new_fl2)
@@ -974,7 +1090,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                 locks_wake_up_blocks(left);
         }
  out:
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         /*
          * Free any unused locks.
          */
@@ -1049,14 +1165,14 @@ int locks_mandatory_locked(struct inode *inode)
         /*
          * Search the lock list for this inode for any POSIX locks.
          */
-        lock_flocks();
+        spin_lock(&inode->i_lock);
         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
                 if (!IS_POSIX(fl))
                         continue;
                 if (fl->fl_owner != owner)
                         break;
         }
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         return fl ? -EAGAIN : 0;
 }
 
@@ -1199,7 +1315,7 @@ int __break_lease(struct inode *inode, unsigned int mode)
         if (IS_ERR(new_fl))
                 return PTR_ERR(new_fl);
 
-        lock_flocks();
+        spin_lock(&inode->i_lock);
 
         time_out_leases(inode);
 
@@ -1249,11 +1365,11 @@ restart:
                         break_time++;
         }
         locks_insert_block(flock, new_fl);
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         error = wait_event_interruptible_timeout(new_fl->fl_wait,
                                                 !new_fl->fl_next, break_time);
-        lock_flocks();
-        __locks_delete_block(new_fl);
+        spin_lock(&inode->i_lock);
+        locks_delete_block(new_fl);
         if (error >= 0) {
                 if (error == 0)
                         time_out_leases(inode);
@@ -1270,7 +1386,7 @@ restart:
         }
 
 out:
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         locks_free_lock(new_fl);
         return error;
 }
@@ -1323,9 +1439,10 @@ EXPORT_SYMBOL(lease_get_mtime);
 int fcntl_getlease(struct file *filp)
 {
         struct file_lock *fl;
+        struct inode *inode = file_inode(filp);
         int type = F_UNLCK;
 
-        lock_flocks();
+        spin_lock(&inode->i_lock);
         time_out_leases(file_inode(filp));
         for (fl = file_inode(filp)->i_flock; fl && IS_LEASE(fl);
                         fl = fl->fl_next) {
@@ -1334,11 +1451,11 @@ int fcntl_getlease(struct file *filp)
                         break;
                 }
         }
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         return type;
 }
 
-int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
+static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
 {
         struct file_lock *fl, **before, **my_before = NULL, *lease;
         struct dentry *dentry = filp->f_path.dentry;
@@ -1351,7 +1468,7 @@ int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
         if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
                 goto out;
         if ((arg == F_WRLCK)
-            && ((dentry->d_count > 1)
+            && ((d_count(dentry) > 1)
                 || (atomic_read(&inode->i_count) > 1)))
                 goto out;
 
@@ -1403,7 +1520,7 @@ out:
         return error;
 }
 
-int generic_delete_lease(struct file *filp, struct file_lock **flp)
+static int generic_delete_lease(struct file *filp, struct file_lock **flp)
 {
         struct file_lock *fl, **before;
         struct dentry *dentry = filp->f_path.dentry;
@@ -1428,7 +1545,7 @@ int generic_delete_lease(struct file *filp, struct file_lock **flp)
  *      The (input) flp->fl_lmops->lm_break function is required
  *      by break_lease().
  *
- *      Called with file_lock_lock held.
+ *      Called with inode->i_lock held.
  */
 int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
 {
@@ -1497,11 +1614,12 @@ static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
 
 int vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
 {
+        struct inode *inode = file_inode(filp);
         int error;
 
-        lock_flocks();
+        spin_lock(&inode->i_lock);
         error = __vfs_setlease(filp, arg, lease);
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
 
         return error;
 }
@@ -1519,6 +1637,7 @@ static int do_fcntl_delete_lease(struct file *filp)
 static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
 {
         struct file_lock *fl, *ret;
+        struct inode *inode = file_inode(filp);
         struct fasync_struct *new;
         int error;
 
@@ -1532,10 +1651,10 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
                 return -ENOMEM;
         }
         ret = fl;
-        lock_flocks();
+        spin_lock(&inode->i_lock);
         error = __vfs_setlease(filp, arg, &ret);
         if (error) {
-                unlock_flocks();
+                spin_unlock(&inode->i_lock);
                 locks_free_lock(fl);
                 goto out_free_fasync;
         }
@@ -1552,7 +1671,7 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
                 new = NULL;
 
         error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
 
 out_free_fasync:
         if (new)
@@ -2076,7 +2195,7 @@ void locks_remove_flock(struct file *filp)
                         fl.fl_ops->fl_release_private(&fl);
         }
 
-        lock_flocks();
+        spin_lock(&inode->i_lock);
         before = &inode->i_flock;
 
         while ((fl = *before) != NULL) {
@@ -2094,30 +2213,28 @@ void locks_remove_flock(struct file *filp)
                 }
                 before = &fl->fl_next;
         }
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
 }
 
 /**
  *      posix_unblock_lock - stop waiting for a file lock
- *      @filp:   how the file was opened
  *      @waiter: the lock which was waiting
  *
  *      lockd needs to block waiting for locks.
  */
 int
-posix_unblock_lock(struct file *filp, struct file_lock *waiter)
+posix_unblock_lock(struct file_lock *waiter)
 {
         int status = 0;
 
-        lock_flocks();
+        spin_lock(&blocked_lock_lock);
         if (waiter->fl_next)
                 __locks_delete_block(waiter);
         else
                 status = -ENOENT;
-        unlock_flocks();
+        spin_unlock(&blocked_lock_lock);
         return status;
 }
-
 EXPORT_SYMBOL(posix_unblock_lock);
 
 /**
@@ -2140,6 +2257,11 @@ EXPORT_SYMBOL_GPL(vfs_cancel_lock);
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
+struct locks_iterator {
+        int     li_cpu;
+        loff_t  li_pos;
+};
+
 static void lock_get_status(struct seq_file *f, struct file_lock *fl,
                             loff_t id, char *pfx)
 {
@@ -2213,37 +2335,41 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
 
 static int locks_show(struct seq_file *f, void *v)
 {
+        struct locks_iterator *iter = f->private;
         struct file_lock *fl, *bfl;
 
-        fl = list_entry(v, struct file_lock, fl_link);
+        fl = hlist_entry(v, struct file_lock, fl_link);
 
-        lock_get_status(f, fl, *((loff_t *)f->private), "");
+        lock_get_status(f, fl, iter->li_pos, "");
 
         list_for_each_entry(bfl, &fl->fl_block, fl_block)
-                lock_get_status(f, bfl, *((loff_t *)f->private), " ->");
+                lock_get_status(f, bfl, iter->li_pos, " ->");
 
         return 0;
 }
 
 static void *locks_start(struct seq_file *f, loff_t *pos)
 {
-        loff_t *p = f->private;
+        struct locks_iterator *iter = f->private;
 
-        lock_flocks();
-        *p = (*pos + 1);
-        return seq_list_start(&file_lock_list, *pos);
+        iter->li_pos = *pos + 1;
+        lg_global_lock(&file_lock_lglock);
+        spin_lock(&blocked_lock_lock);
+        return seq_hlist_start_percpu(&file_lock_list, &iter->li_cpu, *pos);
 }
 
 static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
 {
-        loff_t *p = f->private;
-        ++*p;
-        return seq_list_next(v, &file_lock_list, pos);
+        struct locks_iterator *iter = f->private;
+
+        ++iter->li_pos;
+        return seq_hlist_next_percpu(v, &file_lock_list, &iter->li_cpu, pos);
 }
 
 static void locks_stop(struct seq_file *f, void *v)
 {
-        unlock_flocks();
+        spin_unlock(&blocked_lock_lock);
+        lg_global_unlock(&file_lock_lglock);
 }
 
 static const struct seq_operations locks_seq_operations = {
@@ -2255,7 +2381,8 @@ static const struct seq_operations locks_seq_operations = {
 
 static int locks_open(struct inode *inode, struct file *filp)
 {
-        return seq_open_private(filp, &locks_seq_operations, sizeof(loff_t));
+        return seq_open_private(filp, &locks_seq_operations,
+                                        sizeof(struct locks_iterator));
 }
 
 static const struct file_operations proc_locks_operations = {
@@ -2290,7 +2417,8 @@ int lock_may_read(struct inode *inode, loff_t start, unsigned long len)
 {
         struct file_lock *fl;
         int result = 1;
-        lock_flocks();
+
+        spin_lock(&inode->i_lock);
         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
                 if (IS_POSIX(fl)) {
                         if (fl->fl_type == F_RDLCK)
@@ -2307,7 +2435,7 @@ int lock_may_read(struct inode *inode, loff_t start, unsigned long len)
                 result = 0;
                 break;
         }
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         return result;
 }
 
@@ -2330,7 +2458,8 @@ int lock_may_write(struct inode *inode, loff_t start, unsigned long len)
 {
         struct file_lock *fl;
         int result = 1;
-        lock_flocks();
+
+        spin_lock(&inode->i_lock);
         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
                 if (IS_POSIX(fl)) {
                         if ((fl->fl_end < start) || (fl->fl_start > (start + len)))
@@ -2345,7 +2474,7 @@ int lock_may_write(struct inode *inode, loff_t start, unsigned long len)
                 result = 0;
                 break;
         }
-        unlock_flocks();
+        spin_unlock(&inode->i_lock);
         return result;
 }
 
@@ -2353,9 +2482,16 @@ EXPORT_SYMBOL(lock_may_write);
 
 static int __init filelock_init(void)
 {
+        int i;
+
         filelock_cache = kmem_cache_create("file_lock_cache",
                         sizeof(struct file_lock), 0, SLAB_PANIC, NULL);
 
+        lg_lock_init(&file_lock_lglock, "file_lock_lglock");
+
+        for_each_possible_cpu(i)
+                INIT_HLIST_HEAD(per_cpu_ptr(&file_lock_list, i));
+
         return 0;
 }