fs: dcache scale dentry refcount
[linux-2.6.git] / fs / locks.c
index 4de3a26..08415b2 100644 (file)
 #include <linux/module.h>
 #include <linux/security.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
 #include <linux/syscalls.h>
 #include <linux/time.h>
 #include <linux/rcupdate.h>
@@ -142,6 +141,7 @@ int lease_break_time = 45;
 
 static LIST_HEAD(file_lock_list);
 static LIST_HEAD(blocked_list);
+static DEFINE_SPINLOCK(file_lock_lock);
 
 /*
  * Protects the two list heads above, plus the inode->i_flock list
@@ -149,23 +149,24 @@ static LIST_HEAD(blocked_list);
  */
 void lock_flocks(void)
 {
-       lock_kernel();
+       spin_lock(&file_lock_lock);
 }
 EXPORT_SYMBOL_GPL(lock_flocks);
 
 void unlock_flocks(void)
 {
-       unlock_kernel();
+       spin_unlock(&file_lock_lock);
 }
 EXPORT_SYMBOL_GPL(unlock_flocks);
 
 static struct kmem_cache *filelock_cache __read_mostly;
 
 /* Allocate an empty lock structure. */
-static struct file_lock *locks_alloc_lock(void)
+struct file_lock *locks_alloc_lock(void)
 {
        return kmem_cache_alloc(filelock_cache, GFP_KERNEL);
 }
+EXPORT_SYMBOL_GPL(locks_alloc_lock);
 
 void locks_release_private(struct file_lock *fl)
 {
@@ -184,7 +185,7 @@ void locks_release_private(struct file_lock *fl)
 EXPORT_SYMBOL_GPL(locks_release_private);
 
 /* Free a lock which is not in use. */
-static void locks_free_lock(struct file_lock *fl)
+void locks_free_lock(struct file_lock *fl)
 {
        BUG_ON(waitqueue_active(&fl->fl_wait));
        BUG_ON(!list_empty(&fl->fl_block));
@@ -193,6 +194,7 @@ static void locks_free_lock(struct file_lock *fl)
        locks_release_private(fl);
        kmem_cache_free(filelock_cache, fl);
 }
+EXPORT_SYMBOL(locks_free_lock);
 
 void locks_init_lock(struct file_lock *fl)
 {
@@ -232,11 +234,8 @@ static void locks_copy_private(struct file_lock *new, struct file_lock *fl)
                        fl->fl_ops->fl_copy_lock(new, fl);
                new->fl_ops = fl->fl_ops;
        }
-       if (fl->fl_lmops) {
-               if (fl->fl_lmops->fl_copy_lock)
-                       fl->fl_lmops->fl_copy_lock(new, fl);
+       if (fl->fl_lmops)
                new->fl_lmops = fl->fl_lmops;
-       }
 }
 
 /*
@@ -1365,36 +1364,32 @@ int fcntl_getlease(struct file *filp)
 int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
 {
        struct file_lock *fl, **before, **my_before = NULL, *lease;
-       struct file_lock *new_fl = NULL;
        struct dentry *dentry = filp->f_path.dentry;
        struct inode *inode = dentry->d_inode;
        int error, rdlease_count = 0, wrlease_count = 0;
 
+       lease = *flp;
+
+       error = -EACCES;
        if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE))
-               return -EACCES;
+               goto out;
+       error = -EINVAL;
        if (!S_ISREG(inode->i_mode))
-               return -EINVAL;
+               goto out;
        error = security_file_lock(filp, arg);
        if (error)
-               return error;
+               goto out;
 
        time_out_leases(inode);
 
        BUG_ON(!(*flp)->fl_lmops->fl_break);
 
-       lease = *flp;
-
        if (arg != F_UNLCK) {
-               error = -ENOMEM;
-               new_fl = locks_alloc_lock();
-               if (new_fl == NULL)
-                       goto out;
-
                error = -EAGAIN;
                if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
                        goto out;
                if ((arg == F_WRLCK)
-                   && ((atomic_read(&dentry->d_count) > 1)
+                   && ((dentry->d_count > 1)
                        || (atomic_read(&inode->i_count) > 1)))
                        goto out;
        }
@@ -1429,12 +1424,12 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
                goto out;
 
        if (my_before != NULL) {
-               *flp = *my_before;
                error = lease->fl_lmops->fl_change(my_before, arg);
+               if (!error)
+                       *flp = *my_before;
                goto out;
        }
 
-       error = 0;
        if (arg == F_UNLCK)
                goto out;
 
@@ -1442,15 +1437,10 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
        if (!leases_enable)
                goto out;
 
-       locks_copy_lock(new_fl, lease);
-       locks_insert_lock(before, new_fl);
-
-       *flp = new_fl;
+       locks_insert_lock(before, lease);
        return 0;
 
 out:
-       if (new_fl != NULL)
-               locks_free_lock(new_fl);
        return error;
 }
 EXPORT_SYMBOL(generic_setlease);
@@ -1502,6 +1492,59 @@ int vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
 }
 EXPORT_SYMBOL_GPL(vfs_setlease);
 
+static int do_fcntl_delete_lease(struct file *filp)
+{
+       struct file_lock fl, *flp = &fl;
+
+       lease_init(filp, F_UNLCK, flp);
+
+       return vfs_setlease(filp, F_UNLCK, &flp);
+}
+
+static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
+{
+       struct file_lock *fl, *ret;
+       struct fasync_struct *new;
+       int error;
+
+       fl = lease_alloc(filp, arg);
+       if (IS_ERR(fl))
+               return PTR_ERR(fl);
+
+       new = fasync_alloc();
+       if (!new) {
+               locks_free_lock(fl);
+               return -ENOMEM;
+       }
+       ret = fl;
+       lock_flocks();
+       error = __vfs_setlease(filp, arg, &ret);
+       if (error) {
+               unlock_flocks();
+               locks_free_lock(fl);
+               goto out_free_fasync;
+       }
+       if (ret != fl)
+               locks_free_lock(fl);
+
+       /*
+        * fasync_insert_entry() returns the old entry if any.
+        * If there was no old entry, then it used 'new' and
+        * inserted it into the fasync list. Clear new so that
+        * we don't release it here.
+        */
+       if (!fasync_insert_entry(fd, filp, &ret->fl_fasync, new))
+               new = NULL;
+
+       error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
+       unlock_flocks();
+
+out_free_fasync:
+       if (new)
+               fasync_free(new);
+       return error;
+}
+
 /**
  *     fcntl_setlease  -       sets a lease on an open file
  *     @fd: open file descriptor
@@ -1514,34 +1557,9 @@ EXPORT_SYMBOL_GPL(vfs_setlease);
  */
 int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
 {
-       struct file_lock fl, *flp = &fl;
-       struct inode *inode = filp->f_path.dentry->d_inode;
-       int error;
-
-       locks_init_lock(&fl);
-       error = lease_init(filp, arg, &fl);
-       if (error)
-               return error;
-
-       lock_flocks();
-
-       error = __vfs_setlease(filp, arg, &flp);
-       if (error || arg == F_UNLCK)
-               goto out_unlock;
-
-       error = fasync_helper(fd, filp, 1, &flp->fl_fasync);
-       if (error < 0) {
-               /* remove lease just inserted by setlease */
-               flp->fl_type = F_UNLCK | F_INPROGRESS;
-               flp->fl_break_time = jiffies - 10;
-               time_out_leases(inode);
-               goto out_unlock;
-       }
-
-       error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
-out_unlock:
-       unlock_flocks();
-       return error;
+       if (arg == F_UNLCK)
+               return do_fcntl_delete_lease(filp);
+       return do_fcntl_add_lease(fd, filp, arg);
 }
 
 /**