Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 0 insertions, 2373 deletions

diff --git a/ANDROID_3.4.5/fs/locks.c b/ANDROID_3.4.5/fs/locks.c
deleted file mode 100644
index 0d68f1f8..00000000
--- a/ANDROID_3.4.5/fs/locks.c
+++ /dev/null
@@ -1,2373 +0,0 @@
-/*
- *  linux/fs/locks.c
- *
- *  Provide support for fcntl()'s F_GETLK, F_SETLK, and F_SETLKW calls.
- *  Doug Evans (dje@spiff.uucp), August 07, 1992
- *
- *  Deadlock detection added.
- *  FIXME: one thing isn't handled yet:
- *	- mandatory locks (requires lots of changes elsewhere)
- *  Kelly Carmichael (kelly@[142.24.8.65]), September 17, 1994.
- *
- *  Miscellaneous edits, and a total rewrite of posix_lock_file() code.
- *  Kai Petzke (wpp@marie.physik.tu-berlin.de), 1994
- *  
- *  Converted file_lock_table to a linked list from an array, which eliminates
- *  the limits on how many active file locks are open.
- *  Chad Page (pageone@netcom.com), November 27, 1994
- * 
- *  Removed dependency on file descriptors. dup()'ed file descriptors now
- *  get the same locks as the original file descriptors, and a close() on
- *  any file descriptor removes ALL the locks on the file for the current
- *  process. Since locks still depend on the process id, locks are inherited
- *  after an exec() but not after a fork(). This agrees with POSIX, and both
- *  BSD and SVR4 practice.
- *  Andy Walker (andy@lysaker.kvaerner.no), February 14, 1995
- *
- *  Scrapped free list which is redundant now that we allocate locks
- *  dynamically with kmalloc()/kfree().
- *  Andy Walker (andy@lysaker.kvaerner.no), February 21, 1995
- *
- *  Implemented two lock personalities - FL_FLOCK and FL_POSIX.
- *
- *  FL_POSIX locks are created with calls to fcntl() and lockf() through the
- *  fcntl() system call. They have the semantics described above.
- *
- *  FL_FLOCK locks are created with calls to flock(), through the flock()
- *  system call, which is new. Old C libraries implement flock() via fcntl()
- *  and will continue to use the old, broken implementation.
- *
- *  FL_FLOCK locks follow the 4.4 BSD flock() semantics. They are associated
- *  with a file pointer (filp). As a result they can be shared by a parent
- *  process and its children after a fork(). They are removed when the last
- *  file descriptor referring to the file pointer is closed (unless explicitly
- *  unlocked). 
- *
- *  FL_FLOCK locks never deadlock, an existing lock is always removed before
- *  upgrading from shared to exclusive (or vice versa). When this happens
- *  any processes blocked by the current lock are woken up and allowed to
- *  run before the new lock is applied.
- *  Andy Walker (andy@lysaker.kvaerner.no), June 09, 1995
- *
- *  Removed some race conditions in flock_lock_file(), marked other possible
- *  races. Just grep for FIXME to see them. 
- *  Dmitry Gorodchanin (pgmdsg@ibi.com), February 09, 1996.
- *
- *  Addressed Dmitry's concerns. Deadlock checking no longer recursive.
- *  Lock allocation changed to GFP_ATOMIC as we can't afford to sleep
- *  once we've checked for blocking and deadlocking.
- *  Andy Walker (andy@lysaker.kvaerner.no), April 03, 1996.
- *
- *  Initial implementation of mandatory locks. SunOS turned out to be
- *  a rotten model, so I implemented the "obvious" semantics.
- *  See 'Documentation/filesystems/mandatory-locking.txt' for details.
- *  Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996.
- *
- *  Don't allow mandatory locks on mmap()'ed files. Added simple functions to
- *  check if a file has mandatory locks, used by mmap(), open() and creat() to
- *  see if system call should be rejected. Ref. HP-UX/SunOS/Solaris Reference
- *  Manual, Section 2.
- *  Andy Walker (andy@lysaker.kvaerner.no), April 09, 1996.
- *
- *  Tidied up block list handling. Added '/proc/locks' interface.
- *  Andy Walker (andy@lysaker.kvaerner.no), April 24, 1996.
- *
- *  Fixed deadlock condition for pathological code that mixes calls to
- *  flock() and fcntl().
- *  Andy Walker (andy@lysaker.kvaerner.no), April 29, 1996.
- *
- *  Allow only one type of locking scheme (FL_POSIX or FL_FLOCK) to be in use
- *  for a given file at a time. Changed the CONFIG_LOCK_MANDATORY scheme to
- *  guarantee sensible behaviour in the case where file system modules might
- *  be compiled with different options than the kernel itself.
- *  Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996.
- *
- *  Added a couple of missing wake_up() calls. Thanks to Thomas Meckel
- *  (Thomas.Meckel@mni.fh-giessen.de) for spotting this.
- *  Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996.
- *
- *  Changed FL_POSIX locks to use the block list in the same way as FL_FLOCK
- *  locks. Changed process synchronisation to avoid dereferencing locks that
- *  have already been freed.
- *  Andy Walker (andy@lysaker.kvaerner.no), Sep 21, 1996.
- *
- *  Made the block list a circular list to minimise searching in the list.
- *  Andy Walker (andy@lysaker.kvaerner.no), Sep 25, 1996.
- *
- *  Made mandatory locking a mount option. Default is not to allow mandatory
- *  locking.
- *  Andy Walker (andy@lysaker.kvaerner.no), Oct 04, 1996.
- *
- *  Some adaptations for NFS support.
- *  Olaf Kirch (okir@monad.swb.de), Dec 1996,
- *
- *  Fixed /proc/locks interface so that we can't overrun the buffer we are handed.
- *  Andy Walker (andy@lysaker.kvaerner.no), May 12, 1997.
- *
- *  Use slab allocator instead of kmalloc/kfree.
- *  Use generic list implementation from <linux/list.h>.
- *  Sped up posix_locks_deadlock by only considering blocked locks.
- *  Matthew Wilcox <willy@debian.org>, March, 2000.
- *
- *  Leases and LOCK_MAND
- *  Matthew Wilcox <willy@debian.org>, June, 2000.
- *  Stephen Rothwell <sfr@canb.auug.org.au>, June, 2000.
- */
-
-#include <linux/capability.h>
-#include <linux/file.h>
-#include <linux/fdtable.h>
-#include <linux/fs.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/security.h>
-#include <linux/slab.h>
-#include <linux/syscalls.h>
-#include <linux/time.h>
-#include <linux/rcupdate.h>
-#include <linux/pid_namespace.h>
-
-#include <asm/uaccess.h>
-
-#define IS_POSIX(fl)	(fl->fl_flags & FL_POSIX)
-#define IS_FLOCK(fl)	(fl->fl_flags & FL_FLOCK)
-#define IS_LEASE(fl)	(fl->fl_flags & FL_LEASE)
-
-static bool lease_breaking(struct file_lock *fl)
-{
-	return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING);
-}
-
-static int target_leasetype(struct file_lock *fl)
-{
-	if (fl->fl_flags & FL_UNLOCK_PENDING)
-		return F_UNLCK;
-	if (fl->fl_flags & FL_DOWNGRADE_PENDING)
-		return F_RDLCK;
-	return fl->fl_type;
-}
-
-int leases_enable = 1;
-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);
-
-/*
- * Protects the two list heads above, plus the inode->i_flock list
- */
-void lock_flocks(void)
-{
-	spin_lock(&file_lock_lock);
-}
-EXPORT_SYMBOL_GPL(lock_flocks);
-
-void unlock_flocks(void)
-{
-	spin_unlock(&file_lock_lock);
-}
-EXPORT_SYMBOL_GPL(unlock_flocks);
-
-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_LIST_HEAD(&fl->fl_block);
-	init_waitqueue_head(&fl->fl_wait);
-}
-
-/* Allocate an empty lock structure. */
-struct file_lock *locks_alloc_lock(void)
-{
-	struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL);
-
-	if (fl)
-		locks_init_lock_heads(fl);
-
-	return fl;
-}
-EXPORT_SYMBOL_GPL(locks_alloc_lock);
-
-void locks_release_private(struct file_lock *fl)
-{
-	if (fl->fl_ops) {
-		if (fl->fl_ops->fl_release_private)
-			fl->fl_ops->fl_release_private(fl);
-		fl->fl_ops = NULL;
-	}
-	if (fl->fl_lmops) {
-		if (fl->fl_lmops->lm_release_private)
-			fl->fl_lmops->lm_release_private(fl);
-		fl->fl_lmops = NULL;
-	}
-
-}
-EXPORT_SYMBOL_GPL(locks_release_private);
-
-/* Free a lock which is not in use. */
-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));
-
-	locks_release_private(fl);
-	kmem_cache_free(filelock_cache, fl);
-}
-EXPORT_SYMBOL(locks_free_lock);
-
-void locks_init_lock(struct file_lock *fl)
-{
-	memset(fl, 0, sizeof(struct file_lock));
-	locks_init_lock_heads(fl);
-}
-
-EXPORT_SYMBOL(locks_init_lock);
-
-static void locks_copy_private(struct file_lock *new, struct file_lock *fl)
-{
-	if (fl->fl_ops) {
-		if (fl->fl_ops->fl_copy_lock)
-			fl->fl_ops->fl_copy_lock(new, fl);
-		new->fl_ops = fl->fl_ops;
-	}
-	if (fl->fl_lmops)
-		new->fl_lmops = fl->fl_lmops;
-}
-
-/*
- * Initialize a new lock from an existing file_lock structure.
- */
-void __locks_copy_lock(struct file_lock *new, const struct file_lock *fl)
-{
-	new->fl_owner = fl->fl_owner;
-	new->fl_pid = fl->fl_pid;
-	new->fl_file = NULL;
-	new->fl_flags = fl->fl_flags;
-	new->fl_type = fl->fl_type;
-	new->fl_start = fl->fl_start;
-	new->fl_end = fl->fl_end;
-	new->fl_ops = NULL;
-	new->fl_lmops = NULL;
-}
-EXPORT_SYMBOL(__locks_copy_lock);
-
-void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
-{
-	locks_release_private(new);
-
-	__locks_copy_lock(new, fl);
-	new->fl_file = fl->fl_file;
-	new->fl_ops = fl->fl_ops;
-	new->fl_lmops = fl->fl_lmops;
-
-	locks_copy_private(new, fl);
-}
-
-EXPORT_SYMBOL(locks_copy_lock);
-
-static inline int flock_translate_cmd(int cmd) {
-	if (cmd & LOCK_MAND)
-		return cmd & (LOCK_MAND | LOCK_RW);
-	switch (cmd) {
-	case LOCK_SH:
-		return F_RDLCK;
-	case LOCK_EX:
-		return F_WRLCK;
-	case LOCK_UN:
-		return F_UNLCK;
-	}
-	return -EINVAL;
-}
-
-/* Fill in a file_lock structure with an appropriate FLOCK lock. */
-static int flock_make_lock(struct file *filp, struct file_lock **lock,
-		unsigned int cmd)
-{
-	struct file_lock *fl;
-	int type = flock_translate_cmd(cmd);
-	if (type < 0)
-		return type;
-	
-	fl = locks_alloc_lock();
-	if (fl == NULL)
-		return -ENOMEM;
-
-	fl->fl_file = filp;
-	fl->fl_pid = current->tgid;
-	fl->fl_flags = FL_FLOCK;
-	fl->fl_type = type;
-	fl->fl_end = OFFSET_MAX;
-	
-	*lock = fl;
-	return 0;
-}
-
-static int assign_type(struct file_lock *fl, int type)
-{
-	switch (type) {
-	case F_RDLCK:
-	case F_WRLCK:
-	case F_UNLCK:
-		fl->fl_type = type;
-		break;
-	default:
-		return -EINVAL;
-	}
-	return 0;
-}
-
-/* Verify a "struct flock" and copy it to a "struct file_lock" as a POSIX
- * style lock.
- */
-static int flock_to_posix_lock(struct file *filp, struct file_lock *fl,
-			       struct flock *l)
-{
-	off_t start, end;
-
-	switch (l->l_whence) {
-	case SEEK_SET:
-		start = 0;
-		break;
-	case SEEK_CUR:
-		start = filp->f_pos;
-		break;
-	case SEEK_END:
-		start = i_size_read(filp->f_path.dentry->d_inode);
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	/* POSIX-1996 leaves the case l->l_len < 0 undefined;
-	   POSIX-2001 defines it. */
-	start += l->l_start;
-	if (start < 0)
-		return -EINVAL;
-	fl->fl_end = OFFSET_MAX;
-	if (l->l_len > 0) {
-		end = start + l->l_len - 1;
-		fl->fl_end = end;
-	} else if (l->l_len < 0) {
-		end = start - 1;
-		fl->fl_end = end;
-		start += l->l_len;
-		if (start < 0)
-			return -EINVAL;
-	}
-	fl->fl_start = start;	/* we record the absolute position */
-	if (fl->fl_end < fl->fl_start)
-		return -EOVERFLOW;
-	
-	fl->fl_owner = current->files;
-	fl->fl_pid = current->tgid;
-	fl->fl_file = filp;
-	fl->fl_flags = FL_POSIX;
-	fl->fl_ops = NULL;
-	fl->fl_lmops = NULL;
-
-	return assign_type(fl, l->l_type);
-}
-
-#if BITS_PER_LONG == 32
-static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl,
-				 struct flock64 *l)
-{
-	loff_t start;
-
-	switch (l->l_whence) {
-	case SEEK_SET:
-		start = 0;
-		break;
-	case SEEK_CUR:
-		start = filp->f_pos;
-		break;
-	case SEEK_END:
-		start = i_size_read(filp->f_path.dentry->d_inode);
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	start += l->l_start;
-	if (start < 0)
-		return -EINVAL;
-	fl->fl_end = OFFSET_MAX;
-	if (l->l_len > 0) {
-		fl->fl_end = start + l->l_len - 1;
-	} else if (l->l_len < 0) {
-		fl->fl_end = start - 1;
-		start += l->l_len;
-		if (start < 0)
-			return -EINVAL;
-	}
-	fl->fl_start = start;	/* we record the absolute position */
-	if (fl->fl_end < fl->fl_start)
-		return -EOVERFLOW;
-	
-	fl->fl_owner = current->files;
-	fl->fl_pid = current->tgid;
-	fl->fl_file = filp;
-	fl->fl_flags = FL_POSIX;
-	fl->fl_ops = NULL;
-	fl->fl_lmops = NULL;
-
-	return assign_type(fl, l->l_type);
-}
-#endif
-
-/* default lease lock manager operations */
-static void lease_break_callback(struct file_lock *fl)
-{
-	kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG);
-}
-
-static void lease_release_private_callback(struct file_lock *fl)
-{
-	if (!fl->fl_file)
-		return;
-
-	f_delown(fl->fl_file);
-	fl->fl_file->f_owner.signum = 0;
-}
-
-static const struct lock_manager_operations lease_manager_ops = {
-	.lm_break = lease_break_callback,
-	.lm_release_private = lease_release_private_callback,
-	.lm_change = lease_modify,
-};
-
-/*
- * Initialize a lease, use the default lock manager operations
- */
-static int lease_init(struct file *filp, int type, struct file_lock *fl)
- {
-	if (assign_type(fl, type) != 0)
-		return -EINVAL;
-
-	fl->fl_owner = current->files;
-	fl->fl_pid = current->tgid;
-
-	fl->fl_file = filp;
-	fl->fl_flags = FL_LEASE;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
-	fl->fl_ops = NULL;
-	fl->fl_lmops = &lease_manager_ops;
-	return 0;
-}
-
-/* Allocate a file_lock initialised to this type of lease */
-static struct file_lock *lease_alloc(struct file *filp, int type)
-{
-	struct file_lock *fl = locks_alloc_lock();
-	int error = -ENOMEM;
-
-	if (fl == NULL)
-		return ERR_PTR(error);
-
-	error = lease_init(filp, type, fl);
-	if (error) {
-		locks_free_lock(fl);
-		return ERR_PTR(error);
-	}
-	return fl;
-}
-
-/* Check if two locks overlap each other.
- */
-static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2)
-{
-	return ((fl1->fl_end >= fl2->fl_start) &&
-		(fl2->fl_end >= fl1->fl_start));
-}
-
-/*
- * Check whether two locks have the same owner.
- */
-static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
-{
-	if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner)
-		return fl2->fl_lmops == fl1->fl_lmops &&
-			fl1->fl_lmops->lm_compare_owner(fl1, fl2);
-	return fl1->fl_owner == fl2->fl_owner;
-}
-
-/* Remove waiter from blocker's block list.
- * When blocker ends up pointing to itself then the list is empty.
- */
-static void __locks_delete_block(struct file_lock *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)
-{
-	lock_flocks();
-	__locks_delete_block(waiter);
-	unlock_flocks();
-}
-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.
- */
-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;
-	if (IS_POSIX(blocker))
-		list_add(&waiter->fl_link, &blocked_list);
-}
-
-/* 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.
- */
-static void locks_wake_up_blocks(struct file_lock *blocker)
-{
-	while (!list_empty(&blocker->fl_block)) {
-		struct file_lock *waiter;
-
-		waiter = list_first_entry(&blocker->fl_block,
-				struct file_lock, fl_block);
-		__locks_delete_block(waiter);
-		if (waiter->fl_lmops && waiter->fl_lmops->lm_notify)
-			waiter->fl_lmops->lm_notify(waiter);
-		else
-			wake_up(&waiter->fl_wait);
-	}
-}
-
-/* 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.
- */
-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;
-}
-
-/*
- * Delete a lock and then free it.
- * Wake up processes that are blocked waiting for this lock,
- * notify the FS that the lock has been cleared and
- * finally free the lock.
- */
-static void locks_delete_lock(struct file_lock **thisfl_p)
-{
-	struct file_lock *fl = *thisfl_p;
-
-	*thisfl_p = fl->fl_next;
-	fl->fl_next = NULL;
-	list_del_init(&fl->fl_link);
-
-	fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync);
-	if (fl->fl_fasync != NULL) {
-		printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync);
-		fl->fl_fasync = NULL;
-	}
-
-	if (fl->fl_nspid) {
-		put_pid(fl->fl_nspid);
-		fl->fl_nspid = NULL;
-	}
-
-	locks_wake_up_blocks(fl);
-	locks_free_lock(fl);
-}
-
-/* Determine if lock sys_fl blocks lock caller_fl. Common functionality
- * checks for shared/exclusive status of overlapping locks.
- */
-static int locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl)
-{
-	if (sys_fl->fl_type == F_WRLCK)
-		return 1;
-	if (caller_fl->fl_type == F_WRLCK)
-		return 1;
-	return 0;
-}
-
-/* Determine if lock sys_fl blocks lock caller_fl. POSIX specific
- * checking before calling the locks_conflict().
- */
-static int posix_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl)
-{
-	/* POSIX locks owned by the same process do not conflict with
-	 * each other.
-	 */
-	if (!IS_POSIX(sys_fl) || posix_same_owner(caller_fl, sys_fl))
-		return (0);
-
-	/* Check whether they overlap */
-	if (!locks_overlap(caller_fl, sys_fl))
-		return 0;
-
-	return (locks_conflict(caller_fl, sys_fl));
-}
-
-/* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific
- * checking before calling the locks_conflict().
- */
-static int flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl)
-{
-	/* FLOCK locks referring to the same filp do not conflict with
-	 * each other.
-	 */
-	if (!IS_FLOCK(sys_fl) || (caller_fl->fl_file == sys_fl->fl_file))
-		return (0);
-	if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND))
-		return 0;
-
-	return (locks_conflict(caller_fl, sys_fl));
-}
-
-void
-posix_test_lock(struct file *filp, struct file_lock *fl)
-{
-	struct file_lock *cfl;
-
-	lock_flocks();
-	for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) {
-		if (!IS_POSIX(cfl))
-			continue;
-		if (posix_locks_conflict(fl, cfl))
-			break;
-	}
-	if (cfl) {
-		__locks_copy_lock(fl, cfl);
-		if (cfl->fl_nspid)
-			fl->fl_pid = pid_vnr(cfl->fl_nspid);
-	} else
-		fl->fl_type = F_UNLCK;
-	unlock_flocks();
-	return;
-}
-EXPORT_SYMBOL(posix_test_lock);
-
-/*
- * Deadlock detection:
- *
- * We attempt to detect deadlocks that are due purely to posix file
- * locks.
- *
- * We assume that a task can be waiting for at most one lock at a time.
- * So for any acquired lock, the process holding that lock may be
- * waiting on at most one other lock.  That lock in turns may be held by
- * someone waiting for at most one other lock.  Given a requested lock
- * caller_fl which is about to wait for a conflicting lock block_fl, we
- * follow this chain of waiters to ensure we are not about to create a
- * cycle.
- *
- * Since we do this before we ever put a process to sleep on a lock, we
- * are ensured that there is never a cycle; that is what guarantees that
- * the while() loop in posix_locks_deadlock() eventually completes.
- *
- * Note: the above assumption may not be true when handling lock
- * requests from a broken NFS client. It may also fail in the presence
- * of tasks (such as posix threads) sharing the same open file table.
- *
- * To handle those cases, we just bail out after a few iterations.
- */
-
-#define MAX_DEADLK_ITERATIONS 10
-
-/* Find a lock that the owner of the given block_fl is blocking on. */
-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) {
-		if (posix_same_owner(fl, block_fl))
-			return fl->fl_next;
-	}
-	return NULL;
-}
-
-static int posix_locks_deadlock(struct file_lock *caller_fl,
-				struct file_lock *block_fl)
-{
-	int i = 0;
-
-	while ((block_fl = what_owner_is_waiting_for(block_fl))) {
-		if (i++ > MAX_DEADLK_ITERATIONS)
-			return 0;
-		if (posix_same_owner(caller_fl, block_fl))
-			return 1;
-	}
-	return 0;
-}
-
-/* Try to create a FLOCK lock on filp. We always insert new FLOCK locks
- * after any leases, but before any posix locks.
- *
- * Note that if called with an FL_EXISTS argument, the caller may determine
- * whether or not a lock was successfully freed by testing the return
- * value for -ENOENT.
- */
-static int flock_lock_file(struct file *filp, struct file_lock *request)
-{
-	struct file_lock *new_fl = NULL;
-	struct file_lock **before;
-	struct inode * inode = filp->f_path.dentry->d_inode;
-	int error = 0;
-	int found = 0;
-
-	if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) {
-		new_fl = locks_alloc_lock();
-		if (!new_fl)
-			return -ENOMEM;
-	}
-
-	lock_flocks();
-	if (request->fl_flags & FL_ACCESS)
-		goto find_conflict;
-
-	for_each_lock(inode, before) {
-		struct file_lock *fl = *before;
-		if (IS_POSIX(fl))
-			break;
-		if (IS_LEASE(fl))
-			continue;
-		if (filp != fl->fl_file)
-			continue;
-		if (request->fl_type == fl->fl_type)
-			goto out;
-		found = 1;
-		locks_delete_lock(before);
-		break;
-	}
-
-	if (request->fl_type == F_UNLCK) {
-		if ((request->fl_flags & FL_EXISTS) && !found)
-			error = -ENOENT;
-		goto out;
-	}
-
-	/*
-	 * If a higher-priority process was blocked on the old file lock,
-	 * give it the opportunity to lock the file.
-	 */
-	if (found) {
-		unlock_flocks();
-		cond_resched();
-		lock_flocks();
-	}
-
-find_conflict:
-	for_each_lock(inode, before) {
-		struct file_lock *fl = *before;
-		if (IS_POSIX(fl))
-			break;
-		if (IS_LEASE(fl))
-			continue;
-		if (!flock_locks_conflict(request, fl))
-			continue;
-		error = -EAGAIN;
-		if (!(request->fl_flags & FL_SLEEP))
-			goto out;
-		error = FILE_LOCK_DEFERRED;
-		locks_insert_block(fl, request);
-		goto out;
-	}
-	if (request->fl_flags & FL_ACCESS)
-		goto out;
-	locks_copy_lock(new_fl, request);
-	locks_insert_lock(before, new_fl);
-	new_fl = NULL;
-	error = 0;
-
-out:
-	unlock_flocks();
-	if (new_fl)
-		locks_free_lock(new_fl);
-	return error;
-}
-
-static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
-{
-	struct file_lock *fl;
-	struct file_lock *new_fl = NULL;
-	struct file_lock *new_fl2 = NULL;
-	struct file_lock *left = NULL;
-	struct file_lock *right = NULL;
-	struct file_lock **before;
-	int error, added = 0;
-
-	/*
-	 * We may need two file_lock structures for this operation,
-	 * so we get them in advance to avoid races.
-	 *
-	 * In some cases we can be sure, that no new locks will be needed
-	 */
-	if (!(request->fl_flags & FL_ACCESS) &&
-	    (request->fl_type != F_UNLCK ||
-	     request->fl_start != 0 || request->fl_end != OFFSET_MAX)) {
-		new_fl = locks_alloc_lock();
-		new_fl2 = locks_alloc_lock();
-	}
-
-	lock_flocks();
-	if (request->fl_type != F_UNLCK) {
-		for_each_lock(inode, before) {
-			fl = *before;
-			if (!IS_POSIX(fl))
-				continue;
-			if (!posix_locks_conflict(request, fl))
-				continue;
-			if (conflock)
-				__locks_copy_lock(conflock, fl);
-			error = -EAGAIN;
-			if (!(request->fl_flags & FL_SLEEP))
-				goto out;
-			error = -EDEADLK;
-			if (posix_locks_deadlock(request, fl))
-				goto out;
-			error = FILE_LOCK_DEFERRED;
-			locks_insert_block(fl, request);
-			goto out;
-  		}
-  	}
-
-	/* If we're just looking for a conflict, we're done. */
-	error = 0;
-	if (request->fl_flags & FL_ACCESS)
-		goto out;
-
-	/*
-	 * Find the first old lock with the same owner as the new lock.
-	 */
-	
-	before = &inode->i_flock;
-
-	/* First skip locks owned by other processes.  */
-	while ((fl = *before) && (!IS_POSIX(fl) ||
-				  !posix_same_owner(request, fl))) {
-		before = &fl->fl_next;
-	}
-
-	/* Process locks with this owner.  */
-	while ((fl = *before) && posix_same_owner(request, fl)) {
-		/* Detect adjacent or overlapping regions (if same lock type)
-		 */
-		if (request->fl_type == fl->fl_type) {
-			/* In all comparisons of start vs end, use
-			 * "start - 1" rather than "end + 1". If end
-			 * is OFFSET_MAX, end + 1 will become negative.
-			 */
-			if (fl->fl_end < request->fl_start - 1)
-				goto next_lock;
-			/* If the next lock in the list has entirely bigger
-			 * addresses than the new one, insert the lock here.
-			 */
-			if (fl->fl_start - 1 > request->fl_end)
-				break;
-
-			/* If we come here, the new and old lock are of the
-			 * same type and adjacent or overlapping. Make one
-			 * lock yielding from the lower start address of both
-			 * locks to the higher end address.
-			 */
-			if (fl->fl_start > request->fl_start)
-				fl->fl_start = request->fl_start;
-			else
-				request->fl_start = fl->fl_start;
-			if (fl->fl_end < request->fl_end)
-				fl->fl_end = request->fl_end;
-			else
-				request->fl_end = fl->fl_end;
-			if (added) {
-				locks_delete_lock(before);
-				continue;
-			}
-			request = fl;
-			added = 1;
-		}
-		else {
-			/* Processing for different lock types is a bit
-			 * more complex.
-			 */
-			if (fl->fl_end < request->fl_start)
-				goto next_lock;
-			if (fl->fl_start > request->fl_end)
-				break;
-			if (request->fl_type == F_UNLCK)
-				added = 1;
-			if (fl->fl_start < request->fl_start)
-				left = fl;
-			/* If the next lock in the list has a higher end
-			 * address than the new one, insert the new one here.
-			 */
-			if (fl->fl_end > request->fl_end) {
-				right = fl;
-				break;
-			}
-			if (fl->fl_start >= request->fl_start) {
-				/* The new lock completely replaces an old
-				 * one (This may happen several times).
-				 */
-				if (added) {
-					locks_delete_lock(before);
-					continue;
-				}
-				/* Replace the old lock with the new one.
-				 * Wake up anybody waiting for the old one,
-				 * as the change in lock type might satisfy
-				 * their needs.
-				 */
-				locks_wake_up_blocks(fl);
-				fl->fl_start = request->fl_start;
-				fl->fl_end = request->fl_end;
-				fl->fl_type = request->fl_type;
-				locks_release_private(fl);
-				locks_copy_private(fl, request);
-				request = fl;
-				added = 1;
-			}
-		}
-		/* Go on to next lock.
-		 */
-	next_lock:
-		before = &fl->fl_next;
-	}
-
-	/*
-	 * 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.
-	 */
-	error = -ENOLCK; /* "no luck" */
-	if (right && left == right && !new_fl2)
-		goto out;
-
-	error = 0;
-	if (!added) {
-		if (request->fl_type == F_UNLCK) {
-			if (request->fl_flags & FL_EXISTS)
-				error = -ENOENT;
-			goto out;
-		}
-
-		if (!new_fl) {
-			error = -ENOLCK;
-			goto out;
-		}
-		locks_copy_lock(new_fl, request);
-		locks_insert_lock(before, new_fl);
-		new_fl = NULL;
-	}
-	if (right) {
-		if (left == right) {
-			/* The new lock breaks the old one in two pieces,
-			 * so we have to use the second new lock.
-			 */
-			left = new_fl2;
-			new_fl2 = NULL;
-			locks_copy_lock(left, right);
-			locks_insert_lock(before, left);
-		}
-		right->fl_start = request->fl_end + 1;
-		locks_wake_up_blocks(right);
-	}
-	if (left) {
-		left->fl_end = request->fl_start - 1;
-		locks_wake_up_blocks(left);
-	}
- out:
-	unlock_flocks();
-	/*
-	 * Free any unused locks.
-	 */
-	if (new_fl)
-		locks_free_lock(new_fl);
-	if (new_fl2)
-		locks_free_lock(new_fl2);
-	return error;
-}
-
-/**
- * posix_lock_file - Apply a POSIX-style lock to a file
- * @filp: The file to apply the lock to
- * @fl: The lock to be applied
- * @conflock: Place to return a copy of the conflicting lock, if found.
- *
- * Add a POSIX style lock to a file.
- * We merge adjacent & overlapping locks whenever possible.
- * POSIX locks are sorted by owner task, then by starting address
- *
- * Note that if called with an FL_EXISTS argument, the caller may determine
- * whether or not a lock was successfully freed by testing the return
- * value for -ENOENT.
- */
-int posix_lock_file(struct file *filp, struct file_lock *fl,
-			struct file_lock *conflock)
-{
-	return __posix_lock_file(filp->f_path.dentry->d_inode, fl, conflock);
-}
-EXPORT_SYMBOL(posix_lock_file);
-
-/**
- * posix_lock_file_wait - Apply a POSIX-style lock to a file
- * @filp: The file to apply the lock to
- * @fl: The lock to be applied
- *
- * Add a POSIX style lock to a file.
- * We merge adjacent & overlapping locks whenever possible.
- * POSIX locks are sorted by owner task, then by starting address
- */
-int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
-{
-	int error;
-	might_sleep ();
-	for (;;) {
-		error = posix_lock_file(filp, fl, NULL);
-		if (error != FILE_LOCK_DEFERRED)
-			break;
-		error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
-		if (!error)
-			continue;
-
-		locks_delete_block(fl);
-		break;
-	}
-	return error;
-}
-EXPORT_SYMBOL(posix_lock_file_wait);
-
-/**
- * locks_mandatory_locked - Check for an active lock
- * @inode: the file to check
- *
- * Searches the inode's list of locks to find any POSIX locks which conflict.
- * This function is called from locks_verify_locked() only.
- */
-int locks_mandatory_locked(struct inode *inode)
-{
-	fl_owner_t owner = current->files;
-	struct file_lock *fl;
-
-	/*
-	 * Search the lock list for this inode for any POSIX locks.
-	 */
-	lock_flocks();
-	for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
-		if (!IS_POSIX(fl))
-			continue;
-		if (fl->fl_owner != owner)
-			break;
-	}
-	unlock_flocks();
-	return fl ? -EAGAIN : 0;
-}
-
-/**
- * locks_mandatory_area - Check for a conflicting lock
- * @read_write: %FLOCK_VERIFY_WRITE for exclusive access, %FLOCK_VERIFY_READ
- *		for shared
- * @inode:      the file to check
- * @filp:       how the file was opened (if it was)
- * @offset:     start of area to check
- * @count:      length of area to check
- *
- * Searches the inode's list of locks to find any POSIX locks which conflict.
- * This function is called from rw_verify_area() and
- * locks_verify_truncate().
- */
-int locks_mandatory_area(int read_write, struct inode *inode,
-			 struct file *filp, loff_t offset,
-			 size_t count)
-{
-	struct file_lock fl;
-	int error;
-
-	locks_init_lock(&fl);
-	fl.fl_owner = current->files;
-	fl.fl_pid = current->tgid;
-	fl.fl_file = filp;
-	fl.fl_flags = FL_POSIX | FL_ACCESS;
-	if (filp && !(filp->f_flags & O_NONBLOCK))
-		fl.fl_flags |= FL_SLEEP;
-	fl.fl_type = (read_write == FLOCK_VERIFY_WRITE) ? F_WRLCK : F_RDLCK;
-	fl.fl_start = offset;
-	fl.fl_end = offset + count - 1;
-
-	for (;;) {
-		error = __posix_lock_file(inode, &fl, NULL);
-		if (error != FILE_LOCK_DEFERRED)
-			break;
-		error = wait_event_interruptible(fl.fl_wait, !fl.fl_next);
-		if (!error) {
-			/*
-			 * If we've been sleeping someone might have
-			 * changed the permissions behind our back.
-			 */
-			if (__mandatory_lock(inode))
-				continue;
-		}
-
-		locks_delete_block(&fl);
-		break;
-	}
-
-	return error;
-}
-
-EXPORT_SYMBOL(locks_mandatory_area);
-
-static void lease_clear_pending(struct file_lock *fl, int arg)
-{
-	switch (arg) {
-	case F_UNLCK:
-		fl->fl_flags &= ~FL_UNLOCK_PENDING;
-		/* fall through: */
-	case F_RDLCK:
-		fl->fl_flags &= ~FL_DOWNGRADE_PENDING;
-	}
-}
-
-/* We already had a lease on this file; just change its type */
-int lease_modify(struct file_lock **before, int arg)
-{
-	struct file_lock *fl = *before;
-	int error = assign_type(fl, arg);
-
-	if (error)
-		return error;
-	lease_clear_pending(fl, arg);
-	locks_wake_up_blocks(fl);
-	if (arg == F_UNLCK)
-		locks_delete_lock(before);
-	return 0;
-}
-
-EXPORT_SYMBOL(lease_modify);
-
-static bool past_time(unsigned long then)
-{
-	if (!then)
-		/* 0 is a special value meaning "this never expires": */
-		return false;
-	return time_after(jiffies, then);
-}
-
-static void time_out_leases(struct inode *inode)
-{
-	struct file_lock **before;
-	struct file_lock *fl;
-
-	before = &inode->i_flock;
-	while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) {
-		if (past_time(fl->fl_downgrade_time))
-			lease_modify(before, F_RDLCK);
-		if (past_time(fl->fl_break_time))
-			lease_modify(before, F_UNLCK);
-		if (fl == *before)	/* lease_modify may have freed fl */
-			before = &fl->fl_next;
-	}
-}
-
-/**
- *	__break_lease	-	revoke all outstanding leases on file
- *	@inode: the inode of the file to return
- *	@mode: the open mode (read or write)
- *
- *	break_lease (inlined for speed) has checked there already is at least
- *	some kind of lock (maybe a lease) on this file.  Leases are broken on
- *	a call to open() or truncate().  This function can sleep unless you
- *	specified %O_NONBLOCK to your open().
- */
-int __break_lease(struct inode *inode, unsigned int mode)
-{
-	int error = 0;
-	struct file_lock *new_fl, *flock;
-	struct file_lock *fl;
-	unsigned long break_time;
-	int i_have_this_lease = 0;
-	int want_write = (mode & O_ACCMODE) != O_RDONLY;
-
-	new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK);
-	if (IS_ERR(new_fl))
-		return PTR_ERR(new_fl);
-
-	lock_flocks();
-
-	time_out_leases(inode);
-
-	flock = inode->i_flock;
-	if ((flock == NULL) || !IS_LEASE(flock))
-		goto out;
-
-	if (!locks_conflict(flock, new_fl))
-		goto out;
-
-	for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next)
-		if (fl->fl_owner == current->files)
-			i_have_this_lease = 1;
-
-	break_time = 0;
-	if (lease_break_time > 0) {
-		break_time = jiffies + lease_break_time * HZ;
-		if (break_time == 0)
-			break_time++;	/* so that 0 means no break time */
-	}
-
-	for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
-		if (want_write) {
-			if (fl->fl_flags & FL_UNLOCK_PENDING)
-				continue;
-			fl->fl_flags |= FL_UNLOCK_PENDING;
-			fl->fl_break_time = break_time;
-		} else {
-			if (lease_breaking(flock))
-				continue;
-			fl->fl_flags |= FL_DOWNGRADE_PENDING;
-			fl->fl_downgrade_time = break_time;
-		}
-		fl->fl_lmops->lm_break(fl);
-	}
-
-	if (i_have_this_lease || (mode & O_NONBLOCK)) {
-		error = -EWOULDBLOCK;
-		goto out;
-	}
-
-restart:
-	break_time = flock->fl_break_time;
-	if (break_time != 0) {
-		break_time -= jiffies;
-		if (break_time == 0)
-			break_time++;
-	}
-	locks_insert_block(flock, new_fl);
-	unlock_flocks();
-	error = wait_event_interruptible_timeout(new_fl->fl_wait,
-						!new_fl->fl_next, break_time);
-	lock_flocks();
-	__locks_delete_block(new_fl);
-	if (error >= 0) {
-		if (error == 0)
-			time_out_leases(inode);
-		/*
-		 * Wait for the next conflicting lease that has not been
-		 * broken yet
-		 */
-		for (flock = inode->i_flock; flock && IS_LEASE(flock);
-				flock = flock->fl_next) {
-			if (locks_conflict(new_fl, flock))
-				goto restart;
-		}
-		error = 0;
-	}
-
-out:
-	unlock_flocks();
-	locks_free_lock(new_fl);
-	return error;
-}
-
-EXPORT_SYMBOL(__break_lease);
-
-/**
- *	lease_get_mtime - get the last modified time of an inode
- *	@inode: the inode
- *      @time:  pointer to a timespec which will contain the last modified time
- *
- * This is to force NFS clients to flush their caches for files with
- * exclusive leases.  The justification is that if someone has an
- * exclusive lease, then they could be modifying it.
- */
-void lease_get_mtime(struct inode *inode, struct timespec *time)
-{
-	struct file_lock *flock = inode->i_flock;
-	if (flock && IS_LEASE(flock) && (flock->fl_type & F_WRLCK))
-		*time = current_fs_time(inode->i_sb);
-	else
-		*time = inode->i_mtime;
-}
-
-EXPORT_SYMBOL(lease_get_mtime);
-
-/**
- *	fcntl_getlease - Enquire what lease is currently active
- *	@filp: the file
- *
- *	The value returned by this function will be one of
- *	(if no lease break is pending):
- *
- *	%F_RDLCK to indicate a shared lease is held.
- *
- *	%F_WRLCK to indicate an exclusive lease is held.
- *
- *	%F_UNLCK to indicate no lease is held.
- *
- *	(if a lease break is pending):
- *
- *	%F_RDLCK to indicate an exclusive lease needs to be
- *		changed to a shared lease (or removed).
- *
- *	%F_UNLCK to indicate the lease needs to be removed.
- *
- *	XXX: sfr & willy disagree over whether F_INPROGRESS
- *	should be returned to userspace.
- */
-int fcntl_getlease(struct file *filp)
-{
-	struct file_lock *fl;
-	int type = F_UNLCK;
-
-	lock_flocks();
-	time_out_leases(filp->f_path.dentry->d_inode);
-	for (fl = filp->f_path.dentry->d_inode->i_flock; fl && IS_LEASE(fl);
-			fl = fl->fl_next) {
-		if (fl->fl_file == filp) {
-			type = target_leasetype(fl);
-			break;
-		}
-	}
-	unlock_flocks();
-	return type;
-}
-
-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;
-	struct inode *inode = dentry->d_inode;
-	int error;
-
-	lease = *flp;
-
-	error = -EAGAIN;
-	if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
-		goto out;
-	if ((arg == F_WRLCK)
-	    && ((dentry->d_count > 1)
-		|| (atomic_read(&inode->i_count) > 1)))
-		goto out;
-
-	/*
-	 * At this point, we know that if there is an exclusive
-	 * lease on this file, then we hold it on this filp
-	 * (otherwise our open of this file would have blocked).
-	 * And if we are trying to acquire an exclusive lease,
-	 * then the file is not open by anyone (including us)
-	 * except for this filp.
-	 */
-	error = -EAGAIN;
-	for (before = &inode->i_flock;
-			((fl = *before) != NULL) && IS_LEASE(fl);
-			before = &fl->fl_next) {
-		if (fl->fl_file == filp) {
-			my_before = before;
-			continue;
-		}
-		/*
-		 * No exclusive leases if someone else has a lease on
-		 * this file:
-		 */
-		if (arg == F_WRLCK)
-			goto out;
-		/*
-		 * Modifying our existing lease is OK, but no getting a
-		 * new lease if someone else is opening for write:
-		 */
-		if (fl->fl_flags & FL_UNLOCK_PENDING)
-			goto out;
-	}
-
-	if (my_before != NULL) {
-		error = lease->fl_lmops->lm_change(my_before, arg);
-		if (!error)
-			*flp = *my_before;
-		goto out;
-	}
-
-	error = -EINVAL;
-	if (!leases_enable)
-		goto out;
-
-	locks_insert_lock(before, lease);
-	return 0;
-
-out:
-	return error;
-}
-
-int generic_delete_lease(struct file *filp, struct file_lock **flp)
-{
-	struct file_lock *fl, **before;
-	struct dentry *dentry = filp->f_path.dentry;
-	struct inode *inode = dentry->d_inode;
-
-	for (before = &inode->i_flock;
-			((fl = *before) != NULL) && IS_LEASE(fl);
-			before = &fl->fl_next) {
-		if (fl->fl_file != filp)
-			continue;
-		return (*flp)->fl_lmops->lm_change(before, F_UNLCK);
-	}
-	return -EAGAIN;
-}
-
-/**
- *	generic_setlease	-	sets a lease on an open file
- *	@filp: file pointer
- *	@arg: type of lease to obtain
- *	@flp: input - file_lock to use, output - file_lock inserted
- *
- *	The (input) flp->fl_lmops->lm_break function is required
- *	by break_lease().
- *
- *	Called with file_lock_lock held.
- */
-int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
-{
-	struct dentry *dentry = filp->f_path.dentry;
-	struct inode *inode = dentry->d_inode;
-	int error;
-
-	if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE))
-		return -EACCES;
-	if (!S_ISREG(inode->i_mode))
-		return -EINVAL;
-	error = security_file_lock(filp, arg);
-	if (error)
-		return error;
-
-	time_out_leases(inode);
-
-	BUG_ON(!(*flp)->fl_lmops->lm_break);
-
-	switch (arg) {
-	case F_UNLCK:
-		return generic_delete_lease(filp, flp);
-	case F_RDLCK:
-	case F_WRLCK:
-		return generic_add_lease(filp, arg, flp);
-	default:
-		BUG();
-	}
-}
-EXPORT_SYMBOL(generic_setlease);
-
-static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
-{
-	if (filp->f_op && filp->f_op->setlease)
-		return filp->f_op->setlease(filp, arg, lease);
-	else
-		return generic_setlease(filp, arg, lease);
-}
-
-/**
- *	vfs_setlease        -       sets a lease on an open file
- *	@filp: file pointer
- *	@arg: type of lease to obtain
- *	@lease: file_lock to use
- *
- *	Call this to establish a lease on the file.
- *	The (*lease)->fl_lmops->lm_break operation must be set; if not,
- *	break_lease will oops!
- *
- *	This will call the filesystem's setlease file method, if
- *	defined.  Note that there is no getlease method; instead, the
- *	filesystem setlease method should call back to setlease() to
- *	add a lease to the inode's lease list, where fcntl_getlease() can
- *	find it.  Since fcntl_getlease() only reports whether the current
- *	task holds a lease, a cluster filesystem need only do this for
- *	leases held by processes on this node.
- *
- *	There is also no break_lease method; filesystems that
- *	handle their own leases should break leases themselves from the
- *	filesystem's open, create, and (on truncate) setattr methods.
- *
- *	Warning: the only current setlease methods exist only to disable
- *	leases in certain cases.  More vfs changes may be required to
- *	allow a full filesystem lease implementation.
- */
-
-int vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
-{
-	int error;
-
-	lock_flocks();
-	error = __vfs_setlease(filp, arg, lease);
-	unlock_flocks();
-
-	return error;
-}
-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
- *	@filp: file pointer
- *	@arg: type of lease to obtain
- *
- *	Call this fcntl to establish a lease on the file.
- *	Note that you also need to call %F_SETSIG to
- *	receive a signal when the lease is broken.
- */
-int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
-{
-	if (arg == F_UNLCK)
-		return do_fcntl_delete_lease(filp);
-	return do_fcntl_add_lease(fd, filp, arg);
-}
-
-/**
- * flock_lock_file_wait - Apply a FLOCK-style lock to a file
- * @filp: The file to apply the lock to
- * @fl: The lock to be applied
- *
- * Add a FLOCK style lock to a file.
- */
-int flock_lock_file_wait(struct file *filp, struct file_lock *fl)
-{
-	int error;
-	might_sleep();
-	for (;;) {
-		error = flock_lock_file(filp, fl);
-		if (error != FILE_LOCK_DEFERRED)
-			break;
-		error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
-		if (!error)
-			continue;
-
-		locks_delete_block(fl);
-		break;
-	}
-	return error;
-}
-
-EXPORT_SYMBOL(flock_lock_file_wait);
-
-/**
- *	sys_flock: - flock() system call.
- *	@fd: the file descriptor to lock.
- *	@cmd: the type of lock to apply.
- *
- *	Apply a %FL_FLOCK style lock to an open file descriptor.
- *	The @cmd can be one of
- *
- *	%LOCK_SH -- a shared lock.
- *
- *	%LOCK_EX -- an exclusive lock.
- *
- *	%LOCK_UN -- remove an existing lock.
- *
- *	%LOCK_MAND -- a `mandatory' flock.  This exists to emulate Windows Share Modes.
- *
- *	%LOCK_MAND can be combined with %LOCK_READ or %LOCK_WRITE to allow other
- *	processes read and write access respectively.
- */
-SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
-{
-	struct file *filp;
-	struct file_lock *lock;
-	int can_sleep, unlock;
-	int error;
-
-	error = -EBADF;
-	filp = fget(fd);
-	if (!filp)
-		goto out;
-
-	can_sleep = !(cmd & LOCK_NB);
-	cmd &= ~LOCK_NB;
-	unlock = (cmd == LOCK_UN);
-
-	if (!unlock && !(cmd & LOCK_MAND) &&
-	    !(filp->f_mode & (FMODE_READ|FMODE_WRITE)))
-		goto out_putf;
-
-	error = flock_make_lock(filp, &lock, cmd);
-	if (error)
-		goto out_putf;
-	if (can_sleep)
-		lock->fl_flags |= FL_SLEEP;
-
-	error = security_file_lock(filp, lock->fl_type);
-	if (error)
-		goto out_free;
-
-	if (filp->f_op && filp->f_op->flock)
-		error = filp->f_op->flock(filp,
-					  (can_sleep) ? F_SETLKW : F_SETLK,
-					  lock);
-	else
-		error = flock_lock_file_wait(filp, lock);
-
- out_free:
-	locks_free_lock(lock);
-
- out_putf:
-	fput(filp);
- out:
-	return error;
-}
-
-/**
- * vfs_test_lock - test file byte range lock
- * @filp: The file to test lock for
- * @fl: The lock to test; also used to hold result
- *
- * Returns -ERRNO on failure.  Indicates presence of conflicting lock by
- * setting conf->fl_type to something other than F_UNLCK.
- */
-int vfs_test_lock(struct file *filp, struct file_lock *fl)
-{
-	if (filp->f_op && filp->f_op->lock)
-		return filp->f_op->lock(filp, F_GETLK, fl);
-	posix_test_lock(filp, fl);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(vfs_test_lock);
-
-static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl)
-{
-	flock->l_pid = fl->fl_pid;
-#if BITS_PER_LONG == 32
-	/*
-	 * Make sure we can represent the posix lock via
-	 * legacy 32bit flock.
-	 */
-	if (fl->fl_start > OFFT_OFFSET_MAX)
-		return -EOVERFLOW;
-	if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX)
-		return -EOVERFLOW;
-#endif
-	flock->l_start = fl->fl_start;
-	flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :
-		fl->fl_end - fl->fl_start + 1;
-	flock->l_whence = 0;
-	flock->l_type = fl->fl_type;
-	return 0;
-}
-
-#if BITS_PER_LONG == 32
-static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl)
-{
-	flock->l_pid = fl->fl_pid;
-	flock->l_start = fl->fl_start;
-	flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :
-		fl->fl_end - fl->fl_start + 1;
-	flock->l_whence = 0;
-	flock->l_type = fl->fl_type;
-}
-#endif
-
-/* Report the first existing lock that would conflict with l.
- * This implements the F_GETLK command of fcntl().
- */
-int fcntl_getlk(struct file *filp, struct flock __user *l)
-{
-	struct file_lock file_lock;
-	struct flock flock;
-	int error;
-
-	error = -EFAULT;
-	if (copy_from_user(&flock, l, sizeof(flock)))
-		goto out;
-	error = -EINVAL;
-	if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK))
-		goto out;
-
-	error = flock_to_posix_lock(filp, &file_lock, &flock);
-	if (error)
-		goto out;
-
-	error = vfs_test_lock(filp, &file_lock);
-	if (error)
-		goto out;
- 
-	flock.l_type = file_lock.fl_type;
-	if (file_lock.fl_type != F_UNLCK) {
-		error = posix_lock_to_flock(&flock, &file_lock);
-		if (error)
-			goto out;
-	}
-	error = -EFAULT;
-	if (!copy_to_user(l, &flock, sizeof(flock)))
-		error = 0;
-out:
-	return error;
-}
-
-/**
- * vfs_lock_file - file byte range lock
- * @filp: The file to apply the lock to
- * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.)
- * @fl: The lock to be applied
- * @conf: Place to return a copy of the conflicting lock, if found.
- *
- * A caller that doesn't care about the conflicting lock may pass NULL
- * as the final argument.
- *
- * If the filesystem defines a private ->lock() method, then @conf will
- * be left unchanged; so a caller that cares should initialize it to
- * some acceptable default.
- *
- * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX
- * locks, the ->lock() interface may return asynchronously, before the lock has
- * been granted or denied by the underlying filesystem, if (and only if)
- * lm_grant is set. Callers expecting ->lock() to return asynchronously
- * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if)
- * the request is for a blocking lock. When ->lock() does return asynchronously,
- * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock
- * request completes.
- * If the request is for non-blocking lock the file system should return
- * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine
- * with the result. If the request timed out the callback routine will return a
- * nonzero return code and the file system should release the lock. The file
- * system is also responsible to keep a corresponding posix lock when it
- * grants a lock so the VFS can find out which locks are locally held and do
- * the correct lock cleanup when required.
- * The underlying filesystem must not drop the kernel lock or call
- * ->lm_grant() before returning to the caller with a FILE_LOCK_DEFERRED
- * return code.
- */
-int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)
-{
-	if (filp->f_op && filp->f_op->lock)
-		return filp->f_op->lock(filp, cmd, fl);
-	else
-		return posix_lock_file(filp, fl, conf);
-}
-EXPORT_SYMBOL_GPL(vfs_lock_file);
-
-static int do_lock_file_wait(struct file *filp, unsigned int cmd,
-			     struct file_lock *fl)
-{
-	int error;
-
-	error = security_file_lock(filp, fl->fl_type);
-	if (error)
-		return error;
-
-	for (;;) {
-		error = vfs_lock_file(filp, cmd, fl, NULL);
-		if (error != FILE_LOCK_DEFERRED)
-			break;
-		error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
-		if (!error)
-			continue;
-
-		locks_delete_block(fl);
-		break;
-	}
-
-	return error;
-}
-
-/* Apply the lock described by l to an open file descriptor.
- * This implements both the F_SETLK and F_SETLKW commands of fcntl().
- */
-int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
-		struct flock __user *l)
-{
-	struct file_lock *file_lock = locks_alloc_lock();
-	struct flock flock;
-	struct inode *inode;
-	struct file *f;
-	int error;
-
-	if (file_lock == NULL)
-		return -ENOLCK;
-
-	/*
-	 * This might block, so we do it before checking the inode.
-	 */
-	error = -EFAULT;
-	if (copy_from_user(&flock, l, sizeof(flock)))
-		goto out;
-
-	inode = filp->f_path.dentry->d_inode;
-
-	/* Don't allow mandatory locks on files that may be memory mapped
-	 * and shared.
-	 */
-	if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
-		error = -EAGAIN;
-		goto out;
-	}
-
-again:
-	error = flock_to_posix_lock(filp, file_lock, &flock);
-	if (error)
-		goto out;
-	if (cmd == F_SETLKW) {
-		file_lock->fl_flags |= FL_SLEEP;
-	}
-	
-	error = -EBADF;
-	switch (flock.l_type) {
-	case F_RDLCK:
-		if (!(filp->f_mode & FMODE_READ))
-			goto out;
-		break;
-	case F_WRLCK:
-		if (!(filp->f_mode & FMODE_WRITE))
-			goto out;
-		break;
-	case F_UNLCK:
-		break;
-	default:
-		error = -EINVAL;
-		goto out;
-	}
-
-	error = do_lock_file_wait(filp, cmd, file_lock);
-
-	/*
-	 * Attempt to detect a close/fcntl race and recover by
-	 * releasing the lock that was just acquired.
-	 */
-	/*
-	 * we need that spin_lock here - it prevents reordering between
-	 * update of inode->i_flock and check for it done in close().
-	 * rcu_read_lock() wouldn't do.
-	 */
-	spin_lock(&current->files->file_lock);
-	f = fcheck(fd);
-	spin_unlock(&current->files->file_lock);
-	if (!error && f != filp && flock.l_type != F_UNLCK) {
-		flock.l_type = F_UNLCK;
-		goto again;
-	}
-
-out:
-	locks_free_lock(file_lock);
-	return error;
-}
-
-#if BITS_PER_LONG == 32
-/* Report the first existing lock that would conflict with l.
- * This implements the F_GETLK command of fcntl().
- */
-int fcntl_getlk64(struct file *filp, struct flock64 __user *l)
-{
-	struct file_lock file_lock;
-	struct flock64 flock;
-	int error;
-
-	error = -EFAULT;
-	if (copy_from_user(&flock, l, sizeof(flock)))
-		goto out;
-	error = -EINVAL;
-	if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK))
-		goto out;
-
-	error = flock64_to_posix_lock(filp, &file_lock, &flock);
-	if (error)
-		goto out;
-
-	error = vfs_test_lock(filp, &file_lock);
-	if (error)
-		goto out;
-
-	flock.l_type = file_lock.fl_type;
-	if (file_lock.fl_type != F_UNLCK)
-		posix_lock_to_flock64(&flock, &file_lock);
-
-	error = -EFAULT;
-	if (!copy_to_user(l, &flock, sizeof(flock)))
-		error = 0;
-  
-out:
-	return error;
-}
-
-/* Apply the lock described by l to an open file descriptor.
- * This implements both the F_SETLK and F_SETLKW commands of fcntl().
- */
-int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
-		struct flock64 __user *l)
-{
-	struct file_lock *file_lock = locks_alloc_lock();
-	struct flock64 flock;
-	struct inode *inode;
-	struct file *f;
-	int error;
-
-	if (file_lock == NULL)
-		return -ENOLCK;
-
-	/*
-	 * This might block, so we do it before checking the inode.
-	 */
-	error = -EFAULT;
-	if (copy_from_user(&flock, l, sizeof(flock)))
-		goto out;
-
-	inode = filp->f_path.dentry->d_inode;
-
-	/* Don't allow mandatory locks on files that may be memory mapped
-	 * and shared.
-	 */
-	if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
-		error = -EAGAIN;
-		goto out;
-	}
-
-again:
-	error = flock64_to_posix_lock(filp, file_lock, &flock);
-	if (error)
-		goto out;
-	if (cmd == F_SETLKW64) {
-		file_lock->fl_flags |= FL_SLEEP;
-	}
-	
-	error = -EBADF;
-	switch (flock.l_type) {
-	case F_RDLCK:
-		if (!(filp->f_mode & FMODE_READ))
-			goto out;
-		break;
-	case F_WRLCK:
-		if (!(filp->f_mode & FMODE_WRITE))
-			goto out;
-		break;
-	case F_UNLCK:
-		break;
-	default:
-		error = -EINVAL;
-		goto out;
-	}
-
-	error = do_lock_file_wait(filp, cmd, file_lock);
-
-	/*
-	 * Attempt to detect a close/fcntl race and recover by
-	 * releasing the lock that was just acquired.
-	 */
-	spin_lock(&current->files->file_lock);
-	f = fcheck(fd);
-	spin_unlock(&current->files->file_lock);
-	if (!error && f != filp && flock.l_type != F_UNLCK) {
-		flock.l_type = F_UNLCK;
-		goto again;
-	}
-
-out:
-	locks_free_lock(file_lock);
-	return error;
-}
-#endif /* BITS_PER_LONG == 32 */
-
-/*
- * This function is called when the file is being removed
- * from the task's fd array.  POSIX locks belonging to this task
- * are deleted at this time.
- */
-void locks_remove_posix(struct file *filp, fl_owner_t owner)
-{
-	struct file_lock lock;
-
-	/*
-	 * If there are no locks held on this file, we don't need to call
-	 * posix_lock_file().  Another process could be setting a lock on this
-	 * file at the same time, but we wouldn't remove that lock anyway.
-	 */
-	if (!filp->f_path.dentry->d_inode->i_flock)
-		return;
-
-	lock.fl_type = F_UNLCK;
-	lock.fl_flags = FL_POSIX | FL_CLOSE;
-	lock.fl_start = 0;
-	lock.fl_end = OFFSET_MAX;
-	lock.fl_owner = owner;
-	lock.fl_pid = current->tgid;
-	lock.fl_file = filp;
-	lock.fl_ops = NULL;
-	lock.fl_lmops = NULL;
-
-	vfs_lock_file(filp, F_SETLK, &lock, NULL);
-
-	if (lock.fl_ops && lock.fl_ops->fl_release_private)
-		lock.fl_ops->fl_release_private(&lock);
-}
-
-EXPORT_SYMBOL(locks_remove_posix);
-
-/*
- * This function is called on the last close of an open file.
- */
-void locks_remove_flock(struct file *filp)
-{
-	struct inode * inode = filp->f_path.dentry->d_inode;
-	struct file_lock *fl;
-	struct file_lock **before;
-
-	if (!inode->i_flock)
-		return;
-
-	if (filp->f_op && filp->f_op->flock) {
-		struct file_lock fl = {
-			.fl_pid = current->tgid,
-			.fl_file = filp,
-			.fl_flags = FL_FLOCK,
-			.fl_type = F_UNLCK,
-			.fl_end = OFFSET_MAX,
-		};
-		filp->f_op->flock(filp, F_SETLKW, &fl);
-		if (fl.fl_ops && fl.fl_ops->fl_release_private)
-			fl.fl_ops->fl_release_private(&fl);
-	}
-
-	lock_flocks();
-	before = &inode->i_flock;
-
-	while ((fl = *before) != NULL) {
-		if (fl->fl_file == filp) {
-			if (IS_FLOCK(fl)) {
-				locks_delete_lock(before);
-				continue;
-			}
-			if (IS_LEASE(fl)) {
-				lease_modify(before, F_UNLCK);
-				continue;
-			}
-			/* What? */
-			BUG();
- 		}
-		before = &fl->fl_next;
-	}
-	unlock_flocks();
-}
-
-/**
- *	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)
-{
-	int status = 0;
-
-	lock_flocks();
-	if (waiter->fl_next)
-		__locks_delete_block(waiter);
-	else
-		status = -ENOENT;
-	unlock_flocks();
-	return status;
-}
-
-EXPORT_SYMBOL(posix_unblock_lock);
-
-/**
- * vfs_cancel_lock - file byte range unblock lock
- * @filp: The file to apply the unblock to
- * @fl: The lock to be unblocked
- *
- * Used by lock managers to cancel blocked requests
- */
-int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
-{
-	if (filp->f_op && filp->f_op->lock)
-		return filp->f_op->lock(filp, F_CANCELLK, fl);
-	return 0;
-}
-
-EXPORT_SYMBOL_GPL(vfs_cancel_lock);
-
-#ifdef CONFIG_PROC_FS
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-
-static void lock_get_status(struct seq_file *f, struct file_lock *fl,
-			    loff_t id, char *pfx)
-{
-	struct inode *inode = NULL;
-	unsigned int fl_pid;
-
-	if (fl->fl_nspid)
-		fl_pid = pid_vnr(fl->fl_nspid);
-	else
-		fl_pid = fl->fl_pid;
-
-	if (fl->fl_file != NULL)
-		inode = fl->fl_file->f_path.dentry->d_inode;
-
-	seq_printf(f, "%lld:%s ", id, pfx);
-	if (IS_POSIX(fl)) {
-		seq_printf(f, "%6s %s ",
-			     (fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ",
-			     (inode == NULL) ? "*NOINODE*" :
-			     mandatory_lock(inode) ? "MANDATORY" : "ADVISORY ");
-	} else if (IS_FLOCK(fl)) {
-		if (fl->fl_type & LOCK_MAND) {
-			seq_printf(f, "FLOCK  MSNFS     ");
-		} else {
-			seq_printf(f, "FLOCK  ADVISORY  ");
-		}
-	} else if (IS_LEASE(fl)) {
-		seq_printf(f, "LEASE  ");
-		if (lease_breaking(fl))
-			seq_printf(f, "BREAKING  ");
-		else if (fl->fl_file)
-			seq_printf(f, "ACTIVE    ");
-		else
-			seq_printf(f, "BREAKER   ");
-	} else {
-		seq_printf(f, "UNKNOWN UNKNOWN  ");
-	}
-	if (fl->fl_type & LOCK_MAND) {
-		seq_printf(f, "%s ",
-			       (fl->fl_type & LOCK_READ)
-			       ? (fl->fl_type & LOCK_WRITE) ? "RW   " : "READ "
-			       : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE ");
-	} else {
-		seq_printf(f, "%s ",
-			       (lease_breaking(fl))
-			       ? (fl->fl_type & F_UNLCK) ? "UNLCK" : "READ "
-			       : (fl->fl_type & F_WRLCK) ? "WRITE" : "READ ");
-	}
-	if (inode) {
-#ifdef WE_CAN_BREAK_LSLK_NOW
-		seq_printf(f, "%d %s:%ld ", fl_pid,
-				inode->i_sb->s_id, inode->i_ino);
-#else
-		/* userspace relies on this representation of dev_t ;-( */
-		seq_printf(f, "%d %02x:%02x:%ld ", fl_pid,
-				MAJOR(inode->i_sb->s_dev),
-				MINOR(inode->i_sb->s_dev), inode->i_ino);
-#endif
-	} else {
-		seq_printf(f, "%d <none>:0 ", fl_pid);
-	}
-	if (IS_POSIX(fl)) {
-		if (fl->fl_end == OFFSET_MAX)
-			seq_printf(f, "%Ld EOF\n", fl->fl_start);
-		else
-			seq_printf(f, "%Ld %Ld\n", fl->fl_start, fl->fl_end);
-	} else {
-		seq_printf(f, "0 EOF\n");
-	}
-}
-
-static int locks_show(struct seq_file *f, void *v)
-{
-	struct file_lock *fl, *bfl;
-
-	fl = list_entry(v, struct file_lock, fl_link);
-
-	lock_get_status(f, fl, *((loff_t *)f->private), "");
-
-	list_for_each_entry(bfl, &fl->fl_block, fl_block)
-		lock_get_status(f, bfl, *((loff_t *)f->private), " ->");
-
-	return 0;
-}
-
-static void *locks_start(struct seq_file *f, loff_t *pos)
-{
-	loff_t *p = f->private;
-
-	lock_flocks();
-	*p = (*pos + 1);
-	return seq_list_start(&file_lock_list, *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);
-}
-
-static void locks_stop(struct seq_file *f, void *v)
-{
-	unlock_flocks();
-}
-
-static const struct seq_operations locks_seq_operations = {
-	.start	= locks_start,
-	.next	= locks_next,
-	.stop	= locks_stop,
-	.show	= locks_show,
-};
-
-static int locks_open(struct inode *inode, struct file *filp)
-{
-	return seq_open_private(filp, &locks_seq_operations, sizeof(loff_t));
-}
-
-static const struct file_operations proc_locks_operations = {
-	.open		= locks_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release_private,
-};
-
-static int __init proc_locks_init(void)
-{
-	proc_create("locks", 0, NULL, &proc_locks_operations);
-	return 0;
-}
-module_init(proc_locks_init);
-#endif
-
-/**
- *	lock_may_read - checks that the region is free of locks
- *	@inode: the inode that is being read
- *	@start: the first byte to read
- *	@len: the number of bytes to read
- *
- *	Emulates Windows locking requirements.  Whole-file
- *	mandatory locks (share modes) can prohibit a read and
- *	byte-range POSIX locks can prohibit a read if they overlap.
- *
- *	N.B. this function is only ever called
- *	from knfsd and ownership of locks is never checked.
- */
-int lock_may_read(struct inode *inode, loff_t start, unsigned long len)
-{
-	struct file_lock *fl;
-	int result = 1;
-	lock_flocks();
-	for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
-		if (IS_POSIX(fl)) {
-			if (fl->fl_type == F_RDLCK)
-				continue;
-			if ((fl->fl_end < start) || (fl->fl_start > (start + len)))
-				continue;
-		} else if (IS_FLOCK(fl)) {
-			if (!(fl->fl_type & LOCK_MAND))
-				continue;
-			if (fl->fl_type & LOCK_READ)
-				continue;
-		} else
-			continue;
-		result = 0;
-		break;
-	}
-	unlock_flocks();
-	return result;
-}
-
-EXPORT_SYMBOL(lock_may_read);
-
-/**
- *	lock_may_write - checks that the region is free of locks
- *	@inode: the inode that is being written
- *	@start: the first byte to write
- *	@len: the number of bytes to write
- *
- *	Emulates Windows locking requirements.  Whole-file
- *	mandatory locks (share modes) can prohibit a write and
- *	byte-range POSIX locks can prohibit a write if they overlap.
- *
- *	N.B. this function is only ever called
- *	from knfsd and ownership of locks is never checked.
- */
-int lock_may_write(struct inode *inode, loff_t start, unsigned long len)
-{
-	struct file_lock *fl;
-	int result = 1;
-	lock_flocks();
-	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)))
-				continue;
-		} else if (IS_FLOCK(fl)) {
-			if (!(fl->fl_type & LOCK_MAND))
-				continue;
-			if (fl->fl_type & LOCK_WRITE)
-				continue;
-		} else
-			continue;
-		result = 0;
-		break;
-	}
-	unlock_flocks();
-	return result;
-}
-
-EXPORT_SYMBOL(lock_may_write);
-
-static int __init filelock_init(void)
-{
-	filelock_cache = kmem_cache_create("file_lock_cache",
-			sizeof(struct file_lock), 0, SLAB_PANIC, NULL);
-
-	return 0;
-}
-
-core_initcall(filelock_init);