*
* Initial implementation of mandatory locks. SunOS turned out to be
* a rotten model, so I implemented the "obvious" semantics.
- * See 'Documentation/mandatory.txt' for details.
+ * 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
#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/smp_lock.h>
#include <linux/syscalls.h>
#include <linux/time.h>
#include <linux/rcupdate.h>
+#include <linux/pid_namespace.h>
-#include <asm/semaphore.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;
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. */
-static struct file_lock *locks_alloc_lock(void)
+struct file_lock *locks_alloc_lock(void)
{
- return kmem_cache_alloc(filelock_cache, GFP_KERNEL);
+ 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);
-static void locks_release_private(struct file_lock *fl)
+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->fl_release_private)
- fl->fl_lmops->fl_release_private(fl);
- fl->fl_lmops = NULL;
- }
+ fl->fl_lmops = NULL;
}
+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));
locks_release_private(fl);
kmem_cache_free(filelock_cache, fl);
}
+EXPORT_SYMBOL(locks_free_lock);
void locks_init_lock(struct file_lock *fl)
{
- INIT_LIST_HEAD(&fl->fl_link);
- INIT_LIST_HEAD(&fl->fl_block);
- init_waitqueue_head(&fl->fl_wait);
- fl->fl_next = NULL;
- fl->fl_fasync = NULL;
- fl->fl_owner = NULL;
- fl->fl_pid = 0;
- fl->fl_file = NULL;
- fl->fl_flags = 0;
- fl->fl_type = 0;
- fl->fl_start = fl->fl_end = 0;
- fl->fl_ops = NULL;
- fl->fl_lmops = NULL;
+ memset(fl, 0, sizeof(struct file_lock));
+ locks_init_lock_heads(fl);
}
EXPORT_SYMBOL(locks_init_lock);
-/*
- * Initialises the fields of the file lock which are invariant for
- * free file_locks.
- */
-static void init_once(void *foo, struct kmem_cache *cache, unsigned long flags)
-{
- struct file_lock *lock = (struct file_lock *) foo;
-
- locks_init_lock(lock);
-}
-
static void locks_copy_private(struct file_lock *new, struct file_lock *fl)
{
if (fl->fl_ops) {
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;
- }
}
/*
* Initialize a new lock from an existing file_lock structure.
*/
-static void __locks_copy_lock(struct file_lock *new, const struct file_lock *fl)
+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_ops = NULL;
new->fl_lmops = NULL;
}
+EXPORT_SYMBOL(__locks_copy_lock);
void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{
return 0;
}
-static int assign_type(struct file_lock *fl, int type)
+static int assign_type(struct file_lock *fl, long type)
{
switch (type) {
case F_RDLCK:
start = filp->f_pos;
break;
case SEEK_END:
- start = i_size_read(filp->f_path.dentry->d_inode);
+ start = i_size_read(file_inode(filp));
break;
default:
return -EINVAL;
start = filp->f_pos;
break;
case SEEK_END:
- start = i_size_read(filp->f_path.dentry->d_inode);
+ start = i_size_read(file_inode(filp));
break;
default:
return -EINVAL;
fl->fl_ops = NULL;
fl->fl_lmops = NULL;
- switch (l->l_type) {
- case F_RDLCK:
- case F_WRLCK:
- case F_UNLCK:
- fl->fl_type = l->l_type;
- break;
- default:
- return -EINVAL;
- }
-
- return (0);
+ return assign_type(fl, l->l_type);
}
#endif
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 int lease_mylease_callback(struct file_lock *fl, struct file_lock *try)
-{
- return fl->fl_file == try->fl_file;
-}
-
-static struct lock_manager_operations lease_manager_ops = {
- .fl_break = lease_break_callback,
- .fl_release_private = lease_release_private_callback,
- .fl_mylease = lease_mylease_callback,
- .fl_change = lease_modify,
+static const struct lock_manager_operations lease_manager_ops = {
+ .lm_break = lease_break_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)
+static int lease_init(struct file *filp, long type, struct file_lock *fl)
{
if (assign_type(fl, type) != 0)
return -EINVAL;
}
/* Allocate a file_lock initialised to this type of lease */
-static struct file_lock *lease_alloc(struct file *filp, int type)
+static struct file_lock *lease_alloc(struct file *filp, long type)
{
struct file_lock *fl = locks_alloc_lock();
int error = -ENOMEM;
*/
static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
{
- if (fl1->fl_lmops && fl1->fl_lmops->fl_compare_owner)
+ if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner)
return fl2->fl_lmops == fl1->fl_lmops &&
- fl1->fl_lmops->fl_compare_owner(fl1, fl2);
+ fl1->fl_lmops->lm_compare_owner(fl1, fl2);
return fl1->fl_owner == fl2->fl_owner;
}
/*
*/
-static void locks_delete_block(struct file_lock *waiter)
+void locks_delete_block(struct file_lock *waiter)
{
- lock_kernel();
+ lock_flocks();
__locks_delete_block(waiter);
- unlock_kernel();
+ 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
static void locks_wake_up_blocks(struct file_lock *blocker)
{
while (!list_empty(&blocker->fl_block)) {
- struct file_lock *waiter = list_entry(blocker->fl_block.next,
+ 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->fl_notify)
- waiter->fl_lmops->fl_notify(waiter);
+ if (waiter->fl_lmops && waiter->fl_lmops->lm_notify)
+ waiter->fl_lmops->lm_notify(waiter);
else
wake_up(&waiter->fl_wait);
}
{
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;
-
- if (fl->fl_ops && fl->fl_ops->fl_insert)
- fl->fl_ops->fl_insert(fl);
}
/*
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;
}
- if (fl->fl_ops && fl->fl_ops->fl_remove)
- fl->fl_ops->fl_remove(fl);
-
locks_wake_up_blocks(fl);
locks_free_lock(fl);
}
return (locks_conflict(caller_fl, sys_fl));
}
-static int interruptible_sleep_on_locked(wait_queue_head_t *fl_wait, int timeout)
-{
- int result = 0;
- DECLARE_WAITQUEUE(wait, current);
-
- __set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(fl_wait, &wait);
- if (timeout == 0)
- schedule();
- else
- result = schedule_timeout(timeout);
- if (signal_pending(current))
- result = -ERESTARTSYS;
- remove_wait_queue(fl_wait, &wait);
- __set_current_state(TASK_RUNNING);
- return result;
-}
-
-static int locks_block_on_timeout(struct file_lock *blocker, struct file_lock *waiter, int time)
-{
- int result;
- locks_insert_block(blocker, waiter);
- result = interruptible_sleep_on_locked(&waiter->fl_wait, time);
- __locks_delete_block(waiter);
- return result;
-}
-
void
posix_test_lock(struct file *filp, struct file_lock *fl)
{
struct file_lock *cfl;
- lock_kernel();
- for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) {
+ lock_flocks();
+ for (cfl = file_inode(filp)->i_flock; cfl; cfl = cfl->fl_next) {
if (!IS_POSIX(cfl))
continue;
- if (posix_locks_conflict(cfl, fl))
+ if (posix_locks_conflict(fl, cfl))
break;
}
- if (cfl)
+ if (cfl) {
__locks_copy_lock(fl, cfl);
- else
+ if (cfl->fl_nspid)
+ fl->fl_pid = pid_vnr(cfl->fl_nspid);
+ } else
fl->fl_type = F_UNLCK;
- unlock_kernel();
+ unlock_flocks();
return;
}
-
EXPORT_SYMBOL(posix_test_lock);
-/* This function tests for deadlock condition before putting a process to
- * sleep. The detection scheme is no longer recursive. Recursive was neat,
- * but dangerous - we risked stack corruption if the lock data was bad, or
- * if the recursion was too deep for any other reason.
+/*
+ * Deadlock detection:
*
- * We rely on the fact that a task can only be on one lock's wait queue
- * at a time. When we find blocked_task on a wait queue we can re-search
- * with blocked_task equal to that queue's owner, until either blocked_task
- * isn't found, or blocked_task is found on a queue owned by my_task.
+ * We attempt to detect deadlocks that are due purely to posix file
+ * locks.
*
- * Note: the above assumption may not be true when handling lock requests
- * from a broken NFS client. But broken NFS clients have a lot more to
- * worry about than proper deadlock detection anyway... --okir
+ * 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)
{
- struct list_head *tmp;
+ int i = 0;
-next_task:
- if (posix_same_owner(caller_fl, block_fl))
- return 1;
- list_for_each(tmp, &blocked_list) {
- struct file_lock *fl = list_entry(tmp, struct file_lock, fl_link);
- if (posix_same_owner(fl, block_fl)) {
- fl = fl->fl_next;
- block_fl = fl;
- goto next_task;
- }
+ 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
- * at the head of the list, but that's secret knowledge known only to
- * flock_lock_file and posix_lock_file.
+ * 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
{
struct file_lock *new_fl = NULL;
struct file_lock **before;
- struct inode * inode = filp->f_path.dentry->d_inode;
+ struct inode * inode = file_inode(filp);
int error = 0;
int found = 0;
- lock_kernel();
+ 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))
goto out;
}
- error = -ENOMEM;
- new_fl = locks_alloc_lock();
- if (new_fl == NULL)
- goto out;
/*
* If a higher-priority process was blocked on the old file lock,
* give it the opportunity to lock the file.
*/
- if (found)
+ if (found) {
+ unlock_flocks();
cond_resched();
+ lock_flocks();
+ }
find_conflict:
for_each_lock(inode, before) {
if (!flock_locks_conflict(request, fl))
continue;
error = -EAGAIN;
- if (request->fl_flags & FL_SLEEP)
- locks_insert_block(fl, request);
+ 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(&inode->i_flock, new_fl);
+ locks_insert_lock(before, new_fl);
new_fl = NULL;
error = 0;
out:
- unlock_kernel();
+ unlock_flocks();
if (new_fl)
locks_free_lock(new_fl);
return error;
new_fl2 = locks_alloc_lock();
}
- lock_kernel();
+ lock_flocks();
if (request->fl_type != F_UNLCK) {
for_each_lock(inode, before) {
- struct file_lock *fl = *before;
+ fl = *before;
if (!IS_POSIX(fl))
continue;
if (!posix_locks_conflict(request, fl))
continue;
if (conflock)
- locks_copy_lock(conflock, fl);
+ __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 = -EAGAIN;
+ error = FILE_LOCK_DEFERRED;
locks_insert_block(fl, request);
goto out;
}
locks_wake_up_blocks(left);
}
out:
- unlock_kernel();
+ unlock_flocks();
/*
* Free any unused locks.
*/
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);
+ return __posix_lock_file(file_inode(filp), fl, conflock);
}
EXPORT_SYMBOL(posix_lock_file);
might_sleep ();
for (;;) {
error = posix_lock_file(filp, fl, NULL);
- if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
+ if (error != FILE_LOCK_DEFERRED)
break;
error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
if (!error)
/*
* Search the lock list for this inode for any POSIX locks.
*/
- lock_kernel();
+ 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_kernel();
+ unlock_flocks();
return fl ? -EAGAIN : 0;
}
for (;;) {
error = __posix_lock_file(inode, &fl, NULL);
- if (error != -EAGAIN)
- break;
- if (!(fl.fl_flags & FL_SLEEP))
+ 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 ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
+ if (__mandatory_lock(inode))
continue;
}
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)
{
if (error)
return error;
+ lease_clear_pending(fl, arg);
locks_wake_up_blocks(fl);
- if (arg == F_UNLCK)
+ if (arg == F_UNLCK) {
+ struct file *filp = fl->fl_file;
+
+ f_delown(filp);
+ filp->f_owner.signum = 0;
+ 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;
+ }
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) && (fl->fl_type & F_INPROGRESS)) {
- if ((fl->fl_break_time == 0)
- || time_before(jiffies, fl->fl_break_time)) {
- before = &fl->fl_next;
- continue;
- }
- lease_modify(before, fl->fl_type & ~F_INPROGRESS);
+ 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;
}
*/
int __break_lease(struct inode *inode, unsigned int mode)
{
- int error = 0, future;
+ 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, mode & FMODE_WRITE ? F_WRLCK : F_RDLCK);
+ new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK);
+ if (IS_ERR(new_fl))
+ return PTR_ERR(new_fl);
- lock_kernel();
+ lock_flocks();
time_out_leases(inode);
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;
- if (mode & FMODE_WRITE) {
- /* If we want write access, we have to revoke any lease. */
- future = F_UNLCK | F_INPROGRESS;
- } else if (flock->fl_type & F_INPROGRESS) {
- /* If the lease is already being broken, we just leave it */
- future = flock->fl_type;
- } else if (flock->fl_type & F_WRLCK) {
- /* Downgrade the exclusive lease to a read-only lease. */
- future = F_RDLCK | F_INPROGRESS;
- } else {
- /* the existing lease was read-only, so we can read too. */
- goto out;
- }
-
- if (IS_ERR(new_fl) && !i_have_this_lease
- && ((mode & O_NONBLOCK) == 0)) {
- error = PTR_ERR(new_fl);
- goto out;
- }
-
break_time = 0;
if (lease_break_time > 0) {
break_time = jiffies + lease_break_time * HZ;
}
for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
- if (fl->fl_type != future) {
- fl->fl_type = future;
+ if (want_write) {
+ if (fl->fl_flags & FL_UNLOCK_PENDING)
+ continue;
+ fl->fl_flags |= FL_UNLOCK_PENDING;
fl->fl_break_time = break_time;
- /* lease must have lmops break callback */
- fl->fl_lmops->fl_break(fl);
+ } 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)) {
if (break_time == 0)
break_time++;
}
- error = locks_block_on_timeout(flock, new_fl, 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 lease that has not been broken yet */
+ /*
+ * 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 (flock->fl_type & F_INPROGRESS)
+ if (locks_conflict(new_fl, flock))
goto restart;
}
error = 0;
}
out:
- unlock_kernel();
- if (!IS_ERR(new_fl))
- locks_free_lock(new_fl);
+ unlock_flocks();
+ locks_free_lock(new_fl);
return error;
}
EXPORT_SYMBOL(__break_lease);
/**
- * lease_get_mtime
+ * 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 modifiying it.
+ * 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))
+ if (flock && IS_LEASE(flock) && (flock->fl_type == F_WRLCK))
*time = current_fs_time(inode->i_sb);
else
*time = inode->i_mtime;
struct file_lock *fl;
int type = F_UNLCK;
- lock_kernel();
- time_out_leases(filp->f_path.dentry->d_inode);
- for (fl = filp->f_path.dentry->d_inode->i_flock; fl && IS_LEASE(fl);
+ lock_flocks();
+ time_out_leases(file_inode(filp));
+ for (fl = file_inode(filp)->i_flock; fl && IS_LEASE(fl);
fl = fl->fl_next) {
if (fl->fl_file == filp) {
- type = fl->fl_type & ~F_INPROGRESS;
+ type = target_leasetype(fl);
break;
}
}
- unlock_kernel();
+ unlock_flocks();
return type;
}
-/**
- * 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->fl_break function is required
- * by break_lease().
- *
- * Called with kernel lock held.
- */
-int setlease(struct file *filp, long arg, struct file_lock **flp)
+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, rdlease_count = 0, wrlease_count = 0;
-
- 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->fl_break);
+ int error;
lease = *flp;
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;
* 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 (lease->fl_lmops->fl_mylease(fl, lease))
+ if (fl->fl_file == filp) {
my_before = before;
- else if (fl->fl_type == (F_INPROGRESS | F_UNLCK))
- /*
- * Someone is in the process of opening this
- * file for writing so we may not take an
- * exclusive lease on it.
- */
- wrlease_count++;
- else
- rdlease_count++;
+ 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 ((arg == F_RDLCK && (wrlease_count > 0)) ||
- (arg == F_WRLCK && ((rdlease_count + wrlease_count) > 0)))
- goto out;
-
if (my_before != NULL) {
- *flp = *my_before;
- error = lease->fl_lmops->fl_change(my_before, arg);
+ error = lease->fl_lmops->lm_change(my_before, arg);
+ if (!error)
+ *flp = *my_before;
goto out;
}
- error = 0;
- if (arg == F_UNLCK)
- goto out;
-
error = -EINVAL;
if (!leases_enable)
goto out;
- error = -ENOMEM;
- fl = locks_alloc_lock();
- if (fl == NULL)
- goto out;
-
- locks_copy_lock(fl, lease);
-
- locks_insert_lock(before, fl);
+ locks_insert_lock(before, lease);
+ return 0;
- *flp = fl;
- error = 0;
out:
return error;
}
-EXPORT_SYMBOL(setlease);
- /**
+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 ((!uid_eq(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:
+ return -EINVAL;
+ }
+}
+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->fl_break operation must be set; if not,
+ * 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
* leases held by processes on this node.
*
* There is also no break_lease method; filesystems that
- * handle their own leases shoud break leases themselves from the
+ * 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
{
int error;
- lock_kernel();
- if (filp->f_op && filp->f_op->setlease)
- error = filp->f_op->setlease(filp, arg, lease);
- else
- error = setlease(filp, arg, lease);
- unlock_kernel();
+ 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
*/
int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
{
- struct file_lock fl, *flp = &fl;
- struct dentry *dentry = filp->f_path.dentry;
- struct inode *inode = dentry->d_inode;
- int error;
-
- locks_init_lock(&fl);
- error = lease_init(filp, arg, &fl);
- if (error)
- return error;
-
- lock_kernel();
-
- 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_kernel();
- return error;
+ if (arg == F_UNLCK)
+ return do_fcntl_delete_lease(filp);
+ return do_fcntl_add_lease(fd, filp, arg);
}
/**
might_sleep();
for (;;) {
error = flock_lock_file(filp, fl);
- if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
+ if (error != FILE_LOCK_DEFERRED)
break;
error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
if (!error)
* %LOCK_MAND can be combined with %LOCK_READ or %LOCK_WRITE to allow other
* processes read and write access respectively.
*/
-asmlinkage long sys_flock(unsigned int fd, unsigned int cmd)
+SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
{
- struct file *filp;
+ struct fd f = fdget(fd);
struct file_lock *lock;
int can_sleep, unlock;
int error;
error = -EBADF;
- filp = fget(fd);
- if (!filp)
+ if (!f.file)
goto out;
can_sleep = !(cmd & LOCK_NB);
cmd &= ~LOCK_NB;
unlock = (cmd == LOCK_UN);
- if (!unlock && !(cmd & LOCK_MAND) && !(filp->f_mode & 3))
+ if (!unlock && !(cmd & LOCK_MAND) &&
+ !(f.file->f_mode & (FMODE_READ|FMODE_WRITE)))
goto out_putf;
- error = flock_make_lock(filp, &lock, cmd);
+ error = flock_make_lock(f.file, &lock, cmd);
if (error)
goto out_putf;
if (can_sleep)
lock->fl_flags |= FL_SLEEP;
- error = security_file_lock(filp, cmd);
+ error = security_file_lock(f.file, lock->fl_type);
if (error)
goto out_free;
- if (filp->f_op && filp->f_op->flock)
- error = filp->f_op->flock(filp,
+ if (f.file->f_op && f.file->f_op->flock)
+ error = f.file->f_op->flock(f.file,
(can_sleep) ? F_SETLKW : F_SETLK,
lock);
else
- error = flock_lock_file_wait(filp, lock);
+ error = flock_lock_file_wait(f.file, lock);
out_free:
locks_free_lock(lock);
out_putf:
- fput(filp);
+ fdput(f);
out:
return error;
}
/**
* vfs_test_lock - test file byte range lock
* @filp: The file to test lock for
- * @fl: The lock to test
- * @conf: Place to return a copy of the conflicting lock, if found
+ * @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.
* 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)
- * fl_grant is set. Callers expecting ->lock() to return asynchronously
+ * 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 -EINPROGRESS, and call ->fl_grant() when the lock
+ * 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
- * -EINPROGRESS 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
+ * 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
- * ->fl_grant() before returning to the caller with a -EINPROGRESS
+ * ->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)
}
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().
*/
struct file_lock *file_lock = locks_alloc_lock();
struct flock flock;
struct inode *inode;
+ struct file *f;
int error;
if (file_lock == NULL)
if (copy_from_user(&flock, l, sizeof(flock)))
goto out;
- inode = filp->f_path.dentry->d_inode;
+ inode = file_inode(filp);
/* Don't allow mandatory locks on files that may be memory mapped
* and shared.
*/
- if (IS_MANDLOCK(inode) &&
- (inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
- mapping_writably_mapped(filp->f_mapping)) {
+ if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
error = -EAGAIN;
goto out;
}
goto out;
}
- error = security_file_lock(filp, file_lock->fl_type);
- if (error)
- goto out;
-
- for (;;) {
- error = vfs_lock_file(filp, cmd, file_lock, NULL);
- if (error != -EAGAIN || cmd == F_SETLK)
- break;
- error = wait_event_interruptible(file_lock->fl_wait,
- !file_lock->fl_next);
- if (!error)
- continue;
-
- locks_delete_block(file_lock);
- break;
- }
+ 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.
*/
- if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) {
+ /*
+ * 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(¤t->files->file_lock);
+ f = fcheck(fd);
+ spin_unlock(¤t->files->file_lock);
+ if (!error && f != filp && flock.l_type != F_UNLCK) {
flock.l_type = F_UNLCK;
goto again;
}
struct file_lock *file_lock = locks_alloc_lock();
struct flock64 flock;
struct inode *inode;
+ struct file *f;
int error;
if (file_lock == NULL)
if (copy_from_user(&flock, l, sizeof(flock)))
goto out;
- inode = filp->f_path.dentry->d_inode;
+ inode = file_inode(filp);
/* Don't allow mandatory locks on files that may be memory mapped
* and shared.
*/
- if (IS_MANDLOCK(inode) &&
- (inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
- mapping_writably_mapped(filp->f_mapping)) {
+ if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
error = -EAGAIN;
goto out;
}
goto out;
}
- error = security_file_lock(filp, file_lock->fl_type);
- if (error)
- goto out;
-
- for (;;) {
- error = vfs_lock_file(filp, cmd, file_lock, NULL);
- if (error != -EAGAIN || cmd == F_SETLK64)
- break;
- error = wait_event_interruptible(file_lock->fl_wait,
- !file_lock->fl_next);
- if (!error)
- continue;
-
- locks_delete_block(file_lock);
- break;
- }
+ 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.
*/
- if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) {
+ spin_lock(¤t->files->file_lock);
+ f = fcheck(fd);
+ spin_unlock(¤t->files->file_lock);
+ if (!error && f != filp && flock.l_type != F_UNLCK) {
flock.l_type = F_UNLCK;
goto again;
}
* 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)
+ if (!file_inode(filp)->i_flock)
return;
lock.fl_type = F_UNLCK;
*/
void locks_remove_flock(struct file *filp)
{
- struct inode * inode = filp->f_path.dentry->d_inode;
+ struct inode * inode = file_inode(filp);
struct file_lock *fl;
struct file_lock **before;
fl.fl_ops->fl_release_private(&fl);
}
- lock_kernel();
+ lock_flocks();
before = &inode->i_flock;
while ((fl = *before) != NULL) {
}
before = &fl->fl_next;
}
- unlock_kernel();
+ unlock_flocks();
}
/**
{
int status = 0;
- lock_kernel();
+ lock_flocks();
if (waiter->fl_next)
__locks_delete_block(waiter);
else
status = -ENOENT;
- unlock_kernel();
+ unlock_flocks();
return status;
}
EXPORT_SYMBOL_GPL(vfs_cancel_lock);
-static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx)
+#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;
+ inode = file_inode(fl->fl_file);
- out += sprintf(out, "%d:%s ", id, pfx);
+ seq_printf(f, "%lld:%s ", id, pfx);
if (IS_POSIX(fl)) {
- out += sprintf(out, "%6s %s ",
+ seq_printf(f, "%6s %s ",
(fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ",
(inode == NULL) ? "*NOINODE*" :
- (IS_MANDLOCK(inode) &&
- (inode->i_mode & (S_IXGRP | S_ISGID)) == S_ISGID) ?
- "MANDATORY" : "ADVISORY ");
+ mandatory_lock(inode) ? "MANDATORY" : "ADVISORY ");
} else if (IS_FLOCK(fl)) {
if (fl->fl_type & LOCK_MAND) {
- out += sprintf(out, "FLOCK MSNFS ");
+ seq_printf(f, "FLOCK MSNFS ");
} else {
- out += sprintf(out, "FLOCK ADVISORY ");
+ seq_printf(f, "FLOCK ADVISORY ");
}
} else if (IS_LEASE(fl)) {
- out += sprintf(out, "LEASE ");
- if (fl->fl_type & F_INPROGRESS)
- out += sprintf(out, "BREAKING ");
+ seq_printf(f, "LEASE ");
+ if (lease_breaking(fl))
+ seq_printf(f, "BREAKING ");
else if (fl->fl_file)
- out += sprintf(out, "ACTIVE ");
+ seq_printf(f, "ACTIVE ");
else
- out += sprintf(out, "BREAKER ");
+ seq_printf(f, "BREAKER ");
} else {
- out += sprintf(out, "UNKNOWN UNKNOWN ");
+ seq_printf(f, "UNKNOWN UNKNOWN ");
}
if (fl->fl_type & LOCK_MAND) {
- out += sprintf(out, "%s ",
+ seq_printf(f, "%s ",
(fl->fl_type & LOCK_READ)
? (fl->fl_type & LOCK_WRITE) ? "RW " : "READ "
: (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE ");
} else {
- out += sprintf(out, "%s ",
- (fl->fl_type & F_INPROGRESS)
- ? (fl->fl_type & F_UNLCK) ? "UNLCK" : "READ "
- : (fl->fl_type & F_WRLCK) ? "WRITE" : "READ ");
+ 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
- out += sprintf(out, "%d %s:%ld ", fl->fl_pid,
+ 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 ;-( */
- out += sprintf(out, "%d %02x:%02x:%ld ", fl->fl_pid,
+ 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 {
- out += sprintf(out, "%d <none>:0 ", fl->fl_pid);
+ seq_printf(f, "%d <none>:0 ", fl_pid);
}
if (IS_POSIX(fl)) {
if (fl->fl_end == OFFSET_MAX)
- out += sprintf(out, "%Ld EOF\n", fl->fl_start);
+ seq_printf(f, "%Ld EOF\n", fl->fl_start);
else
- out += sprintf(out, "%Ld %Ld\n", fl->fl_start,
- fl->fl_end);
+ seq_printf(f, "%Ld %Ld\n", fl->fl_start, fl->fl_end);
} else {
- out += sprintf(out, "0 EOF\n");
+ seq_printf(f, "0 EOF\n");
}
}
-static void move_lock_status(char **p, off_t* pos, off_t offset)
+static int locks_show(struct seq_file *f, void *v)
{
- int len;
- len = strlen(*p);
- if(*pos >= offset) {
- /* the complete line is valid */
- *p += len;
- *pos += len;
- return;
- }
- if(*pos+len > offset) {
- /* use the second part of the line */
- int i = offset-*pos;
- memmove(*p,*p+i,len-i);
- *p += len-i;
- *pos += len;
- return;
- }
- /* discard the complete line */
- *pos += len;
+ 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;
}
-/**
- * get_locks_status - reports lock usage in /proc/locks
- * @buffer: address in userspace to write into
- * @start: ?
- * @offset: how far we are through the buffer
- * @length: how much to read
- */
+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);
+}
-int get_locks_status(char *buffer, char **start, off_t offset, int length)
+static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
{
- struct list_head *tmp;
- char *q = buffer;
- off_t pos = 0;
- int i = 0;
+ loff_t *p = f->private;
+ ++*p;
+ return seq_list_next(v, &file_lock_list, pos);
+}
- lock_kernel();
- list_for_each(tmp, &file_lock_list) {
- struct list_head *btmp;
- struct file_lock *fl = list_entry(tmp, struct file_lock, fl_link);
- lock_get_status(q, fl, ++i, "");
- move_lock_status(&q, &pos, offset);
+static void locks_stop(struct seq_file *f, void *v)
+{
+ unlock_flocks();
+}
- if(pos >= offset+length)
- goto done;
+static const struct seq_operations locks_seq_operations = {
+ .start = locks_start,
+ .next = locks_next,
+ .stop = locks_stop,
+ .show = locks_show,
+};
- list_for_each(btmp, &fl->fl_block) {
- struct file_lock *bfl = list_entry(btmp,
- struct file_lock, fl_block);
- lock_get_status(q, bfl, i, " ->");
- move_lock_status(&q, &pos, offset);
+static int locks_open(struct inode *inode, struct file *filp)
+{
+ return seq_open_private(filp, &locks_seq_operations, sizeof(loff_t));
+}
- if(pos >= offset+length)
- goto done;
- }
- }
-done:
- unlock_kernel();
- *start = buffer;
- if(q-buffer < length)
- return (q-buffer);
- return length;
+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
{
struct file_lock *fl;
int result = 1;
- lock_kernel();
+ lock_flocks();
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
if (IS_POSIX(fl)) {
if (fl->fl_type == F_RDLCK)
result = 0;
break;
}
- unlock_kernel();
+ unlock_flocks();
return result;
}
{
struct file_lock *fl;
int result = 1;
- lock_kernel();
+ 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)))
result = 0;
break;
}
- unlock_kernel();
+ unlock_flocks();
return result;
}
static int __init filelock_init(void)
{
filelock_cache = kmem_cache_create("file_lock_cache",
- sizeof(struct file_lock), 0, SLAB_PANIC,
- init_once, NULL);
+ sizeof(struct file_lock), 0, SLAB_PANIC, NULL);
+
return 0;
}
Code Review / linux-3.10.git / blobdiff