This patch removes the annoying and confusing `wait' argument from
many places. The only change in behaviour is that we now yield once
when unblocking other BSD-style flocks instead of once for each lock.
This slightly improves the semantics for userspace. Before, when we
had two tasks waiting on a lock, the first one would receive the lock.
Now, the one with the highest priority receives the lock.
diff -urNX dontdiff linux-2.5.15/fs/locks.c linux-2.5.15-flock/fs/locks.c
--- linux-2.5.15/fs/locks.c Thu May 9 16:23:59 2002
+++ linux-2.5.15-flock/fs/locks.c Sun May 12 09:21:40 2002
@@ -436,24 +436,15 @@
* 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, unsigned int wait)
+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, fl_block);
-
- if (wait) {
- locks_notify_blocked(waiter);
- /* Let the blocked process remove waiter from the
- * block list when it gets scheduled.
- */
- yield();
- } else {
- /* Remove waiter from the block list, because by the
- * time it wakes up blocker won't exist any more.
- */
- locks_delete_block(waiter);
- locks_notify_blocked(waiter);
- }
+ /* Remove waiter from the block list, because by the
+ * time it wakes up blocker won't exist any more.
+ */
+ locks_delete_block(waiter);
+ locks_notify_blocked(waiter);
}
}
@@ -490,7 +481,7 @@
* notify the FS that the lock has been cleared and
* finally free the lock.
*/
-static inline void _delete_lock(struct file_lock *fl, unsigned int wait)
+static inline void _delete_lock(struct file_lock *fl)
{
fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync);
if (fl->fl_fasync != NULL){
@@ -501,19 +492,19 @@
if (fl->fl_remove)
fl->fl_remove(fl);
- locks_wake_up_blocks(fl, wait);
+ locks_wake_up_blocks(fl);
locks_free_lock(fl);
}
/*
* Delete a lock and then free it.
*/
-static void locks_delete_lock(struct file_lock **thisfl_p, unsigned int wait)
+static void locks_delete_lock(struct file_lock **thisfl_p)
{
struct file_lock *fl = *thisfl_p;
_unhash_lock(thisfl_p);
- _delete_lock(fl, wait);
+ _delete_lock(fl);
}
/*
@@ -532,7 +523,7 @@
fl->fl_type = F_UNLCK;
lock(fl->fl_file, F_SETLK, fl);
}
- _delete_lock(fl, 0);
+ _delete_lock(fl);
}
/* Determine if lock sys_fl blocks lock caller_fl. Common functionality
@@ -806,12 +797,14 @@
*/
if (change) {
/* N.B. What if the wait argument is false? */
- locks_delete_lock(before, !unlock);
- /*
- * If we waited, another lock may have been added ...
- */
- if (!unlock)
+ locks_delete_lock(before);
+ if (!unlock) {
+ yield();
+ /*
+ * If we waited, another lock may have been added ...
+ */
goto search;
+ }
}
if (unlock)
goto out;
@@ -944,7 +937,7 @@
else
caller->fl_end = fl->fl_end;
if (added) {
- locks_delete_lock(before, 0);
+ locks_delete_lock(before);
continue;
}
caller = fl;
@@ -974,7 +967,7 @@
* one (This may happen several times).
*/
if (added) {
- locks_delete_lock(before, 0);
+ locks_delete_lock(before);
continue;
}
/* Replace the old lock with the new one.
@@ -982,7 +975,7 @@
* as the change in lock type might satisfy
* their needs.
*/
- locks_wake_up_blocks(fl, 0); /* This cannot schedule()! */
+ locks_wake_up_blocks(fl);
fl->fl_start = caller->fl_start;
fl->fl_end = caller->fl_end;
fl->fl_type = caller->fl_type;
@@ -1016,11 +1009,11 @@
locks_insert_lock(before, left);
}
right->fl_start = caller->fl_end + 1;
- locks_wake_up_blocks(right, 0);
+ locks_wake_up_blocks(right);
}
if (left) {
left->fl_end = caller->fl_start - 1;
- locks_wake_up_blocks(left, 0);
+ locks_wake_up_blocks(left);
}
out:
unlock_kernel();
@@ -1129,7 +1122,7 @@
error = locks_block_on_timeout(flock, new_fl, error);
if (error == 0) {
/* We timed out. Unilaterally break the lease. */
- locks_delete_lock(&inode->i_flock, 0);
+ locks_delete_lock(&inode->i_flock);
printk(KERN_WARNING "lease timed out\n");
} else if (error > 0) {
flock = inode->i_flock;
@@ -1192,14 +1185,14 @@
if (error < 0)
goto out;
- locks_wake_up_blocks(fl, 0);
+ locks_wake_up_blocks(fl);
if (arg == F_UNLCK) {
filp->f_owner.pid = 0;
filp->f_owner.uid = 0;
filp->f_owner.euid = 0;
filp->f_owner.signum = 0;
- locks_delete_lock(before, 0);
+ locks_delete_lock(before);
fasync_helper(fd, filp, 0, &fl->fl_fasync);
}
@@ -1712,7 +1705,7 @@
while ((fl = *before) != NULL) {
if ((fl->fl_flags & (FL_FLOCK|FL_LEASE))
&& (fl->fl_file == filp)) {
- locks_delete_lock(before, 0);
+ locks_delete_lock(before);
continue;
}
before = &fl->fl_next;
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This archive was generated by hypermail 2b29 : Fri Jun 07 2002 - 22:00:28 EST