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Lines 696-712
EXPORT_SYMBOL(posix_test_lock);
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| 696 |
* Note: the above assumption may not be true when handling lock requests |
696 |
* Note: the above assumption may not be true when handling lock requests |
| 697 |
* from a broken NFS client. But broken NFS clients have a lot more to |
697 |
* from a broken NFS client. But broken NFS clients have a lot more to |
| 698 |
* worry about than proper deadlock detection anyway... --okir |
698 |
* worry about than proper deadlock detection anyway... --okir |
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699 |
* |
| 700 |
* However, the failure of this assumption (also possible in the case of |
| 701 |
* multiple tasks sharing the same open file table) also means there's no |
| 702 |
* guarantee that the loop below will terminate. As a hack, we give up |
| 703 |
* after a few iterations. |
| 699 |
*/ |
704 |
*/ |
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705 |
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| 706 |
#define MAX_DEADLK_ITERATIONS 10 |
| 707 |
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| 700 |
static int posix_locks_deadlock(struct file_lock *caller_fl, |
708 |
static int posix_locks_deadlock(struct file_lock *caller_fl, |
| 701 |
struct file_lock *block_fl) |
709 |
struct file_lock *block_fl) |
| 702 |
{ |
710 |
{ |
| 703 |
struct file_lock *fl; |
711 |
struct file_lock *fl; |
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712 |
int i = 0; |
| 704 |
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713 |
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| 705 |
next_task: |
714 |
next_task: |
| 706 |
if (posix_same_owner(caller_fl, block_fl)) |
715 |
if (posix_same_owner(caller_fl, block_fl)) |
| 707 |
return 1; |
716 |
return 1; |
| 708 |
list_for_each_entry(fl, &blocked_list, fl_link) { |
717 |
list_for_each_entry(fl, &blocked_list, fl_link) { |
| 709 |
if (posix_same_owner(fl, block_fl)) { |
718 |
if (posix_same_owner(fl, block_fl)) { |
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719 |
if (i++ > MAX_DEADLK_ITERATIONS) |
| 720 |
return 0; |
| 710 |
fl = fl->fl_next; |
721 |
fl = fl->fl_next; |
| 711 |
block_fl = fl; |
722 |
block_fl = fl; |
| 712 |
goto next_task; |
723 |
goto next_task; |
| 713 |
- |
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