diff options
| -rw-r--r-- | fs/locks.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/fs/locks.c b/fs/locks.c index 442052b413af..ed9fb769b88e 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -564,7 +564,7 @@ static void __locks_insert_block(struct file_lock *blocker, BUG_ON(!list_empty(&waiter->fl_block)); waiter->fl_next = blocker; list_add_tail(&waiter->fl_block, &blocker->fl_block); - if (IS_POSIX(blocker)) + if (IS_POSIX(blocker) && !IS_FILE_PVT(blocker)) locks_insert_global_blocked(waiter); } @@ -757,8 +757,16 @@ EXPORT_SYMBOL(posix_test_lock); * 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. + * + * For FL_FILE_PVT locks, the owner is the filp, not the files_struct. + * Because the owner is not even nominally tied to a thread of + * execution, the deadlock detection below can't reasonably work well. Just + * skip it for those. + * + * In principle, we could do a more limited deadlock detection on FL_FILE_PVT + * locks that just checks for the case where two tasks are attempting to + * upgrade from read to write locks on the same inode. */ #define MAX_DEADLK_ITERATIONS 10 @@ -781,6 +789,13 @@ static int posix_locks_deadlock(struct file_lock *caller_fl, { int i = 0; + /* + * This deadlock detector can't reasonably detect deadlocks with + * FL_FILE_PVT locks, since they aren't owned by a process, per-se. + */ + if (IS_FILE_PVT(caller_fl)) + return 0; + while ((block_fl = what_owner_is_waiting_for(block_fl))) { if (i++ > MAX_DEADLK_ITERATIONS) return 0; |