| null_vnops.c (111841) | null_vnops.c (116469) |
|---|---|
| 1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John Heidemann of the UCLA Ficus project. 7 * 8 * Redistribution and use in source and binary forms, with or without --- 26 unchanged lines hidden (view full) --- 35 * 36 * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95 37 * 38 * Ancestors: 39 * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92 40 * ...and... 41 * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project 42 * | 1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John Heidemann of the UCLA Ficus project. 7 * 8 * Redistribution and use in source and binary forms, with or without --- 26 unchanged lines hidden (view full) --- 35 * 36 * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95 37 * 38 * Ancestors: 39 * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92 40 * ...and... 41 * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project 42 * |
| 43 * $FreeBSD: head/sys/fs/nullfs/null_vnops.c 111841 2003-03-03 19:15:40Z njl $ | 43 * $FreeBSD: head/sys/fs/nullfs/null_vnops.c 116469 2003-06-17 08:52:45Z tjr $ |
| 44 */ 45 46/* 47 * Null Layer 48 * 49 * (See mount_nullfs(8) for more information.) 50 * 51 * The null layer duplicates a portion of the filesystem --- 535 unchanged lines hidden (view full) --- 587 struct thread *a_td; 588 } */ *ap; 589{ 590 struct vnode *vp = ap->a_vp; 591 int flags = ap->a_flags; 592 struct thread *td = ap->a_td; 593 struct vnode *lvp; 594 int error; | 44 */ 45 46/* 47 * Null Layer 48 * 49 * (See mount_nullfs(8) for more information.) 50 * 51 * The null layer duplicates a portion of the filesystem --- 535 unchanged lines hidden (view full) --- 587 struct thread *a_td; 588 } */ *ap; 589{ 590 struct vnode *vp = ap->a_vp; 591 int flags = ap->a_flags; 592 struct thread *td = ap->a_td; 593 struct vnode *lvp; 594 int error; |
| 595 struct null_node *nn; |
|
| 595 596 if (flags & LK_THISLAYER) { 597 if (vp->v_vnlock != NULL) { 598 /* lock is shared across layers */ 599 if (flags & LK_INTERLOCK) 600 mtx_unlock(&vp->v_interlock); 601 return 0; 602 } --- 6 unchanged lines hidden (view full) --- 609 /* 610 * The lower level has exported a struct lock to us. Use 611 * it so that all vnodes in the stack lock and unlock 612 * simultaneously. Note: we don't DRAIN the lock as DRAIN 613 * decommissions the lock - just because our vnode is 614 * going away doesn't mean the struct lock below us is. 615 * LK_EXCLUSIVE is fine. 616 */ | 596 597 if (flags & LK_THISLAYER) { 598 if (vp->v_vnlock != NULL) { 599 /* lock is shared across layers */ 600 if (flags & LK_INTERLOCK) 601 mtx_unlock(&vp->v_interlock); 602 return 0; 603 } --- 6 unchanged lines hidden (view full) --- 610 /* 611 * The lower level has exported a struct lock to us. Use 612 * it so that all vnodes in the stack lock and unlock 613 * simultaneously. Note: we don't DRAIN the lock as DRAIN 614 * decommissions the lock - just because our vnode is 615 * going away doesn't mean the struct lock below us is. 616 * LK_EXCLUSIVE is fine. 617 */ |
| 618 if ((flags & LK_INTERLOCK) == 0) { 619 VI_LOCK(vp); 620 flags |= LK_INTERLOCK; 621 } 622 nn = VTONULL(vp); |
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| 617 if ((flags & LK_TYPE_MASK) == LK_DRAIN) { 618 NULLFSDEBUG("null_lock: avoiding LK_DRAIN\n"); | 623 if ((flags & LK_TYPE_MASK) == LK_DRAIN) { 624 NULLFSDEBUG("null_lock: avoiding LK_DRAIN\n"); |
| 619 return(lockmgr(vp->v_vnlock, 620 (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE, 621 &vp->v_interlock, td)); | 625 /* 626 * Emulate lock draining by waiting for all other 627 * pending locks to complete. Afterwards the 628 * lockmgr call might block, but no other threads 629 * will attempt to use this nullfs vnode due to the 630 * VI_XLOCK flag. 631 */ 632 while (nn->null_pending_locks > 0) { 633 nn->null_drain_wakeup = 1; 634 msleep(&nn->null_pending_locks, 635 VI_MTX(vp), 636 PVFS, 637 "nuldr", 0); 638 } 639 error = lockmgr(vp->v_vnlock, 640 (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE, 641 VI_MTX(vp), td); 642 return error; |
| 622 } | 643 } |
| 623 return(lockmgr(vp->v_vnlock, flags, &vp->v_interlock, td)); | 644 nn->null_pending_locks++; 645 error = lockmgr(vp->v_vnlock, flags, &vp->v_interlock, td); 646 VI_LOCK(vp); 647 /* 648 * If we're called from vrele then v_usecount can have been 0 649 * and another process might have initiated a recycle 650 * operation. When that happens, just back out. 651 */ 652 if (error == 0 && (vp->v_iflag & VI_XLOCK) != 0 && 653 td != vp->v_vxproc) { 654 lockmgr(vp->v_vnlock, 655 (flags & ~LK_TYPE_MASK) | LK_RELEASE, 656 VI_MTX(vp), td); 657 VI_LOCK(vp); 658 error = ENOENT; 659 } 660 nn->null_pending_locks--; 661 /* 662 * Wakeup the process draining the vnode after all 663 * pending lock attempts has been failed. 664 */ 665 if (nn->null_pending_locks == 0 && 666 nn->null_drain_wakeup != 0) { 667 nn->null_drain_wakeup = 0; 668 wakeup(&nn->null_pending_locks); 669 } 670 if (error == ENOENT && (vp->v_iflag & VI_XLOCK) != 0 && 671 vp->v_vxproc != curthread) { 672 vp->v_iflag |= VI_XWANT; 673 msleep(vp, VI_MTX(vp), PINOD, "nulbo", 0); 674 } 675 VI_UNLOCK(vp); 676 return error; |
| 624 } else { 625 /* 626 * To prevent race conditions involving doing a lookup 627 * on "..", we have to lock the lower node, then lock our 628 * node. Most of the time it won't matter that we lock our 629 * node (as any locking would need the lower one locked 630 * first). But we can LK_DRAIN the upper lock as a step 631 * towards decomissioning it. --- 230 unchanged lines hidden --- | 677 } else { 678 /* 679 * To prevent race conditions involving doing a lookup 680 * on "..", we have to lock the lower node, then lock our 681 * node. Most of the time it won't matter that we lock our 682 * node (as any locking would need the lower one locked 683 * first). But we can LK_DRAIN the upper lock as a step 684 * towards decomissioning it. --- 230 unchanged lines hidden --- |