Commit f283c86afe6aa70b733d1ecebad5d9464943b774
Committed by
Al Viro
1 parent
02afc410f3
Exists in
master
and in
4 other branches
fs: remove inode_lock from iput_final and prune_icache
Now that inode state changes are protected by the inode->i_lock and the inode LRU manipulations by the inode_lru_lock, we can remove the inode_lock from prune_icache and the initial part of iput_final(). instead of using the inode_lock to protect the inode during iput_final, use the inode->i_lock instead. This protects the inode against new references being taken while we change the inode state to I_FREEING, as well as preventing prune_icache from grabbing the inode while we are manipulating it. Hence we no longer need the inode_lock in iput_final prior to setting I_FREEING on the inode. For prune_icache, we no longer need the inode_lock to protect the LRU list, and the inodes themselves are protected against freeing races by the inode->i_lock. Hence we can lift the inode_lock from prune_icache as well. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Showing 5 changed files with 17 additions and 22 deletions Side-by-side Diff
Documentation/filesystems/Locking
Documentation/filesystems/porting
... | ... | @@ -298,11 +298,14 @@ |
298 | 298 | remaining links or not. Caller does *not* evict the pagecache or inode-associated |
299 | 299 | metadata buffers; getting rid of those is responsibility of method, as it had |
300 | 300 | been for ->delete_inode(). |
301 | - ->drop_inode() returns int now; it's called on final iput() with inode_lock | |
302 | -held and it returns true if filesystems wants the inode to be dropped. As before, | |
303 | -generic_drop_inode() is still the default and it's been updated appropriately. | |
304 | -generic_delete_inode() is also alive and it consists simply of return 1. Note that | |
305 | -all actual eviction work is done by caller after ->drop_inode() returns. | |
301 | + | |
302 | + ->drop_inode() returns int now; it's called on final iput() with | |
303 | +inode->i_lock held and it returns true if filesystems wants the inode to be | |
304 | +dropped. As before, generic_drop_inode() is still the default and it's been | |
305 | +updated appropriately. generic_delete_inode() is also alive and it consists | |
306 | +simply of return 1. Note that all actual eviction work is done by caller after | |
307 | +->drop_inode() returns. | |
308 | + | |
306 | 309 | clear_inode() is gone; use end_writeback() instead. As before, it must |
307 | 310 | be called exactly once on each call of ->evict_inode() (as it used to be for |
308 | 311 | each call of ->delete_inode()). Unlike before, if you are using inode-associated |
... | ... | @@ -394,6 +397,9 @@ |
394 | 397 | Currently you can only have FALLOC_FL_PUNCH_HOLE with FALLOC_FL_KEEP_SIZE set, |
395 | 398 | so the i_size should not change when hole punching, even when puching the end of |
396 | 399 | a file off. |
400 | + | |
401 | +-- | |
402 | +[mandatory] | |
397 | 403 | |
398 | 404 | -- |
399 | 405 | [mandatory] |
Documentation/filesystems/vfs.txt
... | ... | @@ -254,7 +254,7 @@ |
254 | 254 | should be synchronous or not, not all filesystems check this flag. |
255 | 255 | |
256 | 256 | drop_inode: called when the last access to the inode is dropped, |
257 | - with the inode_lock spinlock held. | |
257 | + with the inode->i_lock spinlock held. | |
258 | 258 | |
259 | 259 | This method should be either NULL (normal UNIX filesystem |
260 | 260 | semantics) or "generic_delete_inode" (for filesystems that do not |
fs/inode.c
... | ... | @@ -650,7 +650,6 @@ |
650 | 650 | unsigned long reap = 0; |
651 | 651 | |
652 | 652 | down_read(&iprune_sem); |
653 | - spin_lock(&inode_lock); | |
654 | 653 | spin_lock(&inode_lru_lock); |
655 | 654 | for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { |
656 | 655 | struct inode *inode; |
657 | 656 | |
... | ... | @@ -676,8 +675,8 @@ |
676 | 675 | */ |
677 | 676 | if (atomic_read(&inode->i_count) || |
678 | 677 | (inode->i_state & ~I_REFERENCED)) { |
679 | - spin_unlock(&inode->i_lock); | |
680 | 678 | list_del_init(&inode->i_lru); |
679 | + spin_unlock(&inode->i_lock); | |
681 | 680 | inodes_stat.nr_unused--; |
682 | 681 | continue; |
683 | 682 | } |
684 | 683 | |
685 | 684 | |
686 | 685 | |
... | ... | @@ -685,20 +684,18 @@ |
685 | 684 | /* recently referenced inodes get one more pass */ |
686 | 685 | if (inode->i_state & I_REFERENCED) { |
687 | 686 | inode->i_state &= ~I_REFERENCED; |
688 | - spin_unlock(&inode->i_lock); | |
689 | 687 | list_move(&inode->i_lru, &inode_lru); |
688 | + spin_unlock(&inode->i_lock); | |
690 | 689 | continue; |
691 | 690 | } |
692 | 691 | if (inode_has_buffers(inode) || inode->i_data.nrpages) { |
693 | 692 | __iget(inode); |
694 | 693 | spin_unlock(&inode->i_lock); |
695 | 694 | spin_unlock(&inode_lru_lock); |
696 | - spin_unlock(&inode_lock); | |
697 | 695 | if (remove_inode_buffers(inode)) |
698 | 696 | reap += invalidate_mapping_pages(&inode->i_data, |
699 | 697 | 0, -1); |
700 | 698 | iput(inode); |
701 | - spin_lock(&inode_lock); | |
702 | 699 | spin_lock(&inode_lru_lock); |
703 | 700 | |
704 | 701 | if (inode != list_entry(inode_lru.next, |
... | ... | @@ -724,7 +721,6 @@ |
724 | 721 | else |
725 | 722 | __count_vm_events(PGINODESTEAL, reap); |
726 | 723 | spin_unlock(&inode_lru_lock); |
727 | - spin_unlock(&inode_lock); | |
728 | 724 | |
729 | 725 | dispose_list(&freeable); |
730 | 726 | up_read(&iprune_sem); |
... | ... | @@ -1082,7 +1078,6 @@ |
1082 | 1078 | |
1083 | 1079 | struct inode *igrab(struct inode *inode) |
1084 | 1080 | { |
1085 | - spin_lock(&inode_lock); | |
1086 | 1081 | spin_lock(&inode->i_lock); |
1087 | 1082 | if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) { |
1088 | 1083 | __iget(inode); |
... | ... | @@ -1096,7 +1091,6 @@ |
1096 | 1091 | */ |
1097 | 1092 | inode = NULL; |
1098 | 1093 | } |
1099 | - spin_unlock(&inode_lock); | |
1100 | 1094 | return inode; |
1101 | 1095 | } |
1102 | 1096 | EXPORT_SYMBOL(igrab); |
... | ... | @@ -1439,7 +1433,6 @@ |
1439 | 1433 | const struct super_operations *op = inode->i_sb->s_op; |
1440 | 1434 | int drop; |
1441 | 1435 | |
1442 | - spin_lock(&inode->i_lock); | |
1443 | 1436 | WARN_ON(inode->i_state & I_NEW); |
1444 | 1437 | |
1445 | 1438 | if (op && op->drop_inode) |
1446 | 1439 | |
1447 | 1440 | |
... | ... | @@ -1452,16 +1445,13 @@ |
1452 | 1445 | if (!(inode->i_state & (I_DIRTY|I_SYNC))) |
1453 | 1446 | inode_lru_list_add(inode); |
1454 | 1447 | spin_unlock(&inode->i_lock); |
1455 | - spin_unlock(&inode_lock); | |
1456 | 1448 | return; |
1457 | 1449 | } |
1458 | 1450 | |
1459 | 1451 | if (!drop) { |
1460 | 1452 | inode->i_state |= I_WILL_FREE; |
1461 | 1453 | spin_unlock(&inode->i_lock); |
1462 | - spin_unlock(&inode_lock); | |
1463 | 1454 | write_inode_now(inode, 1); |
1464 | - spin_lock(&inode_lock); | |
1465 | 1455 | spin_lock(&inode->i_lock); |
1466 | 1456 | WARN_ON(inode->i_state & I_NEW); |
1467 | 1457 | inode->i_state &= ~I_WILL_FREE; |
... | ... | @@ -1470,7 +1460,6 @@ |
1470 | 1460 | inode->i_state |= I_FREEING; |
1471 | 1461 | inode_lru_list_del(inode); |
1472 | 1462 | spin_unlock(&inode->i_lock); |
1473 | - spin_unlock(&inode_lock); | |
1474 | 1463 | |
1475 | 1464 | evict(inode); |
1476 | 1465 | } |
... | ... | @@ -1489,7 +1478,7 @@ |
1489 | 1478 | if (inode) { |
1490 | 1479 | BUG_ON(inode->i_state & I_CLEAR); |
1491 | 1480 | |
1492 | - if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) | |
1481 | + if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock)) | |
1493 | 1482 | iput_final(inode); |
1494 | 1483 | } |
1495 | 1484 | } |
fs/logfs/inode.c