diff options
| -rw-r--r-- | fs/block_dev.c | 16 | ||||
| -rw-r--r-- | fs/fs-writeback.c | 97 | ||||
| -rw-r--r-- | fs/inode.c | 5 | ||||
| -rw-r--r-- | include/linux/backing-dev.h | 2 | ||||
| -rw-r--r-- | include/linux/writeback.h | 2 | ||||
| -rw-r--r-- | mm/backing-dev.c | 21 | ||||
| -rw-r--r-- | mm/filemap.c | 6 | ||||
| -rw-r--r-- | mm/rmap.c | 4 |
8 files changed, 85 insertions, 68 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 1a2421f..3c9a03e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -44,24 +44,28 @@ inline struct block_device *I_BDEV(struct inode *inode) { return &BDEV_I(inode)->bdev; } - EXPORT_SYMBOL(I_BDEV); /* - * move the inode from it's current bdi to the a new bdi. if the inode is dirty - * we need to move it onto the dirty list of @dst so that the inode is always - * on the right list. + * Move the inode from its current bdi to a new bdi. If the inode is dirty we + * need to move it onto the dirty list of @dst so that the inode is always on + * the right list. */ static void bdev_inode_switch_bdi(struct inode *inode, struct backing_dev_info *dst) { - spin_lock(&inode_wb_list_lock); + struct backing_dev_info *old = inode->i_data.backing_dev_info; + + if (unlikely(dst == old)) /* deadlock avoidance */ + return; + bdi_lock_two(&old->wb, &dst->wb); spin_lock(&inode->i_lock); inode->i_data.backing_dev_info = dst; if (inode->i_state & I_DIRTY) list_move(&inode->i_wb_list, &dst->wb.b_dirty); spin_unlock(&inode->i_lock); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&old->wb.list_lock); + spin_unlock(&dst->wb.list_lock); } static sector_t max_block(struct block_device *bdev) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 664acdb..36a3091 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -181,12 +181,13 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi) */ void inode_wb_list_del(struct inode *inode) { - spin_lock(&inode_wb_list_lock); + struct backing_dev_info *bdi = inode_to_bdi(inode); + + spin_lock(&bdi->wb.list_lock); list_del_init(&inode->i_wb_list); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&bdi->wb.list_lock); } - /* * Redirty an inode: set its when-it-was dirtied timestamp and move it to the * furthest end of its superblock's dirty-inode list. @@ -196,11 +197,9 @@ void inode_wb_list_del(struct inode *inode) * the case then the inode must have been redirtied while it was being written * out and we don't reset its dirtied_when. */ -static void redirty_tail(struct inode *inode) +static void redirty_tail(struct inode *inode, struct bdi_writeback *wb) { - struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; - - assert_spin_locked(&inode_wb_list_lock); + assert_spin_locked(&wb->list_lock); if (!list_empty(&wb->b_dirty)) { struct inode *tail; @@ -214,11 +213,9 @@ static void redirty_tail(struct inode *inode) /* * requeue inode for re-scanning after bdi->b_io list is exhausted. */ -static void requeue_io(struct inode *inode) +static void requeue_io(struct inode *inode, struct bdi_writeback *wb) { - struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; - - assert_spin_locked(&inode_wb_list_lock); + assert_spin_locked(&wb->list_lock); list_move(&inode->i_wb_list, &wb->b_more_io); } @@ -226,7 +223,7 @@ static void inode_sync_complete(struct inode *inode) { /* * Prevent speculative execution through - * spin_unlock(&inode_wb_list_lock); + * spin_unlock(&wb->list_lock); */ smp_mb(); @@ -302,7 +299,7 @@ static void move_expired_inodes(struct list_head *delaying_queue, */ static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this) { - assert_spin_locked(&inode_wb_list_lock); + assert_spin_locked(&wb->list_lock); list_splice_init(&wb->b_more_io, &wb->b_io); move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this); } @@ -317,7 +314,8 @@ static int write_inode(struct inode *inode, struct writeback_control *wbc) /* * Wait for writeback on an inode to complete. */ -static void inode_wait_for_writeback(struct inode *inode) +static void inode_wait_for_writeback(struct inode *inode, + struct bdi_writeback *wb) { DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); wait_queue_head_t *wqh; @@ -325,15 +323,15 @@ static void inode_wait_for_writeback(struct inode *inode) wqh = bit_waitqueue(&inode->i_state, __I_SYNC); while (inode->i_state & I_SYNC) { spin_unlock(&inode->i_lock); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); } } /* - * Write out an inode's dirty pages. Called under inode_wb_list_lock and + * Write out an inode's dirty pages. Called under wb->list_lock and * inode->i_lock. Either the caller has an active reference on the inode or * the inode has I_WILL_FREE set. * @@ -344,13 +342,14 @@ static void inode_wait_for_writeback(struct inode *inode) * livelocks, etc. */ static int -writeback_single_inode(struct inode *inode, struct writeback_control *wbc) +writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, + struct writeback_control *wbc) { struct address_space *mapping = inode->i_mapping; unsigned dirty; int ret; - assert_spin_locked(&inode_wb_list_lock); + assert_spin_locked(&wb->list_lock); assert_spin_locked(&inode->i_lock); if (!atomic_read(&inode->i_count)) @@ -368,14 +367,14 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * completed a full scan of b_io. */ if (wbc->sync_mode != WB_SYNC_ALL) { - requeue_io(inode); + requeue_io(inode, wb); return 0; } /* * It's a data-integrity sync. We must wait. */ - inode_wait_for_writeback(inode); + inode_wait_for_writeback(inode, wb); } BUG_ON(inode->i_state & I_SYNC); @@ -384,7 +383,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) inode->i_state |= I_SYNC; inode->i_state &= ~I_DIRTY_PAGES; spin_unlock(&inode->i_lock); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); ret = do_writepages(mapping, wbc); @@ -415,7 +414,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) ret = err; } - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); inode->i_state &= ~I_SYNC; if (!(inode->i_state & I_FREEING)) { @@ -438,7 +437,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) /* * slice used up: queue for next turn */ - requeue_io(inode); + requeue_io(inode, wb); } else { /* * Writeback blocked by something other than @@ -447,7 +446,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * retrying writeback of the dirty page/inode * that cannot be performed immediately. */ - redirty_tail(inode); + redirty_tail(inode, wb); } } else if (inode->i_state & I_DIRTY) { /* @@ -456,7 +455,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * submission or metadata updates after data IO * completion. */ - redirty_tail(inode); + redirty_tail(inode, wb); } else { /* * The inode is clean. At this point we either have @@ -521,7 +520,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, * superblock, move all inodes not belonging * to it back onto the dirty list. */ - redirty_tail(inode); + redirty_tail(inode, wb); continue; } @@ -541,7 +540,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, spin_lock(&inode->i_lock); if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { spin_unlock(&inode->i_lock); - requeue_io(inode); + requeue_io(inode, wb); continue; } @@ -557,19 +556,19 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, __iget(inode); pages_skipped = wbc->pages_skipped; - writeback_single_inode(inode, wbc); + writeback_single_inode(inode, wb, wbc); if (wbc->pages_skipped != pages_skipped) { /* * writeback is not making progress due to locked * buffers. Skip this inode for now. */ - redirty_tail(inode); + redirty_tail(inode, wb); } spin_unlock(&inode->i_lock); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); iput(inode); cond_resched(); - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); if (wbc->nr_to_write <= 0) { wbc->more_io = 1; return 1; @@ -588,7 +587,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb, if (!wbc->wb_start) wbc->wb_start = jiffies; /* livelock avoidance */ - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); if (list_empty(&wb->b_io)) queue_io(wb, wbc->older_than_this); @@ -598,7 +597,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb, struct super_block *sb = inode->i_sb; if (!pin_sb_for_writeback(sb)) { - requeue_io(inode); + requeue_io(inode, wb); continue; } ret = writeback_sb_inodes(sb, wb, wbc, false); @@ -607,7 +606,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb, if (ret) break; } - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); /* Leave any unwritten inodes on b_io */ } @@ -616,11 +615,11 @@ static void __writeback_inodes_sb(struct super_block *sb, { WARN_ON(!rwsem_is_locked(&sb->s_umount)); - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); if (list_empty(&wb->b_io)) queue_io(wb, wbc->older_than_this); writeback_sb_inodes(sb, wb, wbc, true); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); } /* @@ -762,15 +761,15 @@ static long wb_writeback(struct bdi_writeback *wb, * become available for writeback. Otherwise * we'll just busyloop. */ - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); if (!list_empty(&wb->b_more_io)) { inode = wb_inode(wb->b_more_io.prev); trace_wbc_writeback_wait(&wbc, wb->bdi); spin_lock(&inode->i_lock); - inode_wait_for_writeback(inode); + inode_wait_for_writeback(inode, wb); spin_unlock(&inode->i_lock); } - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); } return wrote; @@ -1104,10 +1103,10 @@ void __mark_inode_dirty(struct inode *inode, int flags) } spin_unlock(&inode->i_lock); - spin_lock(&inode_wb_list_lock); + spin_lock(&bdi->wb.list_lock); inode->dirtied_when = jiffies; list_move(&inode->i_wb_list, &bdi->wb.b_dirty); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&bdi->wb.list_lock); if (wakeup_bdi) bdi_wakeup_thread_delayed(bdi); @@ -1309,6 +1308,7 @@ EXPORT_SYMBOL(sync_inodes_sb); */ int write_inode_now(struct inode *inode, int sync) { + struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; int ret; struct writeback_control wbc = { .nr_to_write = LONG_MAX, @@ -1321,11 +1321,11 @@ int write_inode_now(struct inode *inode, int sync) wbc.nr_to_write = 0; might_sleep(); - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); - ret = writeback_single_inode(inode, &wbc); + ret = writeback_single_inode(inode, wb, &wbc); spin_unlock(&inode->i_lock); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); if (sync) inode_sync_wait(inode); return ret; @@ -1345,13 +1345,14 @@ EXPORT_SYMBOL(write_inode_now); */ int sync_inode(struct inode *inode, struct writeback_control *wbc) { + struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; int ret; - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); - ret = writeback_single_inode(inode, wbc); + ret = writeback_single_inode(inode, wb, wbc); spin_unlock(&inode->i_lock); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); return ret; } EXPORT_SYMBOL(sync_inode); @@ -37,7 +37,7 @@ * inode_lru, inode->i_lru * inode_sb_list_lock protects: * sb->s_inodes, inode->i_sb_list - * inode_wb_list_lock protects: + * bdi->wb.list_lock protects: * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list * inode_hash_lock protects: * inode_hashtable, inode->i_hash @@ -48,7 +48,7 @@ * inode->i_lock * inode_lru_lock * - * inode_wb_list_lock + * bdi->wb.list_lock * inode->i_lock * * inode_hash_lock @@ -68,7 +68,6 @@ static LIST_HEAD(inode_lru); static DEFINE_SPINLOCK(inode_lru_lock); __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock); -__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock); /* * iprune_sem provides exclusion between the icache shrinking and the diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 96f4094..47feb2c 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -57,6 +57,7 @@ struct bdi_writeback { struct list_head b_dirty; /* dirty inodes */ struct list_head b_io; /* parked for writeback */ struct list_head b_more_io; /* parked for more writeback */ + spinlock_t list_lock; /* protects the b_* lists */ }; struct backing_dev_info { @@ -106,6 +107,7 @@ int bdi_writeback_thread(void *data); int bdi_has_dirty_io(struct backing_dev_info *bdi); void bdi_arm_supers_timer(void); void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi); +void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2); extern spinlock_t bdi_lock; extern struct list_head bdi_list; diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 7df9026..c2d957f 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -9,8 +9,6 @@ struct backing_dev_info; -extern spinlock_t inode_wb_list_lock; - /* * fs/fs-writeback.c */ diff --git a/mm/backing-dev.c b/mm/backing-dev.c index f032e6e..5f6553e 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -45,6 +45,17 @@ static struct timer_list sync_supers_timer; static int bdi_sync_supers(void *); static void sync_supers_timer_fn(unsigned long); +void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2) +{ + if (wb1 < wb2) { + spin_lock(&wb1->list_lock); + spin_lock_nested(&wb2->list_lock, 1); + } else { + spin_lock(&wb2->list_lock); + spin_lock_nested(&wb1->list_lock, 1); + } +} + #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> #include <linux/seq_file.h> @@ -67,14 +78,14 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) struct inode *inode; nr_dirty = nr_io = nr_more_io = 0; - spin_lock(&inode_wb_list_lock); + spin_lock(&wb->list_lock); list_for_each_entry(inode, &wb->b_dirty, i_wb_list) nr_dirty++; list_for_each_entry(inode, &wb->b_io, i_wb_list) nr_io++; list_for_each_entry(inode, &wb->b_more_io, i_wb_list) nr_more_io++; - spin_unlock(&inode_wb_list_lock); + spin_unlock(&wb->list_lock); global_dirty_limits(&background_thresh, &dirty_thresh); bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh); @@ -628,6 +639,7 @@ static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi) INIT_LIST_HEAD(&wb->b_dirty); INIT_LIST_HEAD(&wb->b_io); INIT_LIST_HEAD(&wb->b_more_io); + spin_lock_init(&wb->list_lock); setup_timer(&wb->wakeup_timer, wakeup_timer_fn, (unsigned long)bdi); } @@ -676,11 +688,12 @@ void bdi_destroy(struct backing_dev_info *bdi) if (bdi_has_dirty_io(bdi)) { struct bdi_writeback *dst = &default_backing_dev_info.wb; - spin_lock(&inode_wb_list_lock); + bdi_lock_two(&bdi->wb, dst); list_splice(&bdi->wb.b_dirty, &dst->b_dirty); list_splice(&bdi->wb.b_io, &dst->b_io); list_splice(&bdi->wb.b_more_io, &dst->b_more_io); - spin_unlock(&inode_wb_list_lock); + spin_unlock(&bdi->wb.list_lock); + spin_unlock(&dst->list_lock); } bdi_unregister(bdi); diff --git a/mm/filemap.c b/mm/filemap.c index d7b1057..1e492c3 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -81,7 +81,7 @@ * ->i_mutex * ->i_alloc_sem (various) * - * inode_wb_list_lock + * bdi->wb.list_lock * sb_lock (fs/fs-writeback.c) * ->mapping->tree_lock (__sync_single_inode) * @@ -99,9 +99,9 @@ * ->zone.lru_lock (check_pte_range->isolate_lru_page) * ->private_lock (page_remove_rmap->set_page_dirty) * ->tree_lock (page_remove_rmap->set_page_dirty) - * inode_wb_list_lock (page_remove_rmap->set_page_dirty) + * bdi.wb->list_lock (page_remove_rmap->set_page_dirty) * ->inode->i_lock (page_remove_rmap->set_page_dirty) - * inode_wb_list_lock (zap_pte_range->set_page_dirty) + * bdi.wb->list_lock (zap_pte_range->set_page_dirty) * ->inode->i_lock (zap_pte_range->set_page_dirty) * ->private_lock (zap_pte_range->__set_page_dirty_buffers) * @@ -32,11 +32,11 @@ * mmlist_lock (in mmput, drain_mmlist and others) * mapping->private_lock (in __set_page_dirty_buffers) * inode->i_lock (in set_page_dirty's __mark_inode_dirty) - * inode_wb_list_lock (in set_page_dirty's __mark_inode_dirty) + * bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty) * sb_lock (within inode_lock in fs/fs-writeback.c) * mapping->tree_lock (widely used, in set_page_dirty, * in arch-dependent flush_dcache_mmap_lock, - * within inode_wb_list_lock in __sync_single_inode) + * within bdi.wb->list_lock in __sync_single_inode) * * (code doesn't rely on that order so it could be switched around) * ->tasklist_lock |
