1 files changed, 92 insertions, 85 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 67f0e88eed01..443f83382b9b 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -120,6 +120,7 @@ static bool inode_io_list_move_locked(struct inode *inode,
 				      struct list_head *head)
 {
 	assert_spin_locked(&wb->list_lock);
+	assert_spin_locked(&inode->i_lock);
 
 	list_move(&inode->i_io_list, head);
 
@@ -133,10 +134,10 @@ static bool inode_io_list_move_locked(struct inode *inode,
 
 static void wb_wakeup(struct bdi_writeback *wb)
 {
-	spin_lock_bh(&wb->work_lock);
+	spin_lock_irq(&wb->work_lock);
 	if (test_bit(WB_registered, &wb->state))
 		mod_delayed_work(bdi_wq, &wb->dwork, 0);
-	spin_unlock_bh(&wb->work_lock);
+	spin_unlock_irq(&wb->work_lock);
 }
 
 static void finish_writeback_work(struct bdi_writeback *wb,
@@ -163,7 +164,7 @@ static void wb_queue_work(struct bdi_writeback *wb,
 	if (work->done)
 		atomic_inc(&work->done->cnt);
 
-	spin_lock_bh(&wb->work_lock);
+	spin_lock_irq(&wb->work_lock);
 
 	if (test_bit(WB_registered, &wb->state)) {
 		list_add_tail(&work->list, &wb->work_list);
@@ -171,7 +172,7 @@ static void wb_queue_work(struct bdi_writeback *wb,
 	} else
 		finish_writeback_work(wb, work);
 
-	spin_unlock_bh(&wb->work_lock);
+	spin_unlock_irq(&wb->work_lock);
 }
 
 /**
@@ -372,7 +373,7 @@ static bool inode_do_switch_wbs(struct inode *inode,
 {
 	struct address_space *mapping = inode->i_mapping;
 	XA_STATE(xas, &mapping->i_pages, 0);
-	struct page *page;
+	struct folio *folio;
 	bool switched = false;
 
 	spin_lock(&inode->i_lock);
@@ -389,21 +390,23 @@ static bool inode_do_switch_wbs(struct inode *inode,
 
 	/*
 	 * Count and transfer stats.  Note that PAGECACHE_TAG_DIRTY points
-	 * to possibly dirty pages while PAGECACHE_TAG_WRITEBACK points to
-	 * pages actually under writeback.
+	 * to possibly dirty folios while PAGECACHE_TAG_WRITEBACK points to
+	 * folios actually under writeback.
 	 */
-	xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_DIRTY) {
-		if (PageDirty(page)) {
-			dec_wb_stat(old_wb, WB_RECLAIMABLE);
-			inc_wb_stat(new_wb, WB_RECLAIMABLE);
+	xas_for_each_marked(&xas, folio, ULONG_MAX, PAGECACHE_TAG_DIRTY) {
+		if (folio_test_dirty(folio)) {
+			long nr = folio_nr_pages(folio);
+			wb_stat_mod(old_wb, WB_RECLAIMABLE, -nr);
+			wb_stat_mod(new_wb, WB_RECLAIMABLE, nr);
 		}
 	}
 
 	xas_set(&xas, 0);
-	xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_WRITEBACK) {
-		WARN_ON_ONCE(!PageWriteback(page));
-		dec_wb_stat(old_wb, WB_WRITEBACK);
-		inc_wb_stat(new_wb, WB_WRITEBACK);
+	xas_for_each_marked(&xas, folio, ULONG_MAX, PAGECACHE_TAG_WRITEBACK) {
+		long nr = folio_nr_pages(folio);
+		WARN_ON_ONCE(!folio_test_writeback(folio));
+		wb_stat_mod(old_wb, WB_WRITEBACK, -nr);
+		wb_stat_mod(new_wb, WB_WRITEBACK, nr);
 	}
 
 	if (mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) {
@@ -736,7 +739,7 @@ EXPORT_SYMBOL_GPL(wbc_attach_and_unlock_inode);
  * incorrectly attributed).
  *
  * To resolve this issue, cgroup writeback detects the majority dirtier of
- * an inode and transfers the ownership to it.  To avoid unnnecessary
+ * an inode and transfers the ownership to it.  To avoid unnecessary
  * oscillation, the detection mechanism keeps track of history and gives
  * out the switch verdict only if the foreign usage pattern is stable over
  * a certain amount of time and/or writeback attempts.
@@ -892,43 +895,6 @@ void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page,
 EXPORT_SYMBOL_GPL(wbc_account_cgroup_owner);
 
 /**
- * inode_congested - test whether an inode is congested
- * @inode: inode to test for congestion (may be NULL)
- * @cong_bits: mask of WB_[a]sync_congested bits to test
- *
- * Tests whether @inode is congested.  @cong_bits is the mask of congestion
- * bits to test and the return value is the mask of set bits.
- *
- * If cgroup writeback is enabled for @inode, the congestion state is
- * determined by whether the cgwb (cgroup bdi_writeback) for the blkcg
- * associated with @inode is congested; otherwise, the root wb's congestion
- * state is used.
- *
- * @inode is allowed to be NULL as this function is often called on
- * mapping->host which is NULL for the swapper space.
- */
-int inode_congested(struct inode *inode, int cong_bits)
-{
-	/*
-	 * Once set, ->i_wb never becomes NULL while the inode is alive.
-	 * Start transaction iff ->i_wb is visible.
-	 */
-	if (inode && inode_to_wb_is_valid(inode)) {
-		struct bdi_writeback *wb;
-		struct wb_lock_cookie lock_cookie = {};
-		bool congested;
-
-		wb = unlocked_inode_to_wb_begin(inode, &lock_cookie);
-		congested = wb_congested(wb, cong_bits);
-		unlocked_inode_to_wb_end(inode, &lock_cookie);
-		return congested;
-	}
-
-	return wb_congested(&inode_to_bdi(inode)->wb, cong_bits);
-}
-EXPORT_SYMBOL_GPL(inode_congested);
-
-/**
  * wb_split_bdi_pages - split nr_pages to write according to bandwidth
  * @wb: target bdi_writeback to split @nr_pages to
  * @nr_pages: number of pages to write for the whole bdi
@@ -1400,9 +1366,9 @@ static int move_expired_inodes(struct list_head *delaying_queue,
 		inode = wb_inode(delaying_queue->prev);
 		if (inode_dirtied_after(inode, dirtied_before))
 			break;
+		spin_lock(&inode->i_lock);
 		list_move(&inode->i_io_list, &tmp);
 		moved++;
-		spin_lock(&inode->i_lock);
 		inode->i_state |= I_SYNC_QUEUED;
 		spin_unlock(&inode->i_lock);
 		if (sb_is_blkdev_sb(inode->i_sb))
@@ -1418,7 +1384,12 @@ static int move_expired_inodes(struct list_head *delaying_queue,
 		goto out;
 	}
 
-	/* Move inodes from one superblock together */
+	/*
+	 * Although inode's i_io_list is moved from 'tmp' to 'dispatch_queue',
+	 * we don't take inode->i_lock here because it is just a pointless overhead.
+	 * Inode is already marked as I_SYNC_QUEUED so writeback list handling is
+	 * fully under our control.
+	 */
 	while (!list_empty(&tmp)) {
 		sb = wb_inode(tmp.prev)->i_sb;
 		list_for_each_prev_safe(pos, node, &tmp) {
@@ -1666,6 +1637,13 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
 
 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
 		inode->i_state |= I_DIRTY_PAGES;
+	else if (unlikely(inode->i_state & I_PINNING_FSCACHE_WB)) {
+		if (!(inode->i_state & I_DIRTY_PAGES)) {
+			inode->i_state &= ~I_PINNING_FSCACHE_WB;
+			wbc->unpinned_fscache_wb = true;
+			dirty |= I_PINNING_FSCACHE_WB; /* Cause write_inode */
+		}
+	}
 
 	spin_unlock(&inode->i_lock);
 
@@ -1675,6 +1653,7 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
 		if (ret == 0)
 			ret = err;
 	}
+	wbc->unpinned_fscache_wb = false;
 	trace_writeback_single_inode(inode, wbc, nr_to_write);
 	return ret;
 }
@@ -1739,6 +1718,15 @@ static int writeback_single_inode(struct inode *inode,
 	 */
 	if (!(inode->i_state & I_DIRTY_ALL))
 		inode_cgwb_move_to_attached(inode, wb);
+	else if (!(inode->i_state & I_SYNC_QUEUED)) {
+		if ((inode->i_state & I_DIRTY))
+			redirty_tail_locked(inode, wb);
+		else if (inode->i_state & I_DIRTY_TIME) {
+			inode->dirtied_when = jiffies;
+			inode_io_list_move_locked(inode, wb, &wb->b_dirty_time);
+		}
+	}
+
 	spin_unlock(&wb->list_lock);
 	inode_sync_complete(inode);
 out:
@@ -1802,11 +1790,12 @@ static long writeback_sb_inodes(struct super_block *sb,
 	};
 	unsigned long start_time = jiffies;
 	long write_chunk;
-	long wrote = 0;  /* count both pages and inodes */
+	long total_wrote = 0;  /* count both pages and inodes */
 
 	while (!list_empty(&wb->b_io)) {
 		struct inode *inode = wb_inode(wb->b_io.prev);
 		struct bdi_writeback *tmp_wb;
+		long wrote;
 
 		if (inode->i_sb != sb) {
 			if (work->sb) {
@@ -1848,8 +1837,8 @@ static long writeback_sb_inodes(struct super_block *sb,
 			 * We'll have another go at writing back this inode
 			 * when we completed a full scan of b_io.
 			 */
-			spin_unlock(&inode->i_lock);
 			requeue_io(inode, wb);
+			spin_unlock(&inode->i_lock);
 			trace_writeback_sb_inodes_requeue(inode);
 			continue;
 		}
@@ -1882,7 +1871,9 @@ static long writeback_sb_inodes(struct super_block *sb,
 
 		wbc_detach_inode(&wbc);
 		work->nr_pages -= write_chunk - wbc.nr_to_write;
-		wrote += write_chunk - wbc.nr_to_write;
+		wrote = write_chunk - wbc.nr_to_write - wbc.pages_skipped;
+		wrote = wrote < 0 ? 0 : wrote;
+		total_wrote += wrote;
 
 		if (need_resched()) {
 			/*
@@ -1893,8 +1884,7 @@ static long writeback_sb_inodes(struct super_block *sb,
 			 * unplug, so get our IOs out the door before we
 			 * give up the CPU.
 			 */
-			if (current->plug)
-				blk_flush_plug(current->plug, false);
+			blk_flush_plug(current->plug, false);
 			cond_resched();
 		}
 
@@ -1905,7 +1895,7 @@ static long writeback_sb_inodes(struct super_block *sb,
 		tmp_wb = inode_to_wb_and_lock_list(inode);
 		spin_lock(&inode->i_lock);
 		if (!(inode->i_state & I_DIRTY_ALL))
-			wrote++;
+			total_wrote++;
 		requeue_inode(inode, tmp_wb, &wbc);
 		inode_sync_complete(inode);
 		spin_unlock(&inode->i_lock);
@@ -1919,14 +1909,14 @@ static long writeback_sb_inodes(struct super_block *sb,
 		 * bail out to wb_writeback() often enough to check
 		 * background threshold and other termination conditions.
 		 */
-		if (wrote) {
+		if (total_wrote) {
 			if (time_is_before_jiffies(start_time + HZ / 10UL))
 				break;
 			if (work->nr_pages <= 0)
 				break;
 		}
 	}
-	return wrote;
+	return total_wrote;
 }
 
 static long __writeback_inodes_wb(struct bdi_writeback *wb,
@@ -2097,13 +2087,13 @@ static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb)
 {
 	struct wb_writeback_work *work = NULL;
 
-	spin_lock_bh(&wb->work_lock);
+	spin_lock_irq(&wb->work_lock);
 	if (!list_empty(&wb->work_list)) {
 		work = list_entry(wb->work_list.next,
 				  struct wb_writeback_work, list);
 		list_del_init(&work->list);
 	}
-	spin_unlock_bh(&wb->work_lock);
+	spin_unlock_irq(&wb->work_lock);
 	return work;
 }
 
@@ -2224,7 +2214,6 @@ void wb_workfn(struct work_struct *work)
 	long pages_written;
 
 	set_worker_desc("flush-%s", bdi_dev_name(wb->bdi));
-	current->flags |= PF_SWAPWRITE;
 
 	if (likely(!current_is_workqueue_rescuer() ||
 		   !test_bit(WB_registered, &wb->state))) {
@@ -2253,8 +2242,6 @@ void wb_workfn(struct work_struct *work)
 		wb_wakeup(wb);
 	else if (wb_has_dirty_io(wb) && dirty_writeback_interval)
 		wb_wakeup_delayed(wb);
-
-	current->flags &= ~PF_SWAPWRITE;
 }
 
 /*
@@ -2291,8 +2278,7 @@ void wakeup_flusher_threads(enum wb_reason reason)
 	/*
 	 * If we are expecting writeback progress we must submit plugged IO.
 	 */
-	if (blk_needs_flush_plug(current))
-		blk_flush_plug(current->plug, true);
+	blk_flush_plug(current->plug, true);
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)
@@ -2383,11 +2369,26 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 {
 	struct super_block *sb = inode->i_sb;
 	int dirtytime = 0;
+	struct bdi_writeback *wb = NULL;
 
 	trace_writeback_mark_inode_dirty(inode, flags);
 
 	if (flags & I_DIRTY_INODE) {
 		/*
+		 * Inode timestamp update will piggback on this dirtying.
+		 * We tell ->dirty_inode callback that timestamps need to
+		 * be updated by setting I_DIRTY_TIME in flags.
+		 */
+		if (inode->i_state & I_DIRTY_TIME) {
+			spin_lock(&inode->i_lock);
+			if (inode->i_state & I_DIRTY_TIME) {
+				inode->i_state &= ~I_DIRTY_TIME;
+				flags |= I_DIRTY_TIME;
+			}
+			spin_unlock(&inode->i_lock);
+		}
+
+		/*
 		 * Notify the filesystem about the inode being dirtied, so that
 		 * (if needed) it can update on-disk fields and journal the
 		 * inode.  This is only needed when the inode itself is being
@@ -2396,7 +2397,8 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 		 */
 		trace_writeback_dirty_inode_start(inode, flags);
 		if (sb->s_op->dirty_inode)
-			sb->s_op->dirty_inode(inode, flags & I_DIRTY_INODE);
+			sb->s_op->dirty_inode(inode,
+				flags & (I_DIRTY_INODE | I_DIRTY_TIME));
 		trace_writeback_dirty_inode(inode, flags);
 
 		/* I_DIRTY_INODE supersedes I_DIRTY_TIME. */
@@ -2417,31 +2419,36 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 	 */
 	smp_mb();
 
-	if (((inode->i_state & flags) == flags) ||
-	    (dirtytime && (inode->i_state & I_DIRTY_INODE)))
+	if ((inode->i_state & flags) == flags)
 		return;
 
 	spin_lock(&inode->i_lock);
-	if (dirtytime && (inode->i_state & I_DIRTY_INODE))
-		goto out_unlock_inode;
 	if ((inode->i_state & flags) != flags) {
 		const int was_dirty = inode->i_state & I_DIRTY;
 
 		inode_attach_wb(inode, NULL);
 
-		/* I_DIRTY_INODE supersedes I_DIRTY_TIME. */
-		if (flags & I_DIRTY_INODE)
-			inode->i_state &= ~I_DIRTY_TIME;
 		inode->i_state |= flags;
 
 		/*
+		 * Grab inode's wb early because it requires dropping i_lock and we
+		 * need to make sure following checks happen atomically with dirty
+		 * list handling so that we don't move inodes under flush worker's
+		 * hands.
+		 */
+		if (!was_dirty) {
+			wb = locked_inode_to_wb_and_lock_list(inode);
+			spin_lock(&inode->i_lock);
+		}
+
+		/*
 		 * If the inode is queued for writeback by flush worker, just
 		 * update its dirty state. Once the flush worker is done with
 		 * the inode it will place it on the appropriate superblock
 		 * list, based upon its state.
 		 */
 		if (inode->i_state & I_SYNC_QUEUED)
-			goto out_unlock_inode;
+			goto out_unlock;
 
 		/*
 		 * Only add valid (hashed) inodes to the superblock's
@@ -2449,22 +2456,19 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 		 */
 		if (!S_ISBLK(inode->i_mode)) {
 			if (inode_unhashed(inode))
-				goto out_unlock_inode;
+				goto out_unlock;
 		}
 		if (inode->i_state & I_FREEING)
-			goto out_unlock_inode;
+			goto out_unlock;
 
 		/*
 		 * If the inode was already on b_dirty/b_io/b_more_io, don't
 		 * reposition it (that would break b_dirty time-ordering).
 		 */
 		if (!was_dirty) {
-			struct bdi_writeback *wb;
 			struct list_head *dirty_list;
 			bool wakeup_bdi = false;
 
-			wb = locked_inode_to_wb_and_lock_list(inode);
-
 			inode->dirtied_when = jiffies;
 			if (dirtytime)
 				inode->dirtied_time_when = jiffies;
@@ -2478,6 +2482,7 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 							       dirty_list);
 
 			spin_unlock(&wb->list_lock);
+			spin_unlock(&inode->i_lock);
 			trace_writeback_dirty_inode_enqueue(inode);
 
 			/*
@@ -2492,7 +2497,9 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 			return;
 		}
 	}
-out_unlock_inode:
+out_unlock:
+	if (wb)
+		spin_unlock(&wb->list_lock);
 	spin_unlock(&inode->i_lock);
 }
 EXPORT_SYMBOL(__mark_inode_dirty);