From 38b669880df44cba24ab1b01715b87318d469217 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 22 Apr 2008 09:22:11 -0400 Subject: [PATCH] Deal with page == NULL in the btrfs_unplug_io_fn Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 7f5aca35494d..19c258d2c7e2 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -911,12 +911,40 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits) return ret; } +/* + * this unplugs every device on the box, and it is only used when page + * is null + */ +static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page) +{ + struct list_head *cur; + struct btrfs_device *device; + struct btrfs_fs_info *info; + + info = (struct btrfs_fs_info *)bdi->unplug_io_data; + list_for_each(cur, &info->fs_devices->devices) { + device = list_entry(cur, struct btrfs_device, dev_list); + bdi = blk_get_backing_dev_info(device->bdev); + if (bdi->unplug_io_fn) { + bdi->unplug_io_fn(bdi, page); + } + } +} + void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) { - struct inode *inode = page->mapping->host; + struct inode *inode; struct extent_map_tree *em_tree; struct extent_map *em; - u64 offset = page_offset(page); + u64 offset; + + if (!page) { + __unplug_io_fn(bdi, page); + return; + } + + inode = page->mapping->host; + offset = page_offset(page); em_tree = &BTRFS_I(inode)->extent_tree; spin_lock(&em_tree->lock);