diff options
Diffstat (limited to 'fs/btrfs/inode.c')
-rw-r--r-- | fs/btrfs/inode.c | 61 |
1 files changed, 44 insertions, 17 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6f0568fb5899..1b4ab02be924 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2181,17 +2181,27 @@ static void btrfs_writepage_fixup_worker(struct btrfs_work *work) struct inode *inode; u64 page_start; u64 page_end; - int ret; + int ret = 0; fixup = container_of(work, struct btrfs_writepage_fixup, work); page = fixup->page; again: lock_page(page); - if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { - ClearPageChecked(page); + + /* + * Before we queued this fixup, we took a reference on the page. + * page->mapping may go NULL, but it shouldn't be moved to a different + * address space. + */ + if (!page->mapping || !PageDirty(page) || !PageChecked(page)) goto out_page; - } + /* + * We keep the PageChecked() bit set until we're done with the + * btrfs_start_ordered_extent() dance that we do below. That drops and + * retakes the page lock, so we don't want new fixup workers queued for + * this page during the churn. + */ inode = page->mapping->host; page_start = page_offset(page); page_end = page_offset(page) + PAGE_SIZE - 1; @@ -2216,24 +2226,22 @@ again: ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start, PAGE_SIZE); - if (ret) { - mapping_set_error(page->mapping, ret); - end_extent_writepage(page, ret, page_start, page_end); - ClearPageChecked(page); + if (ret) goto out; - } ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0, &cached_state); - if (ret) { - mapping_set_error(page->mapping, ret); - end_extent_writepage(page, ret, page_start, page_end); - ClearPageChecked(page); + if (ret) goto out_reserved; - } - ClearPageChecked(page); - set_page_dirty(page); + /* + * Everything went as planned, we're now the owner of a dirty page with + * delayed allocation bits set and space reserved for our COW + * destination. + * + * The page was dirty when we started, nothing should have cleaned it. + */ + BUG_ON(!PageDirty(page)); out_reserved: btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); if (ret) @@ -2243,6 +2251,17 @@ out: unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state); out_page: + if (ret) { + /* + * We hit ENOSPC or other errors. Update the mapping and page + * to reflect the errors and clean the page. + */ + mapping_set_error(page->mapping, ret); + end_extent_writepage(page, ret, page_start, page_end); + clear_page_dirty_for_io(page); + SetPageError(page); + } + ClearPageChecked(page); unlock_page(page); put_page(page); kfree(fixup); @@ -2270,6 +2289,13 @@ int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end) if (TestClearPagePrivate2(page)) return 0; + /* + * PageChecked is set below when we create a fixup worker for this page, + * don't try to create another one if we're already PageChecked() + * + * The extent_io writepage code will redirty the page if we send back + * EAGAIN. + */ if (PageChecked(page)) return -EAGAIN; @@ -2282,7 +2308,8 @@ int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end) btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL); fixup->page = page; btrfs_queue_work(fs_info->fixup_workers, &fixup->work); - return -EBUSY; + + return -EAGAIN; } static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, |