From 490e016f229a79dc7551e7f0e989d2304416c189 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 4 Mar 2021 11:09:17 -0500 Subject: mm/writeback: Add folio_wait_writeback() wait_on_page_writeback_killable() only has one caller, so convert it to call folio_wait_writeback_killable(). For the wait_on_page_writeback() callers, add a compatibility wrapper around folio_wait_writeback(). Turning PageWriteback() into folio_test_writeback() eliminates a call to compound_head() which saves 8 bytes and 15 bytes in the two functions. Unfortunately, that is more than offset by adding the wait_on_page_writeback compatibility wrapper for a net increase in text of 7 bytes. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Jeff Layton Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Acked-by: Mike Rapoport Reviewed-by: David Howells --- mm/folio-compat.c | 6 ++++++ mm/page-writeback.c | 48 +++++++++++++++++++++++++++++++++--------------- 2 files changed, 39 insertions(+), 15 deletions(-) (limited to 'mm') diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 526843d03d58..41275dac7a92 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -23,3 +23,9 @@ void end_page_writeback(struct page *page) return folio_end_writeback(page_folio(page)); } EXPORT_SYMBOL(end_page_writeback); + +void wait_on_page_writeback(struct page *page) +{ + return folio_wait_writeback(page_folio(page)); +} +EXPORT_SYMBOL_GPL(wait_on_page_writeback); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 4812a17b288c..c7f40c954217 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2873,33 +2873,51 @@ int __test_set_page_writeback(struct page *page, bool keep_write) } EXPORT_SYMBOL(__test_set_page_writeback); -/* - * Wait for a page to complete writeback +/** + * folio_wait_writeback - Wait for a folio to finish writeback. + * @folio: The folio to wait for. + * + * If the folio is currently being written back to storage, wait for the + * I/O to complete. + * + * Context: Sleeps. Must be called in process context and with + * no spinlocks held. Caller should hold a reference on the folio. + * If the folio is not locked, writeback may start again after writeback + * has finished. */ -void wait_on_page_writeback(struct page *page) +void folio_wait_writeback(struct folio *folio) { - while (PageWriteback(page)) { - trace_wait_on_page_writeback(page, page_mapping(page)); - wait_on_page_bit(page, PG_writeback); + while (folio_test_writeback(folio)) { + trace_wait_on_page_writeback(&folio->page, folio_mapping(folio)); + wait_on_page_bit(&folio->page, PG_writeback); } } -EXPORT_SYMBOL_GPL(wait_on_page_writeback); +EXPORT_SYMBOL_GPL(folio_wait_writeback); -/* - * Wait for a page to complete writeback. Returns -EINTR if we get a - * fatal signal while waiting. +/** + * folio_wait_writeback_killable - Wait for a folio to finish writeback. + * @folio: The folio to wait for. + * + * If the folio is currently being written back to storage, wait for the + * I/O to complete or a fatal signal to arrive. + * + * Context: Sleeps. Must be called in process context and with + * no spinlocks held. Caller should hold a reference on the folio. + * If the folio is not locked, writeback may start again after writeback + * has finished. + * Return: 0 on success, -EINTR if we get a fatal signal while waiting. */ -int wait_on_page_writeback_killable(struct page *page) +int folio_wait_writeback_killable(struct folio *folio) { - while (PageWriteback(page)) { - trace_wait_on_page_writeback(page, page_mapping(page)); - if (wait_on_page_bit_killable(page, PG_writeback)) + while (folio_test_writeback(folio)) { + trace_wait_on_page_writeback(&folio->page, folio_mapping(folio)); + if (wait_on_page_bit_killable(&folio->page, PG_writeback)) return -EINTR; } return 0; } -EXPORT_SYMBOL_GPL(wait_on_page_writeback_killable); +EXPORT_SYMBOL_GPL(folio_wait_writeback_killable); /** * wait_for_stable_page() - wait for writeback to finish, if necessary. -- cgit