| Message ID | 20220402062218.30709-1-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | filemap: remove obsolete comment in lock_page | expand |
On Sat, Apr 02, 2022 at 02:22:18PM +0800, Miaohe Lin wrote: > lock_page needs the caller to have a reference on the page->mapping inode > due to sync_page. Also lock_page_nosync is introduced which does not do a > sync_page via commit db37648cd6ce ("[PATCH] mm: non syncing lock_page()"). > But commit 7eaceaccab5f ("block: remove per-queue plugging") kills off the > old plugging along with aops->sync_page() and lock_page_nosync. So there > is no need to have a reference on the page->mapping inode when calling > lock_page anymore. Remove this obsolete and confusing comment. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Thanks. I'll fix up the changelog (some of the tenses are a little strange) and take this through my pagecache tree. > include/linux/pagemap.h | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h > index 993994cd943a..8dfe8e49c427 100644 > --- a/include/linux/pagemap.h > +++ b/include/linux/pagemap.h > @@ -908,9 +908,6 @@ static inline void folio_lock(struct folio *folio) > __folio_lock(folio); > } > > -/* > - * lock_page may only be called if we have the page's inode pinned. > - */ > static inline void lock_page(struct page *page) > { > struct folio *folio; > -- > 2.23.0 >
On 2022/4/4 23:32, Matthew Wilcox wrote: > On Sat, Apr 02, 2022 at 02:22:18PM +0800, Miaohe Lin wrote: >> lock_page needs the caller to have a reference on the page->mapping inode >> due to sync_page. Also lock_page_nosync is introduced which does not do a >> sync_page via commit db37648cd6ce ("[PATCH] mm: non syncing lock_page()"). >> But commit 7eaceaccab5f ("block: remove per-queue plugging") kills off the >> old plugging along with aops->sync_page() and lock_page_nosync. So there >> is no need to have a reference on the page->mapping inode when calling >> lock_page anymore. Remove this obsolete and confusing comment. >> >> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > > Thanks. I'll fix up the changelog (some of the tenses are a little > strange) and take this through my pagecache tree. Many thanks for doing this. :) > >> include/linux/pagemap.h | 3 --- >> 1 file changed, 3 deletions(-) >> >> diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h >> index 993994cd943a..8dfe8e49c427 100644 >> --- a/include/linux/pagemap.h >> +++ b/include/linux/pagemap.h >> @@ -908,9 +908,6 @@ static inline void folio_lock(struct folio *folio) >> __folio_lock(folio); >> } >> >> -/* >> - * lock_page may only be called if we have the page's inode pinned. >> - */ >> static inline void lock_page(struct page *page) >> { >> struct folio *folio; >> -- >> 2.23.0 >> > > . >
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 993994cd943a..8dfe8e49c427 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -908,9 +908,6 @@ static inline void folio_lock(struct folio *folio) __folio_lock(folio); } -/* - * lock_page may only be called if we have the page's inode pinned. - */ static inline void lock_page(struct page *page) { struct folio *folio;
lock_page needs the caller to have a reference on the page->mapping inode due to sync_page. Also lock_page_nosync is introduced which does not do a sync_page via commit db37648cd6ce ("[PATCH] mm: non syncing lock_page()"). But commit 7eaceaccab5f ("block: remove per-queue plugging") kills off the old plugging along with aops->sync_page() and lock_page_nosync. So there is no need to have a reference on the page->mapping inode when calling lock_page anymore. Remove this obsolete and confusing comment. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- include/linux/pagemap.h | 3 --- 1 file changed, 3 deletions(-)