| Message ID | 162981151155.1901565.7010079316994382707.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | netfs, afs, ceph: Support folios, at least partially | expand |
On Tue, Aug 24, 2021 at 02:25:11PM +0100, David Howells wrote: > + * For folios which are in the page cache, return the inode that is hosting > + * this folio belongs to. > + * > + * Do not call this for folios which aren't in the page cache. > + */ > +static inline struct inode *folio_inode(struct folio *folio) > +{ > + return folio_file_mapping(folio)->host; You're contradicting yourself here. If you're allowed to call this function for swap cache pages, then the documentation needs to change. If you're not, then we can just use folio->mapping->host.
Matthew Wilcox <willy@infradead.org> wrote: > > +static inline struct inode *folio_inode(struct folio *folio) > > +{ > > + return folio_file_mapping(folio)->host; > > You're contradicting yourself here. If you're allowed to call this > function for swap cache pages, then the documentation needs to change. > If you're not, then we can just use folio->mapping->host. Um. I don't know. I'll do the latter, then, for now. David
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index c8d336e62177..115b4f831e7d 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -203,6 +203,20 @@ static inline struct address_space *page_mapping_file(struct page *page) return folio_mapping(folio); } +/** + * folio_inode - Get the host inode for this folio. + * @folio: The folio. + * + * For folios which are in the page cache, return the inode that is hosting + * this folio belongs to. + * + * Do not call this for folios which aren't in the page cache. + */ +static inline struct inode *folio_inode(struct folio *folio) +{ + return folio_file_mapping(folio)->host; +} + static inline bool page_cache_add_speculative(struct page *page, int count) { VM_BUG_ON_PAGE(PageTail(page), page); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 86b90173baf8..f750946d11f7 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2918,7 +2918,7 @@ EXPORT_SYMBOL_GPL(folio_wait_writeback_killable); */ void folio_wait_stable(struct folio *folio) { - if (folio->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES) + if (folio_inode(folio)->i_sb->s_iflags & SB_I_STABLE_WRITES) folio_wait_writeback(folio); } EXPORT_SYMBOL_GPL(folio_wait_stable);
Add a convenience function, folio_inode() that will get the host inode from a folio's mapping. Signed-off-by: David Howells <dhowells@redhat.com> --- include/linux/pagemap.h | 14 ++++++++++++++ mm/page-writeback.c | 2 +- 2 files changed, 15 insertions(+), 1 deletion(-)