Messages in this thread Patch in this message | | | Subject | [PATCH 07/33] netfs, mm: Add unlock_page_fscache() and wait_on_page_fscache() | From | David Howells <> | Date | Mon, 15 Feb 2021 15:45:35 +0000 |
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Add unlock_page_fscache() as an alias of unlock_page_private_2(). This allows a page 'locked' with PG_fscache to be unlocked.
Add wait_on_page_fscache() to wait for PG_fscache to be unlocked.
[Linus suggested putting the fscache-themed functions into the caching-specific headers rather than pagemap.h]
Signed-off-by: David Howells <dhowells@redhat.com> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: Matthew Wilcox <willy@infradead.org> cc: linux-mm@kvack.org cc: linux-cachefs@redhat.com cc: linux-afs@lists.infradead.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: v9fs-developer@lists.sourceforge.net cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/linux-fsdevel/1330473.1612974547@warthog.procyon.org.uk/ Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wjgA-74ddehziVk=XAEMTKswPu1Yw4uaro1R3ibs27ztw@mail.gmail.com/ ---
include/linux/netfs.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)
diff --git a/include/linux/netfs.h b/include/linux/netfs.h index b3d869ec7d2a..f69703543788 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -22,4 +22,33 @@ #define TestSetPageFsCache(page) TestSetPagePrivate2((page)) #define TestClearPageFsCache(page) TestClearPagePrivate2((page)) +/** + * unlock_page_fscache - Unlock a page that's locked with PG_fscache + * @page: The page + * + * Unlocks a page that's locked with PG_fscache and wakes up sleepers in + * wait_on_page_fscache(). This page bit is used by the netfs helpers when a + * netfs page is being written to a local disk cache, thereby allowing writes + * to the cache for the same page to be serialised. + */ +static inline void unlock_page_fscache(struct page *page) +{ + unlock_page_private_2(page); +} + +/** + * wait_on_page_fscache - Wait for PG_fscache to be cleared on a page + * @page: The page + * + * Wait for the PG_fscache (PG_private_2) page bit to be removed from a page. + * This is, for example, used to handle a netfs page being written to a local + * disk cache, thereby allowing writes to the cache for the same page to be + * serialised. + */ +static inline void wait_on_page_fscache(struct page *page) +{ + if (PageFsCache(page)) + wait_on_page_bit(compound_head(page), PG_fscache); +} + #endif /* _LINUX_NETFS_H */
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