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authorMatthew Wilcox (Oracle) <willy@infradead.org>2021-03-04 11:25:25 -0500
committerMatthew Wilcox (Oracle) <willy@infradead.org>2021-09-27 09:27:30 -0400
commita49d0c507759214a7cfd26555382c314db486792 (patch)
treef4f571565c695d3bd8d10f623f0224ad5c54a7a1
parent490e016f229a79dc7551e7f0e989d2304416c189 (diff)
mm/writeback: Add folio_wait_stable()
Move wait_for_stable_page() into the folio compatibility file. folio_wait_stable() avoids a call to compound_head() and is 14 bytes smaller than wait_for_stable_page() was. The net text size grows by 16 bytes as a result of this patch. We can also remove thp_head() as this was the last user. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: David Howells <dhowells@redhat.com>
-rw-r--r--include/linux/huge_mm.h15
-rw-r--r--include/linux/pagemap.h1
-rw-r--r--mm/folio-compat.c6
-rw-r--r--mm/page-writeback.c24
4 files changed, 21 insertions, 25 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index f123e15d966e..f280f33ff223 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -251,15 +251,6 @@ static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
}
/**
- * thp_head - Head page of a transparent huge page.
- * @page: Any page (tail, head or regular) found in the page cache.
- */
-static inline struct page *thp_head(struct page *page)
-{
- return compound_head(page);
-}
-
-/**
* thp_order - Order of a transparent huge page.
* @page: Head page of a transparent huge page.
*/
@@ -336,12 +327,6 @@ static inline struct list_head *page_deferred_list(struct page *page)
#define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
#define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
-static inline struct page *thp_head(struct page *page)
-{
- VM_BUG_ON_PGFLAGS(PageTail(page), page);
- return page;
-}
-
static inline unsigned int thp_order(struct page *page)
{
VM_BUG_ON_PGFLAGS(PageTail(page), page);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index e6013c063986..ee39ad7b42f1 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -771,6 +771,7 @@ int folio_wait_writeback_killable(struct folio *folio);
void end_page_writeback(struct page *page);
void folio_end_writeback(struct folio *folio);
void wait_for_stable_page(struct page *page);
+void folio_wait_stable(struct folio *folio);
void __set_page_dirty(struct page *, struct address_space *, int warn);
int __set_page_dirty_nobuffers(struct page *page);
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 41275dac7a92..3c83f03b80d7 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -29,3 +29,9 @@ void wait_on_page_writeback(struct page *page)
return folio_wait_writeback(page_folio(page));
}
EXPORT_SYMBOL_GPL(wait_on_page_writeback);
+
+void wait_for_stable_page(struct page *page)
+{
+ return folio_wait_stable(page_folio(page));
+}
+EXPORT_SYMBOL_GPL(wait_for_stable_page);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index c7f40c954217..0b0b7cd81a93 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2920,17 +2920,21 @@ int folio_wait_writeback_killable(struct folio *folio)
EXPORT_SYMBOL_GPL(folio_wait_writeback_killable);
/**
- * wait_for_stable_page() - wait for writeback to finish, if necessary.
- * @page: The page to wait on.
+ * folio_wait_stable() - wait for writeback to finish, if necessary.
+ * @folio: The folio to wait on.
*
- * This function determines if the given page is related to a backing device
- * that requires page contents to be held stable during writeback. If so, then
- * it will wait for any pending writeback to complete.
+ * This function determines if the given folio is related to a backing
+ * device that requires folio contents to be held stable during writeback.
+ * If so, then it will wait for any pending writeback 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_for_stable_page(struct page *page)
+void folio_wait_stable(struct folio *folio)
{
- page = thp_head(page);
- if (page->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES)
- wait_on_page_writeback(page);
+ if (folio->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES)
+ folio_wait_writeback(folio);
}
-EXPORT_SYMBOL_GPL(wait_for_stable_page);
+EXPORT_SYMBOL_GPL(folio_wait_stable);