On Tue, 21 Sep 2021 14:26:28 +1000 Stephen Rothwell [off-list ref] wrote:

quoted

After merging the folio tree, today's linux-next build (x86_64
allmodconfig) failed like this:

fs/9p/vfs_file.c: In function 'v9fs_vm_page_mkwrite':
fs/9p/vfs_file.c:557:6: error: implicit declaration of function 'wait_on_page_bit_killable'; did you mean 'wait_on_page_locked_killable'? [-Werror=implicit-function-declaration]
  557 |      wait_on_page_bit_killable(page, PG_writeback) < 0)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~
      |      wait_on_page_locked_killable

Caused by commit

  be8f72914261 ("mm/filemap: Add folio_wait_bit()")

interacting with commit

  82766b47b26c ("9p: (untested) Convert to using the netfs helper lib to do reads and caching")

from the fscache tree.

I have applied the following merge fix patch.

From: Stephen Rothwell <redacted>
Date: Tue, 21 Sep 2021 14:18:06 +1000
Subject: [PATCH] fix up for "9p: (untested) Convert to using the netfs helper
 lib to do reads and caching"

Signed-off-by: Stephen Rothwell <redacted>
---
 fs/9p/vfs_file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 4b617d10cf28..68d05b2aa290 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c

@@ -554,7 +554,7 @@ v9fs_vm_page_mkwrite(struct vm_fault *vmf)
 #endif
 
 	if (PageWriteback(page) &&
-	    wait_on_page_bit_killable(page, PG_writeback) < 0)
+	    folio_wait_bit_killable(page_folio(page), PG_writeback) < 0)
 		return VM_FAULT_RETRY;
 
 	/* Update file times before taking page lock */  

This fix patch now looks like this:

From: Stephen Rothwell <redacted>
Date: Wed, 22 Sep 2021 14:16:55 +1000
Subject: [PATCH] fix up for "9p: Convert to using the netfs helper lib to do reads and caching"

Signed-off-by: Stephen Rothwell <redacted>
---
 fs/9p/vfs_file.c | 4 ++--
 1 file changed, 2 insertion(+), 2 deletion(-)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 7ed76a4c18f1..0f99ec49006e 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c

@@ -549,12 +549,12 @@ v9fs_vm_page_mkwrite(struct vm_fault *vmf)
 	 */
 #ifdef CONFIG_9P_FSCACHE
 	if (PageFsCache(page) &&
-	    wait_on_page_bit_killable(page, PG_fscache) < 0)
+	    folio_wait_bit_killable(page_folio(page), PG_fscache) < 0)
 		return VM_FAULT_RETRY;
 #endif
 
 	if (PageWriteback(page) &&
-	    wait_on_page_bit_killable(page, PG_writeback) < 0)
+	    folio_wait_bit_killable(page_folio(page), PG_writeback) < 0)
 		return VM_FAULT_RETRY;
 
 	/* Update file times before taking page lock */