mm: Remove the PG_fscache alias for PG_private_2

Remove the PG_fscache alias for PG_private_2 and use the latter directly.
Use of this flag for marking pages undergoing writing to the cache should
be considered deprecated and the folios should be marked dirty instead and
the write done in ->writepages().

Note that PG_private_2 itself should be considered deprecated and up for
future removal by the MM folks too.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: Bharath SM <bharathsm@microsoft.com>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Anna Schumaker <anna@kernel.org>
cc: netfs@lists.linux.dev
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org

8 files changed, 26 insertions, 25 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 28ae4976a4f9..18ddacb00511 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -500,7 +500,7 @@ const struct netfs_request_ops ceph_netfs_ops = {
 #ifdef CONFIG_CEPH_FSCACHE
 static void ceph_set_page_fscache(struct page *page)
 {
-	set_page_fscache(page);
+	folio_start_private_2(page_folio(page)); /* [DEPRECATED] */
 }
 
 static void ceph_fscache_write_terminated(void *priv, ssize_t error, bool was_async)
@@ -800,7 +800,7 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 		return AOP_WRITEPAGE_ACTIVATE;
 	}
 
-	wait_on_page_fscache(page);
+	folio_wait_private_2(page_folio(page)); /* [DEPRECATED] */
 
 	err = writepage_nounlock(page, wbc);
 	if (err == -ERESTARTSYS) {
@@ -1075,7 +1075,8 @@ get_more_pages:
 				unlock_page(page);
 				break;
 			}
-			if (PageWriteback(page) || PageFsCache(page)) {
+			if (PageWriteback(page) ||
+			    PagePrivate2(page) /* [DEPRECATED] */) {
 				if (wbc->sync_mode == WB_SYNC_NONE) {
 					doutc(cl, "%p under writeback\n", page);
 					unlock_page(page);
@@ -1083,7 +1084,7 @@ get_more_pages:
 				}
 				doutc(cl, "waiting on writeback %p\n", page);
 				wait_on_page_writeback(page);
-				wait_on_page_fscache(page);
+				folio_wait_private_2(page_folio(page)); /* [DEPRECATED] */
 			}
 
 			if (!clear_page_dirty_for_io(page)) {
@@ -1513,7 +1514,7 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
 	if (r < 0)
 		return r;
 
-	folio_wait_fscache(folio);
+	folio_wait_private_2(folio); /* [DEPRECATED] */
 	WARN_ON_ONCE(!folio_test_locked(folio));
 	*pagep = &folio->page;
 	return 0;
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 6d49319c82c6..b3fd6e1fa322 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -70,7 +70,7 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
 				if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE,
 							       &subreq->flags)) {
 					trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
-					folio_start_fscache(folio);
+					folio_start_private_2(folio);
 					folio_started = true;
 				}
 			} else {
@@ -506,7 +506,7 @@ retry:
 
 have_folio:
 	if (test_bit(NETFS_ICTX_USE_PGPRIV2, &ctx->flags)) {
-		ret = folio_wait_fscache_killable(folio);
+		ret = folio_wait_private_2_killable(folio);
 		if (ret < 0)
 			goto error;
 	}
diff --git a/fs/netfs/fscache_io.c b/fs/netfs/fscache_io.c
index 5028f2ae30da..38637e5c9b57 100644
--- a/fs/netfs/fscache_io.c
+++ b/fs/netfs/fscache_io.c
@@ -183,7 +183,7 @@ void __fscache_clear_page_bits(struct address_space *mapping,
 
 		rcu_read_lock();
 		xas_for_each(&xas, page, last) {
-			end_page_fscache(page);
+			folio_end_private_2(page_folio(page));
 		}
 		rcu_read_unlock();
 	}
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index b3b9827a9709..60a19f96e0ce 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -129,7 +129,7 @@ static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
 				continue;
 			unlocked = folio_next_index(folio) - 1;
 			trace_netfs_folio(folio, netfs_folio_trace_end_copy);
-			folio_end_fscache(folio);
+			folio_end_private_2(folio);
 			have_unlocked = true;
 		}
 	}
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 407c6e15afe2..6bd127e6683d 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -433,7 +433,7 @@ static void nfs_invalidate_folio(struct folio *folio, size_t offset,
 		return;
 	/* Cancel any unstarted writes on this page */
 	nfs_wb_folio_cancel(inode, folio);
-	folio_wait_fscache(folio);
+	folio_wait_private_2(folio); /* [DEPRECATED] */
 	trace_nfs_invalidate_folio(inode, folio);
 }
 
@@ -500,7 +500,7 @@ static int nfs_launder_folio(struct folio *folio)
 	dfprintk(PAGECACHE, "NFS: launder_folio(%ld, %llu)\n",
 		inode->i_ino, folio_pos(folio));
 
-	folio_wait_fscache(folio);
+	folio_wait_private_2(folio); /* [DEPRECATED] */
 	ret = nfs_wb_folio(inode, folio);
 	trace_nfs_launder_folio_done(inode, folio, ret);
 	return ret;
@@ -593,8 +593,8 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
 	sb_start_pagefault(inode->i_sb);
 
 	/* make sure the cache has finished storing the page */
-	if (folio_test_fscache(folio) &&
-	    folio_wait_fscache_killable(folio) < 0) {
+	if (folio_test_private_2(folio) && /* [DEPRECATED] */
+	    folio_wait_private_2_killable(folio) < 0) {
 		ret = VM_FAULT_RETRY;
 		goto out;
 	}
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 814363d1d7c7..fbed0027996f 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -103,10 +103,10 @@ extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);
 
 static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
 {
-	if (folio_test_fscache(folio)) {
+	if (folio_test_private_2(folio)) { /* [DEPRECATED] */
 		if (current_is_kswapd() || !(gfp & __GFP_FS))
 			return false;
-		folio_wait_fscache(folio);
+		folio_wait_private_2(folio);
 	}
 	fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host)));
 	return true;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 5de85d725fb9..2329cbb0e446 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -2120,10 +2120,10 @@ int nfs_migrate_folio(struct address_space *mapping, struct folio *dst,
 	if (folio_test_private(src))
 		return -EBUSY;
 
-	if (folio_test_fscache(src)) {
+	if (folio_test_private_2(src)) { /* [DEPRECATED] */
 		if (mode == MIGRATE_ASYNC)
 			return -EBUSY;
-		folio_wait_fscache(src);
+		folio_wait_private_2(src);
 	}
 
 	return migrate_folio(mapping, dst, src, mode);
diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index 9be37d0fe724..b39caae652f6 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -3032,12 +3032,12 @@ lock_again:
 	}
 
 	if (folio_test_writeback(folio) ||
-	    folio_test_fscache(folio)) {
+	    folio_test_private_2(folio)) { /* [DEPRECATED] */
 		folio_unlock(folio);
 		if (wbc->sync_mode != WB_SYNC_NONE) {
 			folio_wait_writeback(folio);
 #ifdef CONFIG_CIFS_FSCACHE
-			folio_wait_fscache(folio);
+			folio_wait_private_2(folio);
 #endif
 			goto lock_again;
 		}
@@ -4510,8 +4510,8 @@ static vm_fault_t cifs_page_mkwrite(struct vm_fault *vmf)
 	 * be modified.  We then assume the entire folio will need writing back.
 	 */
 #ifdef CONFIG_CIFS_FSCACHE
-	if (folio_test_fscache(folio) &&
-	    folio_wait_fscache_killable(folio) < 0)
+	if (folio_test_private_2(folio) && /* [DEPRECATED] */
+	    folio_wait_private_2_killable(folio) < 0)
 		return VM_FAULT_RETRY;
 #endif
 
@@ -4977,10 +4977,10 @@ static bool cifs_release_folio(struct folio *folio, gfp_t gfp)
 {
 	if (folio_test_private(folio))
 		return 0;
-	if (folio_test_fscache(folio)) {
+	if (folio_test_private_2(folio)) { /* [DEPRECATED] */
 		if (current_is_kswapd() || !(gfp & __GFP_FS))
 			return false;
-		folio_wait_fscache(folio);
+		folio_wait_private_2(folio);
 	}
 	fscache_note_page_release(cifs_inode_cookie(folio->mapping->host));
 	return true;
@@ -4989,7 +4989,7 @@ static bool cifs_release_folio(struct folio *folio, gfp_t gfp)
 static void cifs_invalidate_folio(struct folio *folio, size_t offset,
 				 size_t length)
 {
-	folio_wait_fscache(folio);
+	folio_wait_private_2(folio); /* [DEPRECATED] */
 }
 
 static int cifs_launder_folio(struct folio *folio)
@@ -5009,7 +5009,7 @@ static int cifs_launder_folio(struct folio *folio)
 	if (folio_clear_dirty_for_io(folio))
 		rc = cifs_writepage_locked(&folio->page, &wbc);
 
-	folio_wait_fscache(folio);
+	folio_wait_private_2(folio); /* [DEPRECATED] */
 	return rc;
 }