remove the implicit .set_page_dirty default

remove the implicit .set_page_dirty default

[Christoph Hellwig]

Hi all,

this series cleans up a few lose ends around ->set_page_dirty, most
importantly removes the default to the buffer head based on if no
method is wired up.

[PATCH 1/3] fs: unexport __set_page_dirty

[Christoph Hellwig]

__set_page_dirty is only used by built-in code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/buffer.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index ea48c01fb76b..3d18831c7ad8 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -611,7 +611,6 @@ void __set_page_dirty(struct page *page, struct address_space *mapping,
 	}
 	xa_unlock_irqrestore(&mapping->i_pages, flags);
 }
-EXPORT_SYMBOL_GPL(__set_page_dirty);
 
 /*
  * Add a page to the dirty page list.
-- 
2.30.2

[PATCH 2/3] fs: move ramfs_aops to libfs

[Christoph Hellwig]

Move the ramfs aops to libfs and reuse them for kernfs and configfs.
Thosw two did not wire up ->set_page_dirty before and now get
__set_page_dirty_no_writeback, which is the right one for no-writeback
address_space usage.

Drop the now unused exports of the libfs helpers only used for
ramfs-style pagecache usage.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/configfs/inode.c |  8 +-------
 fs/kernfs/inode.c   |  8 +-------
 fs/libfs.c          | 17 +++++++++++++----
 fs/ramfs/inode.c    |  9 +--------
 include/linux/fs.h  |  5 +----
 5 files changed, 17 insertions(+), 30 deletions(-)

diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index eb5ec3e46283..b601610e9907 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -28,12 +28,6 @@
 static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
 #endif
 
-static const struct address_space_operations configfs_aops = {
-	.readpage	= simple_readpage,
-	.write_begin	= simple_write_begin,
-	.write_end	= simple_write_end,
-};
-
 static const struct inode_operations configfs_inode_operations ={
 	.setattr	= configfs_setattr,
 };
@@ -114,7 +108,7 @@ struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
 	struct inode * inode = new_inode(s);
 	if (inode) {
 		inode->i_ino = get_next_ino();
-		inode->i_mapping->a_ops = &configfs_aops;
+		inode->i_mapping->a_ops = &ram_aops;
 		inode->i_op = &configfs_inode_operations;
 
 		if (sd->s_iattr) {
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index d73950fc3d57..26f2aa3586f9 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -17,12 +17,6 @@
 
 #include "kernfs-internal.h"
 
-static const struct address_space_operations kernfs_aops = {
-	.readpage	= simple_readpage,
-	.write_begin	= simple_write_begin,
-	.write_end	= simple_write_end,
-};
-
 static const struct inode_operations kernfs_iops = {
 	.permission	= kernfs_iop_permission,
 	.setattr	= kernfs_iop_setattr,
@@ -203,7 +197,7 @@ static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode)
 {
 	kernfs_get(kn);
 	inode->i_private = kn;
-	inode->i_mapping->a_ops = &kernfs_aops;
+	inode->i_mapping->a_ops = &ram_aops;
 	inode->i_op = &kernfs_iops;
 	inode->i_generation = kernfs_gen(kn);
 
diff --git a/fs/libfs.c b/fs/libfs.c
index e9b29c6ffccb..2d7f086b93d6 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -512,7 +512,7 @@ int simple_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 }
 EXPORT_SYMBOL(simple_setattr);
 
-int simple_readpage(struct file *file, struct page *page)
+static int simple_readpage(struct file *file, struct page *page)
 {
 	clear_highpage(page);
 	flush_dcache_page(page);
@@ -520,7 +520,6 @@ int simple_readpage(struct file *file, struct page *page)
 	unlock_page(page);
 	return 0;
 }
-EXPORT_SYMBOL(simple_readpage);
 
 int simple_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
@@ -568,7 +567,7 @@ EXPORT_SYMBOL(simple_write_begin);
  *
  * Use *ONLY* with simple_readpage()
  */
-int simple_write_end(struct file *file, struct address_space *mapping,
+static int simple_write_end(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned copied,
 			struct page *page, void *fsdata)
 {
@@ -597,7 +596,17 @@ int simple_write_end(struct file *file, struct address_space *mapping,
 
 	return copied;
 }
-EXPORT_SYMBOL(simple_write_end);
+
+/*
+ * Provides ramfs-style behavior: data in the pagecache, but no writeback.
+ */
+const struct address_space_operations ram_aops = {
+	.readpage	= simple_readpage,
+	.write_begin	= simple_write_begin,
+	.write_end	= simple_write_end,
+	.set_page_dirty	= __set_page_dirty_no_writeback,
+};
+EXPORT_SYMBOL(ram_aops);
 
 /*
  * the inodes created here are not hashed. If you use iunique to generate
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 9ebd17d7befb..65e7e56005b8 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -53,13 +53,6 @@ struct ramfs_fs_info {
 static const struct super_operations ramfs_ops;
 static const struct inode_operations ramfs_dir_inode_operations;
 
-static const struct address_space_operations ramfs_aops = {
-	.readpage	= simple_readpage,
-	.write_begin	= simple_write_begin,
-	.write_end	= simple_write_end,
-	.set_page_dirty	= __set_page_dirty_no_writeback,
-};
-
 struct inode *ramfs_get_inode(struct super_block *sb,
 				const struct inode *dir, umode_t mode, dev_t dev)
 {
@@ -68,7 +61,7 @@ struct inode *ramfs_get_inode(struct super_block *sb,
 	if (inode) {
 		inode->i_ino = get_next_ino();
 		inode_init_owner(&init_user_ns, inode, dir, mode);
-		inode->i_mapping->a_ops = &ramfs_aops;
+		inode->i_mapping->a_ops = &ram_aops;
 		mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
 		mapping_set_unevictable(inode->i_mapping);
 		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c3c88fdb9b2a..869909345420 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3422,13 +3422,10 @@ extern void noop_invalidatepage(struct page *page, unsigned int offset,
 		unsigned int length);
 extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
 extern int simple_empty(struct dentry *);
-extern int simple_readpage(struct file *file, struct page *page);
 extern int simple_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata);
-extern int simple_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata);
+extern const struct address_space_operations ram_aops;
 extern int always_delete_dentry(const struct dentry *);
 extern struct inode *alloc_anon_inode(struct super_block *);
 extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
-- 
2.30.2

[PATCH 3/3] mm: require ->set_page_dirty to be explicitly wire up

[Christoph Hellwig]

Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just
wire that method up for the missing instances.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/adfs/inode.c     |  1 +
 fs/affs/file.c      |  2 ++
 fs/bfs/file.c       |  1 +
 fs/block_dev.c      |  1 +
 fs/exfat/inode.c    |  1 +
 fs/ext2/inode.c     |  2 ++
 fs/fat/inode.c      |  1 +
 fs/gfs2/meta_io.c   |  2 ++
 fs/hfs/inode.c      |  2 ++
 fs/hfsplus/inode.c  |  2 ++
 fs/hpfs/file.c      |  1 +
 fs/jfs/inode.c      |  1 +
 fs/minix/inode.c    |  1 +
 fs/nilfs2/mdt.c     |  1 +
 fs/ocfs2/aops.c     |  1 +
 fs/omfs/file.c      |  1 +
 fs/sysv/itree.c     |  1 +
 fs/udf/file.c       |  1 +
 fs/udf/inode.c      |  1 +
 fs/ufs/inode.c      |  1 +
 mm/page-writeback.c | 18 ++++--------------
 21 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
index fb7ee026d101..adbb3a1edcbf 100644
--- a/fs/adfs/inode.c
+++ b/fs/adfs/inode.c
@@ -73,6 +73,7 @@ static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
 }
 
 static const struct address_space_operations adfs_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= adfs_readpage,
 	.writepage	= adfs_writepage,
 	.write_begin	= adfs_write_begin,
diff --git a/fs/affs/file.c b/fs/affs/file.c
index d91b0133d95d..75ebd2b576ca 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -453,6 +453,7 @@ static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
 }
 
 const struct address_space_operations affs_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage = affs_readpage,
 	.writepage = affs_writepage,
 	.write_begin = affs_write_begin,
@@ -833,6 +834,7 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
 }
 
 const struct address_space_operations affs_aops_ofs = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage = affs_readpage_ofs,
 	//.writepage = affs_writepage_ofs,
 	.write_begin = affs_write_begin_ofs,
diff --git a/fs/bfs/file.c b/fs/bfs/file.c
index 0dceefc54b48..7f8544abf636 100644
--- a/fs/bfs/file.c
+++ b/fs/bfs/file.c
@@ -188,6 +188,7 @@ static sector_t bfs_bmap(struct address_space *mapping, sector_t block)
 }
 
 const struct address_space_operations bfs_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= bfs_readpage,
 	.writepage	= bfs_writepage,
 	.write_begin	= bfs_write_begin,
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 6cc4d4cfe0c2..eb34f5c357cf 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1754,6 +1754,7 @@ static int blkdev_writepages(struct address_space *mapping,
 }
 
 static const struct address_space_operations def_blk_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= blkdev_readpage,
 	.readahead	= blkdev_readahead,
 	.writepage	= blkdev_writepage,
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 1803ef3220fd..ca37d4344361 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -491,6 +491,7 @@ int exfat_block_truncate_page(struct inode *inode, loff_t from)
 }
 
 static const struct address_space_operations exfat_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= exfat_readpage,
 	.readahead	= exfat_readahead,
 	.writepage	= exfat_writepage,
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 68178b2234bd..bf41f579ed3e 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -961,6 +961,7 @@ ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc
 }
 
 const struct address_space_operations ext2_aops = {
+	.set_page_dirty		= __set_page_dirty_buffers,
 	.readpage		= ext2_readpage,
 	.readahead		= ext2_readahead,
 	.writepage		= ext2_writepage,
@@ -975,6 +976,7 @@ const struct address_space_operations ext2_aops = {
 };
 
 const struct address_space_operations ext2_nobh_aops = {
+	.set_page_dirty		= __set_page_dirty_buffers,
 	.readpage		= ext2_readpage,
 	.readahead		= ext2_readahead,
 	.writepage		= ext2_nobh_writepage,
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index bab9b202b496..de0c9b013a85 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -342,6 +342,7 @@ int fat_block_truncate_page(struct inode *inode, loff_t from)
 }
 
 static const struct address_space_operations fat_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= fat_readpage,
 	.readahead	= fat_readahead,
 	.writepage	= fat_writepage,
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index d68184ebbfdd..7c9619997355 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -89,11 +89,13 @@ static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wb
 }
 
 const struct address_space_operations gfs2_meta_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.writepage = gfs2_aspace_writepage,
 	.releasepage = gfs2_releasepage,
 };
 
 const struct address_space_operations gfs2_rgrp_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.writepage = gfs2_aspace_writepage,
 	.releasepage = gfs2_releasepage,
 };
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 3fc5cb346586..4a95a92546a0 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -159,6 +159,7 @@ static int hfs_writepages(struct address_space *mapping,
 }
 
 const struct address_space_operations hfs_btree_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= hfs_readpage,
 	.writepage	= hfs_writepage,
 	.write_begin	= hfs_write_begin,
@@ -168,6 +169,7 @@ const struct address_space_operations hfs_btree_aops = {
 };
 
 const struct address_space_operations hfs_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= hfs_readpage,
 	.writepage	= hfs_writepage,
 	.write_begin	= hfs_write_begin,
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 8ea447e5c470..70e8374ddac4 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -156,6 +156,7 @@ static int hfsplus_writepages(struct address_space *mapping,
 }
 
 const struct address_space_operations hfsplus_btree_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= hfsplus_readpage,
 	.writepage	= hfsplus_writepage,
 	.write_begin	= hfsplus_write_begin,
@@ -165,6 +166,7 @@ const struct address_space_operations hfsplus_btree_aops = {
 };
 
 const struct address_space_operations hfsplus_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= hfsplus_readpage,
 	.writepage	= hfsplus_writepage,
 	.write_begin	= hfsplus_write_begin,
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 077c25128eb7..c3a49aacf20a 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -196,6 +196,7 @@ static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 }
 
 const struct address_space_operations hpfs_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage = hpfs_readpage,
 	.writepage = hpfs_writepage,
 	.readahead = hpfs_readahead,
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index 6f65bfa9f18d..3663dd5a23bc 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -356,6 +356,7 @@ static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 }
 
 const struct address_space_operations jfs_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= jfs_readpage,
 	.readahead	= jfs_readahead,
 	.writepage	= jfs_writepage,
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index a532a99bbe81..a71f1cf894b9 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -442,6 +442,7 @@ static sector_t minix_bmap(struct address_space *mapping, sector_t block)
 }
 
 static const struct address_space_operations minix_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage = minix_readpage,
 	.writepage = minix_writepage,
 	.write_begin = minix_write_begin,
diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index c0361ce45f62..97769fe4d588 100644
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -434,6 +434,7 @@ nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
 
 
 static const struct address_space_operations def_mdt_aops = {
+	.set_page_dirty		= __set_page_dirty_buffers,
 	.writepage		= nilfs_mdt_write_page,
 };
 
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 1294925ac94a..b3517de178ff 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2454,6 +2454,7 @@ static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 }
 
 const struct address_space_operations ocfs2_aops = {
+	.set_page_dirty		= __set_page_dirty_buffers,
 	.readpage		= ocfs2_readpage,
 	.readahead		= ocfs2_readahead,
 	.writepage		= ocfs2_writepage,
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
index 11e733aab25d..89725b15a64b 100644
--- a/fs/omfs/file.c
+++ b/fs/omfs/file.c
@@ -372,6 +372,7 @@ const struct inode_operations omfs_file_inops = {
 };
 
 const struct address_space_operations omfs_aops = {
+	.set_page_dirty = __set_page_dirty_buffers,
 	.readpage = omfs_readpage,
 	.readahead = omfs_readahead,
 	.writepage = omfs_writepage,
diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
index 8b2e99b7bc9f..749385015a8d 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -495,6 +495,7 @@ static sector_t sysv_bmap(struct address_space *mapping, sector_t block)
 }
 
 const struct address_space_operations sysv_aops = {
+	.set_page_dirty = __set_page_dirty_buffers,
 	.readpage = sysv_readpage,
 	.writepage = sysv_writepage,
 	.write_begin = sysv_write_begin,
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 2846dcd92197..1baff8ddb754 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -125,6 +125,7 @@ static int udf_adinicb_write_end(struct file *file, struct address_space *mappin
 }
 
 const struct address_space_operations udf_adinicb_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= udf_adinicb_readpage,
 	.writepage	= udf_adinicb_writepage,
 	.write_begin	= udf_adinicb_write_begin,
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 0dd2f93ac048..4917670860a0 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -235,6 +235,7 @@ static sector_t udf_bmap(struct address_space *mapping, sector_t block)
 }
 
 const struct address_space_operations udf_aops = {
+	.set_page_dirty	= __set_page_dirty_buffers,
 	.readpage	= udf_readpage,
 	.readahead	= udf_readahead,
 	.writepage	= udf_writepage,
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index debc282c1bb4..ac628de69601 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -526,6 +526,7 @@ static sector_t ufs_bmap(struct address_space *mapping, sector_t block)
 }
 
 const struct address_space_operations ufs_aops = {
+	.set_page_dirty = __set_page_dirty_buffers,
 	.readpage = ufs_readpage,
 	.writepage = ufs_writepage,
 	.write_begin = ufs_write_begin,
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0062d5c57d41..081fa02236c2 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -32,7 +32,6 @@
 #include <linux/sysctl.h>
 #include <linux/cpu.h>
 #include <linux/syscalls.h>
-#include <linux/buffer_head.h> /* __set_page_dirty_buffers */
 #include <linux/pagevec.h>
 #include <linux/timer.h>
 #include <linux/sched/rt.h>
@@ -2546,13 +2545,9 @@ EXPORT_SYMBOL(redirty_page_for_writepage);
 /*
  * Dirty a page.
  *
- * For pages with a mapping this should be done under the page lock
- * for the benefit of asynchronous memory errors who prefer a consistent
- * dirty state. This rule can be broken in some special cases,
- * but should be better not to.
- *
- * If the mapping doesn't provide a set_page_dirty a_op, then
- * just fall through and assume that it wants buffer_heads.
+ * For pages with a mapping this should be done under the page lock for the
+ * benefit of asynchronous memory errors who prefer a consistent dirty state.
+ * This rule can be broken in some special cases, but should be better not to.
  */
 int set_page_dirty(struct page *page)
 {
@@ -2560,7 +2555,6 @@ int set_page_dirty(struct page *page)
 
 	page = compound_head(page);
 	if (likely(mapping)) {
-		int (*spd)(struct page *) = mapping->a_ops->set_page_dirty;
 		/*
 		 * readahead/lru_deactivate_page could remain
 		 * PG_readahead/PG_reclaim due to race with end_page_writeback
@@ -2573,11 +2567,7 @@ int set_page_dirty(struct page *page)
 		 */
 		if (PageReclaim(page))
 			ClearPageReclaim(page);
-#ifdef CONFIG_BLOCK
-		if (!spd)
-			spd = __set_page_dirty_buffers;
-#endif
-		return (*spd)(page);
+		return mapping->a_ops->set_page_dirty(page);
 	}
 	if (!PageDirty(page)) {
 		if (!TestSetPageDirty(page))
-- 
2.30.2

Re: [PATCH 1/3] fs: unexport __set_page_dirty

[Greg Kroah-Hartman]

On Mon, Jun 14, 2021 at 08:15:10AM +0200, Christoph Hellwig wrote:
> __set_page_dirty is only used by built-in code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/buffer.c | 1 -
>  1 file changed, 1 deletion(-)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH 2/3] fs: move ramfs_aops to libfs

[Greg Kroah-Hartman]

On Mon, Jun 14, 2021 at 08:15:11AM +0200, Christoph Hellwig wrote:
> Move the ramfs aops to libfs and reuse them for kernfs and configfs.
> Thosw two did not wire up ->set_page_dirty before and now get
> __set_page_dirty_no_writeback, which is the right one for no-writeback
> address_space usage.
> 
> Drop the now unused exports of the libfs helpers only used for
> ramfs-style pagecache usage.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/configfs/inode.c |  8 +-------
>  fs/kernfs/inode.c   |  8 +-------
>  fs/libfs.c          | 17 +++++++++++++----
>  fs/ramfs/inode.c    |  9 +--------
>  include/linux/fs.h  |  5 +----
>  5 files changed, 17 insertions(+), 30 deletions(-)
> 


Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH 3/3] mm: require ->set_page_dirty to be explicitly wire up

[Greg Kroah-Hartman]

On Mon, Jun 14, 2021 at 08:15:12AM +0200, Christoph Hellwig wrote:
> Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just
> wire that method up for the missing instances.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/adfs/inode.c     |  1 +
>  fs/affs/file.c      |  2 ++
>  fs/bfs/file.c       |  1 +
>  fs/block_dev.c      |  1 +
>  fs/exfat/inode.c    |  1 +
>  fs/ext2/inode.c     |  2 ++
>  fs/fat/inode.c      |  1 +
>  fs/gfs2/meta_io.c   |  2 ++
>  fs/hfs/inode.c      |  2 ++
>  fs/hfsplus/inode.c  |  2 ++
>  fs/hpfs/file.c      |  1 +
>  fs/jfs/inode.c      |  1 +
>  fs/minix/inode.c    |  1 +
>  fs/nilfs2/mdt.c     |  1 +
>  fs/ocfs2/aops.c     |  1 +
>  fs/omfs/file.c      |  1 +
>  fs/sysv/itree.c     |  1 +
>  fs/udf/file.c       |  1 +
>  fs/udf/inode.c      |  1 +
>  fs/ufs/inode.c      |  1 +
>  mm/page-writeback.c | 18 ++++--------------
>  21 files changed, 29 insertions(+), 14 deletions(-)
> 


Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH 1/3] fs: unexport __set_page_dirty

[Jan Kara]

On Mon 14-06-21 08:15:10, Christoph Hellwig wrote:
> __set_page_dirty is only used by built-in code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/buffer.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index ea48c01fb76b..3d18831c7ad8 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -611,7 +611,6 @@ void __set_page_dirty(struct page *page, struct address_space *mapping,
>  	}
>  	xa_unlock_irqrestore(&mapping->i_pages, flags);
>  }
> -EXPORT_SYMBOL_GPL(__set_page_dirty);
>  
>  /*
>   * Add a page to the dirty page list.
> -- 
> 2.30.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 2/3] fs: move ramfs_aops to libfs

[Jan Kara]

On Mon 14-06-21 08:15:11, Christoph Hellwig wrote:
> Move the ramfs aops to libfs and reuse them for kernfs and configfs.
> Thosw two did not wire up ->set_page_dirty before and now get
> __set_page_dirty_no_writeback, which is the right one for no-writeback
> address_space usage.
> 
> Drop the now unused exports of the libfs helpers only used for
> ramfs-style pagecache usage.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/configfs/inode.c |  8 +-------
>  fs/kernfs/inode.c   |  8 +-------
>  fs/libfs.c          | 17 +++++++++++++----
>  fs/ramfs/inode.c    |  9 +--------
>  include/linux/fs.h  |  5 +----
>  5 files changed, 17 insertions(+), 30 deletions(-)
> 
> diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
> index eb5ec3e46283..b601610e9907 100644
> --- a/fs/configfs/inode.c
> +++ b/fs/configfs/inode.c
> @@ -28,12 +28,6 @@
>  static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
>  #endif
>  
> -static const struct address_space_operations configfs_aops = {
> -	.readpage	= simple_readpage,
> -	.write_begin	= simple_write_begin,
> -	.write_end	= simple_write_end,
> -};
> -
>  static const struct inode_operations configfs_inode_operations ={
>  	.setattr	= configfs_setattr,
>  };
> @@ -114,7 +108,7 @@ struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
>  	struct inode * inode = new_inode(s);
>  	if (inode) {
>  		inode->i_ino = get_next_ino();
> -		inode->i_mapping->a_ops = &configfs_aops;
> +		inode->i_mapping->a_ops = &ram_aops;
>  		inode->i_op = &configfs_inode_operations;
>  
>  		if (sd->s_iattr) {
> diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
> index d73950fc3d57..26f2aa3586f9 100644
> --- a/fs/kernfs/inode.c
> +++ b/fs/kernfs/inode.c
> @@ -17,12 +17,6 @@
>  
>  #include "kernfs-internal.h"
>  
> -static const struct address_space_operations kernfs_aops = {
> -	.readpage	= simple_readpage,
> -	.write_begin	= simple_write_begin,
> -	.write_end	= simple_write_end,
> -};
> -
>  static const struct inode_operations kernfs_iops = {
>  	.permission	= kernfs_iop_permission,
>  	.setattr	= kernfs_iop_setattr,
> @@ -203,7 +197,7 @@ static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode)
>  {
>  	kernfs_get(kn);
>  	inode->i_private = kn;
> -	inode->i_mapping->a_ops = &kernfs_aops;
> +	inode->i_mapping->a_ops = &ram_aops;
>  	inode->i_op = &kernfs_iops;
>  	inode->i_generation = kernfs_gen(kn);
>  
> diff --git a/fs/libfs.c b/fs/libfs.c
> index e9b29c6ffccb..2d7f086b93d6 100644
> --- a/fs/libfs.c
> +++ b/fs/libfs.c
> @@ -512,7 +512,7 @@ int simple_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
>  }
>  EXPORT_SYMBOL(simple_setattr);
>  
> -int simple_readpage(struct file *file, struct page *page)
> +static int simple_readpage(struct file *file, struct page *page)
>  {
>  	clear_highpage(page);
>  	flush_dcache_page(page);
> @@ -520,7 +520,6 @@ int simple_readpage(struct file *file, struct page *page)
>  	unlock_page(page);
>  	return 0;
>  }
> -EXPORT_SYMBOL(simple_readpage);
>  
>  int simple_write_begin(struct file *file, struct address_space *mapping,
>  			loff_t pos, unsigned len, unsigned flags,
> @@ -568,7 +567,7 @@ EXPORT_SYMBOL(simple_write_begin);
>   *
>   * Use *ONLY* with simple_readpage()
>   */
> -int simple_write_end(struct file *file, struct address_space *mapping,
> +static int simple_write_end(struct file *file, struct address_space *mapping,
>  			loff_t pos, unsigned len, unsigned copied,
>  			struct page *page, void *fsdata)
>  {
> @@ -597,7 +596,17 @@ int simple_write_end(struct file *file, struct address_space *mapping,
>  
>  	return copied;
>  }
> -EXPORT_SYMBOL(simple_write_end);
> +
> +/*
> + * Provides ramfs-style behavior: data in the pagecache, but no writeback.
> + */
> +const struct address_space_operations ram_aops = {
> +	.readpage	= simple_readpage,
> +	.write_begin	= simple_write_begin,
> +	.write_end	= simple_write_end,
> +	.set_page_dirty	= __set_page_dirty_no_writeback,
> +};
> +EXPORT_SYMBOL(ram_aops);
>  
>  /*
>   * the inodes created here are not hashed. If you use iunique to generate
> diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
> index 9ebd17d7befb..65e7e56005b8 100644
> --- a/fs/ramfs/inode.c
> +++ b/fs/ramfs/inode.c
> @@ -53,13 +53,6 @@ struct ramfs_fs_info {
>  static const struct super_operations ramfs_ops;
>  static const struct inode_operations ramfs_dir_inode_operations;
>  
> -static const struct address_space_operations ramfs_aops = {
> -	.readpage	= simple_readpage,
> -	.write_begin	= simple_write_begin,
> -	.write_end	= simple_write_end,
> -	.set_page_dirty	= __set_page_dirty_no_writeback,
> -};
> -
>  struct inode *ramfs_get_inode(struct super_block *sb,
>  				const struct inode *dir, umode_t mode, dev_t dev)
>  {
> @@ -68,7 +61,7 @@ struct inode *ramfs_get_inode(struct super_block *sb,
>  	if (inode) {
>  		inode->i_ino = get_next_ino();
>  		inode_init_owner(&init_user_ns, inode, dir, mode);
> -		inode->i_mapping->a_ops = &ramfs_aops;
> +		inode->i_mapping->a_ops = &ram_aops;
>  		mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
>  		mapping_set_unevictable(inode->i_mapping);
>  		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index c3c88fdb9b2a..869909345420 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -3422,13 +3422,10 @@ extern void noop_invalidatepage(struct page *page, unsigned int offset,
>  		unsigned int length);
>  extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
>  extern int simple_empty(struct dentry *);
> -extern int simple_readpage(struct file *file, struct page *page);
>  extern int simple_write_begin(struct file *file, struct address_space *mapping,
>  			loff_t pos, unsigned len, unsigned flags,
>  			struct page **pagep, void **fsdata);
> -extern int simple_write_end(struct file *file, struct address_space *mapping,
> -			loff_t pos, unsigned len, unsigned copied,
> -			struct page *page, void *fsdata);
> +extern const struct address_space_operations ram_aops;
>  extern int always_delete_dentry(const struct dentry *);
>  extern struct inode *alloc_anon_inode(struct super_block *);
>  extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
> -- 
> 2.30.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 3/3] mm: require ->set_page_dirty to be explicitly wire up

[Jan Kara]

On Mon 14-06-21 08:15:12, Christoph Hellwig wrote:
> Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just
> wire that method up for the missing instances.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Make sense. Did you somehow autogenerate this? If this patch would race
with addition of new aops struct, we'd get null-ptr-defer out of that so
maybe providing the script would be better. But other than that the changes
look good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>


								Honza

> ---
>  fs/adfs/inode.c     |  1 +
>  fs/affs/file.c      |  2 ++
>  fs/bfs/file.c       |  1 +
>  fs/block_dev.c      |  1 +
>  fs/exfat/inode.c    |  1 +
>  fs/ext2/inode.c     |  2 ++
>  fs/fat/inode.c      |  1 +
>  fs/gfs2/meta_io.c   |  2 ++
>  fs/hfs/inode.c      |  2 ++
>  fs/hfsplus/inode.c  |  2 ++
>  fs/hpfs/file.c      |  1 +
>  fs/jfs/inode.c      |  1 +
>  fs/minix/inode.c    |  1 +
>  fs/nilfs2/mdt.c     |  1 +
>  fs/ocfs2/aops.c     |  1 +
>  fs/omfs/file.c      |  1 +
>  fs/sysv/itree.c     |  1 +
>  fs/udf/file.c       |  1 +
>  fs/udf/inode.c      |  1 +
>  fs/ufs/inode.c      |  1 +
>  mm/page-writeback.c | 18 ++++--------------
>  21 files changed, 29 insertions(+), 14 deletions(-)
> 
> diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
> index fb7ee026d101..adbb3a1edcbf 100644
> --- a/fs/adfs/inode.c
> +++ b/fs/adfs/inode.c
> @@ -73,6 +73,7 @@ static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
>  }
>  
>  static const struct address_space_operations adfs_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= adfs_readpage,
>  	.writepage	= adfs_writepage,
>  	.write_begin	= adfs_write_begin,
> diff --git a/fs/affs/file.c b/fs/affs/file.c
> index d91b0133d95d..75ebd2b576ca 100644
> --- a/fs/affs/file.c
> +++ b/fs/affs/file.c
> @@ -453,6 +453,7 @@ static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
>  }
>  
>  const struct address_space_operations affs_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage = affs_readpage,
>  	.writepage = affs_writepage,
>  	.write_begin = affs_write_begin,
> @@ -833,6 +834,7 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
>  }
>  
>  const struct address_space_operations affs_aops_ofs = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage = affs_readpage_ofs,
>  	//.writepage = affs_writepage_ofs,
>  	.write_begin = affs_write_begin_ofs,
> diff --git a/fs/bfs/file.c b/fs/bfs/file.c
> index 0dceefc54b48..7f8544abf636 100644
> --- a/fs/bfs/file.c
> +++ b/fs/bfs/file.c
> @@ -188,6 +188,7 @@ static sector_t bfs_bmap(struct address_space *mapping, sector_t block)
>  }
>  
>  const struct address_space_operations bfs_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= bfs_readpage,
>  	.writepage	= bfs_writepage,
>  	.write_begin	= bfs_write_begin,
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 6cc4d4cfe0c2..eb34f5c357cf 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -1754,6 +1754,7 @@ static int blkdev_writepages(struct address_space *mapping,
>  }
>  
>  static const struct address_space_operations def_blk_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= blkdev_readpage,
>  	.readahead	= blkdev_readahead,
>  	.writepage	= blkdev_writepage,
> diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
> index 1803ef3220fd..ca37d4344361 100644
> --- a/fs/exfat/inode.c
> +++ b/fs/exfat/inode.c
> @@ -491,6 +491,7 @@ int exfat_block_truncate_page(struct inode *inode, loff_t from)
>  }
>  
>  static const struct address_space_operations exfat_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= exfat_readpage,
>  	.readahead	= exfat_readahead,
>  	.writepage	= exfat_writepage,
> diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
> index 68178b2234bd..bf41f579ed3e 100644
> --- a/fs/ext2/inode.c
> +++ b/fs/ext2/inode.c
> @@ -961,6 +961,7 @@ ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc
>  }
>  
>  const struct address_space_operations ext2_aops = {
> +	.set_page_dirty		= __set_page_dirty_buffers,
>  	.readpage		= ext2_readpage,
>  	.readahead		= ext2_readahead,
>  	.writepage		= ext2_writepage,
> @@ -975,6 +976,7 @@ const struct address_space_operations ext2_aops = {
>  };
>  
>  const struct address_space_operations ext2_nobh_aops = {
> +	.set_page_dirty		= __set_page_dirty_buffers,
>  	.readpage		= ext2_readpage,
>  	.readahead		= ext2_readahead,
>  	.writepage		= ext2_nobh_writepage,
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index bab9b202b496..de0c9b013a85 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -342,6 +342,7 @@ int fat_block_truncate_page(struct inode *inode, loff_t from)
>  }
>  
>  static const struct address_space_operations fat_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= fat_readpage,
>  	.readahead	= fat_readahead,
>  	.writepage	= fat_writepage,
> diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
> index d68184ebbfdd..7c9619997355 100644
> --- a/fs/gfs2/meta_io.c
> +++ b/fs/gfs2/meta_io.c
> @@ -89,11 +89,13 @@ static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wb
>  }
>  
>  const struct address_space_operations gfs2_meta_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.writepage = gfs2_aspace_writepage,
>  	.releasepage = gfs2_releasepage,
>  };
>  
>  const struct address_space_operations gfs2_rgrp_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.writepage = gfs2_aspace_writepage,
>  	.releasepage = gfs2_releasepage,
>  };
> diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
> index 3fc5cb346586..4a95a92546a0 100644
> --- a/fs/hfs/inode.c
> +++ b/fs/hfs/inode.c
> @@ -159,6 +159,7 @@ static int hfs_writepages(struct address_space *mapping,
>  }
>  
>  const struct address_space_operations hfs_btree_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= hfs_readpage,
>  	.writepage	= hfs_writepage,
>  	.write_begin	= hfs_write_begin,
> @@ -168,6 +169,7 @@ const struct address_space_operations hfs_btree_aops = {
>  };
>  
>  const struct address_space_operations hfs_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= hfs_readpage,
>  	.writepage	= hfs_writepage,
>  	.write_begin	= hfs_write_begin,
> diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
> index 8ea447e5c470..70e8374ddac4 100644
> --- a/fs/hfsplus/inode.c
> +++ b/fs/hfsplus/inode.c
> @@ -156,6 +156,7 @@ static int hfsplus_writepages(struct address_space *mapping,
>  }
>  
>  const struct address_space_operations hfsplus_btree_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= hfsplus_readpage,
>  	.writepage	= hfsplus_writepage,
>  	.write_begin	= hfsplus_write_begin,
> @@ -165,6 +166,7 @@ const struct address_space_operations hfsplus_btree_aops = {
>  };
>  
>  const struct address_space_operations hfsplus_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= hfsplus_readpage,
>  	.writepage	= hfsplus_writepage,
>  	.write_begin	= hfsplus_write_begin,
> diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
> index 077c25128eb7..c3a49aacf20a 100644
> --- a/fs/hpfs/file.c
> +++ b/fs/hpfs/file.c
> @@ -196,6 +196,7 @@ static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>  }
>  
>  const struct address_space_operations hpfs_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage = hpfs_readpage,
>  	.writepage = hpfs_writepage,
>  	.readahead = hpfs_readahead,
> diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
> index 6f65bfa9f18d..3663dd5a23bc 100644
> --- a/fs/jfs/inode.c
> +++ b/fs/jfs/inode.c
> @@ -356,6 +356,7 @@ static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>  }
>  
>  const struct address_space_operations jfs_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= jfs_readpage,
>  	.readahead	= jfs_readahead,
>  	.writepage	= jfs_writepage,
> diff --git a/fs/minix/inode.c b/fs/minix/inode.c
> index a532a99bbe81..a71f1cf894b9 100644
> --- a/fs/minix/inode.c
> +++ b/fs/minix/inode.c
> @@ -442,6 +442,7 @@ static sector_t minix_bmap(struct address_space *mapping, sector_t block)
>  }
>  
>  static const struct address_space_operations minix_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage = minix_readpage,
>  	.writepage = minix_writepage,
>  	.write_begin = minix_write_begin,
> diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
> index c0361ce45f62..97769fe4d588 100644
> --- a/fs/nilfs2/mdt.c
> +++ b/fs/nilfs2/mdt.c
> @@ -434,6 +434,7 @@ nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
>  
>  
>  static const struct address_space_operations def_mdt_aops = {
> +	.set_page_dirty		= __set_page_dirty_buffers,
>  	.writepage		= nilfs_mdt_write_page,
>  };
>  
> diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
> index 1294925ac94a..b3517de178ff 100644
> --- a/fs/ocfs2/aops.c
> +++ b/fs/ocfs2/aops.c
> @@ -2454,6 +2454,7 @@ static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>  }
>  
>  const struct address_space_operations ocfs2_aops = {
> +	.set_page_dirty		= __set_page_dirty_buffers,
>  	.readpage		= ocfs2_readpage,
>  	.readahead		= ocfs2_readahead,
>  	.writepage		= ocfs2_writepage,
> diff --git a/fs/omfs/file.c b/fs/omfs/file.c
> index 11e733aab25d..89725b15a64b 100644
> --- a/fs/omfs/file.c
> +++ b/fs/omfs/file.c
> @@ -372,6 +372,7 @@ const struct inode_operations omfs_file_inops = {
>  };
>  
>  const struct address_space_operations omfs_aops = {
> +	.set_page_dirty = __set_page_dirty_buffers,
>  	.readpage = omfs_readpage,
>  	.readahead = omfs_readahead,
>  	.writepage = omfs_writepage,
> diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
> index 8b2e99b7bc9f..749385015a8d 100644
> --- a/fs/sysv/itree.c
> +++ b/fs/sysv/itree.c
> @@ -495,6 +495,7 @@ static sector_t sysv_bmap(struct address_space *mapping, sector_t block)
>  }
>  
>  const struct address_space_operations sysv_aops = {
> +	.set_page_dirty = __set_page_dirty_buffers,
>  	.readpage = sysv_readpage,
>  	.writepage = sysv_writepage,
>  	.write_begin = sysv_write_begin,
> diff --git a/fs/udf/file.c b/fs/udf/file.c
> index 2846dcd92197..1baff8ddb754 100644
> --- a/fs/udf/file.c
> +++ b/fs/udf/file.c
> @@ -125,6 +125,7 @@ static int udf_adinicb_write_end(struct file *file, struct address_space *mappin
>  }
>  
>  const struct address_space_operations udf_adinicb_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= udf_adinicb_readpage,
>  	.writepage	= udf_adinicb_writepage,
>  	.write_begin	= udf_adinicb_write_begin,
> diff --git a/fs/udf/inode.c b/fs/udf/inode.c
> index 0dd2f93ac048..4917670860a0 100644
> --- a/fs/udf/inode.c
> +++ b/fs/udf/inode.c
> @@ -235,6 +235,7 @@ static sector_t udf_bmap(struct address_space *mapping, sector_t block)
>  }
>  
>  const struct address_space_operations udf_aops = {
> +	.set_page_dirty	= __set_page_dirty_buffers,
>  	.readpage	= udf_readpage,
>  	.readahead	= udf_readahead,
>  	.writepage	= udf_writepage,
> diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
> index debc282c1bb4..ac628de69601 100644
> --- a/fs/ufs/inode.c
> +++ b/fs/ufs/inode.c
> @@ -526,6 +526,7 @@ static sector_t ufs_bmap(struct address_space *mapping, sector_t block)
>  }
>  
>  const struct address_space_operations ufs_aops = {
> +	.set_page_dirty = __set_page_dirty_buffers,
>  	.readpage = ufs_readpage,
>  	.writepage = ufs_writepage,
>  	.write_begin = ufs_write_begin,
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 0062d5c57d41..081fa02236c2 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -32,7 +32,6 @@
>  #include <linux/sysctl.h>
>  #include <linux/cpu.h>
>  #include <linux/syscalls.h>
> -#include <linux/buffer_head.h> /* __set_page_dirty_buffers */
>  #include <linux/pagevec.h>
>  #include <linux/timer.h>
>  #include <linux/sched/rt.h>
> @@ -2546,13 +2545,9 @@ EXPORT_SYMBOL(redirty_page_for_writepage);
>  /*
>   * Dirty a page.
>   *
> - * For pages with a mapping this should be done under the page lock
> - * for the benefit of asynchronous memory errors who prefer a consistent
> - * dirty state. This rule can be broken in some special cases,
> - * but should be better not to.
> - *
> - * If the mapping doesn't provide a set_page_dirty a_op, then
> - * just fall through and assume that it wants buffer_heads.
> + * For pages with a mapping this should be done under the page lock for the
> + * benefit of asynchronous memory errors who prefer a consistent dirty state.
> + * This rule can be broken in some special cases, but should be better not to.
>   */
>  int set_page_dirty(struct page *page)
>  {
> @@ -2560,7 +2555,6 @@ int set_page_dirty(struct page *page)
>  
>  	page = compound_head(page);
>  	if (likely(mapping)) {
> -		int (*spd)(struct page *) = mapping->a_ops->set_page_dirty;
>  		/*
>  		 * readahead/lru_deactivate_page could remain
>  		 * PG_readahead/PG_reclaim due to race with end_page_writeback
> @@ -2573,11 +2567,7 @@ int set_page_dirty(struct page *page)
>  		 */
>  		if (PageReclaim(page))
>  			ClearPageReclaim(page);
> -#ifdef CONFIG_BLOCK
> -		if (!spd)
> -			spd = __set_page_dirty_buffers;
> -#endif
> -		return (*spd)(page);
> +		return mapping->a_ops->set_page_dirty(page);
>  	}
>  	if (!PageDirty(page)) {
>  		if (!TestSetPageDirty(page))
> -- 
> 2.30.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 3/3] mm: require ->set_page_dirty to be explicitly wire up

[Christoph Hellwig]

On Mon, Jun 14, 2021 at 11:51:07AM +0200, Jan Kara wrote:
> On Mon 14-06-21 08:15:12, Christoph Hellwig wrote:
> > Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just
> > wire that method up for the missing instances.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Make sense. Did you somehow autogenerate this? If this patch would race
> with addition of new aops struct, we'd get null-ptr-defer out of that so
> maybe providing the script would be better. But other than that the changes
> look good to me. You can add:

No, this was done manually as I audited all instances for actually being
able to dirty pages.

Re: remove the implicit .set_page_dirty default

[Matthew Wilcox]

On Mon, Jun 14, 2021 at 08:15:09AM +0200, Christoph Hellwig wrote:
> Hi all,
> 
> this series cleans up a few lose ends around ->set_page_dirty, most
> importantly removes the default to the buffer head based on if no
> method is wired up.

i have a somewhat similar series in the works ...

https://git.infradead.org/users/willy/pagecache.git/commitdiff/1e7e8c2d82666b55690705d5bbe908e31d437edb
https://git.infradead.org/users/willy/pagecache.git/commitdiff/bf767a4969c0bc6735275ff7457a8082eef4c3fd

... the other patches rather depend on the folio work.

Re: [PATCH 1/3] fs: unexport __set_page_dirty

[Matthew Wilcox]

On Mon, Jun 14, 2021 at 08:15:10AM +0200, Christoph Hellwig wrote:
> __set_page_dirty is only used by built-in code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

You might also want to do the equivalent of this:

https://git.infradead.org/users/willy/pagecache.git/commitdiff/19b3bf0d1a51f41ce5450fdd863969c3d32dfe12

Re: [PATCH 1/3] fs: unexport __set_page_dirty

[Christoph Hellwig]

On Mon, Jun 14, 2021 at 01:32:42PM +0100, Matthew Wilcox wrote:
> On Mon, Jun 14, 2021 at 08:15:10AM +0200, Christoph Hellwig wrote:
> > __set_page_dirty is only used by built-in code.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> 
> You might also want to do the equivalent of this:
> 
> https://git.infradead.org/users/willy/pagecache.git/commitdiff/19b3bf0d1a51f41ce5450fdd863969c3d32dfe12

This looks nice, but not really directly related.  I think you
should just send it to Andrew.

Re: remove the implicit .set_page_dirty default

[Christoph Hellwig]

On Mon, Jun 14, 2021 at 01:23:22PM +0100, Matthew Wilcox wrote:
> i have a somewhat similar series in the works ...
> 
> https://git.infradead.org/users/willy/pagecache.git/commitdiff/1e7e8c2d82666b55690705d5bbe908e31d437edb
> https://git.infradead.org/users/willy/pagecache.git/commitdiff/bf767a4969c0bc6735275ff7457a8082eef4c3fd
> 
> ... the other patches rather depend on the folio work.

Yes, these looks useful to me as well.

Re: remove the implicit .set_page_dirty default

[Christoph Hellwig]

On Mon, Jun 14, 2021 at 05:53:33PM +0200, Christoph Hellwig wrote:
> On Mon, Jun 14, 2021 at 01:23:22PM +0100, Matthew Wilcox wrote:
> > i have a somewhat similar series in the works ...
> > 
> > https://git.infradead.org/users/willy/pagecache.git/commitdiff/1e7e8c2d82666b55690705d5bbe908e31d437edb
> > https://git.infradead.org/users/willy/pagecache.git/commitdiff/bf767a4969c0bc6735275ff7457a8082eef4c3fd
> > 
> > ... the other patches rather depend on the folio work.
> 
> Yes, these looks useful to me as well.


And in fact I suspect the code in __set_page_dirty_no_writeback should
really be the default if no ->set_page_dirty is set up.  It is the
same code as the no-mapping case and really makes sense as the default
case..

Re: remove the implicit .set_page_dirty default

[Matthew Wilcox]

On Mon, Jun 14, 2021 at 05:55:30PM +0200, Christoph Hellwig wrote:
> On Mon, Jun 14, 2021 at 05:53:33PM +0200, Christoph Hellwig wrote:
> > On Mon, Jun 14, 2021 at 01:23:22PM +0100, Matthew Wilcox wrote:
> > > i have a somewhat similar series in the works ...
> > > 
> > > https://git.infradead.org/users/willy/pagecache.git/commitdiff/1e7e8c2d82666b55690705d5bbe908e31d437edb
> > > https://git.infradead.org/users/willy/pagecache.git/commitdiff/bf767a4969c0bc6735275ff7457a8082eef4c3fd
> > > 
> > > ... the other patches rather depend on the folio work.
> > 
> > Yes, these looks useful to me as well.
> 
> 
> And in fact I suspect the code in __set_page_dirty_no_writeback should
> really be the default if no ->set_page_dirty is set up.  It is the
> same code as the no-mapping case and really makes sense as the default
> case..

yes; i was even wondering if that should be conditional on one of the
"no writeback" bits in mapping ...

Re: [PATCH 3/3] mm: require ->set_page_dirty to be explicitly wire up

[Dmitry Osipenko]

14.06.2021 09:15, Christoph Hellwig пишет:
> Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just
> wire that method up for the missing instances.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/adfs/inode.c     |  1 +
>  fs/affs/file.c      |  2 ++
>  fs/bfs/file.c       |  1 +
>  fs/block_dev.c      |  1 +
>  fs/exfat/inode.c    |  1 +
>  fs/ext2/inode.c     |  2 ++
>  fs/fat/inode.c      |  1 +
>  fs/gfs2/meta_io.c   |  2 ++
>  fs/hfs/inode.c      |  2 ++
>  fs/hfsplus/inode.c  |  2 ++
>  fs/hpfs/file.c      |  1 +
>  fs/jfs/inode.c      |  1 +
>  fs/minix/inode.c    |  1 +
>  fs/nilfs2/mdt.c     |  1 +
>  fs/ocfs2/aops.c     |  1 +
>  fs/omfs/file.c      |  1 +
>  fs/sysv/itree.c     |  1 +
>  fs/udf/file.c       |  1 +
>  fs/udf/inode.c      |  1 +
>  fs/ufs/inode.c      |  1 +
>  mm/page-writeback.c | 18 ++++--------------
>  21 files changed, 29 insertions(+), 14 deletions(-)

The ecryptfs is now crashing with NULL deference, please fix.

Re: [PATCH 3/3] mm: require ->set_page_dirty to be explicitly wire up

[Christoph Hellwig]

On Fri, Jun 18, 2021 at 10:23:55PM +0300, Dmitry Osipenko wrote:
> >  21 files changed, 29 insertions(+), 14 deletions(-)
> 
> The ecryptfs is now crashing with NULL deference, please fix.

Which means it crashed the same before on configs without CONFIG_BLOCK.

Tyler, can you look at what ecryptfs should do for ->set_page_dirty?
Currently it implicitly gets __set_page_dirty_buffers for kernels
with COFIG_BLOCK set, but given that this function looks at buffer_heads
that ecryptfs doesn't use it can't really be the right choice.
__set_page_dirty_nobuffers will probably work, but I'd love to see an
audit of the page dirtying and writeback for ecryptfs while we're at it.