All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Howells <dhowells@redhat.com>
To: willy@infradead.org, hch@lst.de, trond.myklebust@primarydata.com
Cc: "Darrick J. Wong" <djwong@kernel.org>,
	Ilya Dryomov <idryomov@gmail.com>,
	Jeff Layton <jlayton@kernel.org>,
	ceph-devel@vger.kernel.org, Steve French <sfrench@samba.org>,
	linux-cifs@vger.kernel.org, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	dhowells@redhat.com, dhowells@redhat.com,
	darrick.wong@oracle.com, viro@zeniv.linux.org.uk,
	jlayton@kernel.org, torvalds@linux-foundation.org,
	linux-nfs@vger.kernel.org, linux-mm@kvack.org,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 2/9] mm: Add 'supports' field to the address_space_operations to list features
Date: Fri, 24 Sep 2021 18:18:14 +0100	[thread overview]
Message-ID: <163250389458.2330363.17234460134406104577.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <163250387273.2330363.13240781819520072222.stgit@warthog.procyon.org.uk>

Rather than depending on .direct_IO to point to something to indicate that
direct I/O is supported, add a 'supports' bitmask that we can test, since
we only need one bit.

We can then remove noop_direct_IO, ceph_direct_io and cifs_direct_io.

[Question: Some filesystems support read DIO but not write DIO - should I
 split the flag?]

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Christoph Hellwig <hch@lst.de>
cc: Darrick J. Wong <djwong@kernel.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: ceph-devel@vger.kernel.org
cc: Steve French <sfrench@samba.org>
cc: linux-cifs@vger.kernel.org
cc: linux-xfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---

 Documentation/filesystems/vfs.rst |    8 ++++++++
 block/fops.c                      |    1 +
 drivers/block/loop.c              |    6 +++---
 fs/9p/vfs_addr.c                  |    1 +
 fs/affs/file.c                    |    1 +
 fs/btrfs/inode.c                  |    2 +-
 fs/ceph/addr.c                    |   13 +------------
 fs/cifs/file.c                    |   21 +--------------------
 fs/erofs/data.c                   |    2 +-
 fs/exfat/inode.c                  |    1 +
 fs/ext2/inode.c                   |    4 +++-
 fs/ext4/inode.c                   |    8 ++++----
 fs/f2fs/data.c                    |    1 +
 fs/fat/inode.c                    |    1 +
 fs/fcntl.c                        |    2 +-
 fs/fuse/dax.c                     |    2 +-
 fs/fuse/file.c                    |    1 +
 fs/gfs2/aops.c                    |    2 +-
 fs/hfs/inode.c                    |    1 +
 fs/hfsplus/inode.c                |    1 +
 fs/jfs/inode.c                    |    1 +
 fs/libfs.c                        |   12 ------------
 fs/nfs/file.c                     |    1 +
 fs/nilfs2/inode.c                 |    1 +
 fs/ntfs3/inode.c                  |    1 +
 fs/ocfs2/aops.c                   |    1 +
 fs/open.c                         |    3 ++-
 fs/orangefs/inode.c               |    1 +
 fs/overlayfs/file.c               |    2 +-
 fs/overlayfs/inode.c              |    3 +--
 fs/reiserfs/inode.c               |    1 +
 fs/udf/file.c                     |    1 +
 fs/udf/inode.c                    |    1 +
 fs/xfs/xfs_aops.c                 |    4 ++--
 fs/zonefs/super.c                 |    2 +-
 include/linux/fs.h                |    4 +++-
 36 files changed, 53 insertions(+), 65 deletions(-)

diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
index bf5c48066fac..abb844792d6a 100644
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -721,6 +721,7 @@ cache in your filesystem.  The following members are defined:
 .. code-block:: c
 
 	struct address_space_operations {
+		unsigned int supports;
 		int (*writepage)(struct page *page, struct writeback_control *wbc);
 		int (*readpage)(struct file *, struct page *);
 		int (*writepages)(struct address_space *, struct writeback_control *);
@@ -755,6 +756,13 @@ cache in your filesystem.  The following members are defined:
 		int (*swap_deactivate)(struct file *);
 	};
 
+``supports``
+	provides a list of features supported by address_spaces using this
+	operations set.  The following feature support flags are provided:
+
+	``AS_SUPPORTS_DIRECT_IO``
+		Direct I/O is supported.
+
 ``writepage``
 	called by the VM to write a dirty page to backing store.  This
 	may happen for data integrity reasons (i.e. 'sync'), or to free
diff --git a/block/fops.c b/block/fops.c
index ffce6f6c68dd..84c64d814d0d 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -384,6 +384,7 @@ const struct address_space_operations def_blk_aops = {
 	.direct_IO	= blkdev_direct_IO,
 	.migratepage	= buffer_migrate_page_norefs,
 	.is_dirty_writeback = buffer_check_dirty_writeback,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 7bf4686af774..76f7a6d85815 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -237,9 +237,9 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
 	 */
 	if (dio) {
 		if (queue_logical_block_size(lo->lo_queue) >= sb_bsize &&
-				!(lo->lo_offset & dio_align) &&
-				mapping->a_ops->direct_IO &&
-				!lo->transfer)
+		    !(lo->lo_offset & dio_align) &&
+		    (mapping->a_ops->supports & AS_SUPPORTS_DIRECT_IO) &&
+		    !lo->transfer)
 			use_dio = true;
 		else
 			use_dio = false;
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index cce9ace651a2..4910898af0d7 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -333,4 +333,5 @@ const struct address_space_operations v9fs_addr_operations = {
 	.invalidatepage = v9fs_invalidate_page,
 	.launder_page = v9fs_launder_page,
 	.direct_IO = v9fs_direct_IO,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
diff --git a/fs/affs/file.c b/fs/affs/file.c
index 75ebd2b576ca..7488bd7d3e0c 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -460,6 +460,7 @@ const struct address_space_operations affs_aops = {
 	.write_end = affs_write_end,
 	.direct_IO = affs_direct_IO,
 	.bmap = _affs_bmap
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 static inline struct buffer_head *
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 487533c35ddb..b479c97e42fc 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10937,7 +10937,6 @@ static const struct address_space_operations btrfs_aops = {
 	.writepage	= btrfs_writepage,
 	.writepages	= btrfs_writepages,
 	.readahead	= btrfs_readahead,
-	.direct_IO	= noop_direct_IO,
 	.invalidatepage = btrfs_invalidatepage,
 	.releasepage	= btrfs_releasepage,
 #ifdef CONFIG_MIGRATION
@@ -10947,6 +10946,7 @@ static const struct address_space_operations btrfs_aops = {
 	.error_remove_page = generic_error_remove_page,
 	.swap_activate	= btrfs_swap_activate,
 	.swap_deactivate = btrfs_swap_deactivate,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 static const struct inode_operations btrfs_file_inode_operations = {
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 99b80b5c7a93..086d4745b99e 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1306,17 +1306,6 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
 	return copied;
 }
 
-/*
- * we set .direct_IO to indicate direct io is supported, but since we
- * intercept O_DIRECT reads and writes early, this function should
- * never get called.
- */
-static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter)
-{
-	WARN_ON(1);
-	return -EINVAL;
-}
-
 const struct address_space_operations ceph_aops = {
 	.readpage = ceph_readpage,
 	.readahead = ceph_readahead,
@@ -1327,7 +1316,7 @@ const struct address_space_operations ceph_aops = {
 	.set_page_dirty = ceph_set_page_dirty,
 	.invalidatepage = ceph_invalidatepage,
 	.releasepage = ceph_releasepage,
-	.direct_IO = ceph_direct_io,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 static void ceph_block_sigs(sigset_t *oldset)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 6796fc73b304..a5787cf3d836 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4891,25 +4891,6 @@ void cifs_oplock_break(struct work_struct *work)
 	cifs_done_oplock_break(cinode);
 }
 
-/*
- * The presence of cifs_direct_io() in the address space ops vector
- * allowes open() O_DIRECT flags which would have failed otherwise.
- *
- * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
- * so this method should never be called.
- *
- * Direct IO is not yet supported in the cached mode. 
- */
-static ssize_t
-cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
-{
-        /*
-         * FIXME
-         * Eventually need to support direct IO for non forcedirectio mounts
-         */
-        return -EINVAL;
-}
-
 static int cifs_swap_activate(struct swap_info_struct *sis,
 			      struct file *swap_file, sector_t *span)
 {
@@ -4974,7 +4955,6 @@ const struct address_space_operations cifs_addr_ops = {
 	.write_end = cifs_write_end,
 	.set_page_dirty = __set_page_dirty_nobuffers,
 	.releasepage = cifs_release_page,
-	.direct_IO = cifs_direct_io,
 	.invalidatepage = cifs_invalidate_page,
 	.launder_page = cifs_launder_page,
 	/*
@@ -4984,6 +4964,7 @@ const struct address_space_operations cifs_addr_ops = {
 	 */
 	.swap_activate = cifs_swap_activate,
 	.swap_deactivate = cifs_swap_deactivate,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 9db829715652..30f19296b268 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -299,7 +299,7 @@ const struct address_space_operations erofs_raw_access_aops = {
 	.readpage = erofs_readpage,
 	.readahead = erofs_readahead,
 	.bmap = erofs_bmap,
-	.direct_IO = noop_direct_IO,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 #ifdef CONFIG_FS_DAX
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index ca37d4344361..f38f42282f54 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -500,6 +500,7 @@ static const struct address_space_operations exfat_aops = {
 	.write_end	= exfat_write_end,
 	.direct_IO	= exfat_direct_IO,
 	.bmap		= exfat_aop_bmap
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 static inline unsigned long exfat_hash(loff_t i_pos)
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 333fa62661d5..4ad3655defd9 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -974,6 +974,7 @@ const struct address_space_operations ext2_aops = {
 	.migratepage		= buffer_migrate_page,
 	.is_partially_uptodate	= block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 const struct address_space_operations ext2_nobh_aops = {
@@ -988,13 +989,14 @@ const struct address_space_operations ext2_nobh_aops = {
 	.writepages		= ext2_writepages,
 	.migratepage		= buffer_migrate_page,
 	.error_remove_page	= generic_error_remove_page,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 static const struct address_space_operations ext2_dax_aops = {
 	.writepages		= ext2_dax_writepages,
-	.direct_IO		= noop_direct_IO,
 	.set_page_dirty		= __set_page_dirty_no_writeback,
 	.invalidatepage		= noop_invalidatepage,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d18852d6029c..08d3541d8daa 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3662,11 +3662,11 @@ static const struct address_space_operations ext4_aops = {
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_invalidatepage,
 	.releasepage		= ext4_releasepage,
-	.direct_IO		= noop_direct_IO,
 	.migratepage		= buffer_migrate_page,
 	.is_partially_uptodate  = block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
 	.swap_activate		= ext4_iomap_swap_activate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 static const struct address_space_operations ext4_journalled_aops = {
@@ -3680,10 +3680,10 @@ static const struct address_space_operations ext4_journalled_aops = {
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_journalled_invalidatepage,
 	.releasepage		= ext4_releasepage,
-	.direct_IO		= noop_direct_IO,
 	.is_partially_uptodate  = block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
 	.swap_activate		= ext4_iomap_swap_activate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 static const struct address_space_operations ext4_da_aops = {
@@ -3697,20 +3697,20 @@ static const struct address_space_operations ext4_da_aops = {
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_invalidatepage,
 	.releasepage		= ext4_releasepage,
-	.direct_IO		= noop_direct_IO,
 	.migratepage		= buffer_migrate_page,
 	.is_partially_uptodate  = block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
 	.swap_activate		= ext4_iomap_swap_activate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 static const struct address_space_operations ext4_dax_aops = {
 	.writepages		= ext4_dax_writepages,
-	.direct_IO		= noop_direct_IO,
 	.set_page_dirty		= __set_page_dirty_no_writeback,
 	.bmap			= ext4_bmap,
 	.invalidatepage		= noop_invalidatepage,
 	.swap_activate		= ext4_iomap_swap_activate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 void ext4_set_aops(struct inode *inode)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f4fd6c246c9a..4c3643969b69 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -4156,6 +4156,7 @@ const struct address_space_operations f2fs_dblock_aops = {
 #ifdef CONFIG_MIGRATION
 	.migratepage    = f2fs_migrate_page,
 #endif
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 void f2fs_clear_page_cache_dirty_tag(struct page *page)
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index de0c9b013a85..4352981dfb82 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -351,6 +351,7 @@ static const struct address_space_operations fat_aops = {
 	.write_end	= fat_write_end,
 	.direct_IO	= fat_direct_IO,
 	.bmap		= _fat_bmap
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 9c6c6a3e2de5..7308e8274ff9 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -58,7 +58,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 	/* Pipe packetized mode is controlled by O_DIRECT flag */
 	if (!S_ISFIFO(inode->i_mode) && (arg & O_DIRECT)) {
 		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
-			!filp->f_mapping->a_ops->direct_IO)
+		    !(filp->f_mapping->a_ops->supports & AS_SUPPORTS_DIRECT_IO))
 				return -EINVAL;
 	}
 
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index 281d79f8b3d3..e39468fd7177 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1325,9 +1325,9 @@ bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi)
 
 static const struct address_space_operations fuse_dax_file_aops  = {
 	.writepages	= fuse_dax_writepages,
-	.direct_IO	= noop_direct_IO,
 	.set_page_dirty	= __set_page_dirty_no_writeback,
 	.invalidatepage	= noop_invalidatepage,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 void fuse_dax_inode_init(struct inode *inode)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 11404f8c21c7..3db64194d346 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3161,6 +3161,7 @@ static const struct address_space_operations fuse_file_aops  = {
 	.direct_IO	= fuse_direct_IO,
 	.write_begin	= fuse_write_begin,
 	.write_end	= fuse_write_end,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 void fuse_init_file_inode(struct inode *inode)
diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 005e920f5d4a..dc50b53d6abd 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -783,10 +783,10 @@ static const struct address_space_operations gfs2_aops = {
 	.releasepage = iomap_releasepage,
 	.invalidatepage = iomap_invalidatepage,
 	.bmap = gfs2_bmap,
-	.direct_IO = noop_direct_IO,
 	.migratepage = iomap_migrate_page,
 	.is_partially_uptodate = iomap_is_partially_uptodate,
 	.error_remove_page = generic_error_remove_page,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 static const struct address_space_operations gfs2_jdata_aops = {
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 4a95a92546a0..5f9e5464a5bf 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -177,6 +177,7 @@ const struct address_space_operations hfs_aops = {
 	.bmap		= hfs_bmap,
 	.direct_IO	= hfs_direct_IO,
 	.writepages	= hfs_writepages,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 6fef67c2a9f0..9f0c27e5e115 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -174,6 +174,7 @@ const struct address_space_operations hfsplus_aops = {
 	.bmap		= hfsplus_bmap,
 	.direct_IO	= hfsplus_direct_IO,
 	.writepages	= hfsplus_writepages,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 const struct dentry_operations hfsplus_dentry_operations = {
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index 57ab424c05ff..a477267471a4 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -366,6 +366,7 @@ const struct address_space_operations jfs_aops = {
 	.write_end	= nobh_write_end,
 	.bmap		= jfs_bmap,
 	.direct_IO	= jfs_direct_IO,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/libfs.c b/fs/libfs.c
index 51b4de3b3447..c27f681291e5 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1182,18 +1182,6 @@ void noop_invalidatepage(struct page *page, unsigned int offset,
 }
 EXPORT_SYMBOL_GPL(noop_invalidatepage);
 
-ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
-{
-	/*
-	 * iomap based filesystems support direct I/O without need for
-	 * this callback. However, it still needs to be set in
-	 * inode->a_ops so that open/fcntl know that direct I/O is
-	 * generally supported.
-	 */
-	return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(noop_direct_IO);
-
 /* Because kfree isn't assignment-compatible with void(void*) ;-/ */
 void kfree_link(void *p)
 {
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index aa353fd58240..7403ec6317cb 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -532,6 +532,7 @@ const struct address_space_operations nfs_file_aops = {
 	.error_remove_page = generic_error_remove_page,
 	.swap_activate = nfs_swap_activate,
 	.swap_deactivate = nfs_swap_deactivate,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 2e8eb263cf0f..c57395c01817 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -307,6 +307,7 @@ const struct address_space_operations nilfs_aops = {
 	.invalidatepage		= block_invalidatepage,
 	.direct_IO		= nilfs_direct_IO,
 	.is_partially_uptodate  = block_is_partially_uptodate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 static int nilfs_insert_inode_locked(struct inode *inode,
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index db2a5a4c38e4..7b3ac1ab5d04 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1948,6 +1948,7 @@ const struct address_space_operations ntfs_aops = {
 	.direct_IO	= ntfs_direct_IO,
 	.bmap		= ntfs_bmap,
 	.set_page_dirty = __set_page_dirty_buffers,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 const struct address_space_operations ntfs_aops_cmpr = {
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 68d11c295dd3..5a158975a4ff 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2466,4 +2466,5 @@ const struct address_space_operations ocfs2_aops = {
 	.migratepage		= buffer_migrate_page,
 	.is_partially_uptodate	= block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
diff --git a/fs/open.c b/fs/open.c
index daa324606a41..d679dc0c1801 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -840,7 +840,8 @@ static int do_dentry_open(struct file *f,
 
 	/* NB: we're sure to have correct a_ops only after f_op->open */
 	if (f->f_flags & O_DIRECT) {
-		if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
+		if (!f->f_mapping->a_ops ||
+		    !(f->f_mapping->a_ops->supports & AS_SUPPORTS_DIRECT_IO))
 			return -EINVAL;
 	}
 
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
index c1bb4c4b5d67..c5bad94dfbd0 100644
--- a/fs/orangefs/inode.c
+++ b/fs/orangefs/inode.c
@@ -641,6 +641,7 @@ static const struct address_space_operations orangefs_address_operations = {
 	.freepage = orangefs_freepage,
 	.launder_page = orangefs_launder_page,
 	.direct_IO = orangefs_direct_IO,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 vm_fault_t orangefs_page_mkwrite(struct vm_fault *vmf)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index d081faa55e83..87d05f1d718a 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -83,7 +83,7 @@ static int ovl_change_flags(struct file *file, unsigned int flags)
 
 	if (flags & O_DIRECT) {
 		if (!file->f_mapping->a_ops ||
-		    !file->f_mapping->a_ops->direct_IO)
+		    !(file->f_mapping->a_ops->supports & AS_SUPPORTS_DIRECT_IO))
 			return -EINVAL;
 	}
 
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 832b17589733..9902608b1715 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -660,8 +660,7 @@ static const struct inode_operations ovl_special_inode_operations = {
 };
 
 static const struct address_space_operations ovl_aops = {
-	/* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */
-	.direct_IO		= noop_direct_IO,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index f49b72ccac4c..890d91847d58 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -3436,4 +3436,5 @@ const struct address_space_operations reiserfs_address_space_operations = {
 	.bmap = reiserfs_aop_bmap,
 	.direct_IO = reiserfs_direct_IO,
 	.set_page_dirty = reiserfs_set_page_dirty,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 1baff8ddb754..2cb1b499e5c7 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -131,6 +131,7 @@ const struct address_space_operations udf_adinicb_aops = {
 	.write_begin	= udf_adinicb_write_begin,
 	.write_end	= udf_adinicb_write_end,
 	.direct_IO	= udf_adinicb_direct_IO,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 1d6b7a50736b..38b799b457d5 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -244,6 +244,7 @@ const struct address_space_operations udf_aops = {
 	.write_end	= generic_write_end,
 	.direct_IO	= udf_direct_IO,
 	.bmap		= udf_bmap,
+	.supports	= AS_SUPPORTS_DIRECT_IO,
 };
 
 /*
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 34fc6148032a..2a4570516591 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -548,17 +548,17 @@ const struct address_space_operations xfs_address_space_operations = {
 	.releasepage		= iomap_releasepage,
 	.invalidatepage		= iomap_invalidatepage,
 	.bmap			= xfs_vm_bmap,
-	.direct_IO		= noop_direct_IO,
 	.migratepage		= iomap_migrate_page,
 	.is_partially_uptodate  = iomap_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
 	.swap_activate		= xfs_iomap_swapfile_activate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 const struct address_space_operations xfs_dax_aops = {
 	.writepages		= xfs_dax_writepages,
-	.direct_IO		= noop_direct_IO,
 	.set_page_dirty		= __set_page_dirty_no_writeback,
 	.invalidatepage		= noop_invalidatepage,
 	.swap_activate		= xfs_iomap_swapfile_activate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index ddc346a9df9b..37ff541467e8 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -191,8 +191,8 @@ static const struct address_space_operations zonefs_file_aops = {
 	.migratepage		= iomap_migrate_page,
 	.is_partially_uptodate	= iomap_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
-	.direct_IO		= noop_direct_IO,
 	.swap_activate		= zonefs_swap_activate,
+	.supports		= AS_SUPPORTS_DIRECT_IO,
 };
 
 static void zonefs_update_stats(struct inode *inode, loff_t new_isize)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e7a633353fd2..c909ca6c0eb6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -369,7 +369,10 @@ typedef struct {
 typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
 		unsigned long, unsigned long);
 
+#define AS_SUPPORTS_DIRECT_IO	0x00000001
+
 struct address_space_operations {
+	unsigned int supports; /* Bitmask of AS_SUPPORTS_* flags */
 	int (*writepage)(struct page *page, struct writeback_control *wbc);
 	int (*readpage)(struct file *, struct page *);
 
@@ -3391,7 +3394,6 @@ extern void simple_recursive_removal(struct dentry *,
 extern int noop_fsync(struct file *, loff_t, loff_t, int);
 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_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,



  parent reply	other threads:[~2021-09-24 17:19 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-24 17:17 [RFC][PATCH v3 0/9] mm: Use DIO for swap and fix NFS swapfiles David Howells
2021-09-24 17:18 ` [PATCH v3 1/9] mm: Remove the callback func argument from __swap_writepage() David Howells
2021-09-24 17:18 ` David Howells [this message]
2021-09-24 20:10   ` [PATCH v3 2/9] mm: Add 'supports' field to the address_space_operations to list features Matthew Wilcox
2021-09-24 17:18 ` [PATCH v3 3/9] mm: Make swap_readpage() void David Howells
2021-09-24 22:07   ` Matthew Wilcox
2021-09-24 17:18 ` [PATCH v3 4/9] Introduce IOCB_SWAP kiocb flag to trigger REQ_SWAP David Howells
2021-09-26 21:56   ` Dave Chinner
2021-09-24 17:18 ` [PATCH v3 5/9] mm: Make swap_readpage() for SWP_FS_OPS use ->swap_rw() not ->readpage() David Howells
2021-09-24 17:18 ` [PATCH v3 6/9] mm: Make __swap_writepage() do async DIO if asked for it David Howells
2021-09-24 17:19 ` [PATCH v3 7/9] nfs: Fix write to swapfile failure due to generic_write_checks() David Howells
2021-09-24 17:19 ` [PATCH v3 8/9] block, btrfs, ext4, xfs: Implement swap_rw David Howells
2021-09-24 17:19 ` [PATCH v3 9/9] mm: Remove swap BIO paths and only use DIO paths David Howells
2021-09-25 14:56   ` Matthew Wilcox
2021-09-25 15:36   ` David Howells
2021-09-25 17:09     ` Matthew Wilcox
2021-09-26 23:08       ` Damien Le Moal
2021-09-27  1:25         ` Dave Chinner
2021-09-27  1:41           ` Damien Le Moal
2021-09-27 20:03     ` David Sterba
2021-09-25 23:42 ` [RFC][PATCH v3 0/9] mm: Use DIO for swap and fix NFS swapfiles Dave Chinner
2021-09-26  3:10   ` Matthew Wilcox
2021-09-26 22:36     ` Dave Chinner
2021-09-27 20:07 ` David Sterba
2021-09-28  3:11 ` NeilBrown
2021-09-30 15:54   ` Steve French
2021-09-30 15:54     ` Steve French
2021-09-29 15:45 ` David Howells

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=163250389458.2330363.17234460134406104577.stgit@warthog.procyon.org.uk \
    --to=dhowells@redhat.com \
    --cc=ceph-devel@vger.kernel.org \
    --cc=darrick.wong@oracle.com \
    --cc=djwong@kernel.org \
    --cc=hch@lst.de \
    --cc=idryomov@gmail.com \
    --cc=jlayton@kernel.org \
    --cc=linux-cifs@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=sfrench@samba.org \
    --cc=torvalds@linux-foundation.org \
    --cc=trond.myklebust@primarydata.com \
    --cc=viro@zeniv.linux.org.uk \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.