xfs, dax: introduce xfs_dax_aops
In preparation for the dax implementation to start associating dax pages
to inodes via page->mapping, we need to provide a 'struct
address_space_operations' instance for dax. Otherwise, direct-I/O
triggers incorrect page cache assumptions and warnings like the
following:
WARNING: CPU: 27 PID: 1783 at fs/xfs/xfs_aops.c:1468
xfs_vm_set_page_dirty+0xf3/0x1b0 [xfs]
[..]
CPU: 27 PID: 1783 Comm: dma-collision Tainted: G O 4.15.0-rc2+ #984
[..]
Call Trace:
set_page_dirty_lock+0x40/0x60
bio_set_pages_dirty+0x37/0x50
iomap_dio_actor+0x2b7/0x3b0
? iomap_dio_zero+0x110/0x110
iomap_apply+0xa4/0x110
iomap_dio_rw+0x29e/0x3b0
? iomap_dio_zero+0x110/0x110
? xfs_file_dio_aio_read+0x7c/0x1a0 [xfs]
xfs_file_dio_aio_read+0x7c/0x1a0 [xfs]
xfs_file_read_iter+0xa0/0xc0 [xfs]
__vfs_read+0xf9/0x170
vfs_read+0xa6/0x150
SyS_pread64+0x93/0xb0
entry_SYSCALL_64_fastpath+0x1f/0x96
...where the default set_page_dirty() handler assumes that dirty state
is being tracked in 'struct page' flags.
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Jan Kara <jack@suse.cz>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 9c6a830..e7a56c4 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1194,16 +1194,22 @@ xfs_vm_writepages(
int ret;
xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
- if (dax_mapping(mapping))
- return dax_writeback_mapping_range(mapping,
- xfs_find_bdev_for_inode(mapping->host), wbc);
-
ret = write_cache_pages(mapping, wbc, xfs_do_writepage, &wpc);
if (wpc.ioend)
ret = xfs_submit_ioend(wbc, wpc.ioend, ret);
return ret;
}
+STATIC int
+xfs_dax_writepages(
+ struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
+ return dax_writeback_mapping_range(mapping,
+ xfs_find_bdev_for_inode(mapping->host), wbc);
+}
+
/*
* Called to move a page into cleanable state - and from there
* to be released. The page should already be clean. We always
@@ -1367,17 +1373,6 @@ xfs_get_blocks(
return error;
}
-STATIC ssize_t
-xfs_vm_direct_IO(
- struct kiocb *iocb,
- struct iov_iter *iter)
-{
- /*
- * We just need the method present so that open/fcntl allow direct I/O.
- */
- return -EINVAL;
-}
-
STATIC sector_t
xfs_vm_bmap(
struct address_space *mapping,
@@ -1500,8 +1495,15 @@ const struct address_space_operations xfs_address_space_operations = {
.releasepage = xfs_vm_releasepage,
.invalidatepage = xfs_vm_invalidatepage,
.bmap = xfs_vm_bmap,
- .direct_IO = xfs_vm_direct_IO,
+ .direct_IO = noop_direct_IO,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
};
+
+const struct address_space_operations xfs_dax_aops = {
+ .writepages = xfs_dax_writepages,
+ .direct_IO = noop_direct_IO,
+ .set_page_dirty = noop_set_page_dirty,
+ .invalidatepage = noop_invalidatepage,
+};