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>
This commit is contained in:
Dan Williams 2018-03-07 15:26:44 -08:00
parent 15aa8a0118
commit 6e2608dfd9
3 changed files with 23 additions and 17 deletions

View File

@ -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 @@ out_unlock:
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,
};

View File

@ -54,6 +54,7 @@ struct xfs_ioend {
};
extern const struct address_space_operations xfs_address_space_operations;
extern const struct address_space_operations xfs_dax_aops;
int xfs_setfilesize(struct xfs_inode *ip, xfs_off_t offset, size_t size);

View File

@ -1272,7 +1272,10 @@ xfs_setup_iops(
case S_IFREG:
inode->i_op = &xfs_inode_operations;
inode->i_fop = &xfs_file_operations;
inode->i_mapping->a_ops = &xfs_address_space_operations;
if (IS_DAX(inode))
inode->i_mapping->a_ops = &xfs_dax_aops;
else
inode->i_mapping->a_ops = &xfs_address_space_operations;
break;
case S_IFDIR:
if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb))