Commit d984648e authored by Shiyang Ruan's avatar Shiyang Ruan Committed by Andrew Morton
Browse files

fsdax,xfs: port unshare to fsdax 

Implement unshare in fsdax mode: copy data from srcmap to iomap.

Link: https://lkml.kernel.org/r/1669908753-169-1-git-send-email-ruansy.fnst@fujitsu.com


Signed-off-by: default avatarShiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 64e6edc1

fs/dax.c

+52 −0
Original line number Diff line number Diff line
@@ -1245,6 +1245,58 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, 
}

#endif /* CONFIG_FS_DAX_PMD */



static s64 dax_unshare_iter(struct iomap_iter *iter)

{

	struct iomap *iomap = &iter->iomap;

	const struct iomap *srcmap = iomap_iter_srcmap(iter);

	loff_t pos = iter->pos;

	loff_t length = iomap_length(iter);

	int id = 0;

	s64 ret = 0;

	void *daddr = NULL, *saddr = NULL;



	/* don't bother with blocks that are not shared to start with */

	if (!(iomap->flags & IOMAP_F_SHARED))

		return length;

	/* don't bother with holes or unwritten extents */

	if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)

		return length;



	id = dax_read_lock();

	ret = dax_iomap_direct_access(iomap, pos, length, &daddr, NULL);

	if (ret < 0)

		goto out_unlock;



	ret = dax_iomap_direct_access(srcmap, pos, length, &saddr, NULL);

	if (ret < 0)

		goto out_unlock;



	ret = copy_mc_to_kernel(daddr, saddr, length);

	if (ret)

		ret = -EIO;



out_unlock:

	dax_read_unlock(id);

	return ret;

}



int dax_file_unshare(struct inode *inode, loff_t pos, loff_t len,

		const struct iomap_ops *ops)

{

	struct iomap_iter iter = {

		.inode		= inode,

		.pos		= pos,

		.len		= len,

		.flags		= IOMAP_WRITE | IOMAP_UNSHARE | IOMAP_DAX,

	};

	int ret;



	while ((ret = iomap_iter(&iter, ops)) > 0)

		iter.processed = dax_unshare_iter(&iter);

	return ret;

}

EXPORT_SYMBOL_GPL(dax_file_unshare);



static int dax_memzero(struct iomap_iter *iter, loff_t pos, size_t size)

{

	const struct iomap *iomap = &iter->iomap;

fs/xfs/xfs_reflink.c

+6 −2
Original line number Diff line number Diff line
@@ -1693,6 +1693,10 @@ xfs_reflink_unshare( 


	inode_dio_wait(inode);



	if (IS_DAX(inode))

		error = dax_file_unshare(inode, offset, len,

				&xfs_dax_write_iomap_ops);

	else

		error = iomap_file_unshare(inode, offset, len,

				&xfs_buffered_write_iomap_ops);

	if (error)

include/linux/dax.h

+2 −0
Original line number Diff line number Diff line
@@ -205,6 +205,8 @@ static inline void dax_unlock_mapping_entry(struct address_space *mapping, 
}

#endif



int dax_file_unshare(struct inode *inode, loff_t pos, loff_t len,

		const struct iomap_ops *ops);

int dax_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,

		const struct iomap_ops *ops);

int dax_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,