This is a note to let you know that I've just added the patch titled
fsdax,xfs: port unshare to fsdax
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fsdax-xfs-port-unshare-to-fsdax.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9720d2239d04b6d2a2b961b35beaf1420468587d
Author: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
Date: Thu Dec 1 15:32:33 2022 +0000
fsdax,xfs: port unshare to fsdax
[ Upstream commit d984648e428bf88cbd94ebe346c73632cb92fffb ]
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@xxxxxxxxxxx
Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Stable-dep-of: a311a08a4237 ("iomap: constrain the file range passed to iomap_file_unshare")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/dax.c b/fs/dax.c
index 1c6867810cbd6..626745bc1ad86 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1221,6 +1221,58 @@ 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;
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 93bdd25680bc9..fe46bce8cae63 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1693,8 +1693,12 @@ xfs_reflink_unshare(
inode_dio_wait(inode);
- error = iomap_file_unshare(inode, offset, len,
- &xfs_buffered_write_iomap_ops);
+ 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)
goto out;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index ba985333e26bf..2b5ecb5910591 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -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,
