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authorShiyang Ruan <ruansy.fnst@fujitsu.com>2022-12-01 18:32:33 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-12-12 05:12:17 +0300
commitd984648e428bf88cbd94ebe346c73632cb92fffb (patch)
treeae98da0d9db614433a4137c7ee6cc1613cc12574 /fs/dax.c
parent64e6edc185da7e101e867c4732c097fedb1da08e (diff)
downloadlinux-d984648e428bf88cbd94ebe346c73632cb92fffb.tar.xz
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: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Darrick 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: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/dax.c')
-rw-r--r--fs/dax.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/fs/dax.c b/fs/dax.c
index 8fb928cd9dce..c48a3a93ab29 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -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;