[RFC PATCH v11 48/51] ceph: add fscrypt decryption support to ceph_netfs_issue_op

[Jeff Layton <jlayton@xxxxxxxxxx>]

Force the use of sparse reads when the inode is encrypted, and add the
appropriate code to decrypt the extent map after receiving.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 fs/ceph/addr.c | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 15bc455bc87f..13a37a568a1d 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -18,6 +18,7 @@
 #include "mds_client.h"
 #include "cache.h"
 #include "metric.h"
+#include "crypto.h"
 #include <linux/ceph/osd_client.h>
 #include <linux/ceph/striper.h>
 
@@ -217,7 +218,8 @@ static bool ceph_netfs_clamp_length(struct netfs_read_subrequest *subreq)
 
 static void finish_netfs_read(struct ceph_osd_request *req)
 {
-	struct ceph_fs_client *fsc = ceph_inode_to_client(req->r_inode);
+	struct inode *inode = req->r_inode;
+	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 	struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
 	struct netfs_read_subrequest *subreq = req->r_priv;
 	struct ceph_osd_req_op *op = &req->r_ops[0];
@@ -232,15 +234,24 @@ static void finish_netfs_read(struct ceph_osd_request *req)
 	     subreq->len, i_size_read(req->r_inode));
 
 	/* no object means success but no data */
-	if (sparse && err >= 0)
-		err = ceph_sparse_ext_map_end(op);
-	else if (err == -ENOENT)
+	if (err == -ENOENT)
 		err = 0;
 	else if (err == -EBLOCKLISTED)
 		fsc->blocklisted = true;
 
-	if (err >= 0 && err < subreq->len)
-		__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+	if (err >= 0) {
+		if (sparse && err > 0)
+			err = ceph_sparse_ext_map_end(op);
+		if (err < subreq->len)
+			__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+		if (IS_ENCRYPTED(inode) && err > 0) {
+			err = ceph_fscrypt_decrypt_extents(inode, osd_data->pages,
+					subreq->start, op->extent.sparse_ext,
+					op->extent.sparse_ext_cnt);
+			if (err > subreq->len)
+				err = subreq->len;
+		}
+	}
 
 	netfs_subreq_terminated(subreq, err, true);
 
@@ -315,13 +326,16 @@ static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
 	size_t page_off;
 	int err = 0;
 	u64 len = subreq->len;
-	bool sparse = ceph_test_mount_opt(fsc, SPARSEREAD);
+	bool sparse = IS_ENCRYPTED(inode) || ceph_test_mount_opt(fsc, SPARSEREAD);
+	u64 off = subreq->start;
 
 	if (ci->i_inline_version != CEPH_INLINE_NONE &&
 	    ceph_netfs_issue_op_inline(subreq))
 		return;
 
-	req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, vino, subreq->start, &len,
+	ceph_fscrypt_adjust_off_and_len(inode, &off, &len);
+
+	req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, vino, off, &len,
 			0, 1, sparse ? CEPH_OSD_OP_SPARSE_READ : CEPH_OSD_OP_READ,
 			CEPH_OSD_FLAG_READ | fsc->client->osdc.client->options->read_from_replica,
 			NULL, ci->i_truncate_seq, ci->i_truncate_size, false);
@@ -341,7 +355,7 @@ static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
 	}
 
 	dout("%s: pos=%llu orig_len=%zu len=%llu\n", __func__, subreq->start, subreq->len, len);
-	iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages, subreq->start, len);
+	iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages, off, len);
 	err = iov_iter_get_pages_alloc(&iter, &pages, len, &page_off);
 	if (err < 0) {
 		dout("%s: iov_ter_get_pages_alloc returned %d\n", __func__, err);
-- 
2.35.1