ceph: add fscrypt decryption support to ceph_netfs_issue_op

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

Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 3369c54d8002a6cfef71855216d7a84ada47d919..8de6b647658d7237321935134df8d387b24c0c1e 100644 (file)
--- 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>
 
@@ -216,7 +217,8 @@ static bool ceph_netfs_clamp_length(struct netfs_io_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_io_subrequest *subreq = req->r_priv;
        struct ceph_osd_req_op *op = &req->r_ops[0];
@@ -230,16 +232,30 @@ 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;
+               }
+       }
 
+       if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
+               ceph_put_page_vector(osd_data->pages,
+                                    calc_pages_for(osd_data->alignment,
+                                       osd_data->length), false);
+       }
        netfs_subreq_terminated(subreq, err, false);
        iput(req->r_inode);
 }
@@ -310,12 +326,15 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq)
        struct iov_iter iter;
        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 (ceph_has_inline_data(ci) && 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);
@@ -334,8 +353,35 @@ static void ceph_netfs_issue_read(struct netfs_io_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);
-       osd_req_op_extent_osd_iter(req, 0, &iter);
+
+       /*
+        * FIXME: For now, use CEPH_OSD_DATA_TYPE_PAGES instead of _ITER for
+        * encrypted inodes. We'd need infrastructure that handles an iov_iter
+        * instead of page arrays, and we don't have that as of yet. Once the
+        * dust settles on the write helpers and encrypt/decrypt routines for
+        * netfs, we should be able to rework this.
+        */
+       if (IS_ENCRYPTED(inode)) {
+               struct page **pages;
+               size_t page_off;
+
+               err = iov_iter_get_pages_alloc2(&iter, &pages, len, &page_off);
+               if (err < 0) {
+                       dout("%s: iov_ter_get_pages_alloc returned %d\n", __func__, err);
+                       goto out;
+               }
+
+               /* should always give us a page-aligned read */
+               WARN_ON_ONCE(page_off);
+               len = err;
+               err = 0;
+
+               osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
+       } else {
+               osd_req_op_extent_osd_iter(req, 0, &iter);
+       }
        req->r_callback = finish_netfs_read;
        req->r_priv = subreq;
        req->r_inode = inode;