ceph: add encryption support to writepage

Allow writepage to issue encrypted writes. Extend out the requested size
and offset to cover complete blocks, and then encrypt and write them to
the OSDs.

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 8de6b647658d7237321935134df8d387b24c0c1e..f76586984d8030627e6daf44f040cab23a04d761 100644 (file)
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -598,10 +598,12 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
        loff_t page_off = page_offset(page);
        int err;
        loff_t len = thp_size(page);
+       loff_t wlen;
        struct ceph_writeback_ctl ceph_wbc;
        struct ceph_osd_client *osdc = &fsc->client->osdc;
        struct ceph_osd_request *req;
        bool caching = ceph_is_cache_enabled(inode);
+       struct page *bounce_page = NULL;
 
        dout("writepage %p idx %lu\n", page, page->index);
 
@@ -634,31 +636,50 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
        if (ceph_wbc.i_size < page_off + len)
                len = ceph_wbc.i_size - page_off;
 
+       wlen = IS_ENCRYPTED(inode) ? round_up(len, CEPH_FSCRYPT_BLOCK_SIZE) : len;
        dout("writepage %p page %p index %lu on %llu~%llu snapc %p seq %lld\n",
-            inode, page, page->index, page_off, len, snapc, snapc->seq);
+            inode, page, page->index, page_off, wlen, snapc, snapc->seq);
 
        if (atomic_long_inc_return(&fsc->writeback_count) >
            CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
                fsc->write_congested = true;
 
-       req = ceph_osdc_new_request(osdc, &ci->i_layout, ceph_vino(inode), page_off, &len, 0, 1,
-                                   CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE, snapc,
-                                   ceph_wbc.truncate_seq, ceph_wbc.truncate_size,
-                                   true);
+       req = ceph_osdc_new_request(osdc, &ci->i_layout, ceph_vino(inode),
+                                   page_off, &wlen, 0, 1, CEPH_OSD_OP_WRITE,
+                                   CEPH_OSD_FLAG_WRITE, snapc,
+                                   ceph_wbc.truncate_seq,
+                                   ceph_wbc.truncate_size, true);
        if (IS_ERR(req)) {
                redirty_page_for_writepage(wbc, page);
                return PTR_ERR(req);
        }
 
+       if (wlen < len)
+               len = wlen;
+
        set_page_writeback(page);
        if (caching)
                ceph_set_page_fscache(page);
        ceph_fscache_write_to_cache(inode, page_off, len, caching);
 
+       if (IS_ENCRYPTED(inode)) {
+               bounce_page = fscrypt_encrypt_pagecache_blocks(page, CEPH_FSCRYPT_BLOCK_SIZE,
+                                                               0, GFP_NOFS);
+               if (IS_ERR(bounce_page)) {
+                       redirty_page_for_writepage(wbc, page);
+                       end_page_writeback(page);
+                       ceph_osdc_put_request(req);
+                       return PTR_ERR(bounce_page);
+               }
+       }
+
        /* it may be a short write due to an object boundary */
        WARN_ON_ONCE(len > thp_size(page));
-       osd_req_op_extent_osd_data_pages(req, 0, &page, len, 0, false, false);
-       dout("writepage %llu~%llu (%llu bytes)\n", page_off, len, len);
+       osd_req_op_extent_osd_data_pages(req, 0,
+                       bounce_page ? &bounce_page : &page, wlen, 0,
+                       false, false);
+       dout("writepage %llu~%llu (%llu bytes, %sencrypted)\n",
+            page_off, len, wlen, IS_ENCRYPTED(inode) ? "" : "not ");
 
        req->r_mtime = inode->i_mtime;
        ceph_osdc_start_request(osdc, req);
@@ -666,7 +687,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 
        ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
                                  req->r_end_latency, len, err);
-
+       fscrypt_free_bounce_page(bounce_page);
        ceph_osdc_put_request(req);
        if (err == 0)
                err = len;