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 d386f3b8d5c97a0acff92110de05cecaff2ba578..ec2d4071b110938ecda46a2b77520fdfe390569b 100644 (file)
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -586,10 +586,12 @@ 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);
 
@@ -621,6 +623,8 @@ 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;
+       if (IS_ENCRYPTED(inode))
+               wlen = round_up(len, CEPH_FSCRYPT_BLOCK_SIZE);
 
        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);
@@ -629,24 +633,42 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
            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;
        err = ceph_osdc_start_request(osdc, req, true);
@@ -655,7 +677,7 @@ 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;