[RFC PATCH v11 50/51] ceph: add encryption support to writepage

Jeff Layton
2022-03-22T14:18:37Z

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.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/addr.c | 34 +++++++++++++++++++++++++++-------
1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 13a37a568a1d..403e7a960a4e 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -594,10 +594,12 @@ 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);

@@ -628,6 +630,8 @@ 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);
@@ -636,22 +640,37 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);

- 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))
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)) {
+ err = PTR_ERR(bounce_page);
+ goto out;
+ }
+ }
/* 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);
@@ -660,7 +679,8 @@ 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);
+out:
ceph_osdc_put_request(req);
if (err == 0)
err = len;
--
2.35.1