On Wed, 2022-04-27 at 15:13 -0400, Jeff Layton wrote:
> 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@xxxxxxxxxx>
> ---
> 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 d65d431ec933..f54940fc96ee 100644
> --- 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);
>
The above is buggy. We're only setting "wlen" in the encrypted case. You
would think that the compiler would catch that, but next usage of wlen
just passes a pointer to it to another function and that cloaks the
warning.
Fixed in the wip-fscrypt branch, but I'll hold off on re-posting the
series in case any other new bugs turn up.
> 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 +633,39 @@ 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)) {
> + 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);
> @@ -655,7 +674,8 @@ 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;
--
Jeff Layton <jlayton@xxxxxxxxxx>
