Make nfsd_splice_actor work with reads with a non-zero offset that doesn't end on a page boundary.
This was found when virtual machines with nfs-mounted qcow2 disks failed to boot properly (originally found
on v6.0.5, fix also needed and tested on v6.0.9 and v6.1-rc6).
Signed-off-by: Anders Blomdell <anders.blomdell@xxxxxxxxxxxxxx>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2142132
Fixes: bfbfb6182ad1 "nfsd_splice_actor(): handle compound pages"
Cc: stable@xxxxxxxxxxxxxxx # v6.0+
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -873,7 +873,7 @@ nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
unsigned offset = buf->offset;
page += offset / PAGE_SIZE;
- for (int i = sd->len; i > 0; i -= PAGE_SIZE)
+ for (int i = sd->len + offset % PAGE_SIZE; i > 0; i -= PAGE_SIZE)
svc_rqst_replace_page(rqstp, page++);
if (rqstp->rq_res.page_len == 0) // first call
rqstp->rq_res.page_base = offset % PAGE_SIZE;
--
Anders Blomdell Email: anders.blomdell@xxxxxxxxxxxxxx
Department of Automatic Control
Lund University Phone: +46 46 222 4625
P.O. Box 118
SE-221 00 Lund, Sweden
