| Message ID | 20190724042518.14363-8-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block/bio, fs: convert put_page() to put_user_page*() | expand |
On 7/23/19 9:25 PM, john.hubbard@gmail.com wrote: > From: Jérôme Glisse <jglisse@redhat.com> > > For pages that were retained via get_user_pages*(), release those pages > via the new put_user_page*() routines, instead of via put_page(). > > This is part a tree-wide conversion, as described in commit fc1d8e7cca2d > ("mm: introduce put_user_page*(), placeholder versions"). > > Changes from Jérôme's original patch: > > * Changed a WARN_ON to a BUG_ON. > Clearly, the above commit log has it backwards (this is quite my night for typos). Please read that as "changed a BUG_ON to a WARN_ON". I'll correct the commit description in next iteration of this patchset. ... > + /* > + * Here in all cases we should have an IOVEC which use GUP. If that is > + * not the case then we will wrongly call put_user_page() and the page > + * refcount will go wrong (this is in vhost_scsi_release_cmd()) > + */ > + WARN_ON(!iov_iter_get_pages_use_gup(iter)); > + ... thanks,
On Tue, Jul 23, 2019 at 09:25:13PM -0700, john.hubbard@gmail.com wrote: > From: Jérôme Glisse <jglisse@redhat.com> > > For pages that were retained via get_user_pages*(), release those pages > via the new put_user_page*() routines, instead of via put_page(). > > This is part a tree-wide conversion, as described in commit fc1d8e7cca2d > ("mm: introduce put_user_page*(), placeholder versions"). > > Changes from Jérôme's original patch: > > * Changed a WARN_ON to a BUG_ON. > > Signed-off-by: Jérôme Glisse <jglisse@redhat.com> > Signed-off-by: John Hubbard <jhubbard@nvidia.com> > Cc: virtualization@lists.linux-foundation.org > Cc: linux-fsdevel@vger.kernel.org > Cc: linux-block@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: Jan Kara <jack@suse.cz> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Cc: Johannes Thumshirn <jthumshirn@suse.de> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: Ming Lei <ming.lei@redhat.com> > Cc: Dave Chinner <david@fromorbit.com> > Cc: Jason Gunthorpe <jgg@ziepe.ca> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: Boaz Harrosh <boaz@plexistor.com> > Cc: Miklos Szeredi <miklos@szeredi.hu> > Cc: "Michael S. Tsirkin" <mst@redhat.com> > Cc: Jason Wang <jasowang@redhat.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/vhost/scsi.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c > index a9caf1bc3c3e..282565ab5e3f 100644 > --- a/drivers/vhost/scsi.c > +++ b/drivers/vhost/scsi.c > @@ -329,11 +329,11 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) > > if (tv_cmd->tvc_sgl_count) { > for (i = 0; i < tv_cmd->tvc_sgl_count; i++) > - put_page(sg_page(&tv_cmd->tvc_sgl[i])); > + put_user_page(sg_page(&tv_cmd->tvc_sgl[i])); > } > if (tv_cmd->tvc_prot_sgl_count) { > for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++) > - put_page(sg_page(&tv_cmd->tvc_prot_sgl[i])); > + put_user_page(sg_page(&tv_cmd->tvc_prot_sgl[i])); > } > > vhost_scsi_put_inflight(tv_cmd->inflight); > @@ -630,6 +630,13 @@ vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd, > size_t offset; > unsigned int npages = 0; > > + /* > + * Here in all cases we should have an IOVEC which use GUP. If that is > + * not the case then we will wrongly call put_user_page() and the page > + * refcount will go wrong (this is in vhost_scsi_release_cmd()) > + */ > + WARN_ON(!iov_iter_get_pages_use_gup(iter)); > + > bytes = iov_iter_get_pages(iter, pages, LONG_MAX, > VHOST_SCSI_PREALLOC_UPAGES, &offset); > /* No pages were pinned */ > @@ -681,7 +688,7 @@ vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write, > while (p < sg) { > struct page *page = sg_page(p++); > if (page) > - put_page(page); > + put_user_page(page); > } > return ret; > } > -- > 2.22.0
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index a9caf1bc3c3e..282565ab5e3f 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -329,11 +329,11 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) if (tv_cmd->tvc_sgl_count) { for (i = 0; i < tv_cmd->tvc_sgl_count; i++) - put_page(sg_page(&tv_cmd->tvc_sgl[i])); + put_user_page(sg_page(&tv_cmd->tvc_sgl[i])); } if (tv_cmd->tvc_prot_sgl_count) { for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++) - put_page(sg_page(&tv_cmd->tvc_prot_sgl[i])); + put_user_page(sg_page(&tv_cmd->tvc_prot_sgl[i])); } vhost_scsi_put_inflight(tv_cmd->inflight); @@ -630,6 +630,13 @@ vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd, size_t offset; unsigned int npages = 0; + /* + * Here in all cases we should have an IOVEC which use GUP. If that is + * not the case then we will wrongly call put_user_page() and the page + * refcount will go wrong (this is in vhost_scsi_release_cmd()) + */ + WARN_ON(!iov_iter_get_pages_use_gup(iter)); + bytes = iov_iter_get_pages(iter, pages, LONG_MAX, VHOST_SCSI_PREALLOC_UPAGES, &offset); /* No pages were pinned */ @@ -681,7 +688,7 @@ vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write, while (p < sg) { struct page *page = sg_page(p++); if (page) - put_page(page); + put_user_page(page); } return ret; }