[PATCH 08/12] fs/cifs: convert put_page() to put_user_page*()

[john.hubbard@gmail.com]

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").

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-block@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-cifs@vger.kernel.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: Steve French <sfrench@samba.org>
---
 fs/cifs/cifsglob.h |  3 +++
 fs/cifs/file.c     | 22 +++++++++++++++++-----
 fs/cifs/misc.c     | 19 +++++++++++++++----
 3 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index fe610e7e3670..e95cb82bfa50 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1283,6 +1283,7 @@ struct cifs_aio_ctx {
 	 * If yes, iter is a copy of the user passed iov_iter
 	 */
 	bool			direct_io;
+	bool			from_gup;
 };
 
 struct cifs_readdata;
@@ -1317,6 +1318,7 @@ struct cifs_readdata {
 	struct cifs_credits		credits;
 	unsigned int			nr_pages;
 	struct page			**pages;
+	bool				from_gup;
 };
 
 struct cifs_writedata;
@@ -1343,6 +1345,7 @@ struct cifs_writedata {
 	struct cifs_credits		credits;
 	unsigned int			nr_pages;
 	struct page			**pages;
+	bool				from_gup;
 };
 
 /*
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 97090693d182..84fa7e0a578f 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2571,8 +2571,13 @@ cifs_uncached_writedata_release(struct kref *refcount)
 					struct cifs_writedata, refcount);
 
 	kref_put(&wdata->ctx->refcount, cifs_aio_ctx_release);
-	for (i = 0; i < wdata->nr_pages; i++)
-		put_page(wdata->pages[i]);
+	if (wdata->from_gup) {
+		for (i = 0; i < wdata->nr_pages; i++)
+			put_user_page(wdata->pages[i]);
+	} else {
+		for (i = 0; i < wdata->nr_pages; i++)
+			put_page(wdata->pages[i]);
+	}
 	cifs_writedata_release(refcount);
 }
 
@@ -2781,7 +2786,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
 				break;
 			}
 
-
+			wdata->from_gup = iov_iter_get_pages_use_gup(from);
 			wdata->page_offset = start;
 			wdata->tailsz =
 				nr_pages > 1 ?
@@ -2797,6 +2802,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
 				add_credits_and_wake_if(server, credits, 0);
 				break;
 			}
+			wdata->from_gup = false;
 
 			rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
 			if (rc) {
@@ -3238,8 +3244,12 @@ cifs_uncached_readdata_release(struct kref *refcount)
 	unsigned int i;
 
 	kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release);
-	for (i = 0; i < rdata->nr_pages; i++) {
-		put_page(rdata->pages[i]);
+	if (rdata->from_gup) {
+		for (i = 0; i < rdata->nr_pages; i++)
+			put_user_page(rdata->pages[i]);
+	} else {
+		for (i = 0; i < rdata->nr_pages; i++)
+			put_page(rdata->pages[i]);
 	}
 	cifs_readdata_release(refcount);
 }
@@ -3502,6 +3512,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
 				break;
 			}
 
+			rdata->from_gup = iov_iter_get_pages_use_gup(&direct_iov);
 			npages = (cur_len + start + PAGE_SIZE-1) / PAGE_SIZE;
 			rdata->page_offset = start;
 			rdata->tailsz = npages > 1 ?
@@ -3519,6 +3530,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
 				rc = -ENOMEM;
 				break;
 			}
+			rdata->from_gup = false;
 
 			rc = cifs_read_allocate_pages(rdata, npages);
 			if (rc) {
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index f383877a6511..5a04c34fea05 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -822,10 +822,18 @@ cifs_aio_ctx_release(struct kref *refcount)
 	if (ctx->bv) {
 		unsigned i;
 
-		for (i = 0; i < ctx->npages; i++) {
-			if (ctx->should_dirty)
-				set_page_dirty(ctx->bv[i].bv_page);
-			put_page(ctx->bv[i].bv_page);
+		if (ctx->from_gup) {
+			for (i = 0; i < ctx->npages; i++) {
+				if (ctx->should_dirty)
+					set_page_dirty(ctx->bv[i].bv_page);
+				put_user_page(ctx->bv[i].bv_page);
+			}
+		} else {
+			for (i = 0; i < ctx->npages; i++) {
+				if (ctx->should_dirty)
+					set_page_dirty(ctx->bv[i].bv_page);
+				put_page(ctx->bv[i].bv_page);
+			}
 		}
 		kvfree(ctx->bv);
 	}
@@ -881,6 +889,9 @@ setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
 
 	saved_len = count;
 
+	/* This is only use by cifs_aio_ctx_release() */
+	ctx->from_gup = iov_iter_get_pages_use_gup(iter);
+
 	while (count && npages < max_pages) {
 		rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
 		if (rc < 0) {
-- 
2.22.0