[PATCH 09/12] fs/fuse: convert put_page() to put_user_page*()

john.hubbard
2019-07-24T04:26:23Z

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:

* Use the enhanced put_user_pages_dirty_lock().

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: 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>
---
fs/fuse/dev.c | 22 +++++++++++++++++----
fs/fuse/file.c | 53 +++++++++++++++++++++++++++++++++++++-------------
2 files changed, 57 insertions(+), 18 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ea8237513dfa..8ef65c9cd3f6 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -780,6 +780,7 @@ struct fuse_copy_state {
unsigned len;
unsigned offset;
unsigned move_pages:1;
+ bool from_gup;
};

static void fuse_copy_init(struct fuse_copy_state *cs, int write,
@@ -800,13 +801,22 @@ static void fuse_copy_finish(struct fuse_copy_state *cs)
buf->len = PAGE_SIZE - cs->len;
cs->currbuf = NULL;
} else if (cs->pg) {
- if (cs->write) {
- flush_dcache_page(cs->pg);
- set_page_dirty_lock(cs->pg);
+ if (cs->from_gup) {
+ if (cs->write) {
+ flush_dcache_page(cs->pg);
+ put_user_pages_dirty_lock(&cs->pg, 1, true);
+ } else
+ put_user_page(cs->pg);
+ } else {
+ if (cs->write) {
+ flush_dcache_page(cs->pg);
+ set_page_dirty_lock(cs->pg);
+ }
+ put_page(cs->pg);
}
- put_page(cs->pg);
}
cs->pg = NULL;
+ cs->from_gup = false;
}

/*
@@ -834,6 +844,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
BUG_ON(!cs->nr_segs);
cs->currbuf = buf;
cs->pg = buf->page;
+ cs->from_gup = false;
cs->offset = buf->offset;
cs->len = buf->len;
cs->pipebufs++;
@@ -851,6 +862,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
buf->len = 0;

cs->currbuf = buf;
+ cs->from_gup = false;
cs->pg = page;
cs->offset = 0;
cs->len = PAGE_SIZE;
@@ -866,6 +878,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
cs->len = err;
cs->offset = off;
cs->pg = page;
+ cs->from_gup = iov_iter_get_pages_use_gup(cs->iter);
iov_iter_advance(cs->iter, err);
}

@@ -1000,6 +1013,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
unlock_page(newpage);
out_fallback:
cs->pg = buf->page;
+ cs->from_gup = false;
cs->offset = buf->offset;

err = lock_request(cs->req);
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 5ae2828beb00..c34c22ac5b22 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -543,12 +543,20 @@ void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
req->out.args[0].size = count;
}

-static void fuse_release_user_pages(struct fuse_req *req, bool should_dirty)
+static void fuse_release_user_pages(struct fuse_req *req, bool should_dirty,
+ bool from_gup)
{
unsigned i;

+ if (from_gup) {
+ put_user_pages_dirty_lock(req->pages, req->num_pages,
+ should_dirty);
+ return;
+ }
+
for (i = 0; i < req->num_pages; i++) {
struct page *page = req->pages[i];
+
if (should_dirty)
set_page_dirty_lock(page);
put_page(page);
@@ -621,12 +629,13 @@ static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
kref_put(&io->refcnt, fuse_io_release);
}

-static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
+static void _fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req,
+ bool from_gup)
{
struct fuse_io_priv *io = req->io;
ssize_t pos = -1;

- fuse_release_user_pages(req, io->should_dirty);
+ fuse_release_user_pages(req, io->should_dirty, from_gup);

if (io->write) {
if (req->misc.write.in.size != req->misc.write.out.size)
@@ -641,8 +650,18 @@ static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
fuse_aio_complete(io, req->out.h.error, pos);
}

+static void fuse_aio_from_gup_complete_req(struct fuse_conn *fc, struct fuse_req *req)
+{
+ _fuse_aio_complete_req(fc, req, true);
+}
+
+static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
+{
+ _fuse_aio_complete_req(fc, req, false);
+}
+
static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
- size_t num_bytes, struct fuse_io_priv *io)
+ size_t num_bytes, struct fuse_io_priv *io, bool from_gup)
{
spin_lock(&io->lock);
kref_get(&io->refcnt);
@@ -651,7 +670,8 @@ static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
spin_unlock(&io->lock);

req->io = io;
- req->end = fuse_aio_complete_req;
+ req->end = from_gup ? fuse_aio_from_gup_complete_req :
+ fuse_aio_complete_req;

__fuse_get_request(req);
fuse_request_send_background(fc, req);
@@ -660,7 +680,8 @@ static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
}

static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
- loff_t pos, size_t count, fl_owner_t owner)
+ loff_t pos, size_t count, fl_owner_t owner,
+ bool from_gup)
{
struct file *file = io->iocb->ki_filp;
struct fuse_file *ff = file->private_data;
@@ -675,7 +696,7 @@ static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
}

if (io->async)
- return fuse_async_req_send(fc, req, count, io);
+ return fuse_async_req_send(fc, req, count, io, from_gup);

fuse_request_send(fc, req);
return req->out.args[0].size;
@@ -755,7 +776,7 @@ static int fuse_do_readpage(struct file *file, struct page *page)
req->page_descs[0].length = count;
init_sync_kiocb(&iocb, file);
io = (struct fuse_io_priv) FUSE_IO_PRIV_SYNC(&iocb);
- num_read = fuse_send_read(req, &io, pos, count, NULL);
+ num_read = fuse_send_read(req, &io, pos, count, NULL, false);
err = req->out.h.error;

if (!err) {
@@ -976,7 +997,8 @@ static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
}

static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
- loff_t pos, size_t count, fl_owner_t owner)
+ loff_t pos, size_t count, fl_owner_t owner,
+ bool from_gup)
{
struct kiocb *iocb = io->iocb;
struct file *file = iocb->ki_filp;
@@ -996,7 +1018,7 @@ static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
}

if (io->async)
- return fuse_async_req_send(fc, req, count, io);
+ return fuse_async_req_send(fc, req, count, io, from_gup);

fuse_request_send(fc, req);
return req->misc.write.out.size;
@@ -1031,7 +1053,7 @@ static size_t fuse_send_write_pages(struct fuse_req *req, struct kiocb *iocb,
for (i = 0; i < req->num_pages; i++)
fuse_wait_on_page_writeback(inode, req->pages[i]->index);

- res = fuse_send_write(req, &io, pos, count, NULL);
+ res = fuse_send_write(req, &io, pos, count, NULL, false);

offset = req->page_descs[0].offset;
count = res;
@@ -1351,6 +1373,7 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
ssize_t res = 0;
struct fuse_req *req;
int err = 0;
+ bool from_gup = iov_iter_get_pages_use_gup(iter);

if (io->async)
req = fuse_get_req_for_background(fc, iov_iter_npages(iter,
@@ -1384,13 +1407,15 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
inarg = &req->misc.write.in;
inarg->write_flags |= FUSE_WRITE_KILL_PRIV;
}
- nres = fuse_send_write(req, io, pos, nbytes, owner);
+ nres = fuse_send_write(req, io, pos, nbytes, owner,
+ from_gup);
} else {
- nres = fuse_send_read(req, io, pos, nbytes, owner);
+ nres = fuse_send_read(req, io, pos, nbytes, owner,
+ from_gup);
}

if (!io->async)
- fuse_release_user_pages(req, io->should_dirty);
+ fuse_release_user_pages(req, io->should_dirty, from_gup);
if (req->out.h.error) {
err = req->out.h.error;
break;
--
2.22.0