From: Miklos Szeredi <mszeredi@redhat.com>
Date: Tue, 10 Sep 2019 15:04:10 +0200
Subject: fuse: convert direct_io to simple api
Git-commit: 45ac96ed7c369112039289cc7c325a5682ef7c03
Patch-mainline: v5.4-rc1
References: jsc#SLE-13782
Change of semantics in fuse_async_req_send/fuse_send_(read|write): these
can now return error, in which case the 'end' callback isn't called, so the
fuse_io_args object needs to be freed.
Added verification that the return value is sane (less than or equal to the
requested read/write size).
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
fs/fuse/file.c | 219 ++++++++++++++++++++++++++++++++-------------------------
1 file changed, 124 insertions(+), 95 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 1dc499ad8606..ee0817a3d5f1 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -563,6 +563,7 @@ struct fuse_io_args {
} write;
};
struct fuse_args_pages ap;
+ struct fuse_io_priv *io;
};
void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
@@ -585,15 +586,15 @@ void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
args->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_args_pages *ap,
+ bool should_dirty)
{
- unsigned i;
+ unsigned int i;
- for (i = 0; i < req->num_pages; i++) {
- struct page *page = req->pages[i];
+ for (i = 0; i < ap->num_pages; i++) {
if (should_dirty)
- set_page_dirty_lock(page);
- put_page(page);
+ set_page_dirty_lock(ap->pages[i]);
+ put_page(ap->pages[i]);
}
}
@@ -663,64 +664,94 @@ 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 struct fuse_io_args *fuse_io_alloc(struct fuse_io_priv *io,
+ unsigned int npages)
+{
+ struct fuse_io_args *ia;
+
+ ia = kzalloc(sizeof(*ia), GFP_KERNEL);
+ if (ia) {
+ ia->io = io;
+ ia->ap.pages = fuse_pages_alloc(npages, GFP_KERNEL,
+ &ia->ap.descs);
+ if (!ia->ap.pages) {
+ kfree(ia);
+ ia = NULL;
+ }
+ }
+ return ia;
+}
+
+static void fuse_io_free(struct fuse_io_args *ia)
+{
+ kfree(ia->ap.pages);
+ kfree(ia);
+}
+
+static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_args *args,
+ int err)
{
- struct fuse_io_priv *io = req->io;
+ struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args);
+ struct fuse_io_priv *io = ia->io;
ssize_t pos = -1;
- fuse_release_user_pages(req, io->should_dirty);
+ fuse_release_user_pages(&ia->ap, io->should_dirty);
- if (io->write) {
- if (req->misc.write.in.size != req->misc.write.out.size)
- pos = req->misc.write.in.offset - io->offset +
- req->misc.write.out.size;
+ if (err) {
+ /* Nothing */
+ } else if (io->write) {
+ if (ia->write.out.size > ia->write.in.size) {
+ err = -EIO;
+ } else if (ia->write.in.size != ia->write.out.size) {
+ pos = ia->write.in.offset - io->offset +
+ ia->write.out.size;
+ }
} else {
- if (req->misc.read.in.size != req->out.args[0].size)
- pos = req->misc.read.in.offset - io->offset +
- req->out.args[0].size;
+ u32 outsize = args->out_args[0].size;
+
+ if (ia->read.in.size != outsize)
+ pos = ia->read.in.offset - io->offset + outsize;
}
- fuse_aio_complete(io, req->out.h.error, pos);
+ fuse_aio_complete(io, err, pos);
+ fuse_io_free(ia);
}
-static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
- size_t num_bytes, struct fuse_io_priv *io)
+static ssize_t fuse_async_req_send(struct fuse_conn *fc,
+ struct fuse_io_args *ia, size_t num_bytes)
{
+ ssize_t err;
+ struct fuse_io_priv *io = ia->io;
+
spin_lock(&io->lock);
kref_get(&io->refcnt);
io->size += num_bytes;
io->reqs++;
spin_unlock(&io->lock);
- req->io = io;
- req->end = fuse_aio_complete_req;
-
- __fuse_get_request(req);
- fuse_request_send_background(fc, req);
+ ia->ap.args.end = fuse_aio_complete_req;
+ err = fuse_simple_background(fc, &ia->ap.args, GFP_KERNEL);
- return num_bytes;
+ return err ?: num_bytes;
}
-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)
+static ssize_t fuse_send_read(struct fuse_io_args *ia, loff_t pos, size_t count,
+ fl_owner_t owner)
{
- struct file *file = io->iocb->ki_filp;
+ struct file *file = ia->io->iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
- fuse_read_fill(req, file, pos, count, FUSE_READ);
+ fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
if (owner != NULL) {
- struct fuse_read_in *inarg = &req->misc.read.in;
-
- inarg->read_flags |= FUSE_READ_LOCKOWNER;
- inarg->lock_owner = fuse_lock_owner_id(fc, owner);
+ ia->read.in.read_flags |= FUSE_READ_LOCKOWNER;
+ ia->read.in.lock_owner = fuse_lock_owner_id(fc, owner);
}
- if (io->async)
- return fuse_async_req_send(fc, req, count, io);
+ if (ia->io->async)
+ return fuse_async_req_send(fc, ia, count);
- fuse_request_send(fc, req);
- return req->out.args[0].size;
+ return fuse_simple_request(fc, &ia->ap.args);
}
static void fuse_read_update_size(struct inode *inode, loff_t size,
@@ -1041,27 +1072,31 @@ static unsigned int fuse_write_flags(struct kiocb *iocb)
return flags;
}
-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)
+static ssize_t fuse_send_write(struct fuse_io_args *ia, loff_t pos,
+ size_t count, fl_owner_t owner)
{
- struct kiocb *iocb = io->iocb;
+ struct kiocb *iocb = ia->io->iocb;
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
- struct fuse_write_in *inarg = &req->misc.write.in;
+ struct fuse_write_in *inarg = &ia->write.in;
+ ssize_t err;
- fuse_write_fill(req, ff, pos, count);
+ fuse_write_args_fill(ia, ff, pos, count);
inarg->flags = fuse_write_flags(iocb);
if (owner != NULL) {
inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
inarg->lock_owner = fuse_lock_owner_id(fc, owner);
}
- if (io->async)
- return fuse_async_req_send(fc, req, count, io);
+ if (ia->io->async)
+ return fuse_async_req_send(fc, ia, count);
+
+ err = fuse_simple_request(fc, &ia->ap.args);
+ if (!err && ia->write.out.size > count)
+ err = -EIO;
- fuse_request_send(fc, req);
- return req->misc.write.out.size;
+ return err ?: ia->write.out.size;
}
bool fuse_write_update_size(struct inode *inode, loff_t pos)
@@ -1347,8 +1382,9 @@ static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
return min(iov_iter_single_seg_count(ii), max_size);
}
-static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
- size_t *nbytesp, int write)
+static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
+ size_t *nbytesp, int write,
+ unsigned int max_pages)
{
size_t nbytes = 0; /* # bytes already packed in req */
ssize_t ret = 0;
@@ -1359,21 +1395,21 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
if (write)
- req->in.args[1].value = (void *) user_addr;
+ ap->args.in_args[1].value = (void *) user_addr;
else
- req->out.args[0].value = (void *) user_addr;
+ ap->args.out_args[0].value = (void *) user_addr;
iov_iter_advance(ii, frag_size);
*nbytesp = frag_size;
return 0;
}
- while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
+ while (nbytes < *nbytesp && ap->num_pages < max_pages) {
unsigned npages;
size_t start;
- ret = iov_iter_get_pages(ii, &req->pages[req->num_pages],
+ ret = iov_iter_get_pages(ii, &ap->pages[ap->num_pages],
*nbytesp - nbytes,
- req->max_pages - req->num_pages,
+ max_pages - ap->num_pages,
&start);
if (ret < 0)
break;
@@ -1384,19 +1420,18 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
ret += start;
npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE;
- req->page_descs[req->num_pages].offset = start;
- fuse_page_descs_length_init(req->page_descs, req->num_pages,
- npages);
+ ap->descs[ap->num_pages].offset = start;
+ fuse_page_descs_length_init(ap->descs, ap->num_pages, npages);
- req->num_pages += npages;
- req->page_descs[req->num_pages - 1].length -=
+ ap->num_pages += npages;
+ ap->descs[ap->num_pages - 1].length -=
(PAGE_SIZE - ret) & (PAGE_SIZE - 1);
}
if (write)
- req->in.argpages = 1;
+ ap->args.in_pages = 1;
else
- req->out.argpages = 1;
+ ap->args.out_pages = 1;
*nbytesp = nbytes;
@@ -1418,17 +1453,16 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
pgoff_t idx_from = pos >> PAGE_SHIFT;
pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT;
ssize_t res = 0;
- struct fuse_req *req;
int err = 0;
+ struct fuse_io_args *ia;
+ unsigned int max_pages;
- if (io->async)
- req = fuse_get_req_for_background(fc, iov_iter_npages(iter,
- fc->max_pages));
- else
- req = fuse_get_req(fc, iov_iter_npages(iter, fc->max_pages));
- if (IS_ERR(req))
- return PTR_ERR(req);
+ max_pages = iov_iter_npages(iter, fc->max_pages);
+ ia = fuse_io_alloc(io, max_pages);
+ if (!ia)
+ return -ENOMEM;
+ ia->io = io;
if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
if (!write)
inode_lock(inode);
@@ -1439,54 +1473,49 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
io->should_dirty = !write && iter_is_iovec(iter);
while (count) {
- size_t nres;
+ ssize_t nres;
fl_owner_t owner = current->files;
size_t nbytes = min(count, nmax);
- err = fuse_get_user_pages(req, iter, &nbytes, write);
+
+ err = fuse_get_user_pages(&ia->ap, iter, &nbytes, write,
+ max_pages);
if (err && !nbytes)
break;
if (write) {
- if (!capable(CAP_FSETID)) {
- struct fuse_write_in *inarg;
+ if (!capable(CAP_FSETID))
+ ia->write.in.write_flags |= FUSE_WRITE_KILL_PRIV;
- 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(ia, pos, nbytes, owner);
} else {
- nres = fuse_send_read(req, io, pos, nbytes, owner);
+ nres = fuse_send_read(ia, pos, nbytes, owner);
}
- if (!io->async)
- fuse_release_user_pages(req, io->should_dirty);
- if (req->out.h.error) {
- err = req->out.h.error;
- break;
- } else if (nres > nbytes) {
- res = 0;
- err = -EIO;
+ if (!io->async || nres < 0) {
+ fuse_release_user_pages(&ia->ap, io->should_dirty);
+ fuse_io_free(ia);
+ }
+ ia = NULL;
+ if (nres < 0) {
+ err = nres;
break;
}
+ WARN_ON(nres > nbytes);
+
count -= nres;
res += nres;
pos += nres;
if (nres != nbytes)
break;
if (count) {
- fuse_put_request(fc, req);
- if (io->async)
- req = fuse_get_req_for_background(fc,
- iov_iter_npages(iter, fc->max_pages));
- else
- req = fuse_get_req(fc, iov_iter_npages(iter,
- fc->max_pages));
- if (IS_ERR(req))
+ max_pages = iov_iter_npages(iter, fc->max_pages);
+ ia = fuse_io_alloc(io, max_pages);
+ if (!ia)
break;
}
}
- if (!IS_ERR(req))
- fuse_put_request(fc, req);
+ if (ia)
+ fuse_io_free(ia);
if (res > 0)
*ppos = pos;