gadget/function/f_fs.c: use put iov_iter into io_data

both on aio and non-aio sides

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 25 insertions, 61 deletions

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 3ab34a2075df..98610e4595de 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -144,10 +144,9 @@ struct ffs_io_data {
         bool read;
 
         struct kiocb *kiocb;
-        const struct iovec *iovec;
-        unsigned long nr_segs;
-        char __user *buf;
-        size_t len;
+        struct iov_iter data;
+        const void *to_free;
+        char *buf;
 
         struct mm_struct *mm;
         struct work_struct work;
@@ -649,29 +648,10 @@ static void ffs_user_copy_worker(struct work_struct *work)
                                          io_data->req->actual;
 
         if (io_data->read && ret > 0) {
-                int i;
-                size_t pos = 0;
-
-                /*
-                 * Since req->length may be bigger than io_data->len (after
-                 * being rounded up to maxpacketsize), we may end up with more
-                 * data then user space has space for.
-                 */
-                ret = min_t(int, ret, io_data->len);
-
                 use_mm(io_data->mm);
-                for (i = 0; i < io_data->nr_segs; i++) {
-                        size_t len = min_t(size_t, ret - pos,
-                                        io_data->iovec[i].iov_len);
-                        if (!len)
-                                break;
-                        if (unlikely(copy_to_user(io_data->iovec[i].iov_base,
-                                                 &io_data->buf[pos], len))) {
-                                ret = -EFAULT;
-                                break;
-                        }
-                        pos += len;
-                }
+                ret = copy_to_iter(io_data->buf, ret, &io_data->data);
+                if (iov_iter_count(&io_data->data))
+                        ret = -EFAULT;
                 unuse_mm(io_data->mm);
         }
 
@@ -684,7 +664,7 @@ static void ffs_user_copy_worker(struct work_struct *work)
 
         io_data->kiocb->private = NULL;
         if (io_data->read)
-                kfree(io_data->iovec);
+                kfree(io_data->to_free);
         kfree(io_data->buf);
         kfree(io_data);
 }
@@ -743,6 +723,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
                  * before the waiting completes, so do not assign to 'gadget' earlier
                  */
                 struct usb_gadget *gadget = epfile->ffs->gadget;
+                size_t copied;
 
                 spin_lock_irq(&epfile->ffs->eps_lock);
                 /* In the meantime, endpoint got disabled or changed. */
@@ -750,34 +731,21 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
                         spin_unlock_irq(&epfile->ffs->eps_lock);
                         return -ESHUTDOWN;
                 }
+                data_len = iov_iter_count(&io_data->data);
                 /*
                  * Controller may require buffer size to be aligned to
                  * maxpacketsize of an out endpoint.
                  */
-                data_len = io_data->read ?
-                           usb_ep_align_maybe(gadget, ep->ep, io_data->len) :
-                           io_data->len;
+                if (io_data->read)
+                        data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
                 spin_unlock_irq(&epfile->ffs->eps_lock);
 
                 data = kmalloc(data_len, GFP_KERNEL);
                 if (unlikely(!data))
                         return -ENOMEM;
-                if (io_data->aio && !io_data->read) {
-                        int i;
-                        size_t pos = 0;
-                        for (i = 0; i < io_data->nr_segs; i++) {
-                                if (unlikely(copy_from_user(&data[pos],
-                                             io_data->iovec[i].iov_base,
-                                             io_data->iovec[i].iov_len))) {
-                                        ret = -EFAULT;
-                                        goto error;
-                                }
-                                pos += io_data->iovec[i].iov_len;
-                        }
-                } else {
-                        if (!io_data->read &&
-                            unlikely(__copy_from_user(data, io_data->buf,
-                                                      io_data->len))) {
+                if (!io_data->read) {
+                        copied = copy_from_iter(data, data_len, &io_data->data);
+                        if (copied != data_len) {
                                 ret = -EFAULT;
                                 goto error;
                         }
@@ -876,10 +844,8 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
                                  */
                                 ret = ep->status;
                                 if (io_data->read && ret > 0) {
-                                        ret = min_t(size_t, ret, io_data->len);
-
-                                        if (unlikely(copy_to_user(io_data->buf,
-                                                data, ret)))
+                                        ret = copy_to_iter(data, ret, &io_data->data);
+                                        if (unlikely(iov_iter_count(&io_data->data)))
                                                 ret = -EFAULT;
                                 }
                         }
@@ -903,13 +869,13 @@ ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
                  loff_t *ptr)
 {
         struct ffs_io_data io_data;
+        struct iovec iov = {.iov_base = buf, .iov_len = len};
 
         ENTER();
 
         io_data.aio = false;
         io_data.read = false;
-        io_data.buf = (char * __user)buf;
-        io_data.len = len;
+        iov_iter_init(&io_data.data, WRITE, &iov, 1, len);
 
         return ffs_epfile_io(file, &io_data);
 }
@@ -918,13 +884,14 @@ static ssize_t
 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
 {
         struct ffs_io_data io_data;
+        struct iovec iov = {.iov_base = buf, .iov_len = len};
 
         ENTER();
 
         io_data.aio = false;
         io_data.read = true;
-        io_data.buf = buf;
-        io_data.len = len;
+        io_data.to_free = NULL;
+        iov_iter_init(&io_data.data, READ, &iov, 1, len);
 
         return ffs_epfile_io(file, &io_data);
 }
@@ -981,9 +948,7 @@ static ssize_t ffs_epfile_aio_write(struct kiocb *kiocb,
         io_data->aio = true;
         io_data->read = false;
         io_data->kiocb = kiocb;
-        io_data->iovec = iovec;
-        io_data->nr_segs = nr_segs;
-        io_data->len = kiocb->ki_nbytes;
+        iov_iter_init(&io_data->data, WRITE, iovec, nr_segs, kiocb->ki_nbytes);
         io_data->mm = current->mm;
 
         kiocb->private = io_data;
@@ -1021,9 +986,8 @@ static ssize_t ffs_epfile_aio_read(struct kiocb *kiocb,
         io_data->aio = true;
         io_data->read = true;
         io_data->kiocb = kiocb;
-        io_data->iovec = iovec_copy;
-        io_data->nr_segs = nr_segs;
-        io_data->len = kiocb->ki_nbytes;
+        io_data->to_free = iovec_copy;
+        iov_iter_init(&io_data->data, READ, iovec_copy, nr_segs, kiocb->ki_nbytes);
         io_data->mm = current->mm;
 
         kiocb->private = io_data;
@@ -1032,8 +996,8 @@ static ssize_t ffs_epfile_aio_read(struct kiocb *kiocb,
 
         res = ffs_epfile_io(kiocb->ki_filp, io_data);
         if (res != -EIOCBQUEUED) {
+                kfree(io_data->to_free);
                 kfree(io_data);
-                kfree(iovec_copy);
         }
         return res;
 }