uml: convert libc layer to call read and write

This patch converts calls in the os layer to os_{read,write}_file to calls
directly to libc read() and write() where it is clear that the I/O buffer is
in the kernel.

We can do that here instead of calling os_{read,write}_file_k since we are in
libc code and can call libc directly.

With the change in the calls, error handling needs to be changed to refer to
errno directly rather than the return value of the call.

CATCH_EINTR wrappers were also added where needed.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 20 insertions, 16 deletions

diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index c1f0f76291cf..5d258eb4f506 100644
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -132,10 +132,10 @@ static int aio_thread(void *arg)
                                 { .data = (void *) (long) event.data,
                                                 .err    = event.res });
                         reply_fd = ((struct aio_context *) reply.data)->reply_fd;
-                        err = os_write_file(reply_fd, &reply, sizeof(reply));
+                        err = write(reply_fd, &reply, sizeof(reply));
                         if(err != sizeof(reply))
                                 printk("aio_thread - write failed, fd = %d, "
-                                       "err = %d\n", reply_fd, -err);
+                                       "err = %d\n", reply_fd, errno);
                 }
         }
         return 0;
@@ -147,7 +147,7 @@ static int do_not_aio(struct aio_thread_req *req)
 {
         char c;
         unsigned long long actual;
-        int err;
+        int n;
 
         actual = lseek64(req->io_fd, req->offset, SEEK_SET);
         if(actual != req->offset)
@@ -155,21 +155,22 @@ static int do_not_aio(struct aio_thread_req *req)
 
         switch(req->type){
         case AIO_READ:
-                err = os_read_file(req->io_fd, req->buf, req->len);
+                n = read(req->io_fd, req->buf, req->len);
                 break;
         case AIO_WRITE:
-                err = os_write_file(req->io_fd, req->buf, req->len);
+                n = write(req->io_fd, req->buf, req->len);
                 break;
         case AIO_MMAP:
-                err = os_read_file(req->io_fd, &c, sizeof(c));
+                n = read(req->io_fd, &c, sizeof(c));
                 break;
         default:
                 printk("do_not_aio - bad request type : %d\n", req->type);
-                err = -EINVAL;
-                break;
+                return -EINVAL;
         }
 
-        return err;
+        if(n < 0)
+                return -errno;
+        return 0;
 }
 
 /* These are initialized in initcalls and not changed */
@@ -185,12 +186,12 @@ static int not_aio_thread(void *arg)
 
         signal(SIGWINCH, SIG_IGN);
         while(1){
-                err = os_read_file(aio_req_fd_r, &req, sizeof(req));
+                err = read(aio_req_fd_r, &req, sizeof(req));
                 if(err != sizeof(req)){
                         if(err < 0)
                                 printk("not_aio_thread - read failed, "
                                        "fd = %d, err = %d\n", aio_req_fd_r,
-                                       -err);
+                                       errno);
                         else {
                                 printk("not_aio_thread - short read, fd = %d, "
                                        "length = %d\n", aio_req_fd_r, err);
@@ -200,10 +201,10 @@ static int not_aio_thread(void *arg)
                 err = do_not_aio(&req);
                 reply = ((struct aio_thread_reply) { .data      = req.aio,
                                                      .err       = err });
-                err = os_write_file(req.aio->reply_fd, &reply, sizeof(reply));
+                err = write(req.aio->reply_fd, &reply, sizeof(reply));
                 if(err != sizeof(reply))
                         printk("not_aio_thread - write failed, fd = %d, "
-                               "err = %d\n", req.aio->reply_fd, -err);
+                               "err = %d\n", req.aio->reply_fd, errno);
         }
 
         return 0;
@@ -277,10 +278,12 @@ static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
         if(err){
                 reply = ((struct aio_thread_reply) { .data = aio,
                                          .err  = err });
-                err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
-                if(err != sizeof(reply))
+                err = write(aio->reply_fd, &reply, sizeof(reply));
+                if(err != sizeof(reply)){
+                        err = -errno;
                         printk("submit_aio_26 - write failed, "
                                "fd = %d, err = %d\n", aio->reply_fd, -err);
+                }
                 else err = 0;
         }
 
@@ -375,9 +378,10 @@ static int submit_aio_24(enum aio_type type, int io_fd, char *buf, int len,
         };
         int err;
 
-        err = os_write_file(aio_req_fd_w, &req, sizeof(req));
+        err = write(aio_req_fd_w, &req, sizeof(req));
         if(err == sizeof(req))
                 err = 0;
+        else err = -errno;
 
         return err;
 }