vfs: pass type instead of fn to do_{loop,iter}_readv_writev()

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/read_write.c b/fs/read_write.c
index 12a2160..198614f 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -23,9 +23,6 @@
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
 
-typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
-typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *);
-
 const struct file_operations generic_ro_fops = {
        .llseek         = generic_file_llseek,
        .read_iter      = generic_file_read_iter,
@@ -675,7 +672,7 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
 EXPORT_SYMBOL(iov_shorten);
 
 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
-               loff_t *ppos, iter_fn_t fn, int flags)
+               loff_t *ppos, int type, int flags)
 {
        struct kiocb kiocb;
        ssize_t ret;
@@ -692,7 +689,10 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
                kiocb.ki_flags |= (IOCB_DSYNC | IOCB_SYNC);
        kiocb.ki_pos = *ppos;
 
-       ret = fn(&kiocb, iter);
+       if (type == READ)
+               ret = filp->f_op->read_iter(&kiocb, iter);
+       else
+               ret = filp->f_op->write_iter(&kiocb, iter);
        BUG_ON(ret == -EIOCBQUEUED);
        *ppos = kiocb.ki_pos;
        return ret;
@@ -700,7 +700,7 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
 
 /* Do it by hand, with file-ops */
 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
-               loff_t *ppos, io_fn_t fn, int flags)
+               loff_t *ppos, int type, int flags)
 {
        ssize_t ret = 0;
 
@@ -711,7 +711,13 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
                struct iovec iovec = iov_iter_iovec(iter);
                ssize_t nr;
 
-               nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);
+               if (type == READ) {
+                       nr = filp->f_op->read(filp, iovec.iov_base,
+                                             iovec.iov_len, ppos);
+               } else {
+                       nr = filp->f_op->write(filp, iovec.iov_base,
+                                              iovec.iov_len, ppos);
+               }
 
                if (nr < 0) {
                        if (!ret)
@@ -839,8 +845,6 @@ static ssize_t __do_readv_writev(int type, struct file *file,
 {
        size_t tot_len;
        ssize_t ret = 0;
-       io_fn_t fn;
-       iter_fn_t iter_fn;
 
        tot_len = iov_iter_count(iter);
        if (!tot_len)
@@ -849,19 +853,14 @@ static ssize_t __do_readv_writev(int type, struct file *file,
        if (ret < 0)
                goto out;
 
-       if (type == READ) {
-               fn = file->f_op->read;
-               iter_fn = file->f_op->read_iter;
-       } else {
-               fn = (io_fn_t)file->f_op->write;
-               iter_fn = file->f_op->write_iter;
+       if (type != READ)
                file_start_write(file);
-       }
 
-       if (iter_fn)
-               ret = do_iter_readv_writev(file, iter, pos, iter_fn, flags);
+       if ((type == READ && file->f_op->read_iter) ||
+           (type == WRITE && file->f_op->write_iter))
+               ret = do_iter_readv_writev(file, iter, pos, type, flags);
        else
-               ret = do_loop_readv_writev(file, iter, pos, fn, flags);
+               ret = do_loop_readv_writev(file, iter, pos, type, flags);
 
        if (type != READ)
                file_end_write(file);