[PATCH] Remove readv/writev methods and use aio_read/aio_write instead

This patch removes readv() and writev() methods and replaces them with
aio_read()/aio_write() methods.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 67 insertions, 34 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index 679dd535380f..32d54cca9bd9 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/syscalls.h>
 #include <linux/pagemap.h>
+#include "read_write.h"
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -450,6 +451,62 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
 
 EXPORT_UNUSED_SYMBOL(iov_shorten);  /*  June 2006  */
 
+ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,
+                unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn)
+{
+        struct kiocb kiocb;
+        ssize_t ret;
+
+        init_sync_kiocb(&kiocb, filp);
+        kiocb.ki_pos = *ppos;
+        kiocb.ki_left = len;
+        kiocb.ki_nbytes = len;
+
+        for (;;) {
+                ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos);
+                if (ret != -EIOCBRETRY)
+                        break;
+                wait_on_retry_sync_kiocb(&kiocb);
+        }
+
+        if (ret == -EIOCBQUEUED)
+                ret = wait_on_sync_kiocb(&kiocb);
+        *ppos = kiocb.ki_pos;
+        return ret;
+}
+
+/* Do it by hand, with file-ops */
+ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,
+                unsigned long nr_segs, loff_t *ppos, io_fn_t fn)
+{
+        struct iovec *vector = iov;
+        ssize_t ret = 0;
+
+        while (nr_segs > 0) {
+                void __user *base;
+                size_t len;
+                ssize_t nr;
+
+                base = vector->iov_base;
+                len = vector->iov_len;
+                vector++;
+                nr_segs--;
+
+                nr = fn(filp, base, len, ppos);
+
+                if (nr < 0) {
+                        if (!ret)
+                                ret = nr;
+                        break;
+                }
+                ret += nr;
+                if (nr != len)
+                        break;
+        }
+
+        return ret;
+}
+
 /* A write operation does a read from user space and vice versa */
 #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
 
@@ -457,12 +514,9 @@ static ssize_t do_readv_writev(int type, struct file *file,
                                const struct iovec __user * uvector,
                                unsigned long nr_segs, loff_t *pos)
 {
-        typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
-        typedef ssize_t (*iov_fn_t)(struct file *, const struct iovec *, unsigned long, loff_t *);
-
         size_t tot_len;
         struct iovec iovstack[UIO_FASTIOV];
-        struct iovec *iov=iovstack, *vector;
+        struct iovec *iov = iovstack;
         ssize_t ret;
         int seg;
         io_fn_t fn;
@@ -532,39 +586,18 @@ static ssize_t do_readv_writev(int type, struct file *file,
         fnv = NULL;
         if (type == READ) {
                 fn = file->f_op->read;
-                fnv = file->f_op->readv;
+                fnv = file->f_op->aio_read;
         } else {
                 fn = (io_fn_t)file->f_op->write;
-                fnv = file->f_op->writev;
-        }
-        if (fnv) {
-                ret = fnv(file, iov, nr_segs, pos);
-                goto out;
+                fnv = file->f_op->aio_write;
         }
 
-        /* Do it by hand, with file-ops */
-        ret = 0;
-        vector = iov;
-        while (nr_segs > 0) {
-                void __user * base;
-                size_t len;
-                ssize_t nr;
-
-                base = vector->iov_base;
-                len = vector->iov_len;
-                vector++;
-                nr_segs--;
-
-                nr = fn(file, base, len, pos);
+        if (fnv)
+                ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
+                                                pos, fnv);
+        else
+                ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);
 
-                if (nr < 0) {
-                        if (!ret) ret = nr;
-                        break;
-                }
-                ret += nr;
-                if (nr != len)
-                        break;
-        }
 out:
         if (iov != iovstack)
                 kfree(iov);
@@ -585,7 +618,7 @@ ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
 {
         if (!(file->f_mode & FMODE_READ))
                 return -EBADF;
-        if (!file->f_op || (!file->f_op->readv && !file->f_op->read))
+        if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
                 return -EINVAL;
 
         return do_readv_writev(READ, file, vec, vlen, pos);
@@ -598,7 +631,7 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 {
         if (!(file->f_mode & FMODE_WRITE))
                 return -EBADF;
-        if (!file->f_op || (!file->f_op->writev && !file->f_op->write))
+        if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
                 return -EINVAL;
 
         return do_readv_writev(WRITE, file, vec, vlen, pos);