[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>
diff --git a/fs/read_write.c b/fs/read_write.c
index 679dd53..32d54cc 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 @@
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 @@
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 @@
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;
+ 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);
- base = vector->iov_base;
- len = vector->iov_len;
- vector++;
- nr_segs--;
-
- nr = fn(file, base, len, pos);
-
- if (nr < 0) {
- if (!ret) ret = nr;
- break;
- }
- ret += nr;
- if (nr != len)
- break;
- }
out:
if (iov != iovstack)
kfree(iov);
@@ -585,7 +618,7 @@
{
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 @@
{
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);