Commit 8d020765 authored by Al Viro's avatar Al Viro

->splice_write() via ->write_iter()

iter_file_splice_write() - a ->splice_write() instance that gathers the
pipe buffers, builds a bio_vec-based iov_iter covering those and feeds
it to ->write_iter().  A bunch of simple cases coverted to that...

[AV: fixed the braino spotted by Cyrill]
Signed-off-by: default avatarAl Viro <[email protected]>
parent 62a8067a
......@@ -1583,7 +1583,7 @@ const struct file_operations def_blk_fops = {
.compat_ioctl = compat_blkdev_ioctl,
#endif
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
};
int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
......
......@@ -77,7 +77,7 @@ const struct file_operations exofs_file_operations = {
.fsync = exofs_file_fsync,
.flush = exofs_flush,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
};
const struct inode_operations exofs_file_inode_operations = {
......
......@@ -75,7 +75,7 @@ const struct file_operations ext2_file_operations = {
.release = ext2_release_file,
.fsync = ext2_fsync,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
};
#ifdef CONFIG_EXT2_FS_XIP
......
......@@ -63,7 +63,7 @@ const struct file_operations ext3_file_operations = {
.release = ext3_release_file,
.fsync = ext3_sync_file,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
};
const struct inode_operations ext3_file_inode_operations = {
......
......@@ -599,7 +599,7 @@ const struct file_operations ext4_file_operations = {
.release = ext4_release_file,
.fsync = ext4_sync_file,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
.fallocate = ext4_fallocate,
};
......
......@@ -692,5 +692,5 @@ const struct file_operations f2fs_file_operations = {
.compat_ioctl = f2fs_compat_ioctl,
#endif
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
};
......@@ -1068,7 +1068,7 @@ const struct file_operations gfs2_file_fops = {
.lock = gfs2_lock,
.flock = gfs2_flock,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
.setlease = gfs2_setlease,
.fallocate = gfs2_fallocate,
};
......@@ -1098,7 +1098,7 @@ const struct file_operations gfs2_file_fops_nolock = {
.release = gfs2_release,
.fsync = gfs2_fsync,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
.setlease = generic_setlease,
.fallocate = gfs2_fallocate,
};
......
......@@ -157,7 +157,7 @@ const struct file_operations jfs_file_operations = {
.write_iter = generic_file_write_iter,
.mmap = generic_file_mmap,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
.fsync = jfs_fsync,
.release = jfs_release,
.unlocked_ioctl = jfs_ioctl,
......
......@@ -38,7 +38,7 @@ const struct file_operations ramfs_file_operations = {
.mmap = generic_file_mmap,
.fsync = noop_fsync,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
.llseek = generic_file_llseek,
};
......
......@@ -43,7 +43,7 @@ const struct file_operations ramfs_file_operations = {
.write_iter = generic_file_write_iter,
.fsync = noop_fsync,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
.llseek = generic_file_llseek,
};
......
......@@ -248,7 +248,7 @@ const struct file_operations reiserfs_file_operations = {
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
.llseek = generic_file_llseek,
};
......
......@@ -32,6 +32,7 @@
#include <linux/gfp.h>
#include <linux/socket.h>
#include <linux/compat.h>
#include <linux/aio.h>
#include "internal.h"
/*
......@@ -1052,6 +1053,145 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
EXPORT_SYMBOL(generic_file_splice_write);
/**
* iter_file_splice_write - splice data from a pipe to a file
* @pipe: pipe info
* @out: file to write to
* @ppos: position in @out
* @len: number of bytes to splice
* @flags: splice modifier flags
*
* Description:
* Will either move or copy pages (determined by @flags options) from
* the given pipe inode to the given file.
* This one is ->write_iter-based.
*
*/
ssize_t
iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
loff_t *ppos, size_t len, unsigned int flags)
{
struct splice_desc sd = {
.total_len = len,
.flags = flags,
.pos = *ppos,
.u.file = out,
};
int nbufs = pipe->buffers;
struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec),
GFP_KERNEL);
ssize_t ret;
if (unlikely(!array))
return -ENOMEM;
pipe_lock(pipe);
splice_from_pipe_begin(&sd);
while (sd.total_len) {
struct iov_iter from;
struct kiocb kiocb;
size_t left;
int n, idx;
ret = splice_from_pipe_next(pipe, &sd);
if (ret <= 0)
break;
if (unlikely(nbufs < pipe->buffers)) {
kfree(array);
nbufs = pipe->buffers;
array = kcalloc(nbufs, sizeof(struct bio_vec),
GFP_KERNEL);
if (!array) {
ret = -ENOMEM;
break;
}
}
/* build the vector */
left = sd.total_len;
for (n = 0, idx = pipe->curbuf; left && n < pipe->nrbufs; n++, idx++) {
struct pipe_buffer *buf = pipe->bufs + idx;
size_t this_len = buf->len;
if (this_len > left)
this_len = left;
if (idx == pipe->buffers - 1)
idx = -1;
ret = buf->ops->confirm(pipe, buf);
if (unlikely(ret)) {
if (ret == -ENODATA)
ret = 0;
goto done;
}
array[n].bv_page = buf->page;
array[n].bv_len = this_len;
array[n].bv_offset = buf->offset;
left -= this_len;
}
/* ... iov_iter */
from.type = ITER_BVEC | WRITE;
from.bvec = array;
from.nr_segs = n;
from.count = sd.total_len - left;
from.iov_offset = 0;
/* ... and iocb */
init_sync_kiocb(&kiocb, out);
kiocb.ki_pos = sd.pos;
kiocb.ki_nbytes = sd.total_len - left;
/* now, send it */
ret = out->f_op->write_iter(&kiocb, &from);
if (-EIOCBQUEUED == ret)
ret = wait_on_sync_kiocb(&kiocb);
if (ret <= 0)
break;
sd.num_spliced += ret;
sd.total_len -= ret;
*ppos = sd.pos = kiocb.ki_pos;
/* dismiss the fully eaten buffers, adjust the partial one */
while (ret) {
struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
if (ret >= buf->len) {
const struct pipe_buf_operations *ops = buf->ops;
ret -= buf->len;
buf->len = 0;
buf->ops = NULL;
ops->release(pipe, buf);
pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
pipe->nrbufs--;
if (pipe->files)
sd.need_wakeup = true;
} else {
buf->offset += ret;
buf->len -= ret;
ret = 0;
}
}
}
done:
kfree(array);
splice_from_pipe_end(pipe, &sd);
pipe_unlock(pipe);
if (sd.num_spliced)
ret = sd.num_spliced;
return ret;
}
EXPORT_SYMBOL(iter_file_splice_write);
static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
struct splice_desc *sd)
{
......
......@@ -1585,7 +1585,7 @@ const struct file_operations ubifs_file_operations = {
.fsync = ubifs_fsync,
.unlocked_ioctl = ubifs_ioctl,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.splice_write = iter_file_splice_write,
#ifdef CONFIG_COMPAT
.compat_ioctl = ubifs_compat_ioctl,
#endif
......
......@@ -342,47 +342,6 @@ xfs_file_splice_read(
return ret;
}
/*
* xfs_file_splice_write() does not use xfs_rw_ilock() because
* generic_file_splice_write() takes the i_mutex itself. This, in theory,
* couuld cause lock inversions between the aio_write path and the splice path
* if someone is doing concurrent splice(2) based writes and write(2) based
* writes to the same inode. The only real way to fix this is to re-implement
* the generic code here with correct locking orders.
*/
STATIC ssize_t
xfs_file_splice_write(
struct pipe_inode_info *pipe,
struct file *outfilp,
loff_t *ppos,
size_t count,
unsigned int flags)
{
struct inode *inode = outfilp->f_mapping->host;
struct xfs_inode *ip = XFS_I(inode);
int ioflags = 0;
ssize_t ret;
XFS_STATS_INC(xs_write_calls);
if (outfilp->f_mode & FMODE_NOCMTIME)
ioflags |= IO_INVIS;
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
return -EIO;
xfs_ilock(ip, XFS_IOLOCK_EXCL);
trace_xfs_file_splice_write(ip, count, *ppos, ioflags);
ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
if (ret > 0)
XFS_STATS_ADD(xs_write_bytes, ret);
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;
}
/*
* This routine is called to handle zeroing any space in the last block of the
* file that is beyond the EOF. We do this since the size is being increased
......@@ -1442,7 +1401,7 @@ const struct file_operations xfs_file_operations = {
.read_iter = xfs_file_read_iter,
.write_iter = xfs_file_write_iter,
.splice_read = xfs_file_splice_read,
.splice_write = xfs_file_splice_write,
.splice_write = iter_file_splice_write,
.unlocked_ioctl = xfs_file_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = xfs_file_compat_ioctl,
......
......@@ -1060,7 +1060,6 @@ DEFINE_RW_EVENT(xfs_file_read);
DEFINE_RW_EVENT(xfs_file_buffered_write);
DEFINE_RW_EVENT(xfs_file_direct_write);
DEFINE_RW_EVENT(xfs_file_splice_read);
DEFINE_RW_EVENT(xfs_file_splice_write);
DECLARE_EVENT_CLASS(xfs_page_class,
TP_PROTO(struct inode *inode, struct page *page, unsigned long off,
......
......@@ -2434,6 +2434,8 @@ extern ssize_t default_file_splice_read(struct file *, loff_t *,
struct pipe_inode_info *, size_t, unsigned int);
extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
struct file *, loff_t *, size_t, unsigned int);
extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
struct file *, loff_t *, size_t, unsigned int);
extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
struct file *out, loff_t *, size_t len, unsigned int flags);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment