default_file_splice_read goes through great lenght to create an
iovec array and iov_iter for all the reads, but is a helper only
useful for files not implementing ->read_iter as we have the much
better generic_file_splice_read version available for those. Remove
the iters and just call __kernel_read in a loop instead.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/read_write.c | 2 +-
fs/splice.c | 53 +++++++++++++---------------------------------
include/linux/fs.h | 2 --
3 files changed, 16 insertions(+), 41 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 6a2170eaee64f9..1c41c25e548d8c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1070,7 +1070,7 @@ ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
}
EXPORT_SYMBOL(vfs_iter_write);
-ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
+static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
unsigned long vlen, loff_t *pos, rwf_t flags)
{
struct iovec iovstack[UIO_FASTIOV];
diff --git a/fs/splice.c b/fs/splice.c
index d7c8a7c4db07ff..d1efc53875bd93 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -342,38 +342,26 @@ const struct pipe_buf_operations nosteal_pipe_buf_ops = {
};
EXPORT_SYMBOL(nosteal_pipe_buf_ops);
-static ssize_t kernel_readv(struct file *file, const struct kvec *vec,
- unsigned long vlen, loff_t offset)
-{
- mm_segment_t old_fs;
- loff_t pos = offset;
- ssize_t res;
-
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- /* The cast to a user pointer is valid due to the set_fs() */
- res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos, 0);
- set_fs(old_fs);
-
- return res;
-}
-
static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
- struct kvec *vec, __vec[PIPE_DEF_BUFFERS];
struct iov_iter to;
struct page **pages;
unsigned int nr_pages;
unsigned int mask;
size_t offset, base, copied = 0;
+ loff_t pos;
ssize_t res;
int i;
if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
return -EAGAIN;
+ res = rw_verify_area(READ, in, ppos, len);
+ if (res < 0)
+ return res;
+
/*
* Try to keep page boundaries matching to source pagecache ones -
* it probably won't be much help, but...
@@ -386,37 +374,26 @@ static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
if (res <= 0)
return -ENOMEM;
- nr_pages = DIV_ROUND_UP(res + base, PAGE_SIZE);
-
- vec = __vec;
- if (nr_pages > PIPE_DEF_BUFFERS) {
- vec = kmalloc_array(nr_pages, sizeof(struct kvec), GFP_KERNEL);
- if (unlikely(!vec)) {
- res = -ENOMEM;
- goto out;
- }
- }
-
mask = pipe->ring_size - 1;
pipe->bufs[to.head & mask].offset = offset;
pipe->bufs[to.head & mask].len -= offset;
+ nr_pages = DIV_ROUND_UP(res + base, PAGE_SIZE);
+
+ pos = *ppos;
for (i = 0; i < nr_pages; i++) {
size_t this_len = min_t(size_t, len, PAGE_SIZE - offset);
- vec[i].iov_base = page_address(pages[i]) + offset;
- vec[i].iov_len = this_len;
+
+ res = __kernel_read(in, page_address(pages[i]) + offset,
+ this_len, &pos);
+ if (res < 0)
+ goto out;
len -= this_len;
offset = 0;
}
+ copied = pos - *ppos;
+ *ppos = pos;
- res = kernel_readv(in, vec, nr_pages, *ppos);
- if (res > 0) {
- copied = res;
- *ppos += res;
- }
-
- if (vec != __vec)
- kfree(vec);
out:
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0c0ec76b600b50..fac6aead402a98 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1919,8 +1919,6 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
-extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
- unsigned long, loff_t *, rwf_t);
extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
loff_t, size_t, unsigned int);
extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
--
2.26.2
