summaryrefslogtreecommitdiff
path: root/fs/splice.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-22 19:59:21 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-22 19:59:21 +0300
commitf56e65dff6ad52395ef45738799b4fb70ff43376 (patch)
tree230e0ac39888f219a6859fb15ef548fb2bd6511c /fs/splice.c
parent24717cfbbbbfa415d1e3dca0f21c417e5faf8208 (diff)
parent7b84b665c874f60d84547635341e418f20cbbab2 (diff)
downloadlinux-f56e65dff6ad52395ef45738799b4fb70ff43376.tar.xz
Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull initial set_fs() removal from Al Viro: "Christoph's set_fs base series + fixups" * 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Allow a NULL pos pointer to __kernel_read fs: Allow a NULL pos pointer to __kernel_write powerpc: remove address space overrides using set_fs() powerpc: use non-set_fs based maccess routines x86: remove address space overrides using set_fs() x86: make TASK_SIZE_MAX usable from assembly code x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h lkdtm: remove set_fs-based tests test_bitmap: remove user bitmap tests uaccess: add infrastructure for kernel builds with set_fs() fs: don't allow splice read/write without explicit ops fs: don't allow kernel reads and writes without iter ops sysctl: Convert to iter interfaces proc: add a read_iter method to proc proc_ops proc: cleanup the compat vs no compat file ops proc: remove a level of indentation in proc_get_inode
Diffstat (limited to 'fs/splice.c')
-rw-r--r--fs/splice.c130
1 files changed, 14 insertions, 116 deletions
diff --git a/fs/splice.c b/fs/splice.c
index 70cc52af780b..599b740f1098 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -341,89 +341,6 @@ 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;
- ssize_t res;
- int i;
-
- if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
- return -EAGAIN;
-
- /*
- * Try to keep page boundaries matching to source pagecache ones -
- * it probably won't be much help, but...
- */
- offset = *ppos & ~PAGE_MASK;
-
- iov_iter_pipe(&to, READ, pipe, len + offset);
-
- res = iov_iter_get_pages_alloc(&to, &pages, len + offset, &base);
- 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;
-
- 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;
- len -= this_len;
- offset = 0;
- }
-
- 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]);
- kvfree(pages);
- iov_iter_advance(&to, copied); /* truncates and discards */
- return res;
-}
-
/*
* Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos'
* using sendpage(). Return the number of bytes sent.
@@ -807,33 +724,6 @@ done:
EXPORT_SYMBOL(iter_file_splice_write);
-static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
- struct splice_desc *sd)
-{
- int ret;
- void *data;
- loff_t tmp = sd->pos;
-
- data = kmap(buf->page);
- ret = __kernel_write(sd->u.file, data + buf->offset, sd->len, &tmp);
- kunmap(buf->page);
-
- return ret;
-}
-
-static ssize_t default_file_splice_write(struct pipe_inode_info *pipe,
- struct file *out, loff_t *ppos,
- size_t len, unsigned int flags)
-{
- ssize_t ret;
-
- ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf);
- if (ret > 0)
- *ppos += ret;
-
- return ret;
-}
-
/**
* generic_splice_sendpage - splice data from a pipe to a socket
* @pipe: pipe to splice from
@@ -855,15 +745,23 @@ ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
EXPORT_SYMBOL(generic_splice_sendpage);
+static int warn_unsupported(struct file *file, const char *op)
+{
+ pr_debug_ratelimited(
+ "splice %s not supported for file %pD4 (pid: %d comm: %.20s)\n",
+ op, file, current->pid, current->comm);
+ return -EINVAL;
+}
+
/*
* Attempt to initiate a splice from pipe to file.
*/
static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
loff_t *ppos, size_t len, unsigned int flags)
{
- if (out->f_op->splice_write)
- return out->f_op->splice_write(pipe, out, ppos, len, flags);
- return default_file_splice_write(pipe, out, ppos, len, flags);
+ if (unlikely(!out->f_op->splice_write))
+ return warn_unsupported(out, "write");
+ return out->f_op->splice_write(pipe, out, ppos, len, flags);
}
/*
@@ -885,9 +783,9 @@ static long do_splice_to(struct file *in, loff_t *ppos,
if (unlikely(len > MAX_RW_COUNT))
len = MAX_RW_COUNT;
- if (in->f_op->splice_read)
- return in->f_op->splice_read(in, ppos, pipe, len, flags);
- return default_file_splice_read(in, ppos, pipe, len, flags);
+ if (unlikely(!in->f_op->splice_read))
+ return warn_unsupported(in, "read");
+ return in->f_op->splice_read(in, ppos, pipe, len, flags);
}
/**