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authorChristoph Hellwig <hch@lst.de>2021-01-20 21:46:29 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-21 18:30:28 +0100
commit4eaad21a6ac9865df7f31983232ed5928450458d (patch)
tree2135bf094c992815cf190ac6420f81157b6a0498 /fs
parent895bee270863588fe3d46dca86cd15d461f47a7a (diff)
kernfs: implement ->read_iter
Switch kernfs to implement the read_iter method instead of plain old read to prepare to supporting splice and sendfile again. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210120204631.274206-2-hch@lst.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/kernfs/file.c35
1 files changed, 12 insertions, 23 deletions
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index f277d023ebcd..8276e4c8722d 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -14,6 +14,7 @@
#include <linux/pagemap.h>
#include <linux/sched/mm.h>
#include <linux/fsnotify.h>
+#include <linux/uio.h>
#include "kernfs-internal.h"
@@ -180,11 +181,10 @@ static const struct seq_operations kernfs_seq_ops = {
* it difficult to use seq_file. Implement simplistic custom buffering for
* bin files.
*/
-static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of,
- char __user *user_buf, size_t count,
- loff_t *ppos)
+static ssize_t kernfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
- ssize_t len = min_t(size_t, count, PAGE_SIZE);
+ struct kernfs_open_file *of = kernfs_of(iocb->ki_filp);
+ ssize_t len = min_t(size_t, iov_iter_count(iter), PAGE_SIZE);
const struct kernfs_ops *ops;
char *buf;
@@ -210,7 +210,7 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of,
of->event = atomic_read(&of->kn->attr.open->event);
ops = kernfs_ops(of->kn);
if (ops->read)
- len = ops->read(of, buf, len, *ppos);
+ len = ops->read(of, buf, len, iocb->ki_pos);
else
len = -EINVAL;
@@ -220,12 +220,12 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of,
if (len < 0)
goto out_free;
- if (copy_to_user(user_buf, buf, len)) {
+ if (copy_to_iter(buf, len, iter) != len) {
len = -EFAULT;
goto out_free;
}
- *ppos += len;
+ iocb->ki_pos += len;
out_free:
if (buf == of->prealloc_buf)
@@ -235,22 +235,11 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of,
return len;
}
-/**
- * kernfs_fop_read - kernfs vfs read callback
- * @file: file pointer
- * @user_buf: data to write
- * @count: number of bytes
- * @ppos: starting offset
- */
-static ssize_t kernfs_fop_read(struct file *file, char __user *user_buf,
- size_t count, loff_t *ppos)
+static ssize_t kernfs_fop_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
- struct kernfs_open_file *of = kernfs_of(file);
-
- if (of->kn->flags & KERNFS_HAS_SEQ_SHOW)
- return seq_read(file, user_buf, count, ppos);
- else
- return kernfs_file_direct_read(of, user_buf, count, ppos);
+ if (kernfs_of(iocb->ki_filp)->kn->flags & KERNFS_HAS_SEQ_SHOW)
+ return seq_read_iter(iocb, iter);
+ return kernfs_file_read_iter(iocb, iter);
}
/**
@@ -960,7 +949,7 @@ void kernfs_notify(struct kernfs_node *kn)
EXPORT_SYMBOL_GPL(kernfs_notify);
const struct file_operations kernfs_file_fops = {
- .read = kernfs_fop_read,
+ .read_iter = kernfs_fop_read_iter,
.write = kernfs_fop_write,
.llseek = generic_file_llseek,
.mmap = kernfs_fop_mmap,