From dbe4e192a234cd6133d86fffb965d0f032c12ccc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 25 Jan 2015 21:11:59 +0100 Subject: [PATCH] fs: add vfs_iter_{read,write} helpers Simple helpers that pass an arbitrary iov_iter to filesystems. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/read_write.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ fs/splice.c | 16 ++-------------- include/linux/fs.h | 3 +++ 3 files changed, 51 insertions(+), 14 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index c0805c93b6fa..ab4f26a7d5cb 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -333,6 +333,52 @@ SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, } #endif +ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos) +{ + struct kiocb kiocb; + ssize_t ret; + + if (!file->f_op->read_iter) + return -EINVAL; + + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = *ppos; + kiocb.ki_nbytes = iov_iter_count(iter); + + iter->type |= READ; + ret = file->f_op->read_iter(&kiocb, iter); + if (ret == -EIOCBQUEUED) + ret = wait_on_sync_kiocb(&kiocb); + + if (ret > 0) + *ppos = kiocb.ki_pos; + return ret; +} +EXPORT_SYMBOL(vfs_iter_read); + +ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos) +{ + struct kiocb kiocb; + ssize_t ret; + + if (!file->f_op->write_iter) + return -EINVAL; + + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = *ppos; + kiocb.ki_nbytes = iov_iter_count(iter); + + iter->type |= WRITE; + ret = file->f_op->write_iter(&kiocb, iter); + if (ret == -EIOCBQUEUED) + ret = wait_on_sync_kiocb(&kiocb); + + if (ret > 0) + *ppos = kiocb.ki_pos; + return ret; +} +EXPORT_SYMBOL(vfs_iter_write); + /* * rw_verify_area doesn't like huge counts. We limit * them to something that fits in "int" so that others diff --git a/fs/splice.c b/fs/splice.c index 7c7176f2d1e7..7968da96bebb 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -961,7 +961,6 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, splice_from_pipe_begin(&sd); while (sd.total_len) { struct iov_iter from; - struct kiocb kiocb; size_t left; int n, idx; @@ -1005,26 +1004,15 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, left -= this_len; } - /* ... iov_iter */ iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n, sd.total_len - left); - - /* ... 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); - + ret = vfs_iter_write(out, &from, &sd.pos); if (ret <= 0) break; sd.num_spliced += ret; sd.total_len -= ret; - *ppos = sd.pos = kiocb.ki_pos; + *ppos = sd.pos; /* dismiss the fully eaten buffers, adjust the partial one */ while (ret) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 42efe13077b6..1f3c43952540 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2494,6 +2494,9 @@ extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t l extern ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); extern ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); +ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos); +ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos); + /* fs/block_dev.c */ extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to); extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from); -- GitLab