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authorChristoph Hellwig <hch@lst.de>2015-01-25 21:11:59 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2015-01-29 00:13:13 -0500
commitdbe4e192a234cd6133d86fffb965d0f032c12ccc (patch)
treee5b5bbc9b22a289ec33fbc808f7e81d926caec06
parent05afcb77eb4713f46e7ebaa3cb54bc465c5d516e (diff)
fs: add vfs_iter_{read,write} helpers
Simple helpers that pass an arbitrary iov_iter to filesystems. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/read_write.c46
-rw-r--r--fs/splice.c16
-rw-r--r--include/linux/fs.h3
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 @@ out_putf:
}
#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);