diff options
| author | Christoph Hellwig <hch@lst.de> | 2015-01-25 21:11:59 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-01-29 00:13:13 -0500 |
| commit | dbe4e192a234cd6133d86fffb965d0f032c12ccc (patch) | |
| tree | e5b5bbc9b22a289ec33fbc808f7e81d926caec06 /fs/read_write.c | |
| parent | 05afcb77eb4713f46e7ebaa3cb54bc465c5d516e (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>
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 46 |
1 files changed, 46 insertions, 0 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 |