ich777/linux_media
1
0
Fork 0
mirror of https://github.com/tbsdtv/linux_media.git synced 2025-07-23 12:43:29 +02:00
Code Issues Packages Projects Releases Wiki Activity

fs: add vfs_iter_{read,write} helpers

Browse Source 
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>
This commit is contained in:
Christoph Hellwig
2015-01-25 21:11:59 +01:00
committed by Al Viro
parent 05afcb77eb
commit dbe4e192a2
3 changed files with 51 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
fs/read_write.c
View File

@@ -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