nfsd: use vfs_iter_read/write

Instead of messing with the address limit to use vfs_read/vfs_writev.

Note that this requires that exported file implement ->read_iter and
->write_iter.  All currently exportable file systems do this.

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 2017-05-27 11:16:53 +03:00 committed by Al Viro
parent abbb65899a
commit 73da852e38
1 changed files with 7 additions and 10 deletions

View File

@ -911,13 +911,12 @@ __be32 nfsd_splice_read(struct svc_rqst *rqstp,
__be32 nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen,
unsigned long *count)
{
mm_segment_t oldfs;
struct iov_iter iter;
int host_err;
oldfs = get_fs();
set_fs(KERNEL_DS);
host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset, 0);
set_fs(oldfs);
iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count);
host_err = vfs_iter_read(file, &iter, &offset, 0);
return nfsd_finish_read(file, count, host_err);
}
@ -974,7 +973,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
unsigned long *cnt, int stable)
{
struct svc_export *exp;
mm_segment_t oldfs;
struct iov_iter iter;
__be32 err = 0;
int host_err;
int use_wgather;
@ -1000,10 +999,8 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
if (stable && !use_wgather)
flags |= RWF_SYNC;
/* Write the data. */
oldfs = get_fs(); set_fs(KERNEL_DS);
host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos, flags);
set_fs(oldfs);
iov_iter_kvec(&iter, WRITE | ITER_KVEC, vec, vlen, *cnt);
host_err = vfs_iter_write(file, &iter, &pos, flags);
if (host_err < 0)
goto out_nfserr;
*cnt = host_err;