Re: [RFC PATCH] NFSD: Use vfs_iocb_iter_read()
From: "NeilBrown" <neil@brown.name>
Date: 2025-06-13 02:03:33
On Fri, 13 Jun 2025, Chuck Lever wrote:
From: Chuck Lever <chuck.lever@oracle.com> Refactor: Enable the use of RWF_ flags to control individual I/O operations.
RWF_ flags such as .... ??? I'm guessing RWF_DIRECT and maybe RWF_NOWAIT based on the earlier conversation. Might be useful to provide this as explicit motivation. But seeing they will be passed to kiocb_set_rw_flags(), shouldn't we be talking about the IOCB_ versions of the flags? The only caller of kiocb_set_rw_flags() I can find which doesn't pass zero is aio_prep_rw() and it uses the IOCB_ versions. And should we be changing the vfs_iter_write() to vfs_iocb_iter_write() too, just for consistency?
Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neil@brown.name> 3 more callers to go and vfs_iter_read() could be discarded. NeilBrown
quoted hunk ↗ jump to hunk
--- fs/nfsd/vfs.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index cd689df2ca5d..f20bacd9b224 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c@@ -1086,10 +1086,18 @@ __be32 nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp, { unsigned long v, total; struct iov_iter iter; - loff_t ppos = offset; + struct kiocb kiocb; ssize_t host_err; size_t len; + init_sync_kiocb(&kiocb, file); + host_err = kiocb_set_rw_flags(&kiocb, 0, READ); + if (host_err) { + *count = 0; + goto out; + } + kiocb.ki_pos = offset; + v = 0; total = *count; while (total) {@@ -1104,7 +1112,8 @@ __be32 nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp, trace_nfsd_read_vector(rqstp, fhp, offset, *count); iov_iter_bvec(&iter, ITER_DEST, rqstp->rq_bvec, v, *count); - host_err = vfs_iter_read(file, &iter, &ppos, 0); + host_err = vfs_iocb_iter_read(file, &kiocb, &iter); +out: return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err); }-- 2.49.0