From c21fd7a8e86c0e069b512462ffd69bcf179387c8 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 17 Nov 2023 17:14:33 -0500 Subject: NFSD: Replace RQ_SPLICE_OK in nfsd_read() RQ_SPLICE_OK is a bit of a layering violation. Also, a subsequent patch is going to provide a mechanism for always disabling splice reads. Splicing is an issue only for NFS READs, so refactor nfsd_read() to check the auth type directly instead of relying on an rq_flag setting. The new helper will be added into the NFSv4 read path in a subsequent patch. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/vfs.c | 26 +++++++++++++++++++++++++- fs/nfsd/vfs.h | 1 + 2 files changed, 26 insertions(+), 1 deletion(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index c260cbfa8176..cc63fd52a493 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1209,6 +1209,30 @@ out_nfserr: return nfserr; } +/** + * nfsd_read_splice_ok - check if spliced reading is supported + * @rqstp: RPC transaction context + * + * Return values: + * %true: nfsd_splice_read() may be used + * %false: nfsd_splice_read() must not be used + * + * NFS READ normally uses splice to send data in-place. However the + * data in cache can change after the reply's MIC is computed but + * before the RPC reply is sent. To prevent the client from + * rejecting the server-computed MIC in this somewhat rare case, do + * not use splice with the GSS integrity and privacy services. + */ +bool nfsd_read_splice_ok(struct svc_rqst *rqstp) +{ + switch (svc_auth_flavor(rqstp)) { + case RPC_AUTH_GSS_KRB5I: + case RPC_AUTH_GSS_KRB5P: + return false; + } + return true; +} + /** * nfsd_read - Read data from a file * @rqstp: RPC transaction context @@ -1238,7 +1262,7 @@ __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, return err; file = nf->nf_file; - if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags)) + if (file->f_op->splice_read && nfsd_read_splice_ok(rqstp)) err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof); else err = nfsd_iter_read(rqstp, fhp, file, offset, count, 0, eof); diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index e3c29596f4df..702fbc4483bf 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -114,6 +114,7 @@ __be32 nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, loff_t offset, unsigned long *count, unsigned int base, u32 *eof); +bool nfsd_read_splice_ok(struct svc_rqst *rqstp); __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, unsigned long *count, u32 *eof); -- cgit