From 19e0663ff9bce2efb87be8b30f9e46b7843600f3 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 6 Jan 2020 13:40:37 -0500 Subject: [PATCH] nfsd: Ensure sampling of the write verifier is atomic with the write When doing an unstable write, we need to ensure that we sample the write verifier before releasing the lock, and allowing a commit to the same file to proceed. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs3proc.c | 2 +- fs/nfsd/nfs3xdr.c | 8 ++------ fs/nfsd/nfs4proc.c | 4 ++-- fs/nfsd/nfsproc.c | 2 +- fs/nfsd/vfs.c | 12 +++++++++--- fs/nfsd/vfs.h | 5 +++-- fs/nfsd/xdr3.h | 1 + 7 files changed, 19 insertions(+), 15 deletions(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index ffdc592..288bc76 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -203,7 +203,7 @@ nfsd3_proc_write(struct svc_rqst *rqstp) RETURN_STATUS(nfserr_io); nfserr = nfsd_write(rqstp, &resp->fh, argp->offset, rqstp->rq_vec, nvecs, &cnt, - resp->committed); + resp->committed, resp->verf); resp->count = cnt; RETURN_STATUS(nfserr); } diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 1ae4fc2..aae514d4 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -747,17 +747,13 @@ int nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p) { struct nfsd3_writeres *resp = rqstp->rq_resp; - struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); - __be32 verf[2]; p = encode_wcc_data(rqstp, p, &resp->fh); if (resp->status == 0) { *p++ = htonl(resp->count); *p++ = htonl(resp->committed); - /* unique identifier, y2038 overflow can be ignored */ - nfsd_copy_boot_verifier(verf, nn); - *p++ = verf[0]; - *p++ = verf[1]; + *p++ = resp->verf[0]; + *p++ = resp->verf[1]; } return xdr_ressize_check(rqstp, p); } diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index c3455e1..e4ddaf8 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1015,7 +1015,6 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, } write->wr_how_written = write->wr_stable_how; - gen_boot_verifier(&write->wr_verifier, SVC_NET(rqstp)); nvecs = svc_fill_write_vector(rqstp, write->wr_pagelist, &write->wr_head, write->wr_buflen); @@ -1023,7 +1022,8 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf, write->wr_offset, rqstp->rq_vec, nvecs, &cnt, - write->wr_how_written); + write->wr_how_written, + (__be32 *)write->wr_verifier.data); nfsd_file_put(nf); write->wr_bytes_written = cnt; diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c index b25c90b..543bbe0 100644 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -226,7 +226,7 @@ nfsd_proc_write(struct svc_rqst *rqstp) return nfserr_io; nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh), argp->offset, rqstp->rq_vec, nvecs, - &cnt, NFS_DATA_SYNC); + &cnt, NFS_DATA_SYNC, NULL); return nfsd_return_attrs(nfserr, resp); } diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index dc07d97..0aa02eb 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -962,7 +962,8 @@ static int wait_for_concurrent_writes(struct file *file) __be32 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, loff_t offset, struct kvec *vec, int vlen, - unsigned long *cnt, int stable) + unsigned long *cnt, int stable, + __be32 *verf) { struct file *file = nf->nf_file; struct svc_export *exp; @@ -1004,6 +1005,10 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, up_write(&nf->nf_rwsem); } else { down_read(&nf->nf_rwsem); + if (verf) + nfsd_copy_boot_verifier(verf, + net_generic(SVC_NET(rqstp), + nfsd_net_id)); host_err = vfs_iter_write(file, &iter, &pos, flags); up_read(&nf->nf_rwsem); } @@ -1074,7 +1079,8 @@ __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, */ __be32 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, - struct kvec *vec, int vlen, unsigned long *cnt, int stable) + struct kvec *vec, int vlen, unsigned long *cnt, int stable, + __be32 *verf) { struct nfsd_file *nf; __be32 err; @@ -1086,7 +1092,7 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, goto out; err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec, - vlen, cnt, stable); + vlen, cnt, stable, verf); nfsd_file_put(nf); out: trace_nfsd_write_done(rqstp, fhp, offset, *cnt); diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index d23d9da..3eb660a 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -94,11 +94,12 @@ __be32 nfsd_read(struct svc_rqst *, struct svc_fh *, loff_t, struct kvec *, int, unsigned long *, u32 *eof); __be32 nfsd_write(struct svc_rqst *, struct svc_fh *, loff_t, - struct kvec *, int, unsigned long *, int); + struct kvec *, int, unsigned long *, + int stable, __be32 *verf); __be32 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, - int stable); + int stable, __be32 *verf); __be32 nfsd_readlink(struct svc_rqst *, struct svc_fh *, char *, int *); __be32 nfsd_symlink(struct svc_rqst *, struct svc_fh *, diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h index fe6fd45..4155fd7 100644 --- a/fs/nfsd/xdr3.h +++ b/fs/nfsd/xdr3.h @@ -159,6 +159,7 @@ struct nfsd3_writeres { struct svc_fh fh; unsigned long count; int committed; + __be32 verf[2]; }; struct nfsd3_renameres { -- 2.7.4