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Message-Id: <20250730-nfsd-testing-v4-8-7f5730570a52@kernel.org>
Date: Wed, 30 Jul 2025 09:24:37 -0400
From: Jeff Layton <jlayton@...nel.org>
To: Alexander Viro <viro@...iv.linux.org.uk>,
Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
Steven Rostedt <rostedt@...dmis.org>,
Masami Hiramatsu <mhiramat@...nel.org>,
Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Chuck Lever <chuck.lever@...cle.com>, NeilBrown <neil@...wn.name>,
Olga Kornievskaia <okorniev@...hat.com>, Dai Ngo <Dai.Ngo@...cle.com>,
Tom Talpey <tom@...pey.com>
Cc: Trond Myklebust <trondmy@...merspace.com>,
Anna Schumaker <anna@...nel.org>, linux-fsdevel@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
linux-nfs@...r.kernel.org, Jeff Layton <jlayton@...nel.org>
Subject: [PATCH v4 8/8] nfsd: freeze c/mtime updates with outstanding
WRITE_ATTRS delegation
Instead of allowing the ctime to roll backward with a WRITE_ATTRS
delegation, set FMODE_NOCMTIME on the file and have it skip mtime and
ctime updates.
It is possible that the client will never send a SETATTR to set the
times before returning the delegation. Add two new bools to struct
nfs4_delegation:
dl_written: tracks whether the file has been written since the
delegation was granted. This is set in the WRITE and LAYOUTCOMMIT
handlers.
dl_setattr: tracks whether the client has sent at least one valid
mtime that can also update the ctime in a SETATTR.
When unlocking the lease for the delegation, clear FMODE_NOCMTIME. If
the file has been written, but no setattr for the delegated mtime and
ctime has been done, update the timestamps to current_time().
Suggested-by: NeilBrown <neil@...wn.name>
Signed-off-by: Jeff Layton <jlayton@...nel.org>
---
fs/nfsd/nfs4proc.c | 26 ++++++++++++++++++++++++--
fs/nfsd/nfs4state.c | 42 ++++++++++++++++++++++++++++++++++++++++++
fs/nfsd/state.h | 4 +++-
3 files changed, 69 insertions(+), 3 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index aacd912a5fbe29ba5ccac206d13243308f36b7fa..bfebe6e25638a76d3607bb79a239bdc92e42e7b5 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1151,7 +1151,9 @@ vet_deleg_attrs(struct nfsd4_setattr *setattr, struct nfs4_delegation *dp)
if (setattr->sa_bmval[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) {
if (nfsd4_vet_deleg_time(&iattr->ia_mtime, &dp->dl_mtime, &now)) {
iattr->ia_ctime = iattr->ia_mtime;
- if (!nfsd4_vet_deleg_time(&iattr->ia_ctime, &dp->dl_ctime, &now))
+ if (nfsd4_vet_deleg_time(&iattr->ia_ctime, &dp->dl_ctime, &now))
+ dp->dl_setattr = true;
+ else
iattr->ia_valid &= ~(ATTR_CTIME | ATTR_CTIME_SET);
} else {
iattr->ia_valid &= ~(ATTR_CTIME | ATTR_CTIME_SET |
@@ -1238,12 +1240,26 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
return status;
}
+static void nfsd4_file_mark_deleg_written(struct nfs4_file *fi)
+{
+ spin_lock(&fi->fi_lock);
+ if (!list_empty(&fi->fi_delegations)) {
+ struct nfs4_delegation *dp = list_first_entry(&fi->fi_delegations,
+ struct nfs4_delegation, dl_perfile);
+
+ if (dp->dl_type == OPEN_DELEGATE_WRITE_ATTRS_DELEG)
+ dp->dl_written = true;
+ }
+ spin_unlock(&fi->fi_lock);
+}
+
static __be32
nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
union nfsd4_op_u *u)
{
struct nfsd4_write *write = &u->write;
stateid_t *stateid = &write->wr_stateid;
+ struct nfs4_stid *stid = NULL;
struct nfsd_file *nf = NULL;
__be32 status = nfs_ok;
unsigned long cnt;
@@ -1256,10 +1272,15 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
trace_nfsd_write_start(rqstp, &cstate->current_fh,
write->wr_offset, cnt);
status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
- stateid, WR_STATE, &nf, NULL);
+ stateid, WR_STATE, &nf, &stid);
if (status)
return status;
+ if (stid) {
+ nfsd4_file_mark_deleg_written(stid->sc_file);
+ nfs4_put_stid(stid);
+ }
+
write->wr_how_written = write->wr_stable_how;
status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf,
write->wr_offset, &write->wr_payload,
@@ -2550,6 +2571,7 @@ nfsd4_layoutcommit(struct svc_rqst *rqstp,
mutex_unlock(&ls->ls_mutex);
nfserr = ops->proc_layoutcommit(inode, rqstp, lcp);
+ nfsd4_file_mark_deleg_written(ls->ls_stid.sc_file);
nfs4_put_stid(&ls->ls_stid);
out:
return nfserr;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 205ee8cc6fa2b9f74d08f7938b323d03bdf8286c..81fa7cc6c77b3cdc5ff22bc60ab0654f95dc258d 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1222,6 +1222,42 @@ static void put_deleg_file(struct nfs4_file *fp)
nfs4_file_put_access(fp, NFS4_SHARE_ACCESS_READ);
}
+static void nfsd4_finalize_deleg_timestamps(struct nfs4_delegation *dp, struct file *f)
+{
+ struct iattr ia = { .ia_valid = ATTR_ATIME | ATTR_CTIME | ATTR_MTIME };
+ struct inode *inode = file_inode(f);
+ int ret;
+
+ /* don't do anything if FMODE_NOCMTIME isn't set */
+ if ((READ_ONCE(f->f_mode) & FMODE_NOCMTIME) == 0)
+ return;
+
+ spin_lock(&f->f_lock);
+ f->f_mode &= ~FMODE_NOCMTIME;
+ spin_unlock(&f->f_lock);
+
+ /* was it never written? */
+ if (!dp->dl_written)
+ return;
+
+ /* did it get a setattr for the timestamps at some point? */
+ if (dp->dl_setattr)
+ return;
+
+ /* Stamp everything to "now" */
+ inode_lock(inode);
+ ret = notify_change(&nop_mnt_idmap, f->f_path.dentry, &ia, NULL);
+ inode_unlock(inode);
+ if (ret) {
+ struct inode *inode = file_inode(f);
+
+ pr_notice_ratelimited("Unable to update timestamps on inode %02x:%02x:%lu: %d\n",
+ MAJOR(inode->i_sb->s_dev),
+ MINOR(inode->i_sb->s_dev),
+ inode->i_ino, ret);
+ }
+}
+
static void nfs4_unlock_deleg_lease(struct nfs4_delegation *dp)
{
struct nfs4_file *fp = dp->dl_stid.sc_file;
@@ -1229,6 +1265,7 @@ static void nfs4_unlock_deleg_lease(struct nfs4_delegation *dp)
WARN_ON_ONCE(!fp->fi_delegees);
+ nfsd4_finalize_deleg_timestamps(dp, nf->nf_file);
kernel_setlease(nf->nf_file, F_UNLCK, NULL, (void **)&dp);
put_deleg_file(fp);
}
@@ -6265,6 +6302,8 @@ nfs4_open_delegation(struct svc_rqst *rqstp, struct nfsd4_open *open,
memcpy(&open->op_delegate_stateid, &dp->dl_stid.sc_stateid, sizeof(dp->dl_stid.sc_stateid));
if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) {
+ struct file *f = dp->dl_stid.sc_file->fi_deleg_file->nf_file;
+
if (!nfsd4_add_rdaccess_to_wrdeleg(rqstp, open, fh, stp) ||
!nfs4_delegation_stat(dp, currentfh, &stat)) {
nfs4_put_stid(&dp->dl_stid);
@@ -6278,6 +6317,9 @@ nfs4_open_delegation(struct svc_rqst *rqstp, struct nfsd4_open *open,
dp->dl_atime = stat.atime;
dp->dl_ctime = stat.ctime;
dp->dl_mtime = stat.mtime;
+ spin_lock(&f->f_lock);
+ f->f_mode |= FMODE_NOCMTIME;
+ spin_unlock(&f->f_lock);
trace_nfsd_deleg_write(&dp->dl_stid.sc_stateid);
} else {
open->op_delegate_type = deleg_ts && nfs4_delegation_stat(dp, currentfh, &stat) ?
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index bf9436cdb93c5dd5502ecf83433ea311e3678711..b6ac0f37e9cdfcfddde5861c8c0c51bad60101b7 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -217,10 +217,12 @@ struct nfs4_delegation {
struct nfs4_clnt_odstate *dl_clnt_odstate;
time64_t dl_time;
u32 dl_type;
-/* For recall: */
+ /* For recall: */
int dl_retries;
struct nfsd4_callback dl_recall;
bool dl_recalled;
+ bool dl_written;
+ bool dl_setattr;
/* for CB_GETATTR */
struct nfs4_cb_fattr dl_cb_fattr;
--
2.50.1
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