Commit e5e9b24a authored by Jeff Layton's avatar Jeff Layton Committed by Chuck Lever
Browse files

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: default avatarNeilBrown <neil@brown.name>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent b40b1ba3

fs/nfsd/nfs4proc.c

+24 −2
Original line number Diff line number Diff line
@@ -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;

fs/nfsd/nfs4state.c

+42 −0
Original line number Diff line number Diff line
@@ -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) ?

fs/nfsd/state.h

+3 −1
Original line number Diff line number Diff line
@@ -221,6 +221,8 @@ struct nfs4_delegation { 
	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;