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nfsd: untangle code in nfsd4_deleg_getattr_conflict()

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The code in nfsd4_deleg_getattr_conflict() is convoluted and buggy.

With this patch we:
 - properly handle non-nfsd leases.  We must not assume flc_owner is a
    delegation unless fl_lmops == &nfsd_lease_mng_ops
 - move the main code out of the for loop
 - have a single exit which calls nfs4_put_stid()
   (and other exits which don't need to call that)

[ jlayton: refactored on top of Neil's other patch: nfsd: fix
	   nfsd4_deleg_getattr_conflict in presence of third party lease ]

Fixes: c5967721e106 ("NFSD: handle GETATTR conflict with write delegation")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
NeilBrown 2024-08-29 09:26:40 -04:00 committed by Chuck Lever
parent 5559c157b7
commit a078a7dc0e
1 changed files with 65 additions and 72 deletions
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137
fs/nfsd/nfs4state.c
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@ -8834,6 +8834,7 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry,
__be32 status;
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
struct file_lock_context *ctx;
struct nfs4_delegation *dp = NULL;
struct file_lease *fl;
struct iattr attrs;
struct nfs4_cb_fattr *ncf;
@ -8843,84 +8844,76 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry,
ctx = locks_inode_context(inode);
if (!ctx)
return 0;
#define NON_NFSD_LEASE ((void *)1)
spin_lock(&ctx->flc_lock);
for_each_file_lock(fl, &ctx->flc_lease) {
unsigned char type = fl->c.flc_type;
if (fl->c.flc_flags == FL_LAYOUT)
continue;
if (fl->fl_lmops != &nfsd_lease_mng_ops) {
/*
* non-nfs lease, if it's a lease with F_RDLCK then
* we are done; there isn't any write delegation
* on this inode
*/
if (type == F_RDLCK)
break;
nfsd_stats_wdeleg_getattr_inc(nn);
spin_unlock(&ctx->flc_lock);
status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
if (status != nfserr_jukebox ||
!nfsd_wait_for_delegreturn(rqstp, inode))
return status;
return 0;
}
if (type == F_WRLCK) {
struct nfs4_delegation *dp = fl->c.flc_owner;
if (dp->dl_recall.cb_clp == *(rqstp->rq_lease_breaker)) {
spin_unlock(&ctx->flc_lock);
return 0;
}
nfsd_stats_wdeleg_getattr_inc(nn);
dp = fl->c.flc_owner;
refcount_inc(&dp->dl_stid.sc_count);
ncf = &dp->dl_cb_fattr;
nfs4_cb_getattr(&dp->dl_cb_fattr);
spin_unlock(&ctx->flc_lock);
wait_on_bit_timeout(&ncf->ncf_cb_flags, CB_GETATTR_BUSY,
TASK_INTERRUPTIBLE, NFSD_CB_GETATTR_TIMEOUT);
if (ncf->ncf_cb_status) {
/* Recall delegation only if client didn't respond */
status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
if (status != nfserr_jukebox ||
!nfsd_wait_for_delegreturn(rqstp, inode)) {
nfs4_put_stid(&dp->dl_stid);
return status;
}
}
if (!ncf->ncf_file_modified &&
(ncf->ncf_initial_cinfo != ncf->ncf_cb_change ||
ncf->ncf_cur_fsize != ncf->ncf_cb_fsize))
ncf->ncf_file_modified = true;
if (ncf->ncf_file_modified) {
int err;
/*
* Per section 10.4.3 of RFC 8881, the server would
* not update the file's metadata with the client's
* modified size
*/
attrs.ia_mtime = attrs.ia_ctime = current_time(inode);
attrs.ia_valid = ATTR_MTIME | ATTR_CTIME | ATTR_DELEG;
inode_lock(inode);
err = notify_change(&nop_mnt_idmap, dentry, &attrs, NULL);
inode_unlock(inode);
if (err) {
nfs4_put_stid(&dp->dl_stid);
return nfserrno(err);
}
ncf->ncf_cur_fsize = ncf->ncf_cb_fsize;
*size = ncf->ncf_cur_fsize;
*modified = true;
}
nfs4_put_stid(&dp->dl_stid);
return 0;
if (fl->c.flc_type == F_WRLCK) {
if (fl->fl_lmops == &nfsd_lease_mng_ops)
dp = fl->c.flc_owner;
else
dp = NON_NFSD_LEASE;
}
break;
}
if (dp == NULL || dp == NON_NFSD_LEASE ||
dp->dl_recall.cb_clp == *(rqstp->rq_lease_breaker)) {
spin_unlock(&ctx->flc_lock);
if (dp == NON_NFSD_LEASE) {
status = nfserrno(nfsd_open_break_lease(inode,
NFSD_MAY_READ));
if (status != nfserr_jukebox ||
!nfsd_wait_for_delegreturn(rqstp, inode))
return status;
}
return 0;
}
nfsd_stats_wdeleg_getattr_inc(nn);
refcount_inc(&dp->dl_stid.sc_count);
ncf = &dp->dl_cb_fattr;
nfs4_cb_getattr(&dp->dl_cb_fattr);
spin_unlock(&ctx->flc_lock);
return 0;
wait_on_bit_timeout(&ncf->ncf_cb_flags, CB_GETATTR_BUSY,
TASK_INTERRUPTIBLE, NFSD_CB_GETATTR_TIMEOUT);
if (ncf->ncf_cb_status) {
/* Recall delegation only if client didn't respond */
status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
if (status != nfserr_jukebox ||
!nfsd_wait_for_delegreturn(rqstp, inode))
goto out_status;
}
if (!ncf->ncf_file_modified &&
(ncf->ncf_initial_cinfo != ncf->ncf_cb_change ||
ncf->ncf_cur_fsize != ncf->ncf_cb_fsize))
ncf->ncf_file_modified = true;
if (ncf->ncf_file_modified) {
int err;
/*
* Per section 10.4.3 of RFC 8881, the server would
* not update the file's metadata with the client's
* modified size
*/
attrs.ia_mtime = attrs.ia_ctime = current_time(inode);
attrs.ia_valid = ATTR_MTIME | ATTR_CTIME | ATTR_DELEG;
inode_lock(inode);
err = notify_change(&nop_mnt_idmap, dentry, &attrs, NULL);
inode_unlock(inode);
if (err) {
status = nfserrno(err);
goto out_status;
}
ncf->ncf_cur_fsize = ncf->ncf_cb_fsize;
*size = ncf->ncf_cur_fsize;
*modified = true;
}
status = 0;
out_status:
nfs4_put_stid(&dp->dl_stid);
return status;
}