[PATCH 4.9 154/223] NFSv4: Fix open create exclusive when the server reboots

Greg Kroah-Hartman
2019-08-02T09:47:54Z

[ Upstream commit 8fd1ab747d2b1ec7ec663ad0b41a32eaa35117a8 ]

If the server that does not implement NFSv4.1 persistent session
semantics reboots while we are performing an exclusive create,
then the return value of NFS4ERR_DELAY when we replay the open
during the grace period causes us to lose the verifier.
When the grace period expires, and we present a new verifier,
the server will then correctly reply NFS4ERR_EXIST.

This commit ensures that we always present the same verifier when
replaying the OPEN.

Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4proc.c | 41 ++++++++++++++++++++++++++---------------
1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6d0d94fc243d..ea29c608be89 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1121,6 +1121,12 @@ struct nfs4_opendata {
int cancelled;
};

+struct nfs4_open_createattrs {
+ struct nfs4_label *label;
+ struct iattr *sattr;
+ const __u32 verf[2];
+};
+
static bool nfs4_clear_cap_atomic_open_v1(struct nfs_server *server,
int err, struct nfs4_exception *exception)
{
@@ -1190,8 +1196,7 @@ static void nfs4_init_opendata_res(struct nfs4_opendata *p)

static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
struct nfs4_state_owner *sp, fmode_t fmode, int flags,
- const struct iattr *attrs,
- struct nfs4_label *label,
+ const struct nfs4_open_createattrs *c,
enum open_claim_type4 claim,
gfp_t gfp_mask)
{
@@ -1199,6 +1204,7 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
struct inode *dir = d_inode(parent);
struct nfs_server *server = NFS_SERVER(dir);
struct nfs_seqid *(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
+ struct nfs4_label *label = (c != NULL) ? c->label : NULL;
struct nfs4_opendata *p;

p = kzalloc(sizeof(*p), gfp_mask);
@@ -1255,15 +1261,11 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
p->o_arg.fh = NFS_FH(d_inode(dentry));
}
- if (attrs != NULL && attrs->ia_valid != 0) {
- __u32 verf[2];
-
+ if (c != NULL && c->sattr != NULL && c->sattr->ia_valid != 0) {
p->o_arg.u.attrs = &p->attrs;
- memcpy(&p->attrs, attrs, sizeof(p->attrs));
+ memcpy(&p->attrs, c->sattr, sizeof(p->attrs));

- verf[0] = jiffies;
- verf[1] = current->pid;
- memcpy(p->o_arg.u.verifier.data, verf,
+ memcpy(p->o_arg.u.verifier.data, c->verf,
sizeof(p->o_arg.u.verifier.data));
}
p->c_arg.fh = &p->o_res.fh;
@@ -1814,7 +1816,7 @@ static struct nfs4_opendata *nfs4_open_recoverdata_alloc(struct nfs_open_context
struct nfs4_opendata *opendata;

opendata = nfs4_opendata_alloc(ctx->dentry, state->owner, 0, 0,
- NULL, NULL, claim, GFP_NOFS);
+ NULL, claim, GFP_NOFS);
if (opendata == NULL)
return ERR_PTR(-ENOMEM);
opendata->state = state;
@@ -2759,8 +2761,7 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata,
static int _nfs4_do_open(struct inode *dir,
struct nfs_open_context *ctx,
int flags,
- struct iattr *sattr,
- struct nfs4_label *label,
+ const struct nfs4_open_createattrs *c,
int *opened)
{
struct nfs4_state_owner *sp;
@@ -2772,6 +2773,8 @@ static int _nfs4_do_open(struct inode *dir,
struct nfs4_threshold **ctx_th = &ctx->mdsthreshold;
fmode_t fmode = ctx->mode & (FMODE_READ|FMODE_WRITE|FMODE_EXEC);
enum open_claim_type4 claim = NFS4_OPEN_CLAIM_NULL;
+ struct iattr *sattr = c->sattr;
+ struct nfs4_label *label = c->label;
struct nfs4_label *olabel = NULL;
int status;

@@ -2790,8 +2793,8 @@ static int _nfs4_do_open(struct inode *dir,
status = -ENOMEM;
if (d_really_is_positive(dentry))
claim = NFS4_OPEN_CLAIM_FH;
- opendata = nfs4_opendata_alloc(dentry, sp, fmode, flags, sattr,
- label, claim, GFP_KERNEL);
+ opendata = nfs4_opendata_alloc(dentry, sp, fmode, flags,
+ c, claim, GFP_KERNEL);
if (opendata == NULL)
goto err_put_state_owner;

@@ -2872,10 +2875,18 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir,
struct nfs_server *server = NFS_SERVER(dir);
struct nfs4_exception exception = { };
struct nfs4_state *res;
+ struct nfs4_open_createattrs c = {
+ .label = label,
+ .sattr = sattr,
+ .verf = {
+ [0] = (__u32)jiffies,
+ [1] = (__u32)current->pid,
+ },
+ };
int status;

do {
- status = _nfs4_do_open(dir, ctx, flags, sattr, label, opened);
+ status = _nfs4_do_open(dir, ctx, flags, &c, opened);
res = ctx->state;
trace_nfs4_open_file(ctx, flags, status);
if (status == 0)
--
2.20.1