[PATCH v2 0/6] idr: add idr_alloc_cyclic and convert existing cyclic users

[PATCH v2 0/6] idr: add idr_alloc_cyclic and convert existing cyclic users

[Jeff Layton]

(Andrew, I think this is probably best routed via -mm since it touches
several different places)

This is the second version of this patchset. The main changes are:

- removed an incorrect comment on the new allocator function that
  stemmed from a misunderstanding of the IDR code. Also fixed up
  the kerneldoc comment.

- the idr_init_cyclic function has been removed, since it doesn't add
  any benefit over a "normal" idr_init.

- minor change to the caller in inotify code to make it not allocate
  an ID of 0. The existing code starts at 1, so this seems like a
  reasonable precaution.

Original cover letter follows:

As Tejun points out, there are several users of the IDR facility that
attempt to use it in a cyclic fashion. These users are likely to see
-ENOSPC errors after the counter wraps one or more times however.

This patchset adds a new idr_alloc_cyclic routine and converts several
of these users to it. Many of these users are in obscure parts of the
kernel, and I don't have a good way to test some of them. The change is
pretty straightforward though, so hopefully it won't be an issue.

There is one other cyclic user of idr_alloc that I didn't touch in
ipc/util.c. That one is doing some strange stuff that I didn't quite
understand, but it looks like it should probably be converted later
somehow.

Jeff Layton (6):
  idr: introduce idr_alloc_cyclic
  amso1100: convert to using idr_alloc_cyclic
  mlx4: convert to using idr_alloc_cyclic
  nfsd: convert nfs4_alloc_stid to use idr_alloc_cyclic
  inotify: convert inotify_add_to_idr to use idr_alloc_cyclic
  sctp: convert sctp_assoc_set_id to use idr_alloc_cyclic

 drivers/infiniband/hw/amso1100/c2.h    |  1 -
 drivers/infiniband/hw/amso1100/c2_qp.c |  3 +--
 drivers/infiniband/hw/mlx4/cm.c        |  4 +---
 fs/nfsd/nfs4state.c                    |  7 +------
 fs/notify/inotify/inotify_user.c       |  8 ++------
 include/linux/fsnotify_backend.h       |  1 -
 include/linux/idr.h                    |  2 ++
 lib/idr.c                              | 27 +++++++++++++++++++++++++++
 net/sctp/associola.c                   | 16 ++--------------
 9 files changed, 36 insertions(+), 33 deletions(-)

-- 
1.7.11.7

[PATCH v2 1/6] idr: introduce idr_alloc_cyclic

[Jeff Layton]

Thus spake Tejun Heo:

    Ooh, BTW, the cyclic allocation is broken.  It's prone to -ENOSPC
    after the first wraparound.  There are several cyclic users in the
    kernel and I think it probably would be best to implement cyclic
    support in idr.

This patch does that by adding new idr_alloc_cyclic function that such
users in the kernel can use. With this, there's no need for a caller to
keep track of the last value used as that's now tracked internally.
This should prevent the ENOSPC problems that can hit when the "last
allocated" counter exceeds INT_MAX.

Later patches will convert existing cyclic users to the new interface.

Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 include/linux/idr.h |  2 ++
 lib/idr.c           | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/linux/idr.h b/include/linux/idr.h
index 2640c7e..a470ac3 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -42,6 +42,7 @@ struct idr {
 	struct idr_layer	*id_free;
 	int			layers;	/* only valid w/o concurrent changes */
 	int			id_free_cnt;
+	int			cur;	/* current pos for cyclic allocation */
 	spinlock_t		lock;
 };
 
@@ -75,6 +76,7 @@ struct idr {
 void *idr_find_slowpath(struct idr *idp, int id);
 void idr_preload(gfp_t gfp_mask);
 int idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t gfp_mask);
+int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask);
 int idr_for_each(struct idr *idp,
 		 int (*fn)(int id, void *p, void *data), void *data);
 void *idr_get_next(struct idr *idp, int *nextid);
diff --git a/lib/idr.c b/lib/idr.c
index 322e281..cca4b93 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -495,6 +495,33 @@ int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(idr_alloc);
 
+/**
+ * idr_alloc_cyclic - allocate new idr entry in a cyclical fashion
+ * @idr: the (initialized) idr
+ * @ptr: pointer to be associated with the new id
+ * @start: the minimum id (inclusive)
+ * @end: the maximum id (exclusive, <= 0 for max)
+ * @gfp_mask: memory allocation flags
+ *
+ * Essentially the same as idr_alloc, but prefers to allocate progressively
+ * higher ids if it can. If the "cur" counter wraps, then it will start again
+ * at the "start" end of the range and allocate one that has already been used.
+ */
+int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end,
+			gfp_t gfp_mask)
+{
+	int id;
+
+	id = idr_alloc(idr, ptr, max(start, idr->cur), end, gfp_mask);
+	if (id == -ENOSPC)
+		id = idr_alloc(idr, ptr, start, end, gfp_mask);
+
+	if (likely(id >= 0))
+		idr->cur = id + 1;
+	return id;
+}
+EXPORT_SYMBOL(idr_alloc_cyclic);
+
 static void idr_remove_warning(int id)
 {
 	printk(KERN_WARNING
-- 
1.7.11.7

[PATCH v2 2/6] amso1100: convert to using idr_alloc_cyclic

[Jeff Layton]

(Note: compile-tested only)

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Tom Tucker <tom@opengridcomputing.com>
Cc: linux-rdma@vger.kernel.org
---
 drivers/infiniband/hw/amso1100/c2.h    | 1 -
 drivers/infiniband/hw/amso1100/c2_qp.c | 3 +--
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/amso1100/c2.h b/drivers/infiniband/hw/amso1100/c2.h
index ba7a1208..d619d73 100644
--- a/drivers/infiniband/hw/amso1100/c2.h
+++ b/drivers/infiniband/hw/amso1100/c2.h
@@ -265,7 +265,6 @@ struct c2_pd_table {
 struct c2_qp_table {
 	struct idr idr;
 	spinlock_t lock;
-	int last;
 };
 
 struct c2_element {
diff --git a/drivers/infiniband/hw/amso1100/c2_qp.c b/drivers/infiniband/hw/amso1100/c2_qp.c
index 0ab826b..86708de 100644
--- a/drivers/infiniband/hw/amso1100/c2_qp.c
+++ b/drivers/infiniband/hw/amso1100/c2_qp.c
@@ -385,8 +385,7 @@ static int c2_alloc_qpn(struct c2_dev *c2dev, struct c2_qp *qp)
 	idr_preload(GFP_KERNEL);
 	spin_lock_irq(&c2dev->qp_table.lock);
 
-	ret = idr_alloc(&c2dev->qp_table.idr, qp, c2dev->qp_table.last++, 0,
-			GFP_NOWAIT);
+	ret = idr_alloc_cyclic(&c2dev->qp_table.idr, qp, 0, 0, GFP_NOWAIT);
 	if (ret >= 0)
 		qp->qpn = ret;
 
-- 
1.7.11.7

[PATCH v2 3/6] mlx4: convert to using idr_alloc_cyclic

[Jeff Layton]

(Note: compile tested only)

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jack Morgenstein <jackm@dev.mellanox.co.il>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: linux-rdma@vger.kernel.org
---
 drivers/infiniband/hw/mlx4/cm.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/mlx4/cm.c b/drivers/infiniband/hw/mlx4/cm.c
index add98d0..d1f5f1d 100644
--- a/drivers/infiniband/hw/mlx4/cm.c
+++ b/drivers/infiniband/hw/mlx4/cm.c
@@ -204,7 +204,6 @@ static struct id_map_entry *
 id_map_alloc(struct ib_device *ibdev, int slave_id, u32 sl_cm_id)
 {
 	int ret;
-	static int next_id;
 	struct id_map_entry *ent;
 	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
 
@@ -223,9 +222,8 @@ id_map_alloc(struct ib_device *ibdev, int slave_id, u32 sl_cm_id)
 	idr_preload(GFP_KERNEL);
 	spin_lock(&to_mdev(ibdev)->sriov.id_map_lock);
 
-	ret = idr_alloc(&sriov->pv_id_table, ent, next_id, 0, GFP_NOWAIT);
+	ret = idr_alloc_cyclic(&sriov->pv_id_table, ent, 0, 0, GFP_NOWAIT);
 	if (ret >= 0) {
-		next_id = max(ret + 1, 0);
 		ent->pv_cm_id = (u32)ret;
 		sl_id_map_add(ibdev, ent);
 		list_add_tail(&ent->list, &sriov->cm_list);
-- 
1.7.11.7

[PATCH v2 4/6] nfsd: convert nfs4_alloc_stid to use idr_alloc_cyclic

[Jeff Layton]

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: linux-nfs@vger.kernel.org
---
 fs/nfsd/nfs4state.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 2e27430..417c848 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -234,7 +234,6 @@ static struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct
 kmem_cache *slab)
 {
 	struct idr *stateids = &cl->cl_stateids;
-	static int min_stateid = 0;
 	struct nfs4_stid *stid;
 	int new_id;
 
@@ -242,7 +241,7 @@ kmem_cache *slab)
 	if (!stid)
 		return NULL;
 
-	new_id = idr_alloc(stateids, stid, min_stateid, 0, GFP_KERNEL);
+	new_id = idr_alloc_cyclic(stateids, stid, 0, 0, GFP_KERNEL);
 	if (new_id < 0)
 		goto out_free;
 	stid->sc_client = cl;
@@ -261,10 +260,6 @@ kmem_cache *slab)
 	 * amount of time until an id is reused, by ensuring they always
 	 * "increase" (mod INT_MAX):
 	 */
-
-	min_stateid = new_id+1;
-	if (min_stateid == INT_MAX)
-		min_stateid = 0;
 	return stid;
 out_free:
 	kfree(stid);
-- 
1.7.11.7

[PATCH v2 5/6] inotify: convert inotify_add_to_idr to use idr_alloc_cyclic

[Jeff Layton]

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Robert Love <rlove@rlove.org>
Cc: Eric Paris <eparis@parisplace.org>
---
 fs/notify/inotify/inotify_user.c | 8 ++------
 include/linux/fsnotify_backend.h | 1 -
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index e0f7c12..8562bd3 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -359,7 +359,6 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns
 }
 
 static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
-			      int *last_wd,
 			      struct inotify_inode_mark *i_mark)
 {
 	int ret;
@@ -367,11 +366,10 @@ static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
 	idr_preload(GFP_KERNEL);
 	spin_lock(idr_lock);
 
-	ret = idr_alloc(idr, i_mark, *last_wd + 1, 0, GFP_NOWAIT);
+	ret = idr_alloc_cyclic(idr, i_mark, 1, 0, GFP_NOWAIT);
 	if (ret >= 0) {
 		/* we added the mark to the idr, take a reference */
 		i_mark->wd = ret;
-		*last_wd = i_mark->wd;
 		fsnotify_get_mark(&i_mark->fsn_mark);
 	}
 
@@ -638,8 +636,7 @@ static int inotify_new_watch(struct fsnotify_group *group,
 	if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
 		goto out_err;
 
-	ret = inotify_add_to_idr(idr, idr_lock, &group->inotify_data.last_wd,
-				 tmp_i_mark);
+	ret = inotify_add_to_idr(idr, idr_lock, tmp_i_mark);
 	if (ret)
 		goto out_err;
 
@@ -697,7 +694,6 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events)
 
 	spin_lock_init(&group->inotify_data.idr_lock);
 	idr_init(&group->inotify_data.idr);
-	group->inotify_data.last_wd = 0;
 	group->inotify_data.user = get_current_user();
 
 	if (atomic_inc_return(&group->inotify_data.user->inotify_devs) >
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index d5b0910..4b2ee8d 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -157,7 +157,6 @@ struct fsnotify_group {
 		struct inotify_group_private_data {
 			spinlock_t	idr_lock;
 			struct idr      idr;
-			u32             last_wd;
 			struct user_struct      *user;
 		} inotify_data;
 #endif
-- 
1.7.11.7

[PATCH v2 6/6] sctp: convert sctp_assoc_set_id to use idr_alloc_cyclic

[Jeff Layton]

(Note: compile-tested only)

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-sctp@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 net/sctp/associola.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index d2709e2..fa261a3 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -66,13 +66,6 @@ static void sctp_assoc_bh_rcv(struct work_struct *work);
 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
 
-/* Keep track of the new idr low so that we don't re-use association id
- * numbers too fast.  It is protected by they idr spin lock is in the
- * range of 1 - INT_MAX.
- */
-static u32 idr_low = 1;
-
-
 /* 1st Level Abstractions. */
 
 /* Initialize a new association from provided memory. */
@@ -1601,13 +1594,8 @@ int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
 	if (preload)
 		idr_preload(gfp);
 	spin_lock_bh(&sctp_assocs_id_lock);
-	/* 0 is not a valid id, idr_low is always >= 1 */
-	ret = idr_alloc(&sctp_assocs_id, asoc, idr_low, 0, GFP_NOWAIT);
-	if (ret >= 0) {
-		idr_low = ret + 1;
-		if (idr_low == INT_MAX)
-			idr_low = 1;
-	}
+	/* 0 is not a valid assoc_id, must be >= 1 */
+	ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT);
 	spin_unlock_bh(&sctp_assocs_id_lock);
 	if (preload)
 		idr_preload_end();
-- 
1.7.11.7

Re: [PATCH v2 2/6] amso1100: convert to using idr_alloc_cyclic

[Tejun Heo]

On Wed, Mar 27, 2013 at 03:29:34PM -0400, Jeff Layton wrote:
> (Note: compile-tested only)
>
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Steve Wise <swise@opengridcomputing.com>
> Cc: Tom Tucker <tom@opengridcomputing.com>
> Cc: linux-rdma@vger.kernel.org

Reviewed-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun

Re: [PATCH v2 0/6] idr: add idr_alloc_cyclic and convert existing cyclic users

[Tejun Heo]

On Wed, Mar 27, 2013 at 03:29:32PM -0400, Jeff Layton wrote:
> (Andrew, I think this is probably best routed via -mm since it touches
> several different places)

Yeap, I think it'd be best to route these through -mm.

Please feel free to add Reviewed-by: Tejun Heo <tj@kernel.org> for the
whole series.

Thanks!

-- 
tejun

Re: [PATCH v2 0/6] idr: add idr_alloc_cyclic and convert existing cyclic users

[Andrew Morton]

On Wed, 27 Mar 2013 12:38:47 -0700 Tejun Heo <tj@kernel.org> wrote:

> On Wed, Mar 27, 2013 at 03:29:32PM -0400, Jeff Layton wrote:
> > (Andrew, I think this is probably best routed via -mm since it touches
> > several different places)
> 
> Yeap, I think it'd be best to route these through -mm.
> 
> Please feel free to add Reviewed-by: Tejun Heo <tj@kernel.org> for the
> whole series.

I understand that Jeff will be sending a v2 series?

btw, I'll be away-from-keyboard until the end of next week.  Nobody be
alarmed ;)

Re: [PATCH v2 0/6] idr: add idr_alloc_cyclic and convert existing cyclic users

[Jeff Layton]

On Wed, 27 Mar 2013 12:50:53 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Wed, 27 Mar 2013 12:38:47 -0700 Tejun Heo <tj@kernel.org> wrote:
> 
> > On Wed, Mar 27, 2013 at 03:29:32PM -0400, Jeff Layton wrote:
> > > (Andrew, I think this is probably best routed via -mm since it touches
> > > several different places)
> > 
> > Yeap, I think it'd be best to route these through -mm.
> > 
> > Please feel free to add Reviewed-by: Tejun Heo <tj@kernel.org> for the
> > whole series.
> 
> I understand that Jeff will be sending a v2 series?
> 

Yes, just sent a few mins ago...

> btw, I'll be away-from-keyboard until the end of next week.  Nobody be
> alarmed ;)
> 

Thanks!
-- 
Jeff Layton <jlayton@redhat.com>

Re: [PATCH v2 6/6] sctp: convert sctp_assoc_set_id to use idr_alloc_cyclic

[Neil Horman]

On Wed, Mar 27, 2013 at 03:29:38PM -0400, Jeff Layton wrote:
> (Note: compile-tested only)
> 
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> Cc: Vlad Yasevich <vyasevich@gmail.com>
> Cc: Sridhar Samudrala <sri@us.ibm.com>
> Cc: Neil Horman <nhorman@tuxdriver.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: linux-sctp@vger.kernel.org
> Cc: netdev@vger.kernel.org
> ---
>  net/sctp/associola.c | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)
> 
I don't see anything wrong with this patch per-se, but the idr_alloc_cyclic call
isn't integrated with net/net-next or Linus' tree yet.  If we don't gate this
patch on that integration, we'll break the build.
Neil

Re: [PATCH v2 6/6] sctp: convert sctp_assoc_set_id to use idr_alloc_cyclic

[Neil Horman]

On Thu, Mar 28, 2013 at 09:53:08AM -0400, Neil Horman wrote:
> On Wed, Mar 27, 2013 at 03:29:38PM -0400, Jeff Layton wrote:
> > (Note: compile-tested only)
> > 
> > Signed-off-by: Jeff Layton <jlayton@redhat.com>
> > Cc: Vlad Yasevich <vyasevich@gmail.com>
> > Cc: Sridhar Samudrala <sri@us.ibm.com>
> > Cc: Neil Horman <nhorman@tuxdriver.com>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: linux-sctp@vger.kernel.org
> > Cc: netdev@vger.kernel.org
> > ---
> >  net/sctp/associola.c | 16 ++--------------
> >  1 file changed, 2 insertions(+), 14 deletions(-)
> > 
> I don't see anything wrong with this patch per-se, but the idr_alloc_cyclic call
> isn't integrated with net/net-next or Linus' tree yet.  If we don't gate this
> patch on that integration, we'll break the build.
> Neil
> 
Actually, I just noticed that you only sent us 6/6 here, I'm assuming a prior
patch in the series adds the idr_alloc_cyclic code?  if so, I've seen the prior
version

Acked-by: Neil Horman <nhorman@tuxdriver.com>

> --
> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: [PATCH v2 6/6] sctp: convert sctp_assoc_set_id to use idr_alloc_cyclic

[Jeff Layton]

On Thu, 28 Mar 2013 10:04:06 -0400
Neil Horman <nhorman@tuxdriver.com> wrote:

> On Thu, Mar 28, 2013 at 09:53:08AM -0400, Neil Horman wrote:
> > On Wed, Mar 27, 2013 at 03:29:38PM -0400, Jeff Layton wrote:
> > > (Note: compile-tested only)
> > > 
> > > Signed-off-by: Jeff Layton <jlayton@redhat.com>
> > > Cc: Vlad Yasevich <vyasevich@gmail.com>
> > > Cc: Sridhar Samudrala <sri@us.ibm.com>
> > > Cc: Neil Horman <nhorman@tuxdriver.com>
> > > Cc: "David S. Miller" <davem@davemloft.net>
> > > Cc: linux-sctp@vger.kernel.org
> > > Cc: netdev@vger.kernel.org
> > > ---
> > >  net/sctp/associola.c | 16 ++--------------
> > >  1 file changed, 2 insertions(+), 14 deletions(-)
> > > 
> > I don't see anything wrong with this patch per-se, but the idr_alloc_cyclic call
> > isn't integrated with net/net-next or Linus' tree yet.  If we don't gate this
> > patch on that integration, we'll break the build.
> > Neil
> > 
> Actually, I just noticed that you only sent us 6/6 here, I'm assuming a prior
> patch in the series adds the idr_alloc_cyclic code?  if so, I've seen the prior
> version


Yes, idr_alloc_cyclic is added in patch #1. v2 has some slight changes
from v1 but it's essentially the same concept.

> 
> Acked-by: Neil Horman <nhorman@tuxdriver.com>
> 

Thanks!
-- 
Jeff Layton <jlayton@redhat.com>

Re: [PATCH v2 4/6] nfsd: convert nfs4_alloc_stid to use idr_alloc_cyclic

[J. Bruce Fields]

Err, and ack v2.--b.

On Wed, Mar 27, 2013 at 03:29:36PM -0400, Jeff Layton wrote:
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> Cc: "J. Bruce Fields" <bfields@fieldses.org>
> Cc: linux-nfs@vger.kernel.org
> ---
>  fs/nfsd/nfs4state.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 2e27430..417c848 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -234,7 +234,6 @@ static struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct
>  kmem_cache *slab)
>  {
>  	struct idr *stateids = &cl->cl_stateids;
> -	static int min_stateid = 0;
>  	struct nfs4_stid *stid;
>  	int new_id;
>  
> @@ -242,7 +241,7 @@ kmem_cache *slab)
>  	if (!stid)
>  		return NULL;
>  
> -	new_id = idr_alloc(stateids, stid, min_stateid, 0, GFP_KERNEL);
> +	new_id = idr_alloc_cyclic(stateids, stid, 0, 0, GFP_KERNEL);
>  	if (new_id < 0)
>  		goto out_free;
>  	stid->sc_client = cl;
> @@ -261,10 +260,6 @@ kmem_cache *slab)
>  	 * amount of time until an id is reused, by ensuring they always
>  	 * "increase" (mod INT_MAX):
>  	 */
> -
> -	min_stateid = new_id+1;
> -	if (min_stateid == INT_MAX)
> -		min_stateid = 0;
>  	return stid;
>  out_free:
>  	kfree(stid);
> -- 
> 1.7.11.7
>