The patch titled
idr: introduce ridr_get_new_above()
has been added to the -mm tree. Its filename is
idr-introduce-ridr_get_new_above.patch
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------------------------------------------------------
Subject: idr: introduce ridr_get_new_above()
From: Nadia Derbey <Nadia.Derbey@xxxxxxxx>
Introduce the ridr_get_new_above() routine, and some common code between the
idr an ridr API's.
Signed-off-by: Nadia Derbey <Nadia.Derbey@xxxxxxxx>
Cc: Jim Houston <jim.houston@xxxxxxxxxxx>
Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: Pierre Peiffer <peifferp@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/idr.h | 21 ++++
include/linux/ridr.h | 1
lib/idr.c | 151 +++++++++++++++++++++--------------
lib/ridr.c | 175 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 287 insertions(+), 61 deletions(-)
diff -puN include/linux/idr.h~idr-introduce-ridr_get_new_above include/linux/idr.h
--- a/include/linux/idr.h~idr-introduce-ridr_get_new_above
+++ a/include/linux/idr.h
@@ -71,6 +71,27 @@ struct idr {
}
#define DEFINE_IDR(name) struct idr name = IDR_INIT(name)
+/* Actions to be taken after a call to _idr_sub_alloc */
+#define IDR_DONE -1
+#define IDR_NEED_TO_GROW -2
+#define IDR_NOMORE_SPACE -3
+#define IDR_GO_TOP -4
+#define IDR_GO_UP -5
+
+#define _idr_rc_to_errno(rc) ((rc) == -1 ? -EAGAIN : -ENOSPC)
+
+static inline void _idr_set_new_slot(struct idr_layer *new,
+ struct idr_layer *p)
+{
+ new->ary[0] = p;
+ new->count = 1;
+ if (p->bitmap == IDR_FULL)
+ __set_bit(0, &new->bitmap);
+}
+
+void _idr_mark_full(struct idr_layer **, int);
+int _idr_sub_alloc(int *, int *, struct idr_layer **, struct idr_layer **);
+
/*
* This is what we export.
*/
diff -puN include/linux/ridr.h~idr-introduce-ridr_get_new_above include/linux/ridr.h
--- a/include/linux/ridr.h~idr-introduce-ridr_get_new_above
+++ a/include/linux/ridr.h
@@ -44,6 +44,7 @@ struct ridr {
* This is what we export.
*/
int ridr_pre_get(struct ridr *, gfp_t);
+int ridr_get_new_above(struct ridr *, void *, int, int *);
void ridr_init(struct ridr *);
diff -puN lib/idr.c~idr-introduce-ridr_get_new_above lib/idr.c
--- a/lib/idr.c~idr-introduce-ridr_get_new_above
+++ a/lib/idr.c
@@ -70,7 +70,7 @@ static void free_layer(struct idr *idp,
spin_unlock_irqrestore(&idp->lock, flags);
}
-static void idr_mark_full(struct idr_layer **pa, int id)
+void _idr_mark_full(struct idr_layer **pa, int id)
{
struct idr_layer *p = pa[0];
int l = 0;
@@ -115,12 +115,71 @@ int idr_pre_get(struct idr *idp, gfp_t g
}
EXPORT_SYMBOL(idr_pre_get);
-static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa)
+int _idr_sub_alloc(int *cur_id, int *layer, struct idr_layer **cur_ptr,
+ struct idr_layer **pa)
{
int n, m, sh;
- struct idr_layer *p, *new;
- int l, id, oid;
+ int l = *layer;
+ int id = *cur_id;
unsigned long bm;
+ struct idr_layer *p = *cur_ptr;
+ int rc;
+
+ n = (id >> (IDR_BITS * l)) & IDR_MASK;
+ bm = ~p->bitmap;
+ m = find_next_bit(&bm, IDR_SIZE, n);
+ if (m == IDR_SIZE) {
+ int oid;
+
+ /* no space available go back to previous layer. */
+ l++;
+ oid = id;
+ id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
+
+ /* if already at the top layer, we need to grow */
+ p = pa[l];
+ if (!p) {
+ *cur_id = id;
+ return IDR_NEED_TO_GROW;
+ }
+
+ /* If we need to go up one layer, continue the
+ * loop; otherwise, restart from the top.
+ */
+ *cur_id = id;
+ *layer = l;
+ *cur_ptr = p;
+ sh = IDR_BITS * (l + 1);
+ if (oid >> sh == id >> sh)
+ rc = IDR_GO_UP;
+ else
+ rc = IDR_GO_TOP;
+ goto end_sub_alloc;
+ }
+ if (m != n) {
+ sh = IDR_BITS * l;
+ id = ((id >> sh) ^ n ^ m) << sh;
+ }
+ if ((id >= MAX_ID_BIT) || (id < 0))
+ return IDR_NOMORE_SPACE;
+
+ if (l == 0)
+ rc = IDR_DONE;
+ else
+ rc = m;
+end_sub_alloc:
+ *cur_id = id;
+ *layer = l;
+ *cur_ptr = p;
+
+ return rc;
+}
+
+static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa)
+{
+ int m;
+ struct idr_layer *p, *new;
+ int l, id;
id = *starting_id;
restart:
@@ -131,38 +190,23 @@ static int sub_alloc(struct idr *idp, in
/*
* We run around this while until we reach the leaf node...
*/
- n = (id >> (IDR_BITS*l)) & IDR_MASK;
- bm = ~p->bitmap;
- m = find_next_bit(&bm, IDR_SIZE, n);
- if (m == IDR_SIZE) {
- /* no space available go back to previous layer. */
- l++;
- oid = id;
- id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
-
- /* if already at the top layer, we need to grow */
- if (!(p = pa[l])) {
- *starting_id = id;
- return -2;
- }
-
- /* If we need to go up one layer, continue the
- * loop; otherwise, restart from the top.
- */
- sh = IDR_BITS * (l + 1);
- if (oid >> sh == id >> sh)
- continue;
- else
- goto restart;
- }
- if (m != n) {
- sh = IDR_BITS*l;
- id = ((id >> sh) ^ n ^ m) << sh;
- }
- if ((id >= MAX_ID_BIT) || (id < 0))
- return -3;
- if (l == 0)
+ int action = _idr_sub_alloc(&id, &l, &p, pa);
+ switch (action) {
+ case IDR_NEED_TO_GROW:
+ *starting_id = id;
+ case IDR_NOMORE_SPACE:
+ return action;
+ case IDR_DONE:
+ goto end_loop;
+ case IDR_GO_UP:
+ continue;
+ case IDR_GO_TOP:
+ goto restart;
+ default:
+ m = action;
break;
+ }
+ BUG_ON(m < 0);
/*
* Create the layer below if it is missing.
*/
@@ -175,7 +219,7 @@ static int sub_alloc(struct idr *idp, in
pa[l--] = p;
p = p->ary[m];
}
-
+end_loop:
pa[l] = p;
return id;
}
@@ -219,16 +263,13 @@ build_up:
spin_unlock_irqrestore(&idp->lock, flags);
return -1;
}
- new->ary[0] = p;
- new->count = 1;
- if (p->bitmap == IDR_FULL)
- __set_bit(0, &new->bitmap);
+ _idr_set_new_slot(new, p);
p = new;
}
idp->top = p;
idp->layers = layers;
v = sub_alloc(idp, &id, pa);
- if (v == -2)
+ if (v == IDR_NEED_TO_GROW)
goto build_up;
return(v);
}
@@ -246,7 +287,7 @@ static int idr_get_new_above_int(struct
*/
pa[0]->ary[id & IDR_MASK] = (struct idr_layer *)ptr;
pa[0]->count++;
- idr_mark_full(pa, id);
+ _idr_mark_full(pa, id);
}
return id;
@@ -277,12 +318,8 @@ int idr_get_new_above(struct idr *idp, v
* This is a cheap hack until the IDR code can be fixed to
* return proper error values.
*/
- if (rv < 0) {
- if (rv == -1)
- return -EAGAIN;
- else /* Will be -3 */
- return -ENOSPC;
- }
+ if (rv < 0)
+ return _idr_rc_to_errno(rv);
*id = rv;
return 0;
}
@@ -312,12 +349,8 @@ int idr_get_new(struct idr *idp, void *p
* This is a cheap hack until the IDR code can be fixed to
* return proper error values.
*/
- if (rv < 0) {
- if (rv == -1)
- return -EAGAIN;
- else /* Will be -3 */
- return -ENOSPC;
- }
+ if (rv < 0)
+ return _idr_rc_to_errno(rv);
*id = rv;
return 0;
}
@@ -694,12 +727,8 @@ int ida_get_new_above(struct ida *ida, i
restart:
/* get vacant slot */
t = idr_get_empty_slot(&ida->idr, idr_id, pa);
- if (t < 0) {
- if (t == -1)
- return -EAGAIN;
- else /* will be -3 */
- return -ENOSPC;
- }
+ if (t < 0)
+ return _idr_rc_to_errno(t);
if (t * IDA_BITMAP_BITS >= MAX_ID_BIT)
return -ENOSPC;
@@ -739,7 +768,7 @@ int ida_get_new_above(struct ida *ida, i
__set_bit(t, bitmap->bitmap);
if (++bitmap->nr_busy == IDA_BITMAP_BITS)
- idr_mark_full(pa, idr_id);
+ _idr_mark_full(pa, idr_id);
*p_id = id;
diff -puN lib/ridr.c~idr-introduce-ridr_get_new_above lib/ridr.c
--- a/lib/ridr.c~idr-introduce-ridr_get_new_above
+++ a/lib/ridr.c
@@ -11,6 +11,23 @@
static struct kmem_cache *ridr_layer_cache;
+static struct ridr_layer *get_from_free_list(struct ridr *idp)
+{
+ struct ridr_layer *q;
+ struct idr_layer *p;
+ unsigned long flags;
+
+ spin_lock_irqsave(&idp->lock, flags);
+ if ((q = idp->id_free)) {
+ p = ridr_to_idr(q);
+ idp->id_free = p->ary[0];
+ idp->id_free_cnt--;
+ p->ary[0] = NULL;
+ }
+ spin_unlock_irqrestore(&idp->lock, flags);
+ return(q);
+}
+
/* only called when idp->lock is held */
/* moves an ridr_layer to the free list */
static void __move_to_free_list(struct ridr *idp, struct ridr_layer *p)
@@ -57,6 +74,164 @@ int ridr_pre_get(struct ridr *idp, gfp_t
}
EXPORT_SYMBOL(ridr_pre_get);
+static int sub_alloc(struct ridr *idp, int *starting_id,
+ struct ridr_layer **rpa, struct idr_layer **pa)
+{
+ int m;
+ struct ridr_layer *q, *new;
+ struct idr_layer *p;
+ int l, id;
+
+ id = *starting_id;
+ restart:
+ q = idp->top;
+ p = ridr_to_idr(q);
+ l = idp->layers;
+ pa[l] = NULL;
+ rpa[l--] = NULL;
+ while (1) {
+ /*
+ * We run around this while until we reach the leaf node...
+ */
+ int action = _idr_sub_alloc(&id, &l, &p, pa);
+ switch (action) {
+ case IDR_NEED_TO_GROW:
+ *starting_id = id;
+ case IDR_NOMORE_SPACE:
+ return action;
+ case IDR_DONE:
+ goto end_loop;
+ case IDR_GO_UP:
+ continue;
+ case IDR_GO_TOP:
+ goto restart;
+ default:
+ m = action;
+ break;
+ }
+ BUG_ON(m < 0);
+ /*
+ * Create the layer below if it is missing.
+ */
+ if (!p->ary[m]) {
+ new = get_from_free_list(idp);
+ if (!new)
+ return -1;
+ rcu_assign_pointer(p->ary[m], new);
+ p->count++;
+ }
+ pa[l] = p;
+ rpa[l--] = idr_to_ridr(p);
+ p = p->ary[m];
+ }
+
+end_loop:
+ pa[l] = p;
+ rpa[l] = idr_to_ridr(p);
+ return id;
+}
+
+static int ridr_get_empty_slot(struct ridr *idp, int starting_id,
+ struct ridr_layer **rpa, struct idr_layer **pa)
+{
+ struct ridr_layer *p, *rnew;
+ int layers, v, id;
+ unsigned long flags;
+
+ id = starting_id;
+build_up:
+ p = idp->top;
+ layers = idp->layers;
+ if (unlikely(!p)) {
+ p = get_from_free_list(idp);
+ if (!p)
+ return -1;
+ layers = 1;
+ }
+ /*
+ * Add a new layer to the top of the tree if the requested
+ * id is larger than the currently allocated space.
+ */
+ while (layers < MAX_LEVEL - 1 && id >= (1 << (layers * IDR_BITS))) {
+ layers++;
+ if (!p->idr.count)
+ continue;
+ rnew = get_from_free_list(idp);
+ if (!rnew) {
+ /*
+ * The allocation failed. If we built part of
+ * the structure tear it down.
+ */
+ spin_lock_irqsave(&idp->lock, flags);
+ for (rnew = p; p && p != idp->top; rnew = p) {
+ p = p->idr.ary[0];
+ rnew->idr.ary[0] = NULL;
+ rnew->idr.bitmap = rnew->idr.count = 0;
+ __move_to_free_list(idp, rnew);
+ }
+ spin_unlock_irqrestore(&idp->lock, flags);
+ return -1;
+ }
+ _idr_set_new_slot(ridr_to_idr(rnew), ridr_to_idr(p));
+ p = rnew;
+ }
+ rcu_assign_pointer(idp->top, p);
+ idp->layers = layers;
+ v = sub_alloc(idp, &id, rpa, pa);
+ if (v == IDR_NEED_TO_GROW)
+ goto build_up;
+ return(v);
+}
+
+static int ridr_get_new_above_int(struct ridr *idp, void *ptr, int starting_id)
+{
+ struct ridr_layer *rpa[MAX_LEVEL];
+ struct idr_layer *pa[MAX_LEVEL];
+ int id;
+
+ id = ridr_get_empty_slot(idp, starting_id, rpa, pa);
+ if (id >= 0) {
+ /*
+ * Successfully found an empty slot. Install the user
+ * pointer and mark the slot full.
+ */
+ rcu_assign_pointer(pa[0]->ary[id & IDR_MASK],
+ (struct ridr_layer *)ptr);
+ pa[0]->count++;
+ _idr_mark_full(pa, id);
+ }
+
+ return id;
+}
+
+/**
+ * ridr_get_new_above - allocate new ridr entry above or equal to a start id
+ * @idp: ridr handle
+ * @ptr: pointer you want associated with the ide
+ * @start_id: id to start search at
+ * @id: pointer to the allocated handle
+ *
+ * This is the allocate id function. It should be called with any
+ * required locks.
+ *
+ * If memory is required, it will return -EAGAIN, you should unlock
+ * and go back to the ridr_pre_get() call. If the ridr is full, it will
+ * return -ENOSPC.
+ *
+ * @id returns a value in the range 0 ... 0x7fffffff
+ */
+int ridr_get_new_above(struct ridr *idp, void *ptr, int starting_id, int *id)
+{
+ int rv;
+
+ rv = ridr_get_new_above_int(idp, ptr, starting_id);
+ if (rv < 0)
+ return _idr_rc_to_errno(rv);
+ *id = rv;
+ return 0;
+}
+EXPORT_SYMBOL(ridr_get_new_above);
+
static void ridr_cache_ctor(struct kmem_cache *ridr_layer_cache,
void *ridr_layer)
{
_
Patches currently in -mm which might be from Nadia.Derbey@xxxxxxxx are
ipc-use-ipc_buildid-directly-from-ipc_addid.patch
ipc-scale-msgmni-to-the-amount-of-lowmem.patch
ipc-scale-msgmni-to-the-number-of-ipc-namespaces.patch
ipc-define-the-slab_memory_callback-priority-as-a-constant.patch
ipc-recompute-msgmni-on-memory-add--remove.patch
ipc-invoke-the-ipcns-notifier-chain-as-a-work-item.patch
ipc-recompute-msgmni-on-ipc-namespace-creation-removal.patch
ipc-do-not-recompute-msgmni-anymore-if-explicitly-set-by-user.patch
ipc-re-enable-msgmni-automatic-recomputing-msgmni-if-set-to-negative.patch
ipc-semaphores-code-factorisation.patch
ipc-shared-memory-introduce-shmctl_down.patch
ipc-message-queues-introduce-msgctl_down.patch
ipc-semaphores-move-the-rwmutex-handling-inside-semctl_down.patch
ipc-semaphores-remove-one-unused-parameter-from-semctl_down.patch
ipc-get-rid-of-the-use-_setbuf-structure.patch
ipc-introduce-ipc_update_perm.patch
ipc-consolidate-all-xxxctl_down-functions.patch
ipc-add-definitions-of-ushort_max-and-others.patch
proc-introduce-proc_create_data-to-setup-de-data.patch
sysvipc-use-non-racy-method-for-proc-entries-creation.patch
idr-fix-idr_remove.patch
idr-introduce-the-ridr-structure.patch
idr-introduce-ridr_pre_get.patch
idr-introduce-ridr_init.patch
idr-introduce-ridr_get_new_above.patch
idr-introduce-ridr_get_new.patch
idr-introduce-ridr_find.patch
idr-introduce-ridr_remove.patch
ipc-integrate-the-ridr-code-into-ipc-code.patch
ipc-get-rid-of-ipc_lock_down.patch
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