[PATCH for-next v2 04/10] RDMA/rxe: Combine rxe_add_index with rxe_alloc
From: Bob Pearson <hidden>
Date: 2021-10-15 22:34:00
Subsystem:
infiniband subsystem, soft-roce driver (rxe), the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Zhu Yanjun, Linus Torvalds
Currently rxe objects which have an index require adding and dropping the indices in a separate API call from allocating and freeing the object. These are always performed together so this patch combines them in a single operation. By taking a single pool lock around allocating the object and adding the index metadata or dropping the index metadata and releasing the object the possibility of a race condition where the metadata is not consistent with the state of the object is removed. Signed-off-by: Bob Pearson <redacted> --- drivers/infiniband/sw/rxe/rxe_mr.c | 1 - drivers/infiniband/sw/rxe/rxe_mw.c | 5 +-- drivers/infiniband/sw/rxe/rxe_pool.c | 59 +++++++++++++++------------ drivers/infiniband/sw/rxe/rxe_pool.h | 22 ---------- drivers/infiniband/sw/rxe/rxe_verbs.c | 13 ------ 5 files changed, 33 insertions(+), 67 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 53271df10e47..6e71f67ccfe9 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c@@ -693,7 +693,6 @@ int rxe_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) mr->state = RXE_MR_STATE_INVALID; rxe_drop_ref(mr_pd(mr)); - rxe_drop_index(mr); rxe_drop_ref(mr); return 0;
diff --git a/drivers/infiniband/sw/rxe/rxe_mw.c b/drivers/infiniband/sw/rxe/rxe_mw.c
index 9534a7fe1a98..854d0c283521 100644
--- a/drivers/infiniband/sw/rxe/rxe_mw.c
+++ b/drivers/infiniband/sw/rxe/rxe_mw.c@@ -20,7 +20,6 @@ int rxe_alloc_mw(struct ib_mw *ibmw, struct ib_udata *udata) return ret; } - rxe_add_index(mw); mw->rkey = ibmw->rkey = (mw->pelem.index << 8) | rxe_get_next_key(-1); mw->state = (mw->ibmw.type == IB_MW_TYPE_2) ? RXE_MW_STATE_FREE : RXE_MW_STATE_VALID;
@@ -335,7 +334,5 @@ struct rxe_mw *rxe_lookup_mw(struct rxe_qp *qp, int access, u32 rkey) void rxe_mw_cleanup(struct rxe_pool_entry *elem) { - struct rxe_mw *mw = container_of(elem, typeof(*mw), pelem); - - rxe_drop_index(mw); + /* nothing to do currently */ }
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index bbc8dc63f53d..b030a774c251 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c@@ -166,12 +166,16 @@ void rxe_pool_cleanup(struct rxe_pool *pool) kfree(pool->index.table); } +/* should never fail because there are at least as many indices as + * max objects + */ static u32 alloc_index(struct rxe_pool *pool) { u32 index; u32 range = pool->index.max_index - pool->index.min_index + 1; - index = find_next_zero_bit(pool->index.table, range, pool->index.last); + index = find_next_zero_bit(pool->index.table, range, + pool->index.last); if (index >= range) index = find_first_zero_bit(pool->index.table, range);
@@ -192,7 +196,8 @@ static int rxe_insert_index(struct rxe_pool *pool, struct rxe_pool_entry *new) elem = rb_entry(parent, struct rxe_pool_entry, index_node); if (elem->index == new->index) { - pr_warn("element already exists!\n"); + pr_warn("element with index = 0x%x already exists!\n", + new->index); return -EINVAL; }
@@ -281,31 +286,21 @@ void __rxe_drop_key(struct rxe_pool_entry *elem) write_unlock_irqrestore(&pool->pool_lock, flags); } -int __rxe_add_index_locked(struct rxe_pool_entry *elem) +static int rxe_add_index(struct rxe_pool_entry *elem) { struct rxe_pool *pool = elem->pool; int err; elem->index = alloc_index(pool); err = rxe_insert_index(pool, elem); + if (err) + clear_bit(elem->index - pool->index.min_index, + pool->index.table); return err; } -int __rxe_add_index(struct rxe_pool_entry *elem) -{ - struct rxe_pool *pool = elem->pool; - unsigned long flags; - int err; - - write_lock_irqsave(&pool->pool_lock, flags); - err = __rxe_add_index_locked(elem); - write_unlock_irqrestore(&pool->pool_lock, flags); - - return err; -} - -void __rxe_drop_index_locked(struct rxe_pool_entry *elem) +static void rxe_drop_index(struct rxe_pool_entry *elem) { struct rxe_pool *pool = elem->pool;
@@ -313,20 +308,11 @@ void __rxe_drop_index_locked(struct rxe_pool_entry *elem) rb_erase(&elem->index_node, &pool->index.tree); } -void __rxe_drop_index(struct rxe_pool_entry *elem) -{ - struct rxe_pool *pool = elem->pool; - unsigned long flags; - - write_lock_irqsave(&pool->pool_lock, flags); - __rxe_drop_index_locked(elem); - write_unlock_irqrestore(&pool->pool_lock, flags); -} - void *rxe_alloc_locked(struct rxe_pool *pool) { struct rxe_pool_entry *elem; void *obj; + int err; if (atomic_inc_return(&pool->num_elem) > pool->max_elem) goto out_cnt;
@@ -341,6 +327,14 @@ void *rxe_alloc_locked(struct rxe_pool *pool) elem->obj = obj; kref_init(&elem->ref_cnt); + if (pool->flags & RXE_POOL_INDEX) { + err = rxe_add_index(elem); + if (err) { + kfree(obj); + goto out_cnt; + } + } + return obj; out_cnt:
@@ -362,6 +356,8 @@ void *rxe_alloc(struct rxe_pool *pool) int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_entry *elem) { + int err; + if (atomic_inc_return(&pool->num_elem) > pool->max_elem) goto out_cnt;
@@ -369,6 +365,12 @@ int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_entry *elem) elem->obj = (u8 *)elem - pool->elem_offset; kref_init(&elem->ref_cnt); + if (pool->flags & RXE_POOL_INDEX) { + err = rxe_add_index(elem); + if (err) + goto out_cnt; + } + return 0; out_cnt:
@@ -386,6 +388,9 @@ void rxe_elem_release(struct kref *kref) if (pool->cleanup) pool->cleanup(elem); + if (pool->flags & RXE_POOL_INDEX) + rxe_drop_index(elem); + if (!(pool->flags & RXE_POOL_NO_ALLOC)) { obj = elem->obj; kfree(obj);
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index e9bda4b14f86..f76addf87b4a 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h@@ -109,28 +109,6 @@ int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_entry *elem); #define rxe_add_to_pool(pool, obj) __rxe_add_to_pool(pool, &(obj)->pelem) -/* assign an index to an indexed object and insert object into - * pool's rb tree holding and not holding the pool_lock - */ -int __rxe_add_index_locked(struct rxe_pool_entry *elem); - -#define rxe_add_index_locked(obj) __rxe_add_index_locked(&(obj)->pelem) - -int __rxe_add_index(struct rxe_pool_entry *elem); - -#define rxe_add_index(obj) __rxe_add_index(&(obj)->pelem) - -/* drop an index and remove object from rb tree - * holding and not holding the pool_lock - */ -void __rxe_drop_index_locked(struct rxe_pool_entry *elem); - -#define rxe_drop_index_locked(obj) __rxe_drop_index_locked(&(obj)->pelem) - -void __rxe_drop_index(struct rxe_pool_entry *elem); - -#define rxe_drop_index(obj) __rxe_drop_index(&(obj)->pelem) - /* assign a key to a keyed object and insert object into * pool's rb tree holding and not holding pool_lock */
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 0aa0d7e52773..84ea03bc6a26 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c@@ -181,7 +181,6 @@ static int rxe_create_ah(struct ib_ah *ibah, return err; /* create index > 0 */ - rxe_add_index(ah); ah->ah_num = ah->pelem.index; if (uresp) {
@@ -189,7 +188,6 @@ static int rxe_create_ah(struct ib_ah *ibah, err = copy_to_user(&uresp->ah_num, &ah->ah_num, sizeof(uresp->ah_num)); if (err) { - rxe_drop_index(ah); rxe_drop_ref(ah); return -EFAULT; }
@@ -230,7 +228,6 @@ static int rxe_destroy_ah(struct ib_ah *ibah, u32 flags) { struct rxe_ah *ah = to_rah(ibah); - rxe_drop_index(ah); rxe_drop_ref(ah); return 0; }
@@ -438,7 +435,6 @@ static int rxe_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init, if (err) return err; - rxe_add_index(qp); err = rxe_qp_from_init(rxe, qp, pd, init, uresp, ibqp->pd, udata); if (err) goto qp_init;
@@ -446,7 +442,6 @@ static int rxe_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init, return 0; qp_init: - rxe_drop_index(qp); rxe_drop_ref(qp); return err; }
@@ -491,7 +486,6 @@ static int rxe_destroy_qp(struct ib_qp *ibqp, struct ib_udata *udata) struct rxe_qp *qp = to_rqp(ibqp); rxe_qp_destroy(qp); - rxe_drop_index(qp); rxe_drop_ref(qp); return 0; }
@@ -898,7 +892,6 @@ static struct ib_mr *rxe_get_dma_mr(struct ib_pd *ibpd, int access) if (!mr) return ERR_PTR(-ENOMEM); - rxe_add_index(mr); rxe_add_ref(pd); rxe_mr_init_dma(pd, access, mr);
@@ -922,8 +915,6 @@ static struct ib_mr *rxe_reg_user_mr(struct ib_pd *ibpd, goto err2; } - rxe_add_index(mr); - rxe_add_ref(pd); err = rxe_mr_init_user(pd, start, length, iova, access, mr);
@@ -934,7 +925,6 @@ static struct ib_mr *rxe_reg_user_mr(struct ib_pd *ibpd, err3: rxe_drop_ref(pd); - rxe_drop_index(mr); rxe_drop_ref(mr); err2: return ERR_PTR(err);
@@ -957,8 +947,6 @@ static struct ib_mr *rxe_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type mr_type, goto err1; } - rxe_add_index(mr); - rxe_add_ref(pd); err = rxe_mr_init_fast(pd, max_num_sg, mr);
@@ -969,7 +957,6 @@ static struct ib_mr *rxe_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type mr_type, err2: rxe_drop_ref(pd); - rxe_drop_index(mr); rxe_drop_ref(mr); err1: return ERR_PTR(err);
--
2.30.2