From 9867f5c6695f0a17cde9a4dc140fe026b4e40d4a Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 25 Jul 2018 21:40:13 -0600 Subject: [PATCH] IB/uverbs: Convert 'bool exclusive' into an enum This is more readable, and future patches will need a 3rd lookup type. Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/rdma_core.c | 94 +++++++++++++++++------------ include/rdma/uverbs_std_types.h | 13 ++-- include/rdma/uverbs_types.h | 16 +++-- 3 files changed, 75 insertions(+), 48 deletions(-) diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index aa1d16d87746..435dbe8ef2a2 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -108,7 +108,8 @@ void uverbs_uobject_put(struct ib_uobject *uobject) kref_put(&uobject->ref, uverbs_uobject_free); } -static int uverbs_try_lock_object(struct ib_uobject *uobj, bool exclusive) +static int uverbs_try_lock_object(struct ib_uobject *uobj, + enum rdma_lookup_mode mode) { /* * When a shared access is required, we use a positive counter. Each @@ -121,21 +122,29 @@ static int uverbs_try_lock_object(struct ib_uobject *uobj, bool exclusive) * concurrently, setting the counter to zero is enough for releasing * this lock. */ - if (!exclusive) + switch (mode) { + case UVERBS_LOOKUP_READ: return __atomic_add_unless(&uobj->usecnt, 1, -1) == -1 ? -EBUSY : 0; - - /* lock is either WRITE or DESTROY - should be exclusive */ - return atomic_cmpxchg(&uobj->usecnt, 0, -1) == 0 ? 0 : -EBUSY; + case UVERBS_LOOKUP_WRITE: + /* lock is either WRITE or DESTROY - should be exclusive */ + return atomic_cmpxchg(&uobj->usecnt, 0, -1) == 0 ? 0 : -EBUSY; + } + return 0; } -static void assert_uverbs_usecnt(struct ib_uobject *uobj, bool exclusive) +static void assert_uverbs_usecnt(struct ib_uobject *uobj, + enum rdma_lookup_mode mode) { #ifdef CONFIG_LOCKDEP - if (exclusive) - WARN_ON(atomic_read(&uobj->usecnt) != -1); - else + switch (mode) { + case UVERBS_LOOKUP_READ: WARN_ON(atomic_read(&uobj->usecnt) <= 0); + break; + case UVERBS_LOOKUP_WRITE: + WARN_ON(atomic_read(&uobj->usecnt) != -1); + break; + } #endif } @@ -164,7 +173,7 @@ static int uverbs_destroy_uobject(struct ib_uobject *uobj, unsigned long flags; int ret; - assert_uverbs_usecnt(uobj, true); + assert_uverbs_usecnt(uobj, UVERBS_LOOKUP_WRITE); if (uobj->object) { ret = uobj->type->type_class->remove_commit(uobj, reason); @@ -229,13 +238,13 @@ struct ib_uobject *__uobj_get_destroy(const struct uverbs_obj_type *type, struct ib_uobject *uobj; int ret; - uobj = rdma_lookup_get_uobject(type, ufile, id, true); + uobj = rdma_lookup_get_uobject(type, ufile, id, UVERBS_LOOKUP_WRITE); if (IS_ERR(uobj)) return uobj; ret = rdma_explicit_destroy(uobj); if (ret) { - rdma_lookup_put_uobject(uobj, true); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE); return ERR_PTR(ret); } @@ -256,7 +265,7 @@ int __uobj_perform_destroy(const struct uverbs_obj_type *type, u32 id, if (IS_ERR(uobj)) return PTR_ERR(uobj); - rdma_lookup_put_uobject(uobj, true); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE); return success_res; } @@ -319,7 +328,8 @@ static int idr_add_uobj(struct ib_uobject *uobj) /* Returns the ib_uobject or an error. The caller should check for IS_ERR. */ static struct ib_uobject * lookup_get_idr_uobject(const struct uverbs_obj_type *type, - struct ib_uverbs_file *ufile, s64 id, bool exclusive) + struct ib_uverbs_file *ufile, s64 id, + enum rdma_lookup_mode mode) { struct ib_uobject *uobj; unsigned long idrno = id; @@ -349,9 +359,10 @@ free: return uobj; } -static struct ib_uobject *lookup_get_fd_uobject(const struct uverbs_obj_type *type, - struct ib_uverbs_file *ufile, - s64 id, bool exclusive) +static struct ib_uobject * +lookup_get_fd_uobject(const struct uverbs_obj_type *type, + struct ib_uverbs_file *ufile, s64 id, + enum rdma_lookup_mode mode) { struct file *f; struct ib_uobject *uobject; @@ -362,7 +373,7 @@ static struct ib_uobject *lookup_get_fd_uobject(const struct uverbs_obj_type *ty if (fdno != id) return ERR_PTR(-EINVAL); - if (exclusive) + if (mode != UVERBS_LOOKUP_READ) return ERR_PTR(-EOPNOTSUPP); f = fget(fdno); @@ -386,12 +397,12 @@ static struct ib_uobject *lookup_get_fd_uobject(const struct uverbs_obj_type *ty struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type, struct ib_uverbs_file *ufile, s64 id, - bool exclusive) + enum rdma_lookup_mode mode) { struct ib_uobject *uobj; int ret; - uobj = type->type_class->lookup_get(type, ufile, id, exclusive); + uobj = type->type_class->lookup_get(type, ufile, id, mode); if (IS_ERR(uobj)) return uobj; @@ -400,13 +411,13 @@ struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type, goto free; } - ret = uverbs_try_lock_object(uobj, exclusive); + ret = uverbs_try_lock_object(uobj, mode); if (ret) goto free; return uobj; free: - uobj->type->type_class->lookup_put(uobj, exclusive); + uobj->type->type_class->lookup_put(uobj, mode); uverbs_uobject_put(uobj); return ERR_PTR(ret); } @@ -643,32 +654,39 @@ void rdma_alloc_abort_uobject(struct ib_uobject *uobj) uverbs_destroy_uobject(uobj, RDMA_REMOVE_ABORT); } -static void lookup_put_idr_uobject(struct ib_uobject *uobj, bool exclusive) +static void lookup_put_idr_uobject(struct ib_uobject *uobj, + enum rdma_lookup_mode mode) { } -static void lookup_put_fd_uobject(struct ib_uobject *uobj, bool exclusive) +static void lookup_put_fd_uobject(struct ib_uobject *uobj, + enum rdma_lookup_mode mode) { struct file *filp = uobj->object; - WARN_ON(exclusive); + WARN_ON(mode != UVERBS_LOOKUP_READ); /* This indirectly calls uverbs_close_fd and free the object */ fput(filp); } -void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool exclusive) +void rdma_lookup_put_uobject(struct ib_uobject *uobj, + enum rdma_lookup_mode mode) { - assert_uverbs_usecnt(uobj, exclusive); - uobj->type->type_class->lookup_put(uobj, exclusive); + assert_uverbs_usecnt(uobj, mode); + uobj->type->type_class->lookup_put(uobj, mode); /* * In order to unlock an object, either decrease its usecnt for * read access or zero it in case of exclusive access. See * uverbs_try_lock_object for locking schema information. */ - if (!exclusive) + switch (mode) { + case UVERBS_LOOKUP_READ: atomic_dec(&uobj->usecnt); - else + break; + case UVERBS_LOOKUP_WRITE: atomic_set(&uobj->usecnt, 0); + break; + } /* Pairs with the kref obtained by type->lookup_get */ uverbs_uobject_put(uobj); @@ -710,7 +728,7 @@ void uverbs_close_fd(struct file *f) * method from being invoked. Meaning we can always get the * write lock here, or we have a kernel bug. */ - WARN_ON(uverbs_try_lock_object(uobj, true)); + WARN_ON(uverbs_try_lock_object(uobj, UVERBS_LOOKUP_WRITE)); uverbs_destroy_uobject(uobj, RDMA_REMOVE_CLOSE); up_read(&ufile->hw_destroy_rwsem); } @@ -807,7 +825,7 @@ static int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile, * if we hit this WARN_ON, that means we are * racing with a lookup_get. */ - WARN_ON(uverbs_try_lock_object(obj, true)); + WARN_ON(uverbs_try_lock_object(obj, UVERBS_LOOKUP_WRITE)); if (!uverbs_destroy_uobject(obj, reason)) ret = 0; } @@ -890,10 +908,12 @@ uverbs_get_uobject_from_file(const struct uverbs_obj_type *type_attrs, { switch (access) { case UVERBS_ACCESS_READ: - return rdma_lookup_get_uobject(type_attrs, ufile, id, false); + return rdma_lookup_get_uobject(type_attrs, ufile, id, + UVERBS_LOOKUP_READ); case UVERBS_ACCESS_DESTROY: case UVERBS_ACCESS_WRITE: - return rdma_lookup_get_uobject(type_attrs, ufile, id, true); + return rdma_lookup_get_uobject(type_attrs, ufile, id, + UVERBS_LOOKUP_WRITE); case UVERBS_ACCESS_NEW: return rdma_alloc_begin_uobject(type_attrs, ufile); default: @@ -916,13 +936,13 @@ int uverbs_finalize_object(struct ib_uobject *uobj, switch (access) { case UVERBS_ACCESS_READ: - rdma_lookup_put_uobject(uobj, false); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_READ); break; case UVERBS_ACCESS_WRITE: - rdma_lookup_put_uobject(uobj, true); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE); break; case UVERBS_ACCESS_DESTROY: - rdma_lookup_put_uobject(uobj, true); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE); break; case UVERBS_ACCESS_NEW: if (commit) diff --git a/include/rdma/uverbs_std_types.h b/include/rdma/uverbs_std_types.h index c2f89e41cbd2..8c54e1439ba1 100644 --- a/include/rdma/uverbs_std_types.h +++ b/include/rdma/uverbs_std_types.h @@ -58,11 +58,12 @@ static inline const struct uverbs_object_tree_def *uverbs_default_get_objects(vo #define uobj_get_read(_type, _id, _ufile) \ rdma_lookup_get_uobject(uobj_get_type(_type), _ufile, \ - _uobj_check_id(_id), false) + _uobj_check_id(_id), UVERBS_LOOKUP_READ) #define ufd_get_read(_type, _fdnum, _ufile) \ rdma_lookup_get_uobject(uobj_get_type(_type), _ufile, \ - (_fdnum)*typecheck(s32, _fdnum), false) + (_fdnum)*typecheck(s32, _fdnum), \ + UVERBS_LOOKUP_READ) static inline void *_uobj_get_obj_read(struct ib_uobject *uobj) { @@ -76,7 +77,7 @@ static inline void *_uobj_get_obj_read(struct ib_uobject *uobj) #define uobj_get_write(_type, _id, _ufile) \ rdma_lookup_get_uobject(uobj_get_type(_type), _ufile, \ - _uobj_check_id(_id), true) + _uobj_check_id(_id), UVERBS_LOOKUP_WRITE) int __uobj_perform_destroy(const struct uverbs_obj_type *type, u32 id, struct ib_uverbs_file *ufile, int success_res); @@ -92,12 +93,12 @@ struct ib_uobject *__uobj_get_destroy(const struct uverbs_obj_type *type, static inline void uobj_put_destroy(struct ib_uobject *uobj) { - rdma_lookup_put_uobject(uobj, true); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE); } static inline void uobj_put_read(struct ib_uobject *uobj) { - rdma_lookup_put_uobject(uobj, false); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_READ); } #define uobj_put_obj_read(_obj) \ @@ -105,7 +106,7 @@ static inline void uobj_put_read(struct ib_uobject *uobj) static inline void uobj_put_write(struct ib_uobject *uobj) { - rdma_lookup_put_uobject(uobj, true); + rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE); } static inline int __must_check uobj_alloc_commit(struct ib_uobject *uobj, diff --git a/include/rdma/uverbs_types.h b/include/rdma/uverbs_types.h index 875dd8c16ba3..0676672dbbb9 100644 --- a/include/rdma/uverbs_types.h +++ b/include/rdma/uverbs_types.h @@ -38,6 +38,11 @@ struct uverbs_obj_type; +enum rdma_lookup_mode { + UVERBS_LOOKUP_READ, + UVERBS_LOOKUP_WRITE, +}; + /* * The following sequences are valid: * Success flow: @@ -78,8 +83,8 @@ struct uverbs_obj_type_class { struct ib_uobject *(*lookup_get)(const struct uverbs_obj_type *type, struct ib_uverbs_file *ufile, s64 id, - bool exclusive); - void (*lookup_put)(struct ib_uobject *uobj, bool exclusive); + enum rdma_lookup_mode mode); + void (*lookup_put)(struct ib_uobject *uobj, enum rdma_lookup_mode mode); /* This does not consume the kref on uobj */ int __must_check (*remove_commit)(struct ib_uobject *uobj, enum rdma_remove_reason why); @@ -116,9 +121,10 @@ struct uverbs_obj_idr_type { }; struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type, - struct ib_uverbs_file *ufile, - s64 id, bool exclusive); -void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool exclusive); + struct ib_uverbs_file *ufile, s64 id, + enum rdma_lookup_mode mode); +void rdma_lookup_put_uobject(struct ib_uobject *uobj, + enum rdma_lookup_mode mode); struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_obj_type *type, struct ib_uverbs_file *ufile); void rdma_alloc_abort_uobject(struct ib_uobject *uobj); -- 2.25.1