Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755193AbZGVKVi (ORCPT ); Wed, 22 Jul 2009 06:21:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753147AbZGVKVh (ORCPT ); Wed, 22 Jul 2009 06:21:37 -0400 Received: from smtp161.dfw.emailsrvr.com ([67.192.241.161]:40236 "EHLO smtp161.dfw.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753951AbZGVKK3 (ORCPT ); Wed, 22 Jul 2009 06:10:29 -0400 From: Oren Laadan To: Andrew Morton Cc: Linus Torvalds , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Serge Hallyn , Dave Hansen , Ingo Molnar , "H. Peter Anvin" , Alexander Viro , Pavel Emelyanov , Alexey Dobriyan , Oren Laadan , Oren Laadan Subject: [RFC v17][PATCH 48/60] c/r (ipc): allow allocation of a desired ipc identifier Date: Wed, 22 Jul 2009 06:00:10 -0400 Message-Id: <1248256822-23416-49-git-send-email-orenl@librato.com> X-Mailer: git-send-email 1.6.0.4 In-Reply-To: <1248256822-23416-1-git-send-email-orenl@librato.com> References: <1248256822-23416-1-git-send-email-orenl@librato.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12551 Lines: 368 During restart, we need to allocate ipc objects that with the same identifiers as recorded during checkpoint. Modify the allocation code allow an in-kernel caller to request a specific ipc identifier. The system call interface remains unchanged. Signed-off-by: Oren Laadan --- ipc/msg.c | 17 ++++++++++++----- ipc/sem.c | 17 ++++++++++++----- ipc/shm.c | 19 +++++++++++++------ ipc/util.c | 42 +++++++++++++++++++++++++++++------------- ipc/util.h | 9 +++++---- 5 files changed, 71 insertions(+), 33 deletions(-) diff --git a/ipc/msg.c b/ipc/msg.c index 2ceab7f..1db7c45 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -73,7 +73,7 @@ struct msg_sender { #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) static void freeque(struct ipc_namespace *, struct kern_ipc_perm *); -static int newque(struct ipc_namespace *, struct ipc_params *); +static int newque(struct ipc_namespace *, struct ipc_params *, int); #ifdef CONFIG_PROC_FS static int sysvipc_msg_proc_show(struct seq_file *s, void *it); #endif @@ -174,10 +174,12 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) * newque - Create a new msg queue * @ns: namespace * @params: ptr to the structure that contains the key and msgflg + * @req_id: request desired id if available (-1 if don't care) * * Called with msg_ids.rw_mutex held (writer) */ -static int newque(struct ipc_namespace *ns, struct ipc_params *params) +static int +newque(struct ipc_namespace *ns, struct ipc_params *params, int req_id) { struct msg_queue *msq; int id, retval; @@ -201,7 +203,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) /* * ipc_addid() locks msq */ - id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); + id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni, req_id); if (id < 0) { security_msg_queue_free(msq); ipc_rcu_putref(msq); @@ -309,7 +311,7 @@ static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) return security_msg_queue_associate(msq, msgflg); } -SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg) +int do_msgget(key_t key, int msgflg, int req_id) { struct ipc_namespace *ns; struct ipc_ops msg_ops; @@ -324,7 +326,12 @@ SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg) msg_params.key = key; msg_params.flg = msgflg; - return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); + return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params, req_id); +} + +SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg) +{ + return do_msgget(key, msgflg, -1); } static inline unsigned long diff --git a/ipc/sem.c b/ipc/sem.c index 87c2b64..a2b2135 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -92,7 +92,7 @@ #define sem_unlock(sma) ipc_unlock(&(sma)->sem_perm) #define sem_checkid(sma, semid) ipc_checkid(&sma->sem_perm, semid) -static int newary(struct ipc_namespace *, struct ipc_params *); +static int newary(struct ipc_namespace *, struct ipc_params *, int); static void freeary(struct ipc_namespace *, struct kern_ipc_perm *); #ifdef CONFIG_PROC_FS static int sysvipc_sem_proc_show(struct seq_file *s, void *it); @@ -227,11 +227,13 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s) * newary - Create a new semaphore set * @ns: namespace * @params: ptr to the structure that contains key, semflg and nsems + * @req_id: request desired id if available (-1 if don't care) * * Called with sem_ids.rw_mutex held (as a writer) */ -static int newary(struct ipc_namespace *ns, struct ipc_params *params) +static int +newary(struct ipc_namespace *ns, struct ipc_params *params, int req_id) { int id; int retval; @@ -263,7 +265,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) return retval; } - id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni); + id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni, req_id); if (id < 0) { security_sem_free(sma); ipc_rcu_putref(sma); @@ -308,7 +310,7 @@ static inline int sem_more_checks(struct kern_ipc_perm *ipcp, return 0; } -SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg) +int do_semget(key_t key, int nsems, int semflg, int req_id) { struct ipc_namespace *ns; struct ipc_ops sem_ops; @@ -327,7 +329,12 @@ SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg) sem_params.flg = semflg; sem_params.u.nsems = nsems; - return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params); + return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params, req_id); +} + +SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg) +{ + return do_semget(key, nsems, semflg, -1); } /* diff --git a/ipc/shm.c b/ipc/shm.c index 15dd238..0ee2c35 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -62,7 +62,7 @@ static struct vm_operations_struct shm_vm_ops; #define shm_unlock(shp) \ ipc_unlock(&(shp)->shm_perm) -static int newseg(struct ipc_namespace *, struct ipc_params *); +static int newseg(struct ipc_namespace *, struct ipc_params *, int); static void shm_open(struct vm_area_struct *vma); static void shm_close(struct vm_area_struct *vma); static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); @@ -83,7 +83,7 @@ void shm_init_ns(struct ipc_namespace *ns) * Called with shm_ids.rw_mutex (writer) and the shp structure locked. * Only shm_ids.rw_mutex remains locked on exit. */ -static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) +void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) { struct shmid_kernel *shp; shp = container_of(ipcp, struct shmid_kernel, shm_perm); @@ -326,11 +326,13 @@ static struct vm_operations_struct shm_vm_ops = { * newseg - Create a new shared memory segment * @ns: namespace * @params: ptr to the structure that contains key, size and shmflg + * @req_id: request desired id if available (-1 if don't care) * * Called with shm_ids.rw_mutex held as a writer. */ -static int newseg(struct ipc_namespace *ns, struct ipc_params *params) +static int +newseg(struct ipc_namespace *ns, struct ipc_params *params, int req_id) { key_t key = params->key; int shmflg = params->flg; @@ -385,7 +387,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) if (IS_ERR(file)) goto no_file; - id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); + id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni, req_id); if (id < 0) { error = id; goto no_id; @@ -443,7 +445,7 @@ static inline int shm_more_checks(struct kern_ipc_perm *ipcp, return 0; } -SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) +int do_shmget(key_t key, size_t size, int shmflg, int req_id) { struct ipc_namespace *ns; struct ipc_ops shm_ops; @@ -459,7 +461,12 @@ SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) shm_params.flg = shmflg; shm_params.u.size = size; - return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); + return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params, req_id); +} + +SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) +{ + return do_shmget(key, size, shmflg, -1); } static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) diff --git a/ipc/util.c b/ipc/util.c index b8e4ba9..ca248ec 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -247,10 +247,12 @@ int ipc_get_maxid(struct ipc_ids *ids) * Called with ipc_ids.rw_mutex held as a writer. */ -int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) +int +ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size, int req_id) { uid_t euid; gid_t egid; + int lid = 0; int id, err; if (size > IPCMNI) @@ -259,28 +261,41 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) if (ids->in_use >= size) return -ENOSPC; + if (req_id >= 0) + lid = ipcid_to_idx(req_id); + spin_lock_init(&new->lock); new->deleted = 0; rcu_read_lock(); spin_lock(&new->lock); - err = idr_get_new(&ids->ipcs_idr, new, &id); + err = idr_get_new_above(&ids->ipcs_idr, new, lid, &id); if (err) { spin_unlock(&new->lock); rcu_read_unlock(); return err; } + if (req_id >= 0) { + if (id != lid) { + idr_remove(&ids->ipcs_idr, id); + spin_unlock(&new->lock); + rcu_read_unlock(); + return -EBUSY; + } + new->seq = req_id / SEQ_MULTIPLIER; + } else { + new->seq = ids->seq++; + if (ids->seq > ids->seq_max) + ids->seq = 0; + } + ids->in_use++; current_euid_egid(&euid, &egid); new->cuid = new->uid = euid; new->gid = new->cgid = egid; - new->seq = ids->seq++; - if(ids->seq > ids->seq_max) - ids->seq = 0; - new->id = ipc_buildid(id, new->seq); return id; } @@ -296,7 +311,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) * when the key is IPC_PRIVATE. */ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids, - struct ipc_ops *ops, struct ipc_params *params) + struct ipc_ops *ops, struct ipc_params *params, int req_id) { int err; retry: @@ -306,7 +321,7 @@ retry: return -ENOMEM; down_write(&ids->rw_mutex); - err = ops->getnew(ns, params); + err = ops->getnew(ns, params, req_id); up_write(&ids->rw_mutex); if (err == -EAGAIN) @@ -351,6 +366,7 @@ static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops, * @ids: IPC identifer set * @ops: the actual creation routine to call * @params: its parameters + * @req_id: request desired id if available (-1 if don't care) * * This routine is called by sys_msgget, sys_semget() and sys_shmget() * when the key is not IPC_PRIVATE. @@ -360,7 +376,7 @@ static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops, * On success, the ipc id is returned. */ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids, - struct ipc_ops *ops, struct ipc_params *params) + struct ipc_ops *ops, struct ipc_params *params, int req_id) { struct kern_ipc_perm *ipcp; int flg = params->flg; @@ -381,7 +397,7 @@ retry: else if (!err) err = -ENOMEM; else - err = ops->getnew(ns, params); + err = ops->getnew(ns, params, req_id); } else { /* ipc object has been locked by ipc_findkey() */ @@ -742,12 +758,12 @@ struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id) * Common routine called by sys_msgget(), sys_semget() and sys_shmget(). */ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, - struct ipc_ops *ops, struct ipc_params *params) + struct ipc_ops *ops, struct ipc_params *params, int req_id) { if (params->key == IPC_PRIVATE) - return ipcget_new(ns, ids, ops, params); + return ipcget_new(ns, ids, ops, params, req_id); else - return ipcget_public(ns, ids, ops, params); + return ipcget_public(ns, ids, ops, params, req_id); } /** diff --git a/ipc/util.h b/ipc/util.h index 764b51a..159a73c 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -71,7 +71,7 @@ struct ipc_params { * . routine to call for an extra check if needed */ struct ipc_ops { - int (*getnew) (struct ipc_namespace *, struct ipc_params *); + int (*getnew) (struct ipc_namespace *, struct ipc_params *, int); int (*associate) (struct kern_ipc_perm *, int); int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *); }; @@ -94,7 +94,7 @@ void __init ipc_init_proc_interface(const char *path, const char *header, #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER) /* must be called with ids->rw_mutex acquired for writing */ -int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); +int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int, int); /* must be called with ids->rw_mutex acquired for reading */ int ipc_get_maxid(struct ipc_ids *); @@ -171,7 +171,8 @@ static inline void ipc_unlock(struct kern_ipc_perm *perm) struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id); int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, - struct ipc_ops *ops, struct ipc_params *params); + struct ipc_ops *ops, struct ipc_params *params, int req_id); void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, - void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); + void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); + #endif -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/