From 7ca7e564e049d8b350ec9d958ff25eaa24226352 Mon Sep 17 00:00:00 2001 From: Nadia Derbey Date: Thu, 18 Oct 2007 23:40:48 -0700 Subject: ipc: store ipcs into IDRs This patch introduces ipcs storage into IDRs. The main changes are: . This ipc_ids structure is changed: the entries array is changed into a root idr structure. . The grow_ary() routine is removed: it is not needed anymore when adding an ipc structure, since we are now using the IDR facility. . The ipc_rmid() routine interface is changed: . there is no need for this routine to return the pointer passed in as argument: it is now declared as a void . since the id is now part of the kern_ipc_perm structure, no need to have it as an argument to the routine Signed-off-by: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/shm.c | 116 +++++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 69 insertions(+), 47 deletions(-) (limited to 'ipc/shm.c') diff --git a/ipc/shm.c b/ipc/shm.c index b9d272900a1e..dcc333239683 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -84,7 +84,7 @@ static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) ns->shm_ctlall = SHMALL; ns->shm_ctlmni = SHMMNI; ns->shm_tot = 0; - ipc_init_ids(ids, 1); + ipc_init_ids(ids); } static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp) @@ -112,20 +112,24 @@ int shm_init_ns(struct ipc_namespace *ns) void shm_exit_ns(struct ipc_namespace *ns) { - int i; struct shmid_kernel *shp; + int next_id; + int total, in_use; mutex_lock(&shm_ids(ns).mutex); - for (i = 0; i <= shm_ids(ns).max_id; i++) { - shp = shm_lock(ns, i); + + in_use = shm_ids(ns).in_use; + + for (total = 0, next_id = 0; total < in_use; next_id++) { + shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); if (shp == NULL) continue; - + ipc_lock_by_ptr(&shp->shm_perm); do_shm_rmid(ns, shp); + total++; } mutex_unlock(&shm_ids(ns).mutex); - ipc_fini_ids(ns->ids[IPC_SHM_IDS]); kfree(ns->ids[IPC_SHM_IDS]); ns->ids[IPC_SHM_IDS] = NULL; } @@ -146,9 +150,9 @@ static inline int shm_checkid(struct ipc_namespace *ns, return 0; } -static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id) +static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) { - return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id); + ipc_rmid(&shm_ids(ns), &s->shm_perm); } static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp) @@ -184,7 +188,7 @@ static void shm_open(struct vm_area_struct *vma) static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) { ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; - shm_rmid(ns, shp->id); + shm_rmid(ns, shp); shm_unlock(shp); if (!is_file_hugepages(shp->shm_file)) shmem_lock(shp->shm_file, 0, shp->mlock_user); @@ -398,17 +402,18 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size) shp->shm_ctim = get_seconds(); shp->shm_segsz = size; shp->shm_nattch = 0; - shp->id = shm_buildid(ns, id, shp->shm_perm.seq); + shp->shm_perm.id = shm_buildid(ns, id, shp->shm_perm.seq); shp->shm_file = file; /* * shmid gets reported as "inode#" in /proc/pid/maps. * proc-ps tools use this. Changing this will break them. */ - file->f_dentry->d_inode->i_ino = shp->id; + file->f_dentry->d_inode->i_ino = shp->shm_perm.id; ns->shm_tot += numpages; + error = shp->shm_perm.id; shm_unlock(shp); - return shp->id; + return error; no_id: fput(file); @@ -421,37 +426,52 @@ no_file: asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) { struct shmid_kernel *shp; - int err, id = 0; + int err; struct ipc_namespace *ns; ns = current->nsproxy->ipc_ns; - mutex_lock(&shm_ids(ns).mutex); + err = idr_pre_get(&shm_ids(ns).ipcs_idr, GFP_KERNEL); + if (key == IPC_PRIVATE) { - err = newseg(ns, key, shmflg, size); - } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) { - if (!(shmflg & IPC_CREAT)) - err = -ENOENT; - else + if (!err) + err = -ENOMEM; + else { + mutex_lock(&shm_ids(ns).mutex); err = newseg(ns, key, shmflg, size); - } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) { - err = -EEXIST; + mutex_unlock(&shm_ids(ns).mutex); + } } else { - shp = shm_lock(ns, id); - BUG_ON(shp==NULL); - if (shp->shm_segsz < size) - err = -EINVAL; - else if (ipcperms(&shp->shm_perm, shmflg)) - err = -EACCES; - else { - int shmid = shm_buildid(ns, id, shp->shm_perm.seq); - err = security_shm_associate(shp, shmflg); - if (!err) - err = shmid; + mutex_lock(&shm_ids(ns).mutex); + shp = (struct shmid_kernel *) ipc_findkey(&shm_ids(ns), key); + if (shp == NULL) { + if (!(shmflg & IPC_CREAT)) + err = -ENOENT; + else if (!err) + err = -ENOMEM; + else + err = newseg(ns, key, shmflg, size); + } else { + /* shp has been locked by ipc_findkey() */ + + if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) + err = -EEXIST; + else { + if (shp->shm_segsz < size) + err = -EINVAL; + else if (ipcperms(&shp->shm_perm, shmflg)) + err = -EACCES; + else { + err = security_shm_associate(shp, + shmflg); + if (!err) + err = shp->shm_perm.id; + } + } + shm_unlock(shp); } - shm_unlock(shp); + mutex_unlock(&shm_ids(ns).mutex); } - mutex_unlock(&shm_ids(ns).mutex); return err; } @@ -550,17 +570,20 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, unsigned long *swp) { - int i; + int next_id; + int total, in_use; *rss = 0; *swp = 0; - for (i = 0; i <= shm_ids(ns).max_id; i++) { + in_use = shm_ids(ns).in_use; + + for (total = 0, next_id = 0; total < in_use; next_id++) { struct shmid_kernel *shp; struct inode *inode; - shp = shm_get(ns, i); - if(!shp) + shp = shm_get(ns, next_id); + if (shp == NULL) continue; inode = shp->shm_file->f_path.dentry->d_inode; @@ -575,6 +598,8 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, *swp += info->swapped; spin_unlock(&info->lock); } + + total++; } } @@ -611,7 +636,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) if(copy_shminfo_to_user (buf, &shminfo, version)) return -EFAULT; /* reading a integer is always atomic */ - err= shm_ids(ns).max_id; + err = ipc_get_maxid(&shm_ids(ns)); if(err<0) err = 0; goto out; @@ -631,7 +656,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) shm_info.shm_tot = ns->shm_tot; shm_info.swap_attempts = 0; shm_info.swap_successes = 0; - err = shm_ids(ns).max_id; + err = ipc_get_maxid(&shm_ids(ns)); mutex_unlock(&shm_ids(ns).mutex); if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { err = -EFAULT; @@ -651,11 +676,8 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) if(shp==NULL) { err = -EINVAL; goto out; - } else if(cmd==SHM_STAT) { - err = -EINVAL; - if (shmid > shm_ids(ns).max_id) - goto out_unlock; - result = shm_buildid(ns, shmid, shp->shm_perm.seq); + } else if (cmd == SHM_STAT) { + result = shp->shm_perm.id; } else { err = shm_checkid(ns, shp,shmid); if(err) @@ -925,7 +947,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) file->private_data = sfd; file->f_mapping = shp->shm_file->f_mapping; - sfd->id = shp->id; + sfd->id = shp->shm_perm.id; sfd->ns = get_ipc_ns(ns); sfd->file = shp->shm_file; sfd->vm_ops = NULL; @@ -1094,7 +1116,7 @@ static int sysvipc_shm_proc_show(struct seq_file *s, void *it) format = BIG_STRING; return seq_printf(s, format, shp->shm_perm.key, - shp->id, + shp->shm_perm.id, shp->shm_perm.mode, shp->shm_segsz, shp->shm_cprid, -- cgit v1.2.3-59-g8ed1b