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 <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/shm.c b/ipc/shm.c
index b9d2729..dcc3332 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -84,7 +84,7 @@
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 @@
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 @@
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_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 @@
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 @@
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
- err = newseg(ns, key, shmflg, size);
- } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
- err = -EEXIST;
- } 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;
+ if (!err)
+ err = -ENOMEM;
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);
+ err = newseg(ns, key, shmflg, size);
+ mutex_unlock(&shm_ids(ns).mutex);
}
- shm_unlock(shp);
+ } else {
+ 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);
+ }
+ mutex_unlock(&shm_ids(ns).mutex);
}
- mutex_unlock(&shm_ids(ns).mutex);
return err;
}
@@ -550,17 +570,20 @@
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 @@
*swp += info->swapped;
spin_unlock(&info->lock);
}
+
+ total++;
}
}
@@ -611,7 +636,7 @@
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 @@
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 @@
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 @@
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 @@
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,