[PATCH] SHM_NORESERVE flags for shmget()
[linux-2.6.git] / ipc / shm.c
index 1d6cf08..587d836 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
 #include <linux/init.h>
 #include <linux/file.h>
 #include <linux/mman.h>
-#include <linux/proc_fs.h>
 #include <linux/shmem_fs.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include <linux/audit.h>
 #include <linux/ptrace.h>
+#include <linux/seq_file.h>
 
 #include <asm/uaccess.h>
 
@@ -51,7 +51,7 @@ static int newseg (key_t key, int shmflg, size_t size);
 static void shm_open (struct vm_area_struct *shmd);
 static void shm_close (struct vm_area_struct *shmd);
 #ifdef CONFIG_PROC_FS
-static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data);
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
 #endif
 
 size_t shm_ctlmax = SHMMAX;
@@ -63,9 +63,10 @@ static int shm_tot; /* total number of shared memory pages */
 void __init shm_init (void)
 {
        ipc_init_ids(&shm_ids, 1);
-#ifdef CONFIG_PROC_FS
-       create_proc_read_entry("sysvipc/shm", 0, NULL, sysvipc_shm_read_proc, NULL);
-#endif
+       ipc_init_proc_interface("sysvipc/shm",
+                               "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime\n",
+                               &shm_ids,
+                               sysvipc_shm_proc_show);
 }
 
 static inline int shm_checkid(struct shmid_kernel *s, int id)
@@ -211,8 +212,16 @@ static int newseg (key_t key, int shmflg, size_t size)
                file = hugetlb_zero_setup(size);
                shp->mlock_user = current->user;
        } else {
+               int acctflag = VM_ACCOUNT;
+               /*
+                * Do not allow no accounting for OVERCOMMIT_NEVER, even
+                * if it's asked for.
+                */
+               if  ((shmflg & SHM_NORESERVE) &&
+                               sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+                       acctflag = 0;
                sprintf (name, "SYSV%08x", key);
-               file = shmem_file_setup(name, size, VM_ACCOUNT);
+               file = shmem_file_setup(name, size, acctflag);
        }
        error = PTR_ERR(file);
        if (IS_ERR(file))
@@ -232,10 +241,11 @@ static int newseg (key_t key, int shmflg, size_t size)
        shp->id = shm_buildid(id,shp->shm_perm.seq);
        shp->shm_file = file;
        file->f_dentry->d_inode->i_ino = shp->id;
-       if (shmflg & SHM_HUGETLB)
-               set_file_hugepages(file);
-       else
+
+       /* Hugetlb ops would have already been assigned. */
+       if (!(shmflg & SHM_HUGETLB))
                file->f_op = &shm_file_operations;
+
        shm_tot += numpages;
        shm_unlock(shp);
        return shp->id;
@@ -869,63 +879,32 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
 }
 
 #ifdef CONFIG_PROC_FS
-static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
 {
-       off_t pos = 0;
-       off_t begin = 0;
-       int i, len = 0;
-
-       down(&shm_ids.sem);
-       len += sprintf(buffer, "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime\n");
+       struct shmid_kernel *shp = it;
+       char *format;
 
-       for(i = 0; i <= shm_ids.max_id; i++) {
-               struct shmid_kernel* shp;
-
-               shp = shm_lock(i);
-               if(shp!=NULL) {
 #define SMALL_STRING "%10d %10d  %4o %10u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
 #define BIG_STRING   "%10d %10d  %4o %21u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
-                       char *format;
 
-                       if (sizeof(size_t) <= sizeof(int))
-                               format = SMALL_STRING;
-                       else
-                               format = BIG_STRING;
-                       len += sprintf(buffer + len, format,
-                               shp->shm_perm.key,
-                               shm_buildid(i, shp->shm_perm.seq),
-                               shp->shm_flags,
-                               shp->shm_segsz,
-                               shp->shm_cprid,
-                               shp->shm_lprid,
-                               is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch,
-                               shp->shm_perm.uid,
-                               shp->shm_perm.gid,
-                               shp->shm_perm.cuid,
-                               shp->shm_perm.cgid,
-                               shp->shm_atim,
-                               shp->shm_dtim,
-                               shp->shm_ctim);
-                       shm_unlock(shp);
-
-                       pos += len;
-                       if(pos < offset) {
-                               len = 0;
-                               begin = pos;
-                       }
-                       if(pos > offset + length)
-                               goto done;
-               }
-       }
-       *eof = 1;
-done:
-       up(&shm_ids.sem);
-       *start = buffer + (offset - begin);
-       len -= (offset - begin);
-       if(len > length)
-               len = length;
-       if(len < 0)
-               len = 0;
-       return len;
+       if (sizeof(size_t) <= sizeof(int))
+               format = SMALL_STRING;
+       else
+               format = BIG_STRING;
+       return seq_printf(s, format,
+                         shp->shm_perm.key,
+                         shp->id,
+                         shp->shm_flags,
+                         shp->shm_segsz,
+                         shp->shm_cprid,
+                         shp->shm_lprid,
+                         is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch,
+                         shp->shm_perm.uid,
+                         shp->shm_perm.gid,
+                         shp->shm_perm.cuid,
+                         shp->shm_perm.cgid,
+                         shp->shm_atim,
+                         shp->shm_dtim,
+                         shp->shm_ctim);
 }
 #endif