diff -uNr 4-1-ac7/Documentation/Changes c1/Documentation/Changes
--- 4-1-ac7/Documentation/Changes Wed May 31 20:29:23 2000
+++ c1/Documentation/Changes Fri Jun 2 13:22:23 2000
@@ -72,6 +72,18 @@
General Information
===================
+ System V shared memory is now implemented via a filesystem. You do
+not have to mount it to use it as long as you can live with the
+default maxima for shared memory and segments. If you wish to change
+these variables, you have to mount it with the options nr_blocks
+and/or nr_inodes. If you want to use POSIX shm, then it needs to be
+mounted somewhere. The recommended place is /dev/shm and this can be
+done by adding the following line to /etc/fstab:
+
+none /dev/shm shm defaults 0 0
+
+Remember to create the directory that you intend to mount shm on.
+
<CTRL><ALT><DEL> now performs a cold reboot instead of a warm reboot
for increased hardware compatibility. If you want a warm reboot and
know it works on your hardware, add a "reboot=warm" command line option
diff -uNr 4-1-ac7/Documentation/Configure.help c1/Documentation/Configure.help
--- 4-1-ac7/Documentation/Configure.help Wed May 31 20:29:23 2000
+++ c1/Documentation/Configure.help Fri Jun 2 13:22:34 2000
@@ -2581,11 +2581,10 @@
http://www.linuxdoc.org/docs.html#guide .
Shared memory is now implemented using a new (minimal) virtual file
- system, which you need to mount before programs can use shared
- memory. To do this automatically at system startup just add the
+ system. To mount it automatically at system startup just add the
following line to your /etc/fstab:
- none /var/shm shm defaults 0 0
+ none /dev/shm shm defaults 0 0
Saying Y here enlarges your kernel by about 18 KB. Just say Y.
diff -uNr 4-1-ac7/include/asm-s390/pgtable.h c1/include/asm-s390/pgtable.h
--- 4-1-ac7/include/asm-s390/pgtable.h Mon May 22 15:02:03 2000
+++ c1/include/asm-s390/pgtable.h Wed May 31 20:38:47 2000
@@ -270,6 +270,7 @@
extern inline int pte_none(pte_t pte) { return ((pte_val(pte) & (_PAGE_INVALID | _PAGE_RO)) == _PAGE_INVALID); }
extern inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_PRESENT; }
extern inline void pte_clear(pte_t *ptep) { pte_val(*ptep) = _PAGE_INVALID; }
+#define PTE_INIT(x) pte_clear(x)
extern inline int pte_pagenr(pte_t pte) { return ((unsigned long)((pte_val(pte) >> PAGE_SHIFT))); }
extern inline int pmd_none(pmd_t pmd) { return pmd_val(pmd) & _PAGE_TABLE_INV; }
diff -uNr 4-1-ac7/ipc/shm.c c1/ipc/shm.c
--- 4-1-ac7/ipc/shm.c Wed May 24 09:10:57 2000
+++ c1/ipc/shm.c Fri Jun 2 12:58:57 2000
@@ -16,11 +16,9 @@
*
* The filesystem has the following restrictions/bugs:
* 1) It only can handle one directory.
- * 2) Because the directory is represented by the SYSV shm array it
- * can only be mounted one time.
- * 3) Private writeable mappings are not supported
- * 4) Read and write are not implemented (should they?)
- * 5) No special nodes are supported
+ * 2) Private writeable mappings are not supported
+ * 3) Read and write are not implemented (should they?)
+ * 4) No special nodes are supported
*
* There are the following mount options:
* - nr_blocks (^= shmall) is the number of blocks of size PAGE_SIZE
@@ -335,7 +333,7 @@
return (struct shmid_kernel *)ipc_rmid(&shm_ids,id);
}
-static __inline__ int shm_addid(struct shmid_kernel *shp)
+static inline int shm_addid(struct shmid_kernel *shp)
{
return ipc_addid(&shm_ids, &shp->shm_perm, shm_ctlmni+1);
}
@@ -544,13 +542,37 @@
return 0;
}
-#define SHM_ENTRY(shp, index) (shp)->shm_dir[(index)/PTRS_PER_PTE][(index)%PTRS_PER_PTE]
+/*
+ * We cannot use kmalloc for shm_alloc since this restricts the
+ * maximum size of the segments.
+ *
+ * We also cannot use vmalloc, since this uses too much of the vmalloc
+ * space and we run out of this on highend machines.
+ *
+ * So we have to use this complicated indirect scheme to alloc the shm
+ * page tables.
+ *
+ */
+
+#ifdef PTE_INIT
+static inline void init_ptes (pte_t *pte, int number) {
+ while (number--)
+ PTE_INIT (pte++);
+}
+#else
+static inline void init_ptes (pte_t *pte, int number) {
+ memset (pte, 0, number*sizeof(*pte));
+}
+#endif
+
+#define PTES_PER_PAGE (PAGE_SIZE/sizeof(pte_t))
+#define SHM_ENTRY(shp, index) (shp)->shm_dir[(index)/PTES_PER_PAGE][(index)%PTES_PER_PAGE]
static pte_t **shm_alloc(unsigned long pages, int doacc)
{
- unsigned short dir = pages / PTRS_PER_PTE;
- unsigned short last = pages % PTRS_PER_PTE;
- pte_t **ret, **ptr, *pte;
+ unsigned short dir = pages / PTES_PER_PAGE;
+ unsigned short last = pages % PTES_PER_PAGE;
+ pte_t **ret, **ptr;
if (pages == 0)
return NULL;
@@ -564,8 +586,7 @@
*ptr = (pte_t *)__get_free_page (GFP_KERNEL);
if (!*ptr)
goto free;
- for (pte = *ptr; pte < *ptr + PTRS_PER_PTE; pte++)
- pte_clear (pte);
+ init_ptes (*ptr, PTES_PER_PAGE);
}
/* The last one is probably not of PAGE_SIZE: we use kmalloc */
@@ -573,8 +594,7 @@
*ptr = kmalloc (last*sizeof(pte_t), GFP_KERNEL);
if (!*ptr)
goto free;
- for (pte = *ptr; pte < *ptr + last; pte++)
- pte_clear (pte);
+ init_ptes (*ptr, last);
}
if (doacc) {
shm_lockall();
@@ -597,14 +617,14 @@
static void shm_free(pte_t** dir, unsigned long pages, int doacc)
{
int i, rss, swp;
- pte_t **ptr = dir+pages/PTRS_PER_PTE;
+ pte_t **ptr = dir+pages/PTES_PER_PAGE;
if (!dir)
return;
for (i = 0, rss = 0, swp = 0; i < pages ; i++) {
pte_t pte;
- pte = dir[i/PTRS_PER_PTE][i%PTRS_PER_PTE];
+ pte = dir[i/PTES_PER_PAGE][i%PTES_PER_PAGE];
if (pte_none(pte))
continue;
if (pte_present(pte)) {
@@ -617,7 +637,7 @@
}
/* first the last page */
- if (pages%PTRS_PER_PTE)
+ if (pages%PTES_PER_PAGE)
kfree (*ptr);
/* now the whole pages */
while (--ptr >= dir)
@@ -663,10 +683,10 @@
BUG();
error = -ENOSPC;
if (shm_tot - shp->shm_npages >= shm_ctlall)
- goto out;
+ goto size_out;
error = 0;
if (shp->shm_segsz == attr->ia_size)
- goto out;
+ goto size_out;
/* Now we set them to the real values */
old_dir = shp->shm_dir;
old_pages = shp->shm_npages;
@@ -674,8 +694,8 @@
pte_t *swap;
int i,j;
i = old_pages < new_pages ? old_pages : new_pages;
- j = i % PTRS_PER_PTE;
- i /= PTRS_PER_PTE;
+ j = i % PTES_PER_PAGE;
+ i /= PTES_PER_PAGE;
if (j)
memcpy (new_dir[i], old_dir[i], j * sizeof (pte_t));
while (i--) {
@@ -687,10 +707,21 @@
shp->shm_dir = new_dir;
shp->shm_npages = new_pages;
shp->shm_segsz = attr->ia_size;
-out:
+size_out:
shm_unlock(inode->i_ino);
shm_free (old_dir, old_pages, 1);
+
set_attr:
+ if (!(shp = shm_lock(inode->i_ino)))
+ BUG();
+ if (attr->ia_valid & ATTR_MODE)
+ shp->shm_perm.mode = attr->ia_mode;
+ if (attr->ia_valid & ATTR_UID)
+ shp->shm_perm.uid = attr->ia_uid;
+ if (attr->ia_valid & ATTR_GID)
+ shp->shm_perm.gid = attr->ia_gid;
+ shm_unlock (inode->i_ino);
+
inode_setattr(inode, attr);
return error;
}
@@ -1073,6 +1104,9 @@
case IPC_SET:
{
+ struct dentry * dentry;
+ char name[SHM_FMT_LEN+1];
+
if ((shmid % SEQ_MULTIPLIER)== zero_id)
return -EINVAL;
@@ -1098,7 +1132,29 @@
shp->shm_flags = (shp->shm_flags & ~S_IRWXUGO)
| (setbuf.mode & S_IRWXUGO);
shp->shm_ctim = CURRENT_TIME;
- break;
+ shm_unlock(shmid);
+ up(&shm_ids.sem);
+
+ sprintf (name, SHM_FMT, shmid);
+ lock_kernel();
+ dentry = lookup_one(name, lock_parent(shm_sb->s_root));
+ unlock_dir(shm_sb->s_root);
+ err = PTR_ERR(dentry);
+ if (IS_ERR(dentry))
+ goto bad_dentry;
+ err = -ENOENT;
+ if (dentry->d_inode) {
+ struct inode *ino = dentry->d_inode;
+ ino->i_uid = setbuf.uid;
+ ino->i_gid = setbuf.gid;
+ ino->i_mode = (setbuf.mode & S_IRWXUGO) | (ino->i_mode & ~S_IALLUGO);;
+ ino->i_atime = ino->i_mtime = ino->i_ctime = CURRENT_TIME;
+ err = 0;
+ }
+ dput (dentry);
+ bad_dentry:
+ unlock_kernel();
+ return err;
}
default:
@@ -1492,7 +1548,7 @@
shm_lockall();
check_id:
shp = shm_get(swap_id);
- if(shp==NULL || shp->shm_flags & SHM_LOCKED) {
+ if(shp==NULL || shp->shm_flags & PRV_LOCKED) {
next_id:
swap_idx = 0;
if (++swap_id > shm_ids.max_id) {
diff -uNr 4-1-ac7/ipc/util.c c1/ipc/util.c
--- 4-1-ac7/ipc/util.c Wed May 24 09:10:57 2000
+++ c1/ipc/util.c Wed May 31 20:30:48 2000
@@ -310,7 +310,7 @@
int map_zero_setup(struct vm_area_struct *vma)
{
- return -EINVAL;
+ return -ENOSYS;
}
#endif /* CONFIG_SYSVIPC */