Hi Alan,
I decided to rename swapfs to tmpfs for administration but to call it
virtual memory fs in Documentation.
Further on the wine people asked me to export shmem_file_setup.
The attached patch does this an updates the docu.
Greetings
Christoph
diff -uNr 2.4.1-ac1/Documentation/Configure.help 2.4.1-ac1-tmpfs/Documentation/Configure.help
--- 2.4.1-ac1/Documentation/Configure.help Thu Feb 1 20:53:21 2001
+++ 2.4.1-ac1-tmpfs/Documentation/Configure.help Thu Feb 1 21:47:15 2001
@@ -11203,31 +11203,34 @@
If unsure, say N.
-Swap file system support
-CONFIG_SWAPFS
- Swapfs is a file system which keeps all files in RAM and swap space.
+Virtual memory file system support
+CONFIG_TMPFS
+ Tmpfs is a file system which keeps all files in virtual memory.
In contrast to RAM disks, which get allocated a fixed amount of
- physical RAM, swapfs grows and shrinks to accommodate the files it
+ physical RAM, tmpfs grows and shrinks to accommodate the files it
contains and is able to swap unneeded pages out to swap space.
Everything is "virtual" in the sense that no files will be created
- on your hard drive; if you reboot, everything in swapfs will be
+ on your hard drive; if you reboot, everything in tmpfs will be
lost.
- You should mount the filesystem under /dev/shm to be able to use
+ You should mount the filesystem somewhere to be able to use
POSIX shared memory. Adding the following line to /etc/fstab should
take care of things:
- swapfs /dev/shm swapfs defaults 0 0
+ tmpfs /dev/shm tmpfs defaults 0 0
- Remember to create the directory that you intend to mount swapfs on
- if necessary (The entry is automagically created if you use devfs).
+ Remember to create the directory that you intend to mount tmpfs on
+ if necessary (/dev/shm is automagically created if you use devfs).
You can set limits for the number of blocks and inodes used by the
- filesystem with the mount options "nr_blocks" and "nr_inodes". The
- initial permissions of the root directory can be set with the mount
- option "mode".
+ filesystem with the mount options "size", "nr_blocks" and
+ "nr_inodes". These parameters accept a suffix k, m or g for kilo,
+ mega and giga and can be changed on remount.
+
+ The initial permissions of the root directory can be set with the
+ mount option "mode".
Simple RAM-based file system support
CONFIG_RAMFS
@@ -11236,7 +11239,7 @@
It is more of an programming example than a useable filesystem. If
you need a file system which lives in RAM with limit checking use
- swapfs.
+ tmpfs.
If you want to compile this as a module ( = code which can be
inserted in and removed from the running kernel whenever you want),
diff -uNr 2.4.1-ac1/fs/Config.in 2.4.1-ac1-tmpfs/fs/Config.in
--- 2.4.1-ac1/fs/Config.in Thu Feb 1 20:53:52 2001
+++ 2.4.1-ac1-tmpfs/fs/Config.in Thu Feb 1 21:11:56 2001
@@ -31,7 +31,7 @@
int 'JFFS debugging verbosity (0 = quiet, 3 = noisy)' CONFIG_JFFS_FS_VERBOSE 0
fi
tristate 'Compressed ROM file system support' CONFIG_CRAMFS
-bool 'Swap file system support (former shm fs)' CONFIG_SWAPFS
+bool 'Virtual memory file system support (former shm fs)' CONFIG_TMPFS
tristate 'Simple RAM-based file system support' CONFIG_RAMFS
tristate 'ISO 9660 CDROM file system support' CONFIG_ISO9660_FS
diff -uNr 2.4.1-ac1/mm/shmem.c 2.4.1-ac1-tmpfs/mm/shmem.c
--- 2.4.1-ac1/mm/shmem.c Thu Feb 1 20:54:01 2001
+++ 2.4.1-ac1-tmpfs/mm/shmem.c Thu Feb 1 22:16:58 2001
@@ -29,7 +29,8 @@
#include <asm/uaccess.h>
-#define SWAPFS_MAGIC 0x01021994
+/* This magic number is used in glibc for posix shared memory */
+#define TMPFS_MAGIC 0x01021994
#define ENTRIES_PER_PAGE (PAGE_SIZE/sizeof(unsigned long))
#define NR_SINGLE (ENTRIES_PER_PAGE + SHMEM_NR_DIRECT)
@@ -478,7 +479,7 @@
return inode;
}
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
static ssize_t
shmem_file_write(struct file *file,const char *buf,size_t count,loff_t *ppos)
{
@@ -692,7 +693,7 @@
static int shmem_statfs(struct super_block *sb, struct statfs *buf)
{
- buf->f_type = SWAPFS_MAGIC;
+ buf->f_type = TMPFS_MAGIC;
buf->f_bsize = PAGE_CACHE_SIZE;
spin_lock (&sb->u.shmem_sb.stat_lock);
if (sb->u.shmem_sb.max_blocks != ULONG_MAX ||
@@ -976,9 +977,9 @@
unsigned long inodes = ULONG_MAX; /* unlimited */
int mode = S_IRWXUGO | S_ISVTX;
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
if (shmem_parse_options (data, &mode, &blocks, &inodes)) {
- printk(KERN_ERR "swapfs invalid option\n");
+ printk(KERN_ERR "tmpfs invalid option\n");
return NULL;
}
#endif
@@ -991,7 +992,7 @@
sb->s_maxbytes = (unsigned long long)(SHMEM_NR_DIRECT + (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)) << PAGE_CACHE_SHIFT;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
- sb->s_magic = SWAPFS_MAGIC;
+ sb->s_magic = TMPFS_MAGIC;
sb->s_op = &shmem_ops;
inode = shmem_get_inode(sb, S_IFDIR | mode, 0);
if (!inode)
@@ -1012,7 +1013,7 @@
static struct file_operations shmem_file_operations = {
mmap: shmem_mmap,
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
read: shmem_file_read,
write: shmem_file_write
#endif
@@ -1024,7 +1025,7 @@
static struct inode_operations shmem_symlink_inode_operations = {
truncate: shmem_truncate,
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
readlink: shmem_readlink,
follow_link: shmem_follow_link,
#endif
@@ -1036,7 +1037,7 @@
};
static struct inode_operations shmem_dir_inode_operations = {
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
create: shmem_create,
lookup: shmem_lookup,
link: shmem_link,
@@ -1050,7 +1051,7 @@
};
static struct super_operations shmem_ops = {
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
statfs: shmem_statfs,
remount_fs: shmem_remount_fs,
#endif
@@ -1062,12 +1063,12 @@
nopage: shmem_nopage,
};
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
/* type "shm" will be tagged obsolete in 2.5 */
static DECLARE_FSTYPE(shmem_fs_type, "shm", shmem_read_super, FS_LITTER);
-static DECLARE_FSTYPE(swapfs_fs_type, "swapfs", shmem_read_super, FS_LITTER);
+static DECLARE_FSTYPE(tmpfs_fs_type, "tmpfs", shmem_read_super, FS_LITTER);
#else
-static DECLARE_FSTYPE(swapfs_fs_type, "swapfs", shmem_read_super, FS_LITTER|FS_NOMOUNT);
+static DECLARE_FSTYPE(tmpfs_fs_type, "tmpfs", shmem_read_super, FS_LITTER|FS_NOMOUNT);
#endif
static int __init init_shmem_fs(void)
@@ -1075,21 +1076,21 @@
int error;
struct vfsmount * res;
- if ((error = register_filesystem(&swapfs_fs_type))) {
- printk (KERN_ERR "Could not register swapfs\n");
+ if ((error = register_filesystem(&tmpfs_fs_type))) {
+ printk (KERN_ERR "Could not register tmpfs\n");
return error;
}
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
if ((error = register_filesystem(&shmem_fs_type))) {
printk (KERN_ERR "Could not register shm fs\n");
return error;
}
devfs_mk_dir (NULL, "shm", NULL);
#endif
- res = kern_mount(&swapfs_fs_type);
+ res = kern_mount(&tmpfs_fs_type);
if (IS_ERR (res)) {
- printk (KERN_ERR "could not kern_mount swapfs\n");
- unregister_filesystem(&swapfs_fs_type);
+ printk (KERN_ERR "could not kern_mount tmpfs\n");
+ unregister_filesystem(&tmpfs_fs_type);
return PTR_ERR(res);
}
@@ -1098,10 +1099,10 @@
static void __exit exit_shmem_fs(void)
{
-#ifdef CONFIG_SWAPFS
+#ifdef CONFIG_TMPFS
unregister_filesystem(&shmem_fs_type);
#endif
- unregister_filesystem(&swapfs_fs_type);
+ unregister_filesystem(&tmpfs_fs_type);
}
module_init(init_shmem_fs)
@@ -1197,7 +1198,7 @@
this.name = name;
this.len = strlen(name);
this.hash = 0; /* will go */
- root = swapfs_fs_type.kern_mnt->mnt_root;
+ root = tmpfs_fs_type.kern_mnt->mnt_root;
dentry = d_alloc(root, &this);
if (!dentry)
goto out;
@@ -1215,7 +1216,7 @@
d_instantiate(dentry, inode);
dentry->d_inode->i_size = size;
shmem_truncate(inode);
- file->f_vfsmnt = mntget(swapfs_fs_type.kern_mnt);
+ file->f_vfsmnt = mntget(tmpfs_fs_type.kern_mnt);
file->f_dentry = dentry;
file->f_op = &shmem_file_operations;
file->f_mode = FMODE_WRITE | FMODE_READ;
@@ -1249,3 +1250,5 @@
vma->vm_ops = &shmem_vm_ops;
return 0;
}
+
+EXPORT_SYMBOL(shmem_file_setup);