#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
+#include <linux/ramfs.h>
#include <asm/uaccess.h>
static struct super_operations ramfs_ops;
static struct address_space_operations ramfs_aops;
-static struct file_operations ramfs_file_operations;
static struct inode_operations ramfs_file_inode_operations;
static struct inode_operations ramfs_dir_inode_operations;
.memory_backed = 1, /* Does not contribute to dirty memory */
};
-static struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev)
+struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev)
{
struct inode * inode = new_inode(sb);
.commit_write = simple_commit_write
};
-static struct file_operations ramfs_file_operations = {
+struct file_operations ramfs_file_operations = {
.read = generic_file_read,
.write = generic_file_write,
.mmap = generic_file_mmap,
return 0;
}
-static struct super_block *ramfs_get_sb(struct file_system_type *fs_type,
+struct super_block *ramfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return get_sb_nodev(fs_type, flags, data, ramfs_fill_super);
extern void show_free_areas(void);
-struct page *shmem_nopage(struct vm_area_struct * vma,
+#ifdef CONFIG_SHMEM
+struct page *shmem_nopage(struct vm_area_struct *vma,
unsigned long address, int *type);
int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new);
struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
unsigned long addr);
-struct file *shmem_file_setup(char * name, loff_t size, unsigned long flags);
int shmem_lock(struct file *file, int lock, struct user_struct *user);
+#else
+#define shmem_nopage filemap_nopage
+#define shmem_lock(a, b) /* always in memory, no need to lock */
+#define shmem_set_policy(a, b) (0)
+#define shmem_get_policy(a, b) (NULL)
+#endif
+struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags);
+
int shmem_zero_setup(struct vm_area_struct *);
static inline int can_do_mlock(void)
--- /dev/null
+#ifndef _LINUX_RAMFS_H
+#define _LINUX_RAMFS_H
+
+struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev);
+struct super_block *ramfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data);
+
+extern struct file_operations ramfs_file_operations;
+extern struct vm_operations_struct generic_file_vm_ops;
+
+#endif
If unsure, say N.
+config SHMEM
+ default y
+ bool "Use full shmem filesystem" if EMBEDDED && MMU
+ help
+ The shmem is an internal filesystem used to manage shared memory.
+ It is backed by swap and manages resource limits. It is also exported
+ to userspace as tmpfs if TMPFS is enabled. Disabling this
+ option replaces shmem and tmpfs with the much simpler ramfs code,
+ which may be appropriate on small systems without swap.
+
endmenu # General setup
+config TINY_SHMEM
+ default !SHMEM
+ bool
+
menu "Loadable module support"
config MODULES
mmu-y := nommu.o
mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \
mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
- shmem.o vmalloc.o
+ vmalloc.o
obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
page_alloc.o page-writeback.o pdflush.o prio_tree.o \
obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o
obj-$(CONFIG_HUGETLBFS) += hugetlb.o
obj-$(CONFIG_NUMA) += mempolicy.o
+obj-$(CONFIG_SHMEM) += shmem.o
+obj-$(CONFIG_TINY_SHMEM) += tiny-shmem.o
+
return 0;
}
-static struct vm_operations_struct generic_file_vm_ops = {
+struct vm_operations_struct generic_file_vm_ops = {
.nopage = filemap_nopage,
.populate = filemap_populate,
};
--- /dev/null
+/*
+ * tiny-shmem.c: simple shmemfs and tmpfs using ramfs code
+ *
+ * Matt Mackall <mpm@selenic.com> January, 2004
+ * derived from mm/shmem.c and fs/ramfs/inode.c
+ *
+ * This is intended for small system where the benefits of the full
+ * shmem code (swap-backed and resource-limited) are outweighed by
+ * their complexity. On systems without swap this code should be
+ * effectively equivalent, but much lighter weight.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/vfs.h>
+#include <linux/mount.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/swap.h>
+#include <linux/ramfs.h>
+
+static struct file_system_type tmpfs_fs_type = {
+ .name = "tmpfs",
+ .get_sb = ramfs_get_sb,
+ .kill_sb = kill_litter_super,
+};
+
+static struct vfsmount *shm_mnt;
+
+static int __init init_tmpfs(void)
+{
+ register_filesystem(&tmpfs_fs_type);
+#ifdef CONFIG_TMPFS
+ devfs_mk_dir("shm");
+#endif
+ shm_mnt = kern_mount(&tmpfs_fs_type);
+ return 0;
+}
+module_init(init_tmpfs)
+
+/*
+ * shmem_file_setup - get an unlinked file living in tmpfs
+ *
+ * @name: name for dentry (to be seen in /proc/<pid>/maps
+ * @size: size to be set for the file
+ *
+ */
+struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags)
+{
+ int error;
+ struct file *file;
+ struct inode *inode;
+ struct dentry *dentry, *root;
+ struct qstr this;
+
+ if (IS_ERR(shm_mnt))
+ return (void *)shm_mnt;
+
+ error = -ENOMEM;
+ this.name = name;
+ this.len = strlen(name);
+ this.hash = 0; /* will go */
+ root = shm_mnt->mnt_root;
+ dentry = d_alloc(root, &this);
+ if (!dentry)
+ goto put_memory;
+
+ error = -ENFILE;
+ file = get_empty_filp();
+ if (!file)
+ goto put_dentry;
+
+ error = -ENOSPC;
+ inode = ramfs_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0);
+ if (!inode)
+ goto close_file;
+
+ d_instantiate(dentry, inode);
+ inode->i_size = size;
+ inode->i_nlink = 0; /* It is unlinked */
+ file->f_vfsmnt = mntget(shm_mnt);
+ file->f_dentry = dentry;
+ file->f_mapping = inode->i_mapping;
+ file->f_op = &ramfs_file_operations;
+ file->f_mode = FMODE_WRITE | FMODE_READ;
+ return file;
+
+close_file:
+ put_filp(file);
+put_dentry:
+ dput(dentry);
+put_memory:
+ return ERR_PTR(error);
+}
+
+/*
+ * shmem_zero_setup - setup a shared anonymous mapping
+ *
+ * @vma: the vma to be mmapped is prepared by do_mmap_pgoff
+ */
+int shmem_zero_setup(struct vm_area_struct *vma)
+{
+ struct file *file;
+ loff_t size = vma->vm_end - vma->vm_start;
+
+ file = shmem_file_setup("dev/zero", size, vma->vm_flags);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+
+ if (vma->vm_file)
+ fput(vma->vm_file);
+ vma->vm_file = file;
+ vma->vm_ops = &generic_file_vm_ops;
+ return 0;
+}
+
+int shmem_unuse(swp_entry_t entry, struct page *page)
+{
+ return 0;
+}
+
+EXPORT_SYMBOL(shmem_file_setup);
projects / linux-flexiantxendom0-3.2.10.git / commitdiff