From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- fs/ramfs/Makefile | 7 ++ fs/ramfs/inode.c | 246 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 253 insertions(+) create mode 100644 fs/ramfs/Makefile create mode 100644 fs/ramfs/inode.c (limited to 'fs/ramfs') diff --git a/fs/ramfs/Makefile b/fs/ramfs/Makefile new file mode 100644 index 000000000000..f096f3007091 --- /dev/null +++ b/fs/ramfs/Makefile @@ -0,0 +1,7 @@ +# +# Makefile for the linux ramfs routines. +# + +obj-$(CONFIG_RAMFS) += ramfs.o + +ramfs-objs := inode.o diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c new file mode 100644 index 000000000000..0a88917605ae --- /dev/null +++ b/fs/ramfs/inode.c @@ -0,0 +1,246 @@ +/* + * Resizable simple ram filesystem for Linux. + * + * Copyright (C) 2000 Linus Torvalds. + * 2000 Transmeta Corp. + * + * Usage limits added by David Gibson, Linuxcare Australia. + * This file is released under the GPL. + */ + +/* + * NOTE! This filesystem is probably most useful + * not as a real filesystem, but as an example of + * how virtual filesystems can be written. + * + * It doesn't get much simpler than this. Consider + * that this file implements the full semantics of + * a POSIX-compliant read-write filesystem. + * + * Note in particular how the filesystem does not + * need to implement any data structures of its own + * to keep track of the virtual data: using the VFS + * caches is sufficient. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* some random number */ +#define RAMFS_MAGIC 0x858458f6 + +static struct super_operations ramfs_ops; +static struct address_space_operations ramfs_aops; +static struct inode_operations ramfs_file_inode_operations; +static struct inode_operations ramfs_dir_inode_operations; + +static struct backing_dev_info ramfs_backing_dev_info = { + .ra_pages = 0, /* No readahead */ + .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK | + BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY | + BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP, +}; + +struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev) +{ + struct inode * inode = new_inode(sb); + + if (inode) { + inode->i_mode = mode; + inode->i_uid = current->fsuid; + inode->i_gid = current->fsgid; + inode->i_blksize = PAGE_CACHE_SIZE; + inode->i_blocks = 0; + inode->i_mapping->a_ops = &ramfs_aops; + inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + switch (mode & S_IFMT) { + default: + init_special_inode(inode, mode, dev); + break; + case S_IFREG: + inode->i_op = &ramfs_file_inode_operations; + inode->i_fop = &ramfs_file_operations; + break; + case S_IFDIR: + inode->i_op = &ramfs_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inode->i_nlink++; + break; + case S_IFLNK: + inode->i_op = &page_symlink_inode_operations; + break; + } + } + return inode; +} + +/* + * File creation. Allocate an inode, and we're done.. + */ +/* SMP-safe */ +static int +ramfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) +{ + struct inode * inode = ramfs_get_inode(dir->i_sb, mode, dev); + int error = -ENOSPC; + + if (inode) { + if (dir->i_mode & S_ISGID) { + inode->i_gid = dir->i_gid; + if (S_ISDIR(mode)) + inode->i_mode |= S_ISGID; + } + d_instantiate(dentry, inode); + dget(dentry); /* Extra count - pin the dentry in core */ + error = 0; + } + return error; +} + +static int ramfs_mkdir(struct inode * dir, struct dentry * dentry, int mode) +{ + int retval = ramfs_mknod(dir, dentry, mode | S_IFDIR, 0); + if (!retval) + dir->i_nlink++; + return retval; +} + +static int ramfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) +{ + return ramfs_mknod(dir, dentry, mode | S_IFREG, 0); +} + +static int ramfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname) +{ + struct inode *inode; + int error = -ENOSPC; + + inode = ramfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0); + if (inode) { + int l = strlen(symname)+1; + error = page_symlink(inode, symname, l); + if (!error) { + if (dir->i_mode & S_ISGID) + inode->i_gid = dir->i_gid; + d_instantiate(dentry, inode); + dget(dentry); + } else + iput(inode); + } + return error; +} + +static struct address_space_operations ramfs_aops = { + .readpage = simple_readpage, + .prepare_write = simple_prepare_write, + .commit_write = simple_commit_write +}; + +struct file_operations ramfs_file_operations = { + .read = generic_file_read, + .write = generic_file_write, + .mmap = generic_file_mmap, + .fsync = simple_sync_file, + .sendfile = generic_file_sendfile, + .llseek = generic_file_llseek, +}; + +static struct inode_operations ramfs_file_inode_operations = { + .getattr = simple_getattr, +}; + +static struct inode_operations ramfs_dir_inode_operations = { + .create = ramfs_create, + .lookup = simple_lookup, + .link = simple_link, + .unlink = simple_unlink, + .symlink = ramfs_symlink, + .mkdir = ramfs_mkdir, + .rmdir = simple_rmdir, + .mknod = ramfs_mknod, + .rename = simple_rename, +}; + +static struct super_operations ramfs_ops = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, +}; + +static int ramfs_fill_super(struct super_block * sb, void * data, int silent) +{ + struct inode * inode; + struct dentry * root; + + sb->s_maxbytes = MAX_LFS_FILESIZE; + sb->s_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = RAMFS_MAGIC; + sb->s_op = &ramfs_ops; + sb->s_time_gran = 1; + inode = ramfs_get_inode(sb, S_IFDIR | 0755, 0); + if (!inode) + return -ENOMEM; + + root = d_alloc_root(inode); + if (!root) { + iput(inode); + return -ENOMEM; + } + sb->s_root = root; + return 0; +} + +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); +} + +static struct super_block *rootfs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + return get_sb_nodev(fs_type, flags|MS_NOUSER, data, ramfs_fill_super); +} + +static struct file_system_type ramfs_fs_type = { + .name = "ramfs", + .get_sb = ramfs_get_sb, + .kill_sb = kill_litter_super, +}; +static struct file_system_type rootfs_fs_type = { + .name = "rootfs", + .get_sb = rootfs_get_sb, + .kill_sb = kill_litter_super, +}; + +static int __init init_ramfs_fs(void) +{ + return register_filesystem(&ramfs_fs_type); +} + +static void __exit exit_ramfs_fs(void) +{ + unregister_filesystem(&ramfs_fs_type); +} + +module_init(init_ramfs_fs) +module_exit(exit_ramfs_fs) + +int __init init_rootfs(void) +{ + return register_filesystem(&rootfs_fs_type); +} + +MODULE_LICENSE("GPL"); -- cgit v1.2.3