diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/romfs/super.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/romfs/super.c | 659 |
1 files changed, 0 insertions, 659 deletions
diff --git a/ANDROID_3.4.5/fs/romfs/super.c b/ANDROID_3.4.5/fs/romfs/super.c deleted file mode 100644 index e64f6b5f..00000000 --- a/ANDROID_3.4.5/fs/romfs/super.c +++ /dev/null @@ -1,659 +0,0 @@ -/* Block- or MTD-based romfs - * - * Copyright © 2007 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * Derived from: ROMFS file system, Linux implementation - * - * Copyright © 1997-1999 Janos Farkas <chexum@shadow.banki.hu> - * - * Using parts of the minix filesystem - * Copyright © 1991, 1992 Linus Torvalds - * - * and parts of the affs filesystem additionally - * Copyright © 1993 Ray Burr - * Copyright © 1996 Hans-Joachim Widmaier - * - * Changes - * Changed for 2.1.19 modules - * Jan 1997 Initial release - * Jun 1997 2.1.43+ changes - * Proper page locking in readpage - * Changed to work with 2.1.45+ fs - * Jul 1997 Fixed follow_link - * 2.1.47 - * lookup shouldn't return -ENOENT - * from Horst von Brand: - * fail on wrong checksum - * double unlock_super was possible - * correct namelen for statfs - * spotted by Bill Hawes: - * readlink shouldn't iput() - * Jun 1998 2.1.106 from Avery Pennarun: glibc scandir() - * exposed a problem in readdir - * 2.1.107 code-freeze spellchecker run - * Aug 1998 2.1.118+ VFS changes - * Sep 1998 2.1.122 another VFS change (follow_link) - * Apr 1999 2.2.7 no more EBADF checking in - * lookup/readdir, use ERR_PTR - * Jun 1999 2.3.6 d_alloc_root use changed - * 2.3.9 clean up usage of ENOENT/negative - * dentries in lookup - * clean up page flags setting - * (error, uptodate, locking) in - * in readpage - * use init_special_inode for - * fifos/sockets (and streamline) in - * read_inode, fix _ops table order - * Aug 1999 2.3.16 __initfunc() => __init change - * Oct 1999 2.3.24 page->owner hack obsoleted - * Nov 1999 2.3.27 2.3.25+ page->offset => index change - * - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public Licence - * as published by the Free Software Foundation; either version - * 2 of the Licence, or (at your option) any later version. - */ - -#include <linux/module.h> -#include <linux/string.h> -#include <linux/fs.h> -#include <linux/time.h> -#include <linux/slab.h> -#include <linux/init.h> -#include <linux/blkdev.h> -#include <linux/parser.h> -#include <linux/mount.h> -#include <linux/namei.h> -#include <linux/statfs.h> -#include <linux/mtd/super.h> -#include <linux/ctype.h> -#include <linux/highmem.h> -#include <linux/pagemap.h> -#include <linux/uaccess.h> -#include "internal.h" - -static struct kmem_cache *romfs_inode_cachep; - -static const umode_t romfs_modemap[8] = { - 0, /* hard link */ - S_IFDIR | 0644, /* directory */ - S_IFREG | 0644, /* regular file */ - S_IFLNK | 0777, /* symlink */ - S_IFBLK | 0600, /* blockdev */ - S_IFCHR | 0600, /* chardev */ - S_IFSOCK | 0644, /* socket */ - S_IFIFO | 0644 /* FIFO */ -}; - -static const unsigned char romfs_dtype_table[] = { - DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_SOCK, DT_FIFO -}; - -static struct inode *romfs_iget(struct super_block *sb, unsigned long pos); - -/* - * read a page worth of data from the image - */ -static int romfs_readpage(struct file *file, struct page *page) -{ - struct inode *inode = page->mapping->host; - loff_t offset, size; - unsigned long fillsize, pos; - void *buf; - int ret; - - buf = kmap(page); - if (!buf) - return -ENOMEM; - - /* 32 bit warning -- but not for us :) */ - offset = page_offset(page); - size = i_size_read(inode); - fillsize = 0; - ret = 0; - if (offset < size) { - size -= offset; - fillsize = size > PAGE_SIZE ? PAGE_SIZE : size; - - pos = ROMFS_I(inode)->i_dataoffset + offset; - - ret = romfs_dev_read(inode->i_sb, pos, buf, fillsize); - if (ret < 0) { - SetPageError(page); - fillsize = 0; - ret = -EIO; - } - } - - if (fillsize < PAGE_SIZE) - memset(buf + fillsize, 0, PAGE_SIZE - fillsize); - if (ret == 0) - SetPageUptodate(page); - - flush_dcache_page(page); - kunmap(page); - unlock_page(page); - return ret; -} - -static const struct address_space_operations romfs_aops = { - .readpage = romfs_readpage -}; - -/* - * read the entries from a directory - */ -static int romfs_readdir(struct file *filp, void *dirent, filldir_t filldir) -{ - struct inode *i = filp->f_dentry->d_inode; - struct romfs_inode ri; - unsigned long offset, maxoff; - int j, ino, nextfh; - int stored = 0; - char fsname[ROMFS_MAXFN]; /* XXX dynamic? */ - int ret; - - maxoff = romfs_maxsize(i->i_sb); - - offset = filp->f_pos; - if (!offset) { - offset = i->i_ino & ROMFH_MASK; - ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE); - if (ret < 0) - goto out; - offset = be32_to_cpu(ri.spec) & ROMFH_MASK; - } - - /* Not really failsafe, but we are read-only... */ - for (;;) { - if (!offset || offset >= maxoff) { - offset = maxoff; - filp->f_pos = offset; - goto out; - } - filp->f_pos = offset; - - /* Fetch inode info */ - ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE); - if (ret < 0) - goto out; - - j = romfs_dev_strnlen(i->i_sb, offset + ROMFH_SIZE, - sizeof(fsname) - 1); - if (j < 0) - goto out; - - ret = romfs_dev_read(i->i_sb, offset + ROMFH_SIZE, fsname, j); - if (ret < 0) - goto out; - fsname[j] = '\0'; - - ino = offset; - nextfh = be32_to_cpu(ri.next); - if ((nextfh & ROMFH_TYPE) == ROMFH_HRD) - ino = be32_to_cpu(ri.spec); - if (filldir(dirent, fsname, j, offset, ino, - romfs_dtype_table[nextfh & ROMFH_TYPE]) < 0) - goto out; - - stored++; - offset = nextfh & ROMFH_MASK; - } - -out: - return stored; -} - -/* - * look up an entry in a directory - */ -static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry, - struct nameidata *nd) -{ - unsigned long offset, maxoff; - struct inode *inode; - struct romfs_inode ri; - const char *name; /* got from dentry */ - int len, ret; - - offset = dir->i_ino & ROMFH_MASK; - ret = romfs_dev_read(dir->i_sb, offset, &ri, ROMFH_SIZE); - if (ret < 0) - goto error; - - /* search all the file entries in the list starting from the one - * pointed to by the directory's special data */ - maxoff = romfs_maxsize(dir->i_sb); - offset = be32_to_cpu(ri.spec) & ROMFH_MASK; - - name = dentry->d_name.name; - len = dentry->d_name.len; - - for (;;) { - if (!offset || offset >= maxoff) - goto out0; - - ret = romfs_dev_read(dir->i_sb, offset, &ri, sizeof(ri)); - if (ret < 0) - goto error; - - /* try to match the first 16 bytes of name */ - ret = romfs_dev_strcmp(dir->i_sb, offset + ROMFH_SIZE, name, - len); - if (ret < 0) - goto error; - if (ret == 1) - break; - - /* next entry */ - offset = be32_to_cpu(ri.next) & ROMFH_MASK; - } - - /* Hard link handling */ - if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD) - offset = be32_to_cpu(ri.spec) & ROMFH_MASK; - - inode = romfs_iget(dir->i_sb, offset); - if (IS_ERR(inode)) { - ret = PTR_ERR(inode); - goto error; - } - goto outi; - - /* - * it's a bit funky, _lookup needs to return an error code - * (negative) or a NULL, both as a dentry. ENOENT should not - * be returned, instead we need to create a negative dentry by - * d_add(dentry, NULL); and return 0 as no error. - * (Although as I see, it only matters on writable file - * systems). - */ -out0: - inode = NULL; -outi: - d_add(dentry, inode); - ret = 0; -error: - return ERR_PTR(ret); -} - -static const struct file_operations romfs_dir_operations = { - .read = generic_read_dir, - .readdir = romfs_readdir, - .llseek = default_llseek, -}; - -static const struct inode_operations romfs_dir_inode_operations = { - .lookup = romfs_lookup, -}; - -/* - * get a romfs inode based on its position in the image (which doubles as the - * inode number) - */ -static struct inode *romfs_iget(struct super_block *sb, unsigned long pos) -{ - struct romfs_inode_info *inode; - struct romfs_inode ri; - struct inode *i; - unsigned long nlen; - unsigned nextfh; - int ret; - umode_t mode; - - /* we might have to traverse a chain of "hard link" file entries to get - * to the actual file */ - for (;;) { - ret = romfs_dev_read(sb, pos, &ri, sizeof(ri)); - if (ret < 0) - goto error; - - /* XXX: do romfs_checksum here too (with name) */ - - nextfh = be32_to_cpu(ri.next); - if ((nextfh & ROMFH_TYPE) != ROMFH_HRD) - break; - - pos = be32_to_cpu(ri.spec) & ROMFH_MASK; - } - - /* determine the length of the filename */ - nlen = romfs_dev_strnlen(sb, pos + ROMFH_SIZE, ROMFS_MAXFN); - if (IS_ERR_VALUE(nlen)) - goto eio; - - /* get an inode for this image position */ - i = iget_locked(sb, pos); - if (!i) - return ERR_PTR(-ENOMEM); - - if (!(i->i_state & I_NEW)) - return i; - - /* precalculate the data offset */ - inode = ROMFS_I(i); - inode->i_metasize = (ROMFH_SIZE + nlen + 1 + ROMFH_PAD) & ROMFH_MASK; - inode->i_dataoffset = pos + inode->i_metasize; - - set_nlink(i, 1); /* Hard to decide.. */ - i->i_size = be32_to_cpu(ri.size); - i->i_mtime.tv_sec = i->i_atime.tv_sec = i->i_ctime.tv_sec = 0; - i->i_mtime.tv_nsec = i->i_atime.tv_nsec = i->i_ctime.tv_nsec = 0; - - /* set up mode and ops */ - mode = romfs_modemap[nextfh & ROMFH_TYPE]; - - switch (nextfh & ROMFH_TYPE) { - case ROMFH_DIR: - i->i_size = ROMFS_I(i)->i_metasize; - i->i_op = &romfs_dir_inode_operations; - i->i_fop = &romfs_dir_operations; - if (nextfh & ROMFH_EXEC) - mode |= S_IXUGO; - break; - case ROMFH_REG: - i->i_fop = &romfs_ro_fops; - i->i_data.a_ops = &romfs_aops; - if (i->i_sb->s_mtd) - i->i_data.backing_dev_info = - i->i_sb->s_mtd->backing_dev_info; - if (nextfh & ROMFH_EXEC) - mode |= S_IXUGO; - break; - case ROMFH_SYM: - i->i_op = &page_symlink_inode_operations; - i->i_data.a_ops = &romfs_aops; - mode |= S_IRWXUGO; - break; - default: - /* depending on MBZ for sock/fifos */ - nextfh = be32_to_cpu(ri.spec); - init_special_inode(i, mode, MKDEV(nextfh >> 16, - nextfh & 0xffff)); - break; - } - - i->i_mode = mode; - - unlock_new_inode(i); - return i; - -eio: - ret = -EIO; -error: - printk(KERN_ERR "ROMFS: read error for inode 0x%lx\n", pos); - return ERR_PTR(ret); -} - -/* - * allocate a new inode - */ -static struct inode *romfs_alloc_inode(struct super_block *sb) -{ - struct romfs_inode_info *inode; - inode = kmem_cache_alloc(romfs_inode_cachep, GFP_KERNEL); - return inode ? &inode->vfs_inode : NULL; -} - -/* - * return a spent inode to the slab cache - */ -static void romfs_i_callback(struct rcu_head *head) -{ - struct inode *inode = container_of(head, struct inode, i_rcu); - kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode)); -} - -static void romfs_destroy_inode(struct inode *inode) -{ - call_rcu(&inode->i_rcu, romfs_i_callback); -} - -/* - * get filesystem statistics - */ -static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf) -{ - struct super_block *sb = dentry->d_sb; - u64 id = huge_encode_dev(sb->s_bdev->bd_dev); - - buf->f_type = ROMFS_MAGIC; - buf->f_namelen = ROMFS_MAXFN; - buf->f_bsize = ROMBSIZE; - buf->f_bfree = buf->f_bavail = buf->f_ffree; - buf->f_blocks = - (romfs_maxsize(dentry->d_sb) + ROMBSIZE - 1) >> ROMBSBITS; - buf->f_fsid.val[0] = (u32)id; - buf->f_fsid.val[1] = (u32)(id >> 32); - return 0; -} - -/* - * remounting must involve read-only - */ -static int romfs_remount(struct super_block *sb, int *flags, char *data) -{ - *flags |= MS_RDONLY; - return 0; -} - -static const struct super_operations romfs_super_ops = { - .alloc_inode = romfs_alloc_inode, - .destroy_inode = romfs_destroy_inode, - .statfs = romfs_statfs, - .remount_fs = romfs_remount, -}; - -/* - * checksum check on part of a romfs filesystem - */ -static __u32 romfs_checksum(const void *data, int size) -{ - const __be32 *ptr = data; - __u32 sum; - - sum = 0; - size >>= 2; - while (size > 0) { - sum += be32_to_cpu(*ptr++); - size--; - } - return sum; -} - -/* - * fill in the superblock - */ -static int romfs_fill_super(struct super_block *sb, void *data, int silent) -{ - struct romfs_super_block *rsb; - struct inode *root; - unsigned long pos, img_size; - const char *storage; - size_t len; - int ret; - -#ifdef CONFIG_BLOCK - if (!sb->s_mtd) { - sb_set_blocksize(sb, ROMBSIZE); - } else { - sb->s_blocksize = ROMBSIZE; - sb->s_blocksize_bits = blksize_bits(ROMBSIZE); - } -#endif - - sb->s_maxbytes = 0xFFFFFFFF; - sb->s_magic = ROMFS_MAGIC; - sb->s_flags |= MS_RDONLY | MS_NOATIME; - sb->s_op = &romfs_super_ops; - - /* read the image superblock and check it */ - rsb = kmalloc(512, GFP_KERNEL); - if (!rsb) - return -ENOMEM; - - sb->s_fs_info = (void *) 512; - ret = romfs_dev_read(sb, 0, rsb, 512); - if (ret < 0) - goto error_rsb; - - img_size = be32_to_cpu(rsb->size); - - if (sb->s_mtd && img_size > sb->s_mtd->size) - goto error_rsb_inval; - - sb->s_fs_info = (void *) img_size; - - if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 || - img_size < ROMFH_SIZE) { - if (!silent) - printk(KERN_WARNING "VFS:" - " Can't find a romfs filesystem on dev %s.\n", - sb->s_id); - goto error_rsb_inval; - } - - if (romfs_checksum(rsb, min_t(size_t, img_size, 512))) { - printk(KERN_ERR "ROMFS: bad initial checksum on dev %s.\n", - sb->s_id); - goto error_rsb_inval; - } - - storage = sb->s_mtd ? "MTD" : "the block layer"; - - len = strnlen(rsb->name, ROMFS_MAXFN); - if (!silent) - printk(KERN_NOTICE "ROMFS: Mounting image '%*.*s' through %s\n", - (unsigned) len, (unsigned) len, rsb->name, storage); - - kfree(rsb); - rsb = NULL; - - /* find the root directory */ - pos = (ROMFH_SIZE + len + 1 + ROMFH_PAD) & ROMFH_MASK; - - root = romfs_iget(sb, pos); - if (IS_ERR(root)) - goto error; - - sb->s_root = d_make_root(root); - if (!sb->s_root) - goto error; - - return 0; - -error: - return -EINVAL; -error_rsb_inval: - ret = -EINVAL; -error_rsb: - kfree(rsb); - return ret; -} - -/* - * get a superblock for mounting - */ -static struct dentry *romfs_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, - void *data) -{ - struct dentry *ret = ERR_PTR(-EINVAL); - -#ifdef CONFIG_ROMFS_ON_MTD - ret = mount_mtd(fs_type, flags, dev_name, data, romfs_fill_super); -#endif -#ifdef CONFIG_ROMFS_ON_BLOCK - if (ret == ERR_PTR(-EINVAL)) - ret = mount_bdev(fs_type, flags, dev_name, data, - romfs_fill_super); -#endif - return ret; -} - -/* - * destroy a romfs superblock in the appropriate manner - */ -static void romfs_kill_sb(struct super_block *sb) -{ -#ifdef CONFIG_ROMFS_ON_MTD - if (sb->s_mtd) { - kill_mtd_super(sb); - return; - } -#endif -#ifdef CONFIG_ROMFS_ON_BLOCK - if (sb->s_bdev) { - kill_block_super(sb); - return; - } -#endif -} - -static struct file_system_type romfs_fs_type = { - .owner = THIS_MODULE, - .name = "romfs", - .mount = romfs_mount, - .kill_sb = romfs_kill_sb, - .fs_flags = FS_REQUIRES_DEV, -}; - -/* - * inode storage initialiser - */ -static void romfs_i_init_once(void *_inode) -{ - struct romfs_inode_info *inode = _inode; - - inode_init_once(&inode->vfs_inode); -} - -/* - * romfs module initialisation - */ -static int __init init_romfs_fs(void) -{ - int ret; - - printk(KERN_INFO "ROMFS MTD (C) 2007 Red Hat, Inc.\n"); - - romfs_inode_cachep = - kmem_cache_create("romfs_i", - sizeof(struct romfs_inode_info), 0, - SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, - romfs_i_init_once); - - if (!romfs_inode_cachep) { - printk(KERN_ERR - "ROMFS error: Failed to initialise inode cache\n"); - return -ENOMEM; - } - ret = register_filesystem(&romfs_fs_type); - if (ret) { - printk(KERN_ERR "ROMFS error: Failed to register filesystem\n"); - goto error_register; - } - return 0; - -error_register: - kmem_cache_destroy(romfs_inode_cachep); - return ret; -} - -/* - * romfs module removal - */ -static void __exit exit_romfs_fs(void) -{ - unregister_filesystem(&romfs_fs_type); - kmem_cache_destroy(romfs_inode_cachep); -} - -module_init(init_romfs_fs); -module_exit(exit_romfs_fs); - -MODULE_DESCRIPTION("Direct-MTD Capable RomFS"); -MODULE_AUTHOR("Red Hat, Inc."); -MODULE_LICENSE("GPL"); /* Actually dual-licensed, but it doesn't matter for */ |