Contributors: 32
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| David Howells |
1289 |
50.41% |
6 |
5.88% |
| Linus Torvalds (pre-git) |
737 |
28.82% |
33 |
32.35% |
| Al Viro |
224 |
8.76% |
18 |
17.65% |
| Coly Li |
83 |
3.25% |
2 |
1.96% |
| Linus Torvalds |
35 |
1.37% |
10 |
9.80% |
| Jan Kara |
24 |
0.94% |
2 |
1.96% |
| Fabian Frederick |
19 |
0.74% |
2 |
1.96% |
| Matthew Wilcox |
16 |
0.63% |
1 |
0.98% |
| Art Haas |
14 |
0.55% |
1 |
0.98% |
| Libing Zhou |
14 |
0.55% |
1 |
0.98% |
| Jeff Layton |
13 |
0.51% |
2 |
1.96% |
| Deepa Dinamani |
12 |
0.47% |
1 |
0.98% |
| Dave Jones |
9 |
0.35% |
1 |
0.98% |
| Rui Xiang |
9 |
0.35% |
1 |
0.98% |
| Andrew Morton |
7 |
0.27% |
2 |
1.96% |
| Dave Hansen |
7 |
0.27% |
1 |
0.98% |
| Eric W. Biedermann |
5 |
0.20% |
1 |
0.98% |
| Theodore Y. Ts'o |
4 |
0.16% |
1 |
0.98% |
| Miklos Szeredi |
4 |
0.16% |
1 |
0.98% |
| Arnd Bergmann |
4 |
0.16% |
1 |
0.98% |
| Kirill A. Shutemov |
4 |
0.16% |
1 |
0.98% |
| Nicholas Piggin |
3 |
0.12% |
1 |
0.98% |
| Julia Lawall |
3 |
0.12% |
1 |
0.98% |
| Song Muchun |
3 |
0.12% |
1 |
0.98% |
| Christoph Hellwig |
3 |
0.12% |
2 |
1.96% |
| Roel Kluin |
3 |
0.12% |
2 |
1.96% |
| Paul Jackson |
2 |
0.08% |
1 |
0.98% |
| Christoph Lameter |
2 |
0.08% |
1 |
0.98% |
| Vladimir Davydov |
2 |
0.08% |
1 |
0.98% |
| Alexey Dobriyan |
1 |
0.04% |
1 |
0.98% |
| Arjan van de Ven |
1 |
0.04% |
1 |
0.98% |
| Josef 'Jeff' Sipek |
1 |
0.04% |
1 |
0.98% |
| Total |
2557 |
|
102 |
|
/* 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 read_folio
* 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 read_folio
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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/fs_context.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 <linux/major.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_read_folio(struct file *file, struct folio *folio)
{
struct page *page = &folio->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 = {
.read_folio = romfs_read_folio
};
/*
* read the entries from a directory
*/
static int romfs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *i = file_inode(file);
struct romfs_inode ri;
unsigned long offset, maxoff;
int j, ino, nextfh;
char fsname[ROMFS_MAXFN]; /* XXX dynamic? */
int ret;
maxoff = romfs_maxsize(i->i_sb);
offset = ctx->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;
ctx->pos = offset;
goto out;
}
ctx->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 (!dir_emit(ctx, fsname, j, ino,
romfs_dtype_table[nextfh & ROMFH_TYPE]))
goto out;
offset = nextfh & ROMFH_MASK;
}
out:
return 0;
}
/*
* look up an entry in a directory
*/
static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
unsigned long offset, maxoff;
struct inode *inode = NULL;
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)
break;
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) {
/* 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);
break;
}
/* next entry */
offset = be32_to_cpu(ri.next) & ROMFH_MASK;
}
return d_splice_alias(inode, dentry);
error:
return ERR_PTR(ret);
}
static const struct file_operations romfs_dir_operations = {
.read = generic_read_dir,
.iterate_shared = romfs_readdir,
.llseek = generic_file_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);
inode_set_mtime_to_ts(i,
inode_set_atime_to_ts(i, inode_set_ctime(i, 0, 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 (nextfh & ROMFH_EXEC)
mode |= S_IXUGO;
break;
case ROMFH_SYM:
i->i_op = &page_symlink_inode_operations;
inode_nohighmem(i);
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;
i->i_blocks = (i->i_size + 511) >> 9;
unlock_new_inode(i);
return i;
eio:
ret = -EIO;
error:
pr_err("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 = alloc_inode_sb(sb, romfs_inode_cachep, GFP_KERNEL);
return inode ? &inode->vfs_inode : NULL;
}
/*
* return a spent inode to the slab cache
*/
static void romfs_free_inode(struct inode *inode)
{
kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode));
}
/*
* get filesystem statistics
*/
static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
u64 id = 0;
/* When calling huge_encode_dev(),
* use sb->s_bdev->bd_dev when,
* - CONFIG_ROMFS_ON_BLOCK defined
* use sb->s_dev when,
* - CONFIG_ROMFS_ON_BLOCK undefined and
* - CONFIG_ROMFS_ON_MTD defined
* leave id as 0 when,
* - CONFIG_ROMFS_ON_BLOCK undefined and
* - CONFIG_ROMFS_ON_MTD undefined
*/
if (sb->s_bdev)
id = huge_encode_dev(sb->s_bdev->bd_dev);
else if (sb->s_dev)
id = huge_encode_dev(sb->s_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 = u64_to_fsid(id);
return 0;
}
/*
* remounting must involve read-only
*/
static int romfs_reconfigure(struct fs_context *fc)
{
sync_filesystem(fc->root->d_sb);
fc->sb_flags |= SB_RDONLY;
return 0;
}
static const struct super_operations romfs_super_ops = {
.alloc_inode = romfs_alloc_inode,
.free_inode = romfs_free_inode,
.statfs = romfs_statfs,
};
/*
* 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, struct fs_context *fc)
{
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 |= SB_RDONLY | SB_NOATIME;
sb->s_time_min = 0;
sb->s_time_max = 0;
sb->s_op = &romfs_super_ops;
#ifdef CONFIG_ROMFS_ON_MTD
/* Use same dev ID from the underlying mtdblock device */
if (sb->s_mtd)
sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, sb->s_mtd->index);
#endif
/* 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 (!(fc->sb_flags & SB_SILENT))
errorf(fc, "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))) {
pr_err("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 (!(fc->sb_flags & SB_SILENT))
pr_notice("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))
return PTR_ERR(root);
sb->s_root = d_make_root(root);
if (!sb->s_root)
return -ENOMEM;
return 0;
error_rsb_inval:
ret = -EINVAL;
error_rsb:
kfree(rsb);
return ret;
}
/*
* get a superblock for mounting
*/
static int romfs_get_tree(struct fs_context *fc)
{
int ret = -EINVAL;
#ifdef CONFIG_ROMFS_ON_MTD
ret = get_tree_mtd(fc, romfs_fill_super);
#endif
#ifdef CONFIG_ROMFS_ON_BLOCK
if (ret == -EINVAL)
ret = get_tree_bdev(fc, romfs_fill_super);
#endif
return ret;
}
static const struct fs_context_operations romfs_context_ops = {
.get_tree = romfs_get_tree,
.reconfigure = romfs_reconfigure,
};
/*
* Set up the filesystem mount context.
*/
static int romfs_init_fs_context(struct fs_context *fc)
{
fc->ops = &romfs_context_ops;
return 0;
}
/*
* destroy a romfs superblock in the appropriate manner
*/
static void romfs_kill_sb(struct super_block *sb)
{
generic_shutdown_super(sb);
#ifdef CONFIG_ROMFS_ON_MTD
if (sb->s_mtd) {
put_mtd_device(sb->s_mtd);
sb->s_mtd = NULL;
}
#endif
#ifdef CONFIG_ROMFS_ON_BLOCK
if (sb->s_bdev) {
sync_blockdev(sb->s_bdev);
bdev_release(sb->s_bdev_handle);
}
#endif
}
static struct file_system_type romfs_fs_type = {
.owner = THIS_MODULE,
.name = "romfs",
.init_fs_context = romfs_init_fs_context,
.kill_sb = romfs_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("romfs");
/*
* 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;
pr_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 |
SLAB_ACCOUNT, romfs_i_init_once);
if (!romfs_inode_cachep) {
pr_err("Failed to initialise inode cache\n");
return -ENOMEM;
}
ret = register_filesystem(&romfs_fs_type);
if (ret) {
pr_err("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);
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
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 */