linux/fs/jfs/super.c
Eric W. Biederman 7f78e03513 fs: Limit sys_mount to only request filesystem modules.
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00

967 lines
23 KiB
C

/*
* Copyright (C) International Business Machines Corp., 2000-2004
* Portions Copyright (C) Christoph Hellwig, 2001-2002
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/parser.h>
#include <linux/completion.h>
#include <linux/vfs.h>
#include <linux/quotaops.h>
#include <linux/mount.h>
#include <linux/moduleparam.h>
#include <linux/kthread.h>
#include <linux/posix_acl.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/crc32.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <linux/seq_file.h>
#include <linux/blkdev.h>
#include "jfs_incore.h"
#include "jfs_filsys.h"
#include "jfs_inode.h"
#include "jfs_metapage.h"
#include "jfs_superblock.h"
#include "jfs_dmap.h"
#include "jfs_imap.h"
#include "jfs_acl.h"
#include "jfs_debug.h"
MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
MODULE_LICENSE("GPL");
static struct kmem_cache * jfs_inode_cachep;
static const struct super_operations jfs_super_operations;
static const struct export_operations jfs_export_operations;
static struct file_system_type jfs_fs_type;
#define MAX_COMMIT_THREADS 64
static int commit_threads = 0;
module_param(commit_threads, int, 0);
MODULE_PARM_DESC(commit_threads, "Number of commit threads");
static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
struct task_struct *jfsIOthread;
struct task_struct *jfsSyncThread;
#ifdef CONFIG_JFS_DEBUG
int jfsloglevel = JFS_LOGLEVEL_WARN;
module_param(jfsloglevel, int, 0644);
MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
#endif
static void jfs_handle_error(struct super_block *sb)
{
struct jfs_sb_info *sbi = JFS_SBI(sb);
if (sb->s_flags & MS_RDONLY)
return;
updateSuper(sb, FM_DIRTY);
if (sbi->flag & JFS_ERR_PANIC)
panic("JFS (device %s): panic forced after error\n",
sb->s_id);
else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
jfs_err("ERROR: (device %s): remounting filesystem "
"as read-only\n",
sb->s_id);
sb->s_flags |= MS_RDONLY;
}
/* nothing is done for continue beyond marking the superblock dirty */
}
void jfs_error(struct super_block *sb, const char * function, ...)
{
static char error_buf[256];
va_list args;
va_start(args, function);
vsnprintf(error_buf, sizeof(error_buf), function, args);
va_end(args);
pr_err("ERROR: (device %s): %s\n", sb->s_id, error_buf);
jfs_handle_error(sb);
}
static struct inode *jfs_alloc_inode(struct super_block *sb)
{
struct jfs_inode_info *jfs_inode;
jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
if (!jfs_inode)
return NULL;
return &jfs_inode->vfs_inode;
}
static void jfs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
struct jfs_inode_info *ji = JFS_IP(inode);
kmem_cache_free(jfs_inode_cachep, ji);
}
static void jfs_destroy_inode(struct inode *inode)
{
struct jfs_inode_info *ji = JFS_IP(inode);
BUG_ON(!list_empty(&ji->anon_inode_list));
spin_lock_irq(&ji->ag_lock);
if (ji->active_ag != -1) {
struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
atomic_dec(&bmap->db_active[ji->active_ag]);
ji->active_ag = -1;
}
spin_unlock_irq(&ji->ag_lock);
call_rcu(&inode->i_rcu, jfs_i_callback);
}
static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
s64 maxinodes;
struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
jfs_info("In jfs_statfs");
buf->f_type = JFS_SUPER_MAGIC;
buf->f_bsize = sbi->bsize;
buf->f_blocks = sbi->bmap->db_mapsize;
buf->f_bfree = sbi->bmap->db_nfree;
buf->f_bavail = sbi->bmap->db_nfree;
/*
* If we really return the number of allocated & free inodes, some
* applications will fail because they won't see enough free inodes.
* We'll try to calculate some guess as to how many inodes we can
* really allocate
*
* buf->f_files = atomic_read(&imap->im_numinos);
* buf->f_ffree = atomic_read(&imap->im_numfree);
*/
maxinodes = min((s64) atomic_read(&imap->im_numinos) +
((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
<< L2INOSPEREXT), (s64) 0xffffffffLL);
buf->f_files = maxinodes;
buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
atomic_read(&imap->im_numfree));
buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
sizeof(sbi->uuid)/2);
buf->f_namelen = JFS_NAME_MAX;
return 0;
}
static void jfs_put_super(struct super_block *sb)
{
struct jfs_sb_info *sbi = JFS_SBI(sb);
int rc;
jfs_info("In jfs_put_super");
dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
rc = jfs_umount(sb);
if (rc)
jfs_err("jfs_umount failed with return code %d", rc);
unload_nls(sbi->nls_tab);
truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
iput(sbi->direct_inode);
kfree(sbi);
}
enum {
Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask,
Opt_discard, Opt_nodiscard, Opt_discard_minblk
};
static const match_table_t tokens = {
{Opt_integrity, "integrity"},
{Opt_nointegrity, "nointegrity"},
{Opt_iocharset, "iocharset=%s"},
{Opt_resize, "resize=%u"},
{Opt_resize_nosize, "resize"},
{Opt_errors, "errors=%s"},
{Opt_ignore, "noquota"},
{Opt_ignore, "quota"},
{Opt_usrquota, "usrquota"},
{Opt_grpquota, "grpquota"},
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_umask, "umask=%u"},
{Opt_discard, "discard"},
{Opt_nodiscard, "nodiscard"},
{Opt_discard_minblk, "discard=%u"},
{Opt_err, NULL}
};
static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
int *flag)
{
void *nls_map = (void *)-1; /* -1: no change; NULL: none */
char *p;
struct jfs_sb_info *sbi = JFS_SBI(sb);
*newLVSize = 0;
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
substring_t args[MAX_OPT_ARGS];
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_integrity:
*flag &= ~JFS_NOINTEGRITY;
break;
case Opt_nointegrity:
*flag |= JFS_NOINTEGRITY;
break;
case Opt_ignore:
/* Silently ignore the quota options */
/* Don't do anything ;-) */
break;
case Opt_iocharset:
if (nls_map && nls_map != (void *) -1)
unload_nls(nls_map);
if (!strcmp(args[0].from, "none"))
nls_map = NULL;
else {
nls_map = load_nls(args[0].from);
if (!nls_map) {
pr_err("JFS: charset not found\n");
goto cleanup;
}
}
break;
case Opt_resize:
{
char *resize = args[0].from;
*newLVSize = simple_strtoull(resize, &resize, 0);
break;
}
case Opt_resize_nosize:
{
*newLVSize = sb->s_bdev->bd_inode->i_size >>
sb->s_blocksize_bits;
if (*newLVSize == 0)
pr_err("JFS: Cannot determine volume size\n");
break;
}
case Opt_errors:
{
char *errors = args[0].from;
if (!errors || !*errors)
goto cleanup;
if (!strcmp(errors, "continue")) {
*flag &= ~JFS_ERR_REMOUNT_RO;
*flag &= ~JFS_ERR_PANIC;
*flag |= JFS_ERR_CONTINUE;
} else if (!strcmp(errors, "remount-ro")) {
*flag &= ~JFS_ERR_CONTINUE;
*flag &= ~JFS_ERR_PANIC;
*flag |= JFS_ERR_REMOUNT_RO;
} else if (!strcmp(errors, "panic")) {
*flag &= ~JFS_ERR_CONTINUE;
*flag &= ~JFS_ERR_REMOUNT_RO;
*flag |= JFS_ERR_PANIC;
} else {
pr_err("JFS: %s is an invalid error handler\n",
errors);
goto cleanup;
}
break;
}
#ifdef CONFIG_QUOTA
case Opt_quota:
case Opt_usrquota:
*flag |= JFS_USRQUOTA;
break;
case Opt_grpquota:
*flag |= JFS_GRPQUOTA;
break;
#else
case Opt_usrquota:
case Opt_grpquota:
case Opt_quota:
pr_err("JFS: quota operations not supported\n");
break;
#endif
case Opt_uid:
{
char *uid = args[0].from;
uid_t val = simple_strtoul(uid, &uid, 0);
sbi->uid = make_kuid(current_user_ns(), val);
if (!uid_valid(sbi->uid))
goto cleanup;
break;
}
case Opt_gid:
{
char *gid = args[0].from;
gid_t val = simple_strtoul(gid, &gid, 0);
sbi->gid = make_kgid(current_user_ns(), val);
if (!gid_valid(sbi->gid))
goto cleanup;
break;
}
case Opt_umask:
{
char *umask = args[0].from;
sbi->umask = simple_strtoul(umask, &umask, 8);
if (sbi->umask & ~0777) {
pr_err("JFS: Invalid value of umask\n");
goto cleanup;
}
break;
}
case Opt_discard:
{
struct request_queue *q = bdev_get_queue(sb->s_bdev);
/* if set to 1, even copying files will cause
* trimming :O
* -> user has more control over the online trimming
*/
sbi->minblks_trim = 64;
if (blk_queue_discard(q)) {
*flag |= JFS_DISCARD;
} else {
pr_err("JFS: discard option " \
"not supported on device\n");
}
break;
}
case Opt_nodiscard:
*flag &= ~JFS_DISCARD;
break;
case Opt_discard_minblk:
{
struct request_queue *q = bdev_get_queue(sb->s_bdev);
char *minblks_trim = args[0].from;
if (blk_queue_discard(q)) {
*flag |= JFS_DISCARD;
sbi->minblks_trim = simple_strtoull(
minblks_trim, &minblks_trim, 0);
} else {
pr_err("JFS: discard option " \
"not supported on device\n");
}
break;
}
default:
printk("jfs: Unrecognized mount option \"%s\" "
" or missing value\n", p);
goto cleanup;
}
}
if (nls_map != (void *) -1) {
/* Discard old (if remount) */
unload_nls(sbi->nls_tab);
sbi->nls_tab = nls_map;
}
return 1;
cleanup:
if (nls_map && nls_map != (void *) -1)
unload_nls(nls_map);
return 0;
}
static int jfs_remount(struct super_block *sb, int *flags, char *data)
{
s64 newLVSize = 0;
int rc = 0;
int flag = JFS_SBI(sb)->flag;
int ret;
if (!parse_options(data, sb, &newLVSize, &flag)) {
return -EINVAL;
}
if (newLVSize) {
if (sb->s_flags & MS_RDONLY) {
pr_err("JFS: resize requires volume" \
" to be mounted read-write\n");
return -EROFS;
}
rc = jfs_extendfs(sb, newLVSize, 0);
if (rc)
return rc;
}
if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
/*
* Invalidate any previously read metadata. fsck may have
* changed the on-disk data since we mounted r/o
*/
truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
JFS_SBI(sb)->flag = flag;
ret = jfs_mount_rw(sb, 1);
/* mark the fs r/w for quota activity */
sb->s_flags &= ~MS_RDONLY;
dquot_resume(sb, -1);
return ret;
}
if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
rc = dquot_suspend(sb, -1);
if (rc < 0) {
return rc;
}
rc = jfs_umount_rw(sb);
JFS_SBI(sb)->flag = flag;
return rc;
}
if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
if (!(sb->s_flags & MS_RDONLY)) {
rc = jfs_umount_rw(sb);
if (rc)
return rc;
JFS_SBI(sb)->flag = flag;
ret = jfs_mount_rw(sb, 1);
return ret;
}
JFS_SBI(sb)->flag = flag;
return 0;
}
static int jfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct jfs_sb_info *sbi;
struct inode *inode;
int rc;
s64 newLVSize = 0;
int flag, ret = -EINVAL;
jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
if (!new_valid_dev(sb->s_bdev->bd_dev))
return -EOVERFLOW;
sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
sb->s_max_links = JFS_LINK_MAX;
sbi->sb = sb;
sbi->uid = INVALID_UID;
sbi->gid = INVALID_GID;
sbi->umask = -1;
/* initialize the mount flag and determine the default error handler */
flag = JFS_ERR_REMOUNT_RO;
if (!parse_options((char *) data, sb, &newLVSize, &flag))
goto out_kfree;
sbi->flag = flag;
#ifdef CONFIG_JFS_POSIX_ACL
sb->s_flags |= MS_POSIXACL;
#endif
if (newLVSize) {
pr_err("resize option for remount only\n");
goto out_kfree;
}
/*
* Initialize blocksize to 4K.
*/
sb_set_blocksize(sb, PSIZE);
/*
* Set method vectors.
*/
sb->s_op = &jfs_super_operations;
sb->s_export_op = &jfs_export_operations;
#ifdef CONFIG_QUOTA
sb->dq_op = &dquot_operations;
sb->s_qcop = &dquot_quotactl_ops;
#endif
/*
* Initialize direct-mapping inode/address-space
*/
inode = new_inode(sb);
if (inode == NULL) {
ret = -ENOMEM;
goto out_unload;
}
inode->i_ino = 0;
inode->i_size = sb->s_bdev->bd_inode->i_size;
inode->i_mapping->a_ops = &jfs_metapage_aops;
insert_inode_hash(inode);
mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
sbi->direct_inode = inode;
rc = jfs_mount(sb);
if (rc) {
if (!silent) {
jfs_err("jfs_mount failed w/return code = %d", rc);
}
goto out_mount_failed;
}
if (sb->s_flags & MS_RDONLY)
sbi->log = NULL;
else {
rc = jfs_mount_rw(sb, 0);
if (rc) {
if (!silent) {
jfs_err("jfs_mount_rw failed, return code = %d",
rc);
}
goto out_no_rw;
}
}
sb->s_magic = JFS_SUPER_MAGIC;
if (sbi->mntflag & JFS_OS2)
sb->s_d_op = &jfs_ci_dentry_operations;
inode = jfs_iget(sb, ROOT_I);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto out_no_rw;
}
sb->s_root = d_make_root(inode);
if (!sb->s_root)
goto out_no_root;
/* logical blocks are represented by 40 bits in pxd_t, etc. */
sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
#if BITS_PER_LONG == 32
/*
* Page cache is indexed by long.
* I would use MAX_LFS_FILESIZE, but it's only half as big
*/
sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
#endif
sb->s_time_gran = 1;
return 0;
out_no_root:
jfs_err("jfs_read_super: get root dentry failed");
out_no_rw:
rc = jfs_umount(sb);
if (rc) {
jfs_err("jfs_umount failed with return code %d", rc);
}
out_mount_failed:
filemap_write_and_wait(sbi->direct_inode->i_mapping);
truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
make_bad_inode(sbi->direct_inode);
iput(sbi->direct_inode);
sbi->direct_inode = NULL;
out_unload:
if (sbi->nls_tab)
unload_nls(sbi->nls_tab);
out_kfree:
kfree(sbi);
return ret;
}
static int jfs_freeze(struct super_block *sb)
{
struct jfs_sb_info *sbi = JFS_SBI(sb);
struct jfs_log *log = sbi->log;
if (!(sb->s_flags & MS_RDONLY)) {
txQuiesce(sb);
lmLogShutdown(log);
updateSuper(sb, FM_CLEAN);
}
return 0;
}
static int jfs_unfreeze(struct super_block *sb)
{
struct jfs_sb_info *sbi = JFS_SBI(sb);
struct jfs_log *log = sbi->log;
int rc = 0;
if (!(sb->s_flags & MS_RDONLY)) {
updateSuper(sb, FM_MOUNT);
if ((rc = lmLogInit(log)))
jfs_err("jfs_unlock failed with return code %d", rc);
else
txResume(sb);
}
return 0;
}
static struct dentry *jfs_do_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, jfs_fill_super);
}
static int jfs_sync_fs(struct super_block *sb, int wait)
{
struct jfs_log *log = JFS_SBI(sb)->log;
/* log == NULL indicates read-only mount */
if (log) {
/*
* Write quota structures to quota file, sync_blockdev() will
* write them to disk later
*/
dquot_writeback_dquots(sb, -1);
jfs_flush_journal(log, wait);
jfs_syncpt(log, 0);
}
return 0;
}
static int jfs_show_options(struct seq_file *seq, struct dentry *root)
{
struct jfs_sb_info *sbi = JFS_SBI(root->d_sb);
if (uid_valid(sbi->uid))
seq_printf(seq, ",uid=%d", from_kuid(&init_user_ns, sbi->uid));
if (gid_valid(sbi->gid))
seq_printf(seq, ",gid=%d", from_kgid(&init_user_ns, sbi->gid));
if (sbi->umask != -1)
seq_printf(seq, ",umask=%03o", sbi->umask);
if (sbi->flag & JFS_NOINTEGRITY)
seq_puts(seq, ",nointegrity");
if (sbi->flag & JFS_DISCARD)
seq_printf(seq, ",discard=%u", sbi->minblks_trim);
if (sbi->nls_tab)
seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
if (sbi->flag & JFS_ERR_CONTINUE)
seq_printf(seq, ",errors=continue");
if (sbi->flag & JFS_ERR_PANIC)
seq_printf(seq, ",errors=panic");
#ifdef CONFIG_QUOTA
if (sbi->flag & JFS_USRQUOTA)
seq_puts(seq, ",usrquota");
if (sbi->flag & JFS_GRPQUOTA)
seq_puts(seq, ",grpquota");
#endif
return 0;
}
#ifdef CONFIG_QUOTA
/* Read data from quotafile - avoid pagecache and such because we cannot afford
* acquiring the locks... As quota files are never truncated and quota code
* itself serializes the operations (and no one else should touch the files)
* we don't have to be afraid of races */
static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
size_t len, loff_t off)
{
struct inode *inode = sb_dqopt(sb)->files[type];
sector_t blk = off >> sb->s_blocksize_bits;
int err = 0;
int offset = off & (sb->s_blocksize - 1);
int tocopy;
size_t toread;
struct buffer_head tmp_bh;
struct buffer_head *bh;
loff_t i_size = i_size_read(inode);
if (off > i_size)
return 0;
if (off+len > i_size)
len = i_size-off;
toread = len;
while (toread > 0) {
tocopy = sb->s_blocksize - offset < toread ?
sb->s_blocksize - offset : toread;
tmp_bh.b_state = 0;
tmp_bh.b_size = 1 << inode->i_blkbits;
err = jfs_get_block(inode, blk, &tmp_bh, 0);
if (err)
return err;
if (!buffer_mapped(&tmp_bh)) /* A hole? */
memset(data, 0, tocopy);
else {
bh = sb_bread(sb, tmp_bh.b_blocknr);
if (!bh)
return -EIO;
memcpy(data, bh->b_data+offset, tocopy);
brelse(bh);
}
offset = 0;
toread -= tocopy;
data += tocopy;
blk++;
}
return len;
}
/* Write to quotafile */
static ssize_t jfs_quota_write(struct super_block *sb, int type,
const char *data, size_t len, loff_t off)
{
struct inode *inode = sb_dqopt(sb)->files[type];
sector_t blk = off >> sb->s_blocksize_bits;
int err = 0;
int offset = off & (sb->s_blocksize - 1);
int tocopy;
size_t towrite = len;
struct buffer_head tmp_bh;
struct buffer_head *bh;
mutex_lock(&inode->i_mutex);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?
sb->s_blocksize - offset : towrite;
tmp_bh.b_state = 0;
tmp_bh.b_size = 1 << inode->i_blkbits;
err = jfs_get_block(inode, blk, &tmp_bh, 1);
if (err)
goto out;
if (offset || tocopy != sb->s_blocksize)
bh = sb_bread(sb, tmp_bh.b_blocknr);
else
bh = sb_getblk(sb, tmp_bh.b_blocknr);
if (!bh) {
err = -EIO;
goto out;
}
lock_buffer(bh);
memcpy(bh->b_data+offset, data, tocopy);
flush_dcache_page(bh->b_page);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
unlock_buffer(bh);
brelse(bh);
offset = 0;
towrite -= tocopy;
data += tocopy;
blk++;
}
out:
if (len == towrite) {
mutex_unlock(&inode->i_mutex);
return err;
}
if (inode->i_size < off+len-towrite)
i_size_write(inode, off+len-towrite);
inode->i_version++;
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(inode);
mutex_unlock(&inode->i_mutex);
return len - towrite;
}
#endif
static const struct super_operations jfs_super_operations = {
.alloc_inode = jfs_alloc_inode,
.destroy_inode = jfs_destroy_inode,
.dirty_inode = jfs_dirty_inode,
.write_inode = jfs_write_inode,
.evict_inode = jfs_evict_inode,
.put_super = jfs_put_super,
.sync_fs = jfs_sync_fs,
.freeze_fs = jfs_freeze,
.unfreeze_fs = jfs_unfreeze,
.statfs = jfs_statfs,
.remount_fs = jfs_remount,
.show_options = jfs_show_options,
#ifdef CONFIG_QUOTA
.quota_read = jfs_quota_read,
.quota_write = jfs_quota_write,
#endif
};
static const struct export_operations jfs_export_operations = {
.fh_to_dentry = jfs_fh_to_dentry,
.fh_to_parent = jfs_fh_to_parent,
.get_parent = jfs_get_parent,
};
static struct file_system_type jfs_fs_type = {
.owner = THIS_MODULE,
.name = "jfs",
.mount = jfs_do_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("jfs");
static void init_once(void *foo)
{
struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
init_rwsem(&jfs_ip->rdwrlock);
mutex_init(&jfs_ip->commit_mutex);
init_rwsem(&jfs_ip->xattr_sem);
spin_lock_init(&jfs_ip->ag_lock);
jfs_ip->active_ag = -1;
inode_init_once(&jfs_ip->vfs_inode);
}
static int __init init_jfs_fs(void)
{
int i;
int rc;
jfs_inode_cachep =
kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
init_once);
if (jfs_inode_cachep == NULL)
return -ENOMEM;
/*
* Metapage initialization
*/
rc = metapage_init();
if (rc) {
jfs_err("metapage_init failed w/rc = %d", rc);
goto free_slab;
}
/*
* Transaction Manager initialization
*/
rc = txInit();
if (rc) {
jfs_err("txInit failed w/rc = %d", rc);
goto free_metapage;
}
/*
* I/O completion thread (endio)
*/
jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
if (IS_ERR(jfsIOthread)) {
rc = PTR_ERR(jfsIOthread);
jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
goto end_txmngr;
}
if (commit_threads < 1)
commit_threads = num_online_cpus();
if (commit_threads > MAX_COMMIT_THREADS)
commit_threads = MAX_COMMIT_THREADS;
for (i = 0; i < commit_threads; i++) {
jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
if (IS_ERR(jfsCommitThread[i])) {
rc = PTR_ERR(jfsCommitThread[i]);
jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
commit_threads = i;
goto kill_committask;
}
}
jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
if (IS_ERR(jfsSyncThread)) {
rc = PTR_ERR(jfsSyncThread);
jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
goto kill_committask;
}
#ifdef PROC_FS_JFS
jfs_proc_init();
#endif
rc = register_filesystem(&jfs_fs_type);
if (!rc)
return 0;
#ifdef PROC_FS_JFS
jfs_proc_clean();
#endif
kthread_stop(jfsSyncThread);
kill_committask:
for (i = 0; i < commit_threads; i++)
kthread_stop(jfsCommitThread[i]);
kthread_stop(jfsIOthread);
end_txmngr:
txExit();
free_metapage:
metapage_exit();
free_slab:
kmem_cache_destroy(jfs_inode_cachep);
return rc;
}
static void __exit exit_jfs_fs(void)
{
int i;
jfs_info("exit_jfs_fs called");
txExit();
metapage_exit();
kthread_stop(jfsIOthread);
for (i = 0; i < commit_threads; i++)
kthread_stop(jfsCommitThread[i]);
kthread_stop(jfsSyncThread);
#ifdef PROC_FS_JFS
jfs_proc_clean();
#endif
unregister_filesystem(&jfs_fs_type);
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(jfs_inode_cachep);
}
module_init(init_jfs_fs)
module_exit(exit_jfs_fs)