super.c

linux 内核源代码

/*
 *   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/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 <asm/uaccess.h>
#include <linux/seq_file.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);

	printk(KERN_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_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);

#ifdef CONFIG_JFS_POSIX_ACL
	if (ji->i_acl != JFS_ACL_NOT_CACHED) {
		posix_acl_release(ji->i_acl);
		ji->i_acl = JFS_ACL_NOT_CACHED;
	}
	if (ji->i_default_acl != JFS_ACL_NOT_CACHED) {
		posix_acl_release(ji->i_default_acl);
		ji->i_default_acl = JFS_ACL_NOT_CACHED;
	}
#endif

	kmem_cache_free(jfs_inode_cachep, ji);
}

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 may 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_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");
	rc = jfs_umount(sb);
	if (rc)
		jfs_err("jfs_umount failed with return code %d", rc);
	if (sbi->nls_tab)
		unload_nls(sbi->nls_tab);
	sbi->nls_tab = NULL;

	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
	iput(sbi->direct_inode);
	sbi->direct_inode = NULL;

	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
};

static 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_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) {
					printk(KERN_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)
				printk(KERN_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 {
				printk(KERN_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:
			printk(KERN_ERR
			       "JFS: quota operations not supported\n");
			break;
#endif
		case Opt_uid:
		{
			char *uid = args[0].from;
			sbi->uid = simple_strtoul(uid, &uid, 0);
			break;
		}
		case Opt_gid:
		{
			char *gid = args[0].from;
			sbi->gid = simple_strtoul(gid, &gid, 0);
			break;
		}
		case Opt_umask:
		{
			char *umask = args[0].from;
			sbi->umask = simple_strtoul(umask, &umask, 8);
			if (sbi->umask & ~0777) {
				printk(KERN_ERR
				       "JFS: Invalid value of umask\n");
				goto cleanup;
			}
			break;
		}
		default:
			printk("jfs: Unrecognized mount option \"%s\" "
					" or missing value\n", p);
			goto cleanup;
		}
	}

	if (nls_map != (void *) -1) {
		/* Discard old (if remount) */
		if (sbi->nls_tab)
			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;

	if (!parse_options(data, sb, &newLVSize, &flag)) {
		return -EINVAL;
	}
	if (newLVSize) {
		if (sb->s_flags & MS_RDONLY) {
			printk(KERN_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;
		return jfs_mount_rw(sb, 1);
	}
	if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
		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;
			return jfs_mount_rw(sb, 1);
		}
	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;

	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;
	sbi->sb = sb;
	sbi->uid = sbi->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)) {
		kfree(sbi);
		return -EINVAL;
	}
	sbi->flag = flag;