super.c 34.8 KB
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/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * 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 021110-1307, USA.
 */

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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <linux/buffer_head.h>
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#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
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#include <linux/seq_file.h>
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#include <linux/string.h>
#include <linux/backing-dev.h>
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#include <linux/mount.h>
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#include <linux/mpage.h>
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#include <linux/swap.h>
#include <linux/writeback.h>
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#include <linux/statfs.h>
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#include <linux/compat.h>
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#include <linux/parser.h>
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#include <linux/ctype.h>
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#include <linux/namei.h>
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#include <linux/miscdevice.h>
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#include <linux/magic.h>
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#include <linux/slab.h>
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#include <linux/cleancache.h>
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#include <linux/mnt_namespace.h>
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#include "compat.h"
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#include "delayed-inode.h"
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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#include "btrfs_inode.h"
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#include "ioctl.h"
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#include "print-tree.h"
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#include "xattr.h"
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#include "volumes.h"
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#include "version.h"
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#include "export.h"
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#include "compression.h"
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#define CREATE_TRACE_POINTS
#include <trace/events/btrfs.h>

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static const struct super_operations btrfs_super_ops;
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static struct file_system_type btrfs_fs_type;
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static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
				      char nbuf[16])
{
	char *errstr = NULL;

	switch (errno) {
	case -EIO:
		errstr = "IO failure";
		break;
	case -ENOMEM:
		errstr = "Out of memory";
		break;
	case -EROFS:
		errstr = "Readonly filesystem";
		break;
	default:
		if (nbuf) {
			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
				errstr = nbuf;
		}
		break;
	}

	return errstr;
}

static void __save_error_info(struct btrfs_fs_info *fs_info)
{
	/*
	 * today we only save the error info into ram.  Long term we'll
	 * also send it down to the disk
	 */
	fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
}

/* NOTE:
 *	We move write_super stuff at umount in order to avoid deadlock
 *	for umount hold all lock.
 */
static void save_error_info(struct btrfs_fs_info *fs_info)
{
	__save_error_info(fs_info);
}

/* btrfs handle error by forcing the filesystem readonly */
static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
{
	struct super_block *sb = fs_info->sb;

	if (sb->s_flags & MS_RDONLY)
		return;

	if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
		sb->s_flags |= MS_RDONLY;
		printk(KERN_INFO "btrfs is forced readonly\n");
	}
}

/*
 * __btrfs_std_error decodes expected errors from the caller and
 * invokes the approciate error response.
 */
void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
		     unsigned int line, int errno)
{
	struct super_block *sb = fs_info->sb;
	char nbuf[16];
	const char *errstr;

	/*
	 * Special case: if the error is EROFS, and we're already
	 * under MS_RDONLY, then it is safe here.
	 */
	if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
		return;

	errstr = btrfs_decode_error(fs_info, errno, nbuf);
	printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
		sb->s_id, function, line, errstr);
	save_error_info(fs_info);

	btrfs_handle_error(fs_info);
}

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static void btrfs_put_super(struct super_block *sb)
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{
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	struct btrfs_root *root = btrfs_sb(sb);
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	int ret;

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	ret = close_ctree(root);
	sb->s_fs_info = NULL;
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	(void)ret; /* FIXME: need to fix VFS to return error? */
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}

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enum {
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	Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
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	Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
	Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
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	Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
	Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
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	Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
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	Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
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	Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err,
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};

static match_table_t tokens = {
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	{Opt_degraded, "degraded"},
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	{Opt_subvol, "subvol=%s"},
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	{Opt_subvolid, "subvolid=%d"},
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	{Opt_device, "device=%s"},
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	{Opt_nodatasum, "nodatasum"},
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	{Opt_nodatacow, "nodatacow"},
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	{Opt_nobarrier, "nobarrier"},
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	{Opt_max_inline, "max_inline=%s"},
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	{Opt_alloc_start, "alloc_start=%s"},
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	{Opt_thread_pool, "thread_pool=%d"},
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	{Opt_compress, "compress"},
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	{Opt_compress_type, "compress=%s"},
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	{Opt_compress_force, "compress-force"},
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	{Opt_compress_force_type, "compress-force=%s"},
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	{Opt_ssd, "ssd"},
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	{Opt_ssd_spread, "ssd_spread"},
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	{Opt_nossd, "nossd"},
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	{Opt_noacl, "noacl"},
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	{Opt_notreelog, "notreelog"},
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	{Opt_flushoncommit, "flushoncommit"},
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	{Opt_ratio, "metadata_ratio=%d"},
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	{Opt_discard, "discard"},
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	{Opt_space_cache, "space_cache"},
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	{Opt_clear_cache, "clear_cache"},
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	{Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
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	{Opt_enospc_debug, "enospc_debug"},
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	{Opt_subvolrootid, "subvolrootid=%d"},
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	{Opt_defrag, "autodefrag"},
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	{Opt_inode_cache, "inode_cache"},
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	{Opt_no_space_cache, "no_space_cache"},
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	{Opt_recovery, "recovery"},
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	{Opt_err, NULL},
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};

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/*
 * Regular mount options parser.  Everything that is needed only when
 * reading in a new superblock is parsed here.
 */
int btrfs_parse_options(struct btrfs_root *root, char *options)
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{
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	struct btrfs_fs_info *info = root->fs_info;
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	substring_t args[MAX_OPT_ARGS];
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	char *p, *num, *orig = NULL;
	u64 cache_gen;
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	int intarg;
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	int ret = 0;
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	char *compress_type;
	bool compress_force = false;
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	cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
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	if (cache_gen)
		btrfs_set_opt(info->mount_opt, SPACE_CACHE);

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	if (!options)
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		goto out;
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	/*
	 * strsep changes the string, duplicate it because parse_options
	 * gets called twice
	 */
	options = kstrdup(options, GFP_NOFS);
	if (!options)
		return -ENOMEM;

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	orig = options;
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	while ((p = strsep(&options, ",")) != NULL) {
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		int token;
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
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		case Opt_degraded:
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			printk(KERN_INFO "btrfs: allowing degraded mounts\n");
			btrfs_set_opt(info->mount_opt, DEGRADED);
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			break;
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		case Opt_subvol:
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		case Opt_subvolid:
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		case Opt_subvolrootid:
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		case Opt_device:
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			/*
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			 * These are parsed by btrfs_parse_early_options
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			 * and can be happily ignored here.
			 */
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			break;
		case Opt_nodatasum:
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			printk(KERN_INFO "btrfs: setting nodatasum\n");
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			btrfs_set_opt(info->mount_opt, NODATASUM);
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			break;
		case Opt_nodatacow:
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			printk(KERN_INFO "btrfs: setting nodatacow\n");
			btrfs_set_opt(info->mount_opt, NODATACOW);
			btrfs_set_opt(info->mount_opt, NODATASUM);
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			break;
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		case Opt_compress_force:
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		case Opt_compress_force_type:
			compress_force = true;
		case Opt_compress:
		case Opt_compress_type:
			if (token == Opt_compress ||
			    token == Opt_compress_force ||
			    strcmp(args[0].from, "zlib") == 0) {
				compress_type = "zlib";
				info->compress_type = BTRFS_COMPRESS_ZLIB;
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			} else if (strcmp(args[0].from, "lzo") == 0) {
				compress_type = "lzo";
				info->compress_type = BTRFS_COMPRESS_LZO;
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			} else {
				ret = -EINVAL;
				goto out;
			}

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			btrfs_set_opt(info->mount_opt, COMPRESS);
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			if (compress_force) {
				btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
				pr_info("btrfs: force %s compression\n",
					compress_type);
			} else
				pr_info("btrfs: use %s compression\n",
					compress_type);
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			break;
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		case Opt_ssd:
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			printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
			btrfs_set_opt(info->mount_opt, SSD);
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			break;
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		case Opt_ssd_spread:
			printk(KERN_INFO "btrfs: use spread ssd "
			       "allocation scheme\n");
			btrfs_set_opt(info->mount_opt, SSD);
			btrfs_set_opt(info->mount_opt, SSD_SPREAD);
			break;
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		case Opt_nossd:
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			printk(KERN_INFO "btrfs: not using ssd allocation "
			       "scheme\n");
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			btrfs_set_opt(info->mount_opt, NOSSD);
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			btrfs_clear_opt(info->mount_opt, SSD);
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			btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
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			break;
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		case Opt_nobarrier:
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			printk(KERN_INFO "btrfs: turning off barriers\n");
			btrfs_set_opt(info->mount_opt, NOBARRIER);
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			break;
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		case Opt_thread_pool:
			intarg = 0;
			match_int(&args[0], &intarg);
			if (intarg) {
				info->thread_pool_size = intarg;
				printk(KERN_INFO "btrfs: thread pool %d\n",
				       info->thread_pool_size);
			}
			break;
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		case Opt_max_inline:
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			num = match_strdup(&args[0]);
			if (num) {
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				info->max_inline = memparse(num, NULL);
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				kfree(num);

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				if (info->max_inline) {
					info->max_inline = max_t(u64,
						info->max_inline,
						root->sectorsize);
				}
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				printk(KERN_INFO "btrfs: max_inline at %llu\n",
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					(unsigned long long)info->max_inline);
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			}
			break;
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		case Opt_alloc_start:
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			num = match_strdup(&args[0]);
			if (num) {
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				info->alloc_start = memparse(num, NULL);
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				kfree(num);
				printk(KERN_INFO
					"btrfs: allocations start at %llu\n",
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					(unsigned long long)info->alloc_start);
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			}
			break;
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		case Opt_noacl:
			root->fs_info->sb->s_flags &= ~MS_POSIXACL;
			break;
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		case Opt_notreelog:
			printk(KERN_INFO "btrfs: disabling tree log\n");
			btrfs_set_opt(info->mount_opt, NOTREELOG);
			break;
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		case Opt_flushoncommit:
			printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
			btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
			break;
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		case Opt_ratio:
			intarg = 0;
			match_int(&args[0], &intarg);
			if (intarg) {
				info->metadata_ratio = intarg;
				printk(KERN_INFO "btrfs: metadata ratio %d\n",
				       info->metadata_ratio);
			}
			break;
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		case Opt_discard:
			btrfs_set_opt(info->mount_opt, DISCARD);
			break;
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		case Opt_space_cache:
			btrfs_set_opt(info->mount_opt, SPACE_CACHE);
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			break;
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		case Opt_no_space_cache:
			printk(KERN_INFO "btrfs: disabling disk space caching\n");
			btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
			break;
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		case Opt_inode_cache:
			printk(KERN_INFO "btrfs: enabling inode map caching\n");
			btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
			break;
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		case Opt_clear_cache:
			printk(KERN_INFO "btrfs: force clearing of disk cache\n");
			btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
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			break;
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		case Opt_user_subvol_rm_allowed:
			btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
			break;
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		case Opt_enospc_debug:
			btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
			break;
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		case Opt_defrag:
			printk(KERN_INFO "btrfs: enabling auto defrag");
			btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
			break;
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		case Opt_recovery:
			printk(KERN_INFO "btrfs: enabling auto recovery");
			btrfs_set_opt(info->mount_opt, RECOVERY);
			break;
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		case Opt_err:
			printk(KERN_INFO "btrfs: unrecognized mount option "
			       "'%s'\n", p);
			ret = -EINVAL;
			goto out;
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		default:
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			break;
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		}
	}
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out:
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	if (!ret && btrfs_test_opt(root, SPACE_CACHE))
		printk(KERN_INFO "btrfs: disk space caching is enabled\n");
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	kfree(orig);
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	return ret;
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}

/*
 * Parse mount options that are required early in the mount process.
 *
 * All other options will be parsed on much later in the mount process and
 * only when we need to allocate a new super block.
 */
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static int btrfs_parse_early_options(const char *options, fmode_t flags,
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		void *holder, char **subvol_name, u64 *subvol_objectid,
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		u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
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{
	substring_t args[MAX_OPT_ARGS];
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	char *device_name, *opts, *orig, *p;
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	int error = 0;
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	int intarg;
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	if (!options)
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		return 0;
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	/*
	 * strsep changes the string, duplicate it because parse_options
	 * gets called twice
	 */
	opts = kstrdup(options, GFP_KERNEL);
	if (!opts)
		return -ENOMEM;
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	orig = opts;
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	while ((p = strsep(&opts, ",")) != NULL) {
		int token;
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_subvol:
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			kfree(*subvol_name);
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			*subvol_name = match_strdup(&args[0]);
			break;
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		case Opt_subvolid:
			intarg = 0;
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			error = match_int(&args[0], &intarg);
			if (!error) {
				/* we want the original fs_tree */
				if (!intarg)
					*subvol_objectid =
						BTRFS_FS_TREE_OBJECTID;
				else
					*subvol_objectid = intarg;
			}
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			break;
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		case Opt_subvolrootid:
			intarg = 0;
			error = match_int(&args[0], &intarg);
			if (!error) {
				/* we want the original fs_tree */
				if (!intarg)
					*subvol_rootid =
						BTRFS_FS_TREE_OBJECTID;
				else
					*subvol_rootid = intarg;
			}
			break;
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		case Opt_device:
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			device_name = match_strdup(&args[0]);
			if (!device_name) {
				error = -ENOMEM;
				goto out;
			}
			error = btrfs_scan_one_device(device_name,
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					flags, holder, fs_devices);
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			kfree(device_name);
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			if (error)
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				goto out;
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			break;
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		default:
			break;
		}
	}

495
out:
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	kfree(orig);
497
	return error;
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}

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static struct dentry *get_default_root(struct super_block *sb,
				       u64 subvol_objectid)
{
	struct btrfs_root *root = sb->s_fs_info;
	struct btrfs_root *new_root;
	struct btrfs_dir_item *di;
	struct btrfs_path *path;
	struct btrfs_key location;
	struct inode *inode;
	u64 dir_id;
	int new = 0;

	/*
	 * We have a specific subvol we want to mount, just setup location and
	 * go look up the root.
	 */
	if (subvol_objectid) {
		location.objectid = subvol_objectid;
		location.type = BTRFS_ROOT_ITEM_KEY;
		location.offset = (u64)-1;
		goto find_root;
	}

	path = btrfs_alloc_path();
	if (!path)
		return ERR_PTR(-ENOMEM);
	path->leave_spinning = 1;

	/*
	 * Find the "default" dir item which points to the root item that we
	 * will mount by default if we haven't been given a specific subvolume
	 * to mount.
	 */
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	dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
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	di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
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	if (IS_ERR(di)) {
		btrfs_free_path(path);
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		return ERR_CAST(di);
538
	}
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	if (!di) {
		/*
		 * Ok the default dir item isn't there.  This is weird since
		 * it's always been there, but don't freak out, just try and
		 * mount to root most subvolume.
		 */
		btrfs_free_path(path);
		dir_id = BTRFS_FIRST_FREE_OBJECTID;
		new_root = root->fs_info->fs_root;
		goto setup_root;
	}

	btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
	btrfs_free_path(path);

find_root:
	new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
	if (IS_ERR(new_root))
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		return ERR_CAST(new_root);
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	if (btrfs_root_refs(&new_root->root_item) == 0)
		return ERR_PTR(-ENOENT);

	dir_id = btrfs_root_dirid(&new_root->root_item);
setup_root:
	location.objectid = dir_id;
	location.type = BTRFS_INODE_ITEM_KEY;
	location.offset = 0;

	inode = btrfs_iget(sb, &location, new_root, &new);
569 570
	if (IS_ERR(inode))
		return ERR_CAST(inode);
571 572 573 574 575 576 577 578 579 580 581

	/*
	 * If we're just mounting the root most subvol put the inode and return
	 * a reference to the dentry.  We will have already gotten a reference
	 * to the inode in btrfs_fill_super so we're good to go.
	 */
	if (!new && sb->s_root->d_inode == inode) {
		iput(inode);
		return dget(sb->s_root);
	}

582
	return d_obtain_alias(inode);
583 584
}

C
Chris Mason 已提交
585
static int btrfs_fill_super(struct super_block *sb,
586
			    struct btrfs_fs_devices *fs_devices,
C
Chris Mason 已提交
587
			    void *data, int silent)
C
Chris Mason 已提交
588
{
C
Chris Mason 已提交
589 590
	struct inode *inode;
	struct dentry *root_dentry;
C
Chris Mason 已提交
591
	struct btrfs_root *tree_root;
592
	struct btrfs_key key;
C
Chris Mason 已提交
593
	int err;
594

C
Chris Mason 已提交
595 596 597
	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_magic = BTRFS_SUPER_MAGIC;
	sb->s_op = &btrfs_super_ops;
A
Al Viro 已提交
598
	sb->s_d_op = &btrfs_dentry_operations;
B
Balaji Rao 已提交
599
	sb->s_export_op = &btrfs_export_ops;
J
Josef Bacik 已提交
600
	sb->s_xattr = btrfs_xattr_handlers;
C
Chris Mason 已提交
601
	sb->s_time_gran = 1;
C
Chris Mason 已提交
602
#ifdef CONFIG_BTRFS_FS_POSIX_ACL
J
Josef Bacik 已提交
603
	sb->s_flags |= MS_POSIXACL;
604
#endif
605

606
	tree_root = open_ctree(sb, fs_devices, (char *)data);
607

608
	if (IS_ERR(tree_root)) {
C
Chris Mason 已提交
609
		printk("btrfs: open_ctree failed\n");
610
		return PTR_ERR(tree_root);
611
	}
C
Chris Mason 已提交
612
	sb->s_fs_info = tree_root;
613

614 615 616
	key.objectid = BTRFS_FIRST_FREE_OBJECTID;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;
617
	inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
618 619
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
C
Chris Mason 已提交
620
		goto fail_close;
C
Chris Mason 已提交
621 622
	}

C
Chris Mason 已提交
623 624 625 626 627
	root_dentry = d_alloc_root(inode);
	if (!root_dentry) {
		iput(inode);
		err = -ENOMEM;
		goto fail_close;
C
Chris Mason 已提交
628
	}
629

C
Chris Mason 已提交
630
	sb->s_root = root_dentry;
C
Chris Mason 已提交
631 632

	save_mount_options(sb, data);
D
Dan Magenheimer 已提交
633
	cleancache_init_fs(sb);
C
Chris Mason 已提交
634
	return 0;
C
Chris Mason 已提交
635 636 637 638

fail_close:
	close_ctree(tree_root);
	return err;
C
Chris Mason 已提交
639 640
}

S
Sage Weil 已提交
641
int btrfs_sync_fs(struct super_block *sb, int wait)
C
Chris Mason 已提交
642 643
{
	struct btrfs_trans_handle *trans;
644
	struct btrfs_root *root = btrfs_sb(sb);
C
Chris Mason 已提交
645
	int ret;
C
Chris Mason 已提交
646

647 648
	trace_btrfs_sync_fs(wait);

C
Chris Mason 已提交
649 650 651 652
	if (!wait) {
		filemap_flush(root->fs_info->btree_inode->i_mapping);
		return 0;
	}
653

Y
Yan, Zheng 已提交
654 655
	btrfs_start_delalloc_inodes(root, 0);
	btrfs_wait_ordered_extents(root, 0, 0);
656

657
	trans = btrfs_start_transaction(root, 0);
658 659
	if (IS_ERR(trans))
		return PTR_ERR(trans);
C
Chris Mason 已提交
660
	ret = btrfs_commit_transaction(trans, root);
661
	return ret;
C
Chris Mason 已提交
662 663
}

E
Eric Paris 已提交
664 665 666 667
static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
{
	struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
	struct btrfs_fs_info *info = root->fs_info;
T
Tsutomu Itoh 已提交
668
	char *compress_type;
E
Eric Paris 已提交
669 670 671 672 673 674 675 676 677 678

	if (btrfs_test_opt(root, DEGRADED))
		seq_puts(seq, ",degraded");
	if (btrfs_test_opt(root, NODATASUM))
		seq_puts(seq, ",nodatasum");
	if (btrfs_test_opt(root, NODATACOW))
		seq_puts(seq, ",nodatacow");
	if (btrfs_test_opt(root, NOBARRIER))
		seq_puts(seq, ",nobarrier");
	if (info->max_inline != 8192 * 1024)
679 680
		seq_printf(seq, ",max_inline=%llu",
			   (unsigned long long)info->max_inline);
E
Eric Paris 已提交
681
	if (info->alloc_start != 0)
682 683
		seq_printf(seq, ",alloc_start=%llu",
			   (unsigned long long)info->alloc_start);
E
Eric Paris 已提交
684 685 686
	if (info->thread_pool_size !=  min_t(unsigned long,
					     num_online_cpus() + 2, 8))
		seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
T
Tsutomu Itoh 已提交
687 688 689 690 691 692 693 694 695 696
	if (btrfs_test_opt(root, COMPRESS)) {
		if (info->compress_type == BTRFS_COMPRESS_ZLIB)
			compress_type = "zlib";
		else
			compress_type = "lzo";
		if (btrfs_test_opt(root, FORCE_COMPRESS))
			seq_printf(seq, ",compress-force=%s", compress_type);
		else
			seq_printf(seq, ",compress=%s", compress_type);
	}
C
Chris Mason 已提交
697 698
	if (btrfs_test_opt(root, NOSSD))
		seq_puts(seq, ",nossd");
699 700 701
	if (btrfs_test_opt(root, SSD_SPREAD))
		seq_puts(seq, ",ssd_spread");
	else if (btrfs_test_opt(root, SSD))
E
Eric Paris 已提交
702
		seq_puts(seq, ",ssd");
S
Sage Weil 已提交
703
	if (btrfs_test_opt(root, NOTREELOG))
704
		seq_puts(seq, ",notreelog");
705
	if (btrfs_test_opt(root, FLUSHONCOMMIT))
706
		seq_puts(seq, ",flushoncommit");
707 708
	if (btrfs_test_opt(root, DISCARD))
		seq_puts(seq, ",discard");
E
Eric Paris 已提交
709 710
	if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
		seq_puts(seq, ",noacl");
T
Tsutomu Itoh 已提交
711 712
	if (btrfs_test_opt(root, SPACE_CACHE))
		seq_puts(seq, ",space_cache");
713 714
	else
		seq_puts(seq, ",no_space_cache");
T
Tsutomu Itoh 已提交
715 716 717 718
	if (btrfs_test_opt(root, CLEAR_CACHE))
		seq_puts(seq, ",clear_cache");
	if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
		seq_puts(seq, ",user_subvol_rm_allowed");
719 720 721 722 723 724
	if (btrfs_test_opt(root, ENOSPC_DEBUG))
		seq_puts(seq, ",enospc_debug");
	if (btrfs_test_opt(root, AUTO_DEFRAG))
		seq_puts(seq, ",autodefrag");
	if (btrfs_test_opt(root, INODE_MAP_CACHE))
		seq_puts(seq, ",inode_cache");
E
Eric Paris 已提交
725 726 727
	return 0;
}

728
static int btrfs_test_super(struct super_block *s, void *data)
Y
Yan 已提交
729
{
730
	struct btrfs_root *test_root = data;
731
	struct btrfs_root *root = btrfs_sb(s);
Y
Yan 已提交
732

733 734 735 736 737 738
	/*
	 * If this super block is going away, return false as it
	 * can't match as an existing super block.
	 */
	if (!atomic_read(&s->s_active))
		return 0;
739
	return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
Y
Yan 已提交
740 741
}

742 743 744 745 746
static int btrfs_set_super(struct super_block *s, void *data)
{
	s->s_fs_info = data;

	return set_anon_super(s, data);
Y
Yan 已提交
747 748
}

749 750 751 752 753 754 755 756 757 758
/*
 * subvolumes are identified by ino 256
 */
static inline int is_subvolume_inode(struct inode *inode)
{
	if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
		return 1;
	return 0;
}

759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861
/*
 * This will strip out the subvol=%s argument for an argument string and add
 * subvolid=0 to make sure we get the actual tree root for path walking to the
 * subvol we want.
 */
static char *setup_root_args(char *args)
{
	unsigned copied = 0;
	unsigned len = strlen(args) + 2;
	char *pos;
	char *ret;

	/*
	 * We need the same args as before, but minus
	 *
	 * subvol=a
	 *
	 * and add
	 *
	 * subvolid=0
	 *
	 * which is a difference of 2 characters, so we allocate strlen(args) +
	 * 2 characters.
	 */
	ret = kzalloc(len * sizeof(char), GFP_NOFS);
	if (!ret)
		return NULL;
	pos = strstr(args, "subvol=");

	/* This shouldn't happen, but just in case.. */
	if (!pos) {
		kfree(ret);
		return NULL;
	}

	/*
	 * The subvol=<> arg is not at the front of the string, copy everybody
	 * up to that into ret.
	 */
	if (pos != args) {
		*pos = '\0';
		strcpy(ret, args);
		copied += strlen(args);
		pos++;
	}

	strncpy(ret + copied, "subvolid=0", len - copied);

	/* Length of subvolid=0 */
	copied += 10;

	/*
	 * If there is no , after the subvol= option then we know there's no
	 * other options and we can just return.
	 */
	pos = strchr(pos, ',');
	if (!pos)
		return ret;

	/* Copy the rest of the arguments into our buffer */
	strncpy(ret + copied, pos, len - copied);
	copied += strlen(pos);

	return ret;
}

static struct dentry *mount_subvol(const char *subvol_name, int flags,
				   const char *device_name, char *data)
{
	struct super_block *s;
	struct dentry *root;
	struct vfsmount *mnt;
	struct mnt_namespace *ns_private;
	char *newargs;
	struct path path;
	int error;

	newargs = setup_root_args(data);
	if (!newargs)
		return ERR_PTR(-ENOMEM);
	mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
			     newargs);
	kfree(newargs);
	if (IS_ERR(mnt))
		return ERR_CAST(mnt);

	ns_private = create_mnt_ns(mnt);
	if (IS_ERR(ns_private)) {
		mntput(mnt);
		return ERR_CAST(ns_private);
	}

	/*
	 * This will trigger the automount of the subvol so we can just
	 * drop the mnt we have here and return the dentry that we
	 * found.
	 */
	error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name,
				LOOKUP_FOLLOW, &path);
	put_mnt_ns(ns_private);
	if (error)
		return ERR_PTR(error);

862 863 864 865 866 867 868 869 870
	if (!is_subvolume_inode(path.dentry->d_inode)) {
		path_put(&path);
		mntput(mnt);
		error = -EINVAL;
		printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
				subvol_name);
		return ERR_PTR(-EINVAL);
	}

871 872 873 874 875 876 877 878 879
	/* Get a ref to the sb and the dentry we found and return it */
	s = path.mnt->mnt_sb;
	atomic_inc(&s->s_active);
	root = dget(path.dentry);
	path_put(&path);
	down_write(&s->s_umount);

	return root;
}
880

881 882 883 884 885 886
/*
 * Find a superblock for the given device / mount point.
 *
 * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
 *	  for multiple device setup.  Make sure to keep it in sync.
 */
A
Al Viro 已提交
887
static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
888
		const char *device_name, void *data)
Y
Yan 已提交
889 890 891 892
{
	struct block_device *bdev = NULL;
	struct super_block *s;
	struct dentry *root;
893
	struct btrfs_fs_devices *fs_devices = NULL;
894 895
	struct btrfs_root *tree_root = NULL;
	struct btrfs_fs_info *fs_info = NULL;
896
	fmode_t mode = FMODE_READ;
897 898
	char *subvol_name = NULL;
	u64 subvol_objectid = 0;
899
	u64 subvol_rootid = 0;
Y
Yan 已提交
900 901
	int error = 0;

902 903 904 905
	if (!(flags & MS_RDONLY))
		mode |= FMODE_WRITE;

	error = btrfs_parse_early_options(data, mode, fs_type,
906
					  &subvol_name, &subvol_objectid,
907
					  &subvol_rootid, &fs_devices);
908 909
	if (error) {
		kfree(subvol_name);
A
Al Viro 已提交
910
		return ERR_PTR(error);
911
	}
912

913 914 915 916 917 918
	if (subvol_name) {
		root = mount_subvol(subvol_name, flags, device_name, data);
		kfree(subvol_name);
		return root;
	}

919
	error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
920
	if (error)
921
		return ERR_PTR(error);
Y
Yan 已提交
922

923
	error = btrfs_open_devices(fs_devices, mode, fs_type);
924
	if (error)
925
		return ERR_PTR(error);
926

Y
Yan Zheng 已提交
927 928 929 930 931
	if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
		error = -EACCES;
		goto error_close_devices;
	}

932 933 934 935 936 937 938
	/*
	 * Setup a dummy root and fs_info for test/set super.  This is because
	 * we don't actually fill this stuff out until open_ctree, but we need
	 * it for searching for existing supers, so this lets us do that and
	 * then open_ctree will properly initialize everything later.
	 */
	fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
939 940 941 942
	if (!fs_info) {
		error = -ENOMEM;
		goto error_close_devices;
	}
943
	tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
944
	if (!tree_root) {
945 946 947 948 949 950 951
		error = -ENOMEM;
		goto error_close_devices;
	}
	fs_info->tree_root = tree_root;
	fs_info->fs_devices = fs_devices;
	tree_root->fs_info = fs_info;

952 953 954 955 956 957 958
	fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
	fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
	if (!fs_info->super_copy || !fs_info->super_for_commit) {
		error = -ENOMEM;
		goto error_close_devices;
	}

959
	bdev = fs_devices->latest_bdev;
960
	s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
961 962 963 964
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto error_close_devices;
	}
Y
Yan 已提交
965 966 967

	if (s->s_root) {
		if ((flags ^ s->s_flags) & MS_RDONLY) {
968
			deactivate_locked_super(s);
969
			return ERR_PTR(-EBUSY);
Y
Yan 已提交
970 971
		}

Y
Yan Zheng 已提交
972
		btrfs_close_devices(fs_devices);
973
		free_fs_info(fs_info);
Y
Yan 已提交
974 975 976
	} else {
		char b[BDEVNAME_SIZE];

A
Al Viro 已提交
977
		s->s_flags = flags | MS_NOSEC;
Y
Yan 已提交
978
		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
979
		btrfs_sb(s)->fs_info->bdev_holder = fs_type;
980 981
		error = btrfs_fill_super(s, fs_devices, data,
					 flags & MS_SILENT ? 1 : 0);
Y
Yan 已提交
982
		if (error) {
983
			deactivate_locked_super(s);
984
			return ERR_PTR(error);
Y
Yan 已提交
985 986 987 988 989
		}

		s->s_flags |= MS_ACTIVE;
	}

990 991 992 993
	root = get_default_root(s, subvol_objectid);
	if (IS_ERR(root)) {
		deactivate_locked_super(s);
		return root;
Y
Yan 已提交
994 995
	}

A
Al Viro 已提交
996
	return root;
Y
Yan 已提交
997

Y
Yan Zheng 已提交
998
error_close_devices:
999
	btrfs_close_devices(fs_devices);
1000
	free_fs_info(fs_info);
A
Al Viro 已提交
1001
	return ERR_PTR(error);
Y
Yan 已提交
1002
}
1003

Y
Yan Zheng 已提交
1004 1005 1006 1007 1008
static int btrfs_remount(struct super_block *sb, int *flags, char *data)
{
	struct btrfs_root *root = btrfs_sb(sb);
	int ret;

1009 1010 1011 1012
	ret = btrfs_parse_options(root, data);
	if (ret)
		return -EINVAL;

Y
Yan Zheng 已提交
1013 1014 1015 1016 1017 1018 1019 1020 1021
	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
		return 0;

	if (*flags & MS_RDONLY) {
		sb->s_flags |= MS_RDONLY;

		ret =  btrfs_commit_super(root);
		WARN_ON(ret);
	} else {
Y
Yan Zheng 已提交
1022 1023 1024
		if (root->fs_info->fs_devices->rw_devices == 0)
			return -EACCES;

1025
		if (btrfs_super_log_root(root->fs_info->super_copy) != 0)
Y
Yan Zheng 已提交
1026 1027
			return -EINVAL;

1028
		ret = btrfs_cleanup_fs_roots(root->fs_info);
Y
Yan Zheng 已提交
1029 1030
		WARN_ON(ret);

1031 1032
		/* recover relocation */
		ret = btrfs_recover_relocation(root);
Y
Yan Zheng 已提交
1033 1034 1035 1036 1037 1038 1039 1040
		WARN_ON(ret);

		sb->s_flags &= ~MS_RDONLY;
	}

	return 0;
}

1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066
/* Used to sort the devices by max_avail(descending sort) */
static int btrfs_cmp_device_free_bytes(const void *dev_info1,
				       const void *dev_info2)
{
	if (((struct btrfs_device_info *)dev_info1)->max_avail >
	    ((struct btrfs_device_info *)dev_info2)->max_avail)
		return -1;
	else if (((struct btrfs_device_info *)dev_info1)->max_avail <
		 ((struct btrfs_device_info *)dev_info2)->max_avail)
		return 1;
	else
	return 0;
}

/*
 * sort the devices by max_avail, in which max free extent size of each device
 * is stored.(Descending Sort)
 */
static inline void btrfs_descending_sort_devices(
					struct btrfs_device_info *devices,
					size_t nr_devices)
{
	sort(devices, nr_devices, sizeof(struct btrfs_device_info),
	     btrfs_cmp_device_free_bytes, NULL);
}

1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187
/*
 * The helper to calc the free space on the devices that can be used to store
 * file data.
 */
static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
{
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct btrfs_device_info *devices_info;
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct btrfs_device *device;
	u64 skip_space;
	u64 type;
	u64 avail_space;
	u64 used_space;
	u64 min_stripe_size;
	int min_stripes = 1;
	int i = 0, nr_devices;
	int ret;

	nr_devices = fs_info->fs_devices->rw_devices;
	BUG_ON(!nr_devices);

	devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
			       GFP_NOFS);
	if (!devices_info)
		return -ENOMEM;

	/* calc min stripe number for data space alloction */
	type = btrfs_get_alloc_profile(root, 1);
	if (type & BTRFS_BLOCK_GROUP_RAID0)
		min_stripes = 2;
	else if (type & BTRFS_BLOCK_GROUP_RAID1)
		min_stripes = 2;
	else if (type & BTRFS_BLOCK_GROUP_RAID10)
		min_stripes = 4;

	if (type & BTRFS_BLOCK_GROUP_DUP)
		min_stripe_size = 2 * BTRFS_STRIPE_LEN;
	else
		min_stripe_size = BTRFS_STRIPE_LEN;

	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
		if (!device->in_fs_metadata)
			continue;

		avail_space = device->total_bytes - device->bytes_used;

		/* align with stripe_len */
		do_div(avail_space, BTRFS_STRIPE_LEN);
		avail_space *= BTRFS_STRIPE_LEN;

		/*
		 * In order to avoid overwritting the superblock on the drive,
		 * btrfs starts at an offset of at least 1MB when doing chunk
		 * allocation.
		 */
		skip_space = 1024 * 1024;

		/* user can set the offset in fs_info->alloc_start. */
		if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
		    device->total_bytes)
			skip_space = max(fs_info->alloc_start, skip_space);

		/*
		 * btrfs can not use the free space in [0, skip_space - 1],
		 * we must subtract it from the total. In order to implement
		 * it, we account the used space in this range first.
		 */
		ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
						     &used_space);
		if (ret) {
			kfree(devices_info);
			return ret;
		}

		/* calc the free space in [0, skip_space - 1] */
		skip_space -= used_space;

		/*
		 * we can use the free space in [0, skip_space - 1], subtract
		 * it from the total.
		 */
		if (avail_space && avail_space >= skip_space)
			avail_space -= skip_space;
		else
			avail_space = 0;

		if (avail_space < min_stripe_size)
			continue;

		devices_info[i].dev = device;
		devices_info[i].max_avail = avail_space;

		i++;
	}

	nr_devices = i;

	btrfs_descending_sort_devices(devices_info, nr_devices);

	i = nr_devices - 1;
	avail_space = 0;
	while (nr_devices >= min_stripes) {
		if (devices_info[i].max_avail >= min_stripe_size) {
			int j;
			u64 alloc_size;

			avail_space += devices_info[i].max_avail * min_stripes;
			alloc_size = devices_info[i].max_avail;
			for (j = i + 1 - min_stripes; j <= i; j++)
				devices_info[j].max_avail -= alloc_size;
		}
		i--;
		nr_devices--;
	}

	kfree(devices_info);
	*free_bytes = avail_space;
	return 0;
}

C
Chris Mason 已提交
1188 1189 1190
static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct btrfs_root *root = btrfs_sb(dentry->d_sb);
1191
	struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1192 1193 1194
	struct list_head *head = &root->fs_info->space_info;
	struct btrfs_space_info *found;
	u64 total_used = 0;
1195
	u64 total_free_data = 0;
1196
	int bits = dentry->d_sb->s_blocksize_bits;
1197
	__be32 *fsid = (__be32 *)root->fs_info->fsid;
1198
	int ret;
C
Chris Mason 已提交
1199

1200 1201
	/* holding chunk_muext to avoid allocating new chunks */
	mutex_lock(&root->fs_info->chunk_mutex);
1202
	rcu_read_lock();
J
Josef Bacik 已提交
1203
	list_for_each_entry_rcu(found, head, list) {
1204 1205 1206 1207 1208 1209
		if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
			total_free_data += found->disk_total - found->disk_used;
			total_free_data -=
				btrfs_account_ro_block_groups_free_space(found);
		}

1210
		total_used += found->disk_used;
J
Josef Bacik 已提交
1211
	}
1212 1213
	rcu_read_unlock();

C
Chris Mason 已提交
1214
	buf->f_namelen = BTRFS_NAME_LEN;
1215
	buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1216
	buf->f_bfree = buf->f_blocks - (total_used >> bits);
C
Chris Mason 已提交
1217 1218
	buf->f_bsize = dentry->d_sb->s_blocksize;
	buf->f_type = BTRFS_SUPER_MAGIC;
1219 1220 1221 1222 1223 1224 1225 1226 1227
	buf->f_bavail = total_free_data;
	ret = btrfs_calc_avail_data_space(root, &total_free_data);
	if (ret) {
		mutex_unlock(&root->fs_info->chunk_mutex);
		return ret;
	}
	buf->f_bavail += total_free_data;
	buf->f_bavail = buf->f_bavail >> bits;
	mutex_unlock(&root->fs_info->chunk_mutex);
C
Chris Mason 已提交
1228

1229
	/* We treat it as constant endianness (it doesn't matter _which_)
C
Chris Mason 已提交
1230
	   because we want the fsid to come out the same whether mounted
1231 1232 1233
	   on a big-endian or little-endian host */
	buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
	buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1234 1235 1236 1237
	/* Mask in the root object ID too, to disambiguate subvols */
	buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
	buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;

C
Chris Mason 已提交
1238 1239
	return 0;
}
C
Chris Mason 已提交
1240

1241 1242 1243
static struct file_system_type btrfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "btrfs",
A
Al Viro 已提交
1244
	.mount		= btrfs_mount,
1245
	.kill_sb	= kill_anon_super,
1246 1247
	.fs_flags	= FS_REQUIRES_DEV,
};
1248

C
Chris Mason 已提交
1249 1250 1251
/*
 * used by btrfsctl to scan devices when no FS is mounted
 */
1252 1253 1254 1255 1256
static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
				unsigned long arg)
{
	struct btrfs_ioctl_vol_args *vol;
	struct btrfs_fs_devices *fs_devices;
1257
	int ret = -ENOTTY;
1258

1259 1260 1261
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

L
Li Zefan 已提交
1262 1263 1264
	vol = memdup_user((void __user *)arg, sizeof(*vol));
	if (IS_ERR(vol))
		return PTR_ERR(vol);
1265

1266 1267
	switch (cmd) {
	case BTRFS_IOC_SCAN_DEV:
1268
		ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1269 1270 1271
					    &btrfs_fs_type, &fs_devices);
		break;
	}
L
Li Zefan 已提交
1272

1273
	kfree(vol);
L
Linda Knippers 已提交
1274
	return ret;
1275 1276
}

1277
static int btrfs_freeze(struct super_block *sb)
Y
Yan 已提交
1278 1279
{
	struct btrfs_root *root = btrfs_sb(sb);
1280 1281
	mutex_lock(&root->fs_info->transaction_kthread_mutex);
	mutex_lock(&root->fs_info->cleaner_mutex);
1282
	return 0;
Y
Yan 已提交
1283 1284
}

1285
static int btrfs_unfreeze(struct super_block *sb)
Y
Yan 已提交
1286 1287
{
	struct btrfs_root *root = btrfs_sb(sb);
1288 1289
	mutex_unlock(&root->fs_info->cleaner_mutex);
	mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1290
	return 0;
Y
Yan 已提交
1291
}
1292

1293
static const struct super_operations btrfs_super_ops = {
1294
	.drop_inode	= btrfs_drop_inode,
A
Al Viro 已提交
1295
	.evict_inode	= btrfs_evict_inode,
C
Chris Mason 已提交
1296
	.put_super	= btrfs_put_super,
1297
	.sync_fs	= btrfs_sync_fs,
E
Eric Paris 已提交
1298
	.show_options	= btrfs_show_options,
C
Chris Mason 已提交
1299
	.write_inode	= btrfs_write_inode,
C
Chris Mason 已提交
1300
	.dirty_inode	= btrfs_dirty_inode,
C
Chris Mason 已提交
1301 1302
	.alloc_inode	= btrfs_alloc_inode,
	.destroy_inode	= btrfs_destroy_inode,
C
Chris Mason 已提交
1303
	.statfs		= btrfs_statfs,
Y
Yan Zheng 已提交
1304
	.remount_fs	= btrfs_remount,
1305 1306
	.freeze_fs	= btrfs_freeze,
	.unfreeze_fs	= btrfs_unfreeze,
C
Chris Mason 已提交
1307
};
1308 1309 1310 1311 1312

static const struct file_operations btrfs_ctl_fops = {
	.unlocked_ioctl	 = btrfs_control_ioctl,
	.compat_ioctl = btrfs_control_ioctl,
	.owner	 = THIS_MODULE,
1313
	.llseek = noop_llseek,
1314 1315 1316
};

static struct miscdevice btrfs_misc = {
1317
	.minor		= BTRFS_MINOR,
1318 1319 1320 1321
	.name		= "btrfs-control",
	.fops		= &btrfs_ctl_fops
};

1322 1323 1324
MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
MODULE_ALIAS("devname:btrfs-control");

1325 1326 1327 1328 1329
static int btrfs_interface_init(void)
{
	return misc_register(&btrfs_misc);
}

1330
static void btrfs_interface_exit(void)
1331 1332
{
	if (misc_deregister(&btrfs_misc) < 0)
C
Chris Mason 已提交
1333
		printk(KERN_INFO "misc_deregister failed for control device");
1334 1335
}

1336 1337
static int __init init_btrfs_fs(void)
{
C
Chris Mason 已提交
1338
	int err;
1339 1340 1341 1342 1343

	err = btrfs_init_sysfs();
	if (err)
		return err;

1344
	err = btrfs_init_compress();
C
Chris Mason 已提交
1345
	if (err)
1346
		goto free_sysfs;
1347

1348 1349 1350 1351
	err = btrfs_init_cachep();
	if (err)
		goto free_compress;

1352
	err = extent_io_init();
1353 1354 1355
	if (err)
		goto free_cachep;

1356 1357 1358 1359
	err = extent_map_init();
	if (err)
		goto free_extent_io;

1360
	err = btrfs_delayed_inode_init();
1361 1362
	if (err)
		goto free_extent_map;
C
Chris Mason 已提交
1363

1364 1365 1366 1367
	err = btrfs_interface_init();
	if (err)
		goto free_delayed_inode;

1368 1369 1370
	err = register_filesystem(&btrfs_fs_type);
	if (err)
		goto unregister_ioctl;
1371 1372

	printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1373 1374
	return 0;

1375 1376
unregister_ioctl:
	btrfs_interface_exit();
1377 1378
free_delayed_inode:
	btrfs_delayed_inode_exit();
1379 1380
free_extent_map:
	extent_map_exit();
1381 1382
free_extent_io:
	extent_io_exit();
1383 1384
free_cachep:
	btrfs_destroy_cachep();
1385 1386
free_compress:
	btrfs_exit_compress();
1387
free_sysfs:
1388 1389
	btrfs_exit_sysfs();
	return err;
1390 1391 1392 1393
}

static void __exit exit_btrfs_fs(void)
{
C
Chris Mason 已提交
1394
	btrfs_destroy_cachep();
1395
	btrfs_delayed_inode_exit();
1396
	extent_map_exit();
1397
	extent_io_exit();
1398
	btrfs_interface_exit();
1399
	unregister_filesystem(&btrfs_fs_type);
1400
	btrfs_exit_sysfs();
1401
	btrfs_cleanup_fs_uuids();
1402
	btrfs_exit_compress();
1403 1404 1405 1406 1407 1408
}

module_init(init_btrfs_fs)
module_exit(exit_btrfs_fs)

MODULE_LICENSE("GPL");