1 files changed, 722 insertions, 0 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
new file mode 100644
index 000000000000..0a14b495532f
--- /dev/null
+++ b/fs/btrfs/super.c
@@ -0,0 +1,722 @@
+/*
+ * 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.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mount.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/parser.h>
+#include <linux/ctype.h>
+#include <linux/namei.h>
+#include <linux/miscdevice.h>
+#include <linux/version.h>
+#include "compat.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+#include "xattr.h"
+#include "volumes.h"
+#include "version.h"
+#include "export.h"
+#include "compression.h"
+
+#define BTRFS_SUPER_MAGIC 0x9123683E
+
+static struct super_operations btrfs_super_ops;
+
+static void btrfs_put_super(struct super_block *sb)
+{
+	struct btrfs_root *root = btrfs_sb(sb);
+	int ret;
+
+	ret = close_ctree(root);
+	sb->s_fs_info = NULL;
+}
+
+enum {
+	Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
+	Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
+	Opt_ssd, Opt_thread_pool, Opt_noacl,  Opt_compress, Opt_err,
+};
+
+static match_table_t tokens = {
+	{Opt_degraded, "degraded"},
+	{Opt_subvol, "subvol=%s"},
+	{Opt_device, "device=%s"},
+	{Opt_nodatasum, "nodatasum"},
+	{Opt_nodatacow, "nodatacow"},
+	{Opt_nobarrier, "nobarrier"},
+	{Opt_max_extent, "max_extent=%s"},
+	{Opt_max_inline, "max_inline=%s"},
+	{Opt_alloc_start, "alloc_start=%s"},
+	{Opt_thread_pool, "thread_pool=%d"},
+	{Opt_compress, "compress"},
+	{Opt_ssd, "ssd"},
+	{Opt_noacl, "noacl"},
+	{Opt_err, NULL},
+};
+
+u64 btrfs_parse_size(char *str)
+{
+	u64 res;
+	int mult = 1;
+	char *end;
+	char last;
+
+	res = simple_strtoul(str, &end, 10);
+
+	last = end[0];
+	if (isalpha(last)) {
+		last = tolower(last);
+		switch (last) {
+		case 'g':
+			mult *= 1024;
+		case 'm':
+			mult *= 1024;
+		case 'k':
+			mult *= 1024;
+		}
+		res = res * mult;
+	}
+	return res;
+}
+
+/*
+ * 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)
+{
+	struct btrfs_fs_info *info = root->fs_info;
+	substring_t args[MAX_OPT_ARGS];
+	char *p, *num;
+	int intarg;
+
+	if (!options)
+		return 0;
+
+	/*
+	 * strsep changes the string, duplicate it because parse_options
+	 * gets called twice
+	 */
+	options = kstrdup(options, GFP_NOFS);
+	if (!options)
+		return -ENOMEM;
+
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_degraded:
+			printk(KERN_INFO "btrfs: allowing degraded mounts\n");
+			btrfs_set_opt(info->mount_opt, DEGRADED);
+			break;
+		case Opt_subvol:
+		case Opt_device:
+			/*
+			 * These are parsed by btrfs_parse_early_options
+			 * and can be happily ignored here.
+			 */
+			break;
+		case Opt_nodatasum:
+			printk(KERN_INFO "btrfs: setting nodatacsum\n");
+			btrfs_set_opt(info->mount_opt, NODATASUM);
+			break;
+		case Opt_nodatacow:
+			printk(KERN_INFO "btrfs: setting nodatacow\n");
+			btrfs_set_opt(info->mount_opt, NODATACOW);
+			btrfs_set_opt(info->mount_opt, NODATASUM);
+			break;
+		case Opt_compress:
+			printk(KERN_INFO "btrfs: use compression\n");
+			btrfs_set_opt(info->mount_opt, COMPRESS);
+			break;
+		case Opt_ssd:
+			printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
+			btrfs_set_opt(info->mount_opt, SSD);
+			break;
+		case Opt_nobarrier:
+			printk(KERN_INFO "btrfs: turning off barriers\n");
+			btrfs_set_opt(info->mount_opt, NOBARRIER);
+			break;
+		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;
+		case Opt_max_extent:
+			num = match_strdup(&args[0]);
+			if (num) {
+				info->max_extent = btrfs_parse_size(num);
+				kfree(num);
+
+				info->max_extent = max_t(u64,
+					info->max_extent, root->sectorsize);
+				printk(KERN_INFO "btrfs: max_extent at %llu\n",
+				       info->max_extent);
+			}
+			break;
+		case Opt_max_inline:
+			num = match_strdup(&args[0]);
+			if (num) {
+				info->max_inline = btrfs_parse_size(num);
+				kfree(num);
+
+				if (info->max_inline) {
+					info->max_inline = max_t(u64,
+						info->max_inline,
+						root->sectorsize);
+				}
+				printk(KERN_INFO "btrfs: max_inline at %llu\n",
+					info->max_inline);
+			}
+			break;
+		case Opt_alloc_start:
+			num = match_strdup(&args[0]);
+			if (num) {
+				info->alloc_start = btrfs_parse_size(num);
+				kfree(num);
+				printk(KERN_INFO
+					"btrfs: allocations start at %llu\n",
+					info->alloc_start);
+			}
+			break;
+		case Opt_noacl:
+			root->fs_info->sb->s_flags &= ~MS_POSIXACL;
+			break;
+		default:
+			break;
+		}
+	}
+	kfree(options);
+	return 0;
+}
+
+/*
+ * 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.
+ */
+static int btrfs_parse_early_options(const char *options, fmode_t flags,
+		void *holder, char **subvol_name,
+		struct btrfs_fs_devices **fs_devices)
+{
+	substring_t args[MAX_OPT_ARGS];
+	char *opts, *p;
+	int error = 0;
+
+	if (!options)
+		goto out;
+
+	/*
+	 * strsep changes the string, duplicate it because parse_options
+	 * gets called twice
+	 */
+	opts = kstrdup(options, GFP_KERNEL);
+	if (!opts)
+		return -ENOMEM;
+
+	while ((p = strsep(&opts, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_subvol:
+			*subvol_name = match_strdup(&args[0]);
+			break;
+		case Opt_device:
+			error = btrfs_scan_one_device(match_strdup(&args[0]),
+					flags, holder, fs_devices);
+			if (error)
+				goto out_free_opts;
+			break;
+		default:
+			break;
+		}
+	}
+
+ out_free_opts:
+	kfree(opts);
+ out:
+	/*
+	 * If no subvolume name is specified we use the default one.  Allocate
+	 * a copy of the string "." here so that code later in the
+	 * mount path doesn't care if it's the default volume or another one.
+	 */
+	if (!*subvol_name) {
+		*subvol_name = kstrdup(".", GFP_KERNEL);
+		if (!*subvol_name)
+			return -ENOMEM;
+	}
+	return error;
+}
+
+static int btrfs_fill_super(struct super_block *sb,
+			    struct btrfs_fs_devices *fs_devices,
+			    void *data, int silent)
+{
+	struct inode *inode;
+	struct dentry *root_dentry;
+	struct btrfs_super_block *disk_super;
+	struct btrfs_root *tree_root;
+	struct btrfs_inode *bi;
+	int err;
+
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_magic = BTRFS_SUPER_MAGIC;
+	sb->s_op = &btrfs_super_ops;
+	sb->s_export_op = &btrfs_export_ops;
+	sb->s_xattr = btrfs_xattr_handlers;
+	sb->s_time_gran = 1;
+	sb->s_flags |= MS_POSIXACL;
+
+	tree_root = open_ctree(sb, fs_devices, (char *)data);
+
+	if (IS_ERR(tree_root)) {
+		printk("btrfs: open_ctree failed\n");
+		return PTR_ERR(tree_root);
+	}
+	sb->s_fs_info = tree_root;
+	disk_super = &tree_root->fs_info->super_copy;
+	inode = btrfs_iget_locked(sb, BTRFS_FIRST_FREE_OBJECTID,
+				  tree_root->fs_info->fs_root);
+	bi = BTRFS_I(inode);
+	bi->location.objectid = inode->i_ino;
+	bi->location.offset = 0;
+	bi->root = tree_root->fs_info->fs_root;
+
+	btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
+
+	if (!inode) {
+		err = -ENOMEM;
+		goto fail_close;
+	}
+	if (inode->i_state & I_NEW) {
+		btrfs_read_locked_inode(inode);
+		unlock_new_inode(inode);
+	}
+
+	root_dentry = d_alloc_root(inode);
+	if (!root_dentry) {
+		iput(inode);
+		err = -ENOMEM;
+		goto fail_close;
+	}
+#if 0
+	/* this does the super kobj at the same time */
+	err = btrfs_sysfs_add_super(tree_root->fs_info);
+	if (err)
+		goto fail_close;
+#endif
+
+	sb->s_root = root_dentry;
+
+	save_mount_options(sb, data);
+	return 0;
+
+fail_close:
+	close_ctree(tree_root);
+	return err;
+}
+
+int btrfs_sync_fs(struct super_block *sb, int wait)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_root *root;
+	int ret;
+	root = btrfs_sb(sb);
+
+	if (sb->s_flags & MS_RDONLY)
+		return 0;
+
+	sb->s_dirt = 0;
+	if (!wait) {
+		filemap_flush(root->fs_info->btree_inode->i_mapping);
+		return 0;
+	}
+
+	btrfs_start_delalloc_inodes(root);
+	btrfs_wait_ordered_extents(root, 0);
+
+	btrfs_clean_old_snapshots(root);
+	trans = btrfs_start_transaction(root, 1);
+	ret = btrfs_commit_transaction(trans, root);
+	sb->s_dirt = 0;
+	return ret;
+}
+
+static void btrfs_write_super(struct super_block *sb)
+{
+	sb->s_dirt = 0;
+}
+
+static int btrfs_test_super(struct super_block *s, void *data)
+{
+	struct btrfs_fs_devices *test_fs_devices = data;
+	struct btrfs_root *root = btrfs_sb(s);
+
+	return root->fs_info->fs_devices == test_fs_devices;
+}
+
+/*
+ * 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.
+ */
+static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
+		const char *dev_name, void *data, struct vfsmount *mnt)
+{
+	char *subvol_name = NULL;
+	struct block_device *bdev = NULL;
+	struct super_block *s;
+	struct dentry *root;
+	struct btrfs_fs_devices *fs_devices = NULL;
+	fmode_t mode = FMODE_READ;
+	int error = 0;
+
+	if (!(flags & MS_RDONLY))
+		mode |= FMODE_WRITE;
+
+	error = btrfs_parse_early_options(data, mode, fs_type,
+					  &subvol_name, &fs_devices);
+	if (error)
+		return error;
+
+	error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices);
+	if (error)
+		goto error_free_subvol_name;
+
+	error = btrfs_open_devices(fs_devices, mode, fs_type);
+	if (error)
+		goto error_free_subvol_name;
+
+	if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
+		error = -EACCES;
+		goto error_close_devices;
+	}
+
+	bdev = fs_devices->latest_bdev;
+	s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
+	if (IS_ERR(s))
+		goto error_s;
+
+	if (s->s_root) {
+		if ((flags ^ s->s_flags) & MS_RDONLY) {
+			up_write(&s->s_umount);
+			deactivate_super(s);
+			error = -EBUSY;
+			goto error_close_devices;
+		}
+
+		btrfs_close_devices(fs_devices);
+	} else {
+		char b[BDEVNAME_SIZE];
+
+		s->s_flags = flags;
+		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
+		error = btrfs_fill_super(s, fs_devices, data,
+					 flags & MS_SILENT ? 1 : 0);
+		if (error) {
+			up_write(&s->s_umount);
+			deactivate_super(s);
+			goto error_free_subvol_name;
+		}
+
+		btrfs_sb(s)->fs_info->bdev_holder = fs_type;
+		s->s_flags |= MS_ACTIVE;
+	}
+
+	if (!strcmp(subvol_name, "."))
+		root = dget(s->s_root);
+	else {
+		mutex_lock(&s->s_root->d_inode->i_mutex);
+		root = lookup_one_len(subvol_name, s->s_root,
+				      strlen(subvol_name));
+		mutex_unlock(&s->s_root->d_inode->i_mutex);
+
+		if (IS_ERR(root)) {
+			up_write(&s->s_umount);
+			deactivate_super(s);
+			error = PTR_ERR(root);
+			goto error_free_subvol_name;
+		}
+		if (!root->d_inode) {
+			dput(root);
+			up_write(&s->s_umount);
+			deactivate_super(s);
+			error = -ENXIO;
+			goto error_free_subvol_name;
+		}
+	}
+
+	mnt->mnt_sb = s;
+	mnt->mnt_root = root;
+
+	kfree(subvol_name);
+	return 0;
+
+error_s:
+	error = PTR_ERR(s);
+error_close_devices:
+	btrfs_close_devices(fs_devices);
+error_free_subvol_name:
+	kfree(subvol_name);
+	return error;
+}
+
+static int btrfs_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct btrfs_root *root = btrfs_sb(sb);
+	int ret;
+
+	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 {
+		if (root->fs_info->fs_devices->rw_devices == 0)
+			return -EACCES;
+
+		if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
+			return -EINVAL;
+
+		ret = btrfs_cleanup_reloc_trees(root);
+		WARN_ON(ret);
+
+		ret = btrfs_cleanup_fs_roots(root->fs_info);
+		WARN_ON(ret);
+
+		sb->s_flags &= ~MS_RDONLY;
+	}
+
+	return 0;
+}
+
+static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct btrfs_root *root = btrfs_sb(dentry->d_sb);
+	struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
+	int bits = dentry->d_sb->s_blocksize_bits;
+	__be32 *fsid = (__be32 *)root->fs_info->fsid;
+
+	buf->f_namelen = BTRFS_NAME_LEN;
+	buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
+	buf->f_bfree = buf->f_blocks -
+		(btrfs_super_bytes_used(disk_super) >> bits);
+	buf->f_bavail = buf->f_bfree;
+	buf->f_bsize = dentry->d_sb->s_blocksize;
+	buf->f_type = BTRFS_SUPER_MAGIC;
+
+	/* We treat it as constant endianness (it doesn't matter _which_)
+	   because we want the fsid to come out the same whether mounted
+	   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]);
+	/* 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;
+
+	return 0;
+}
+
+static struct file_system_type btrfs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "btrfs",
+	.get_sb		= btrfs_get_sb,
+	.kill_sb	= kill_anon_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
+/*
+ * used by btrfsctl to scan devices when no FS is mounted
+ */
+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;
+	int ret = 0;
+	int len;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	vol = kmalloc(sizeof(*vol), GFP_KERNEL);
+	if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
+		ret = -EFAULT;
+		goto out;
+	}
+	len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
+	switch (cmd) {
+	case BTRFS_IOC_SCAN_DEV:
+		ret = btrfs_scan_one_device(vol->name, FMODE_READ,
+					    &btrfs_fs_type, &fs_devices);
+		break;
+	}
+out:
+	kfree(vol);
+	return ret;
+}
+
+static int btrfs_freeze(struct super_block *sb)
+{
+	struct btrfs_root *root = btrfs_sb(sb);
+	mutex_lock(&root->fs_info->transaction_kthread_mutex);
+	mutex_lock(&root->fs_info->cleaner_mutex);
+	return 0;
+}
+
+static int btrfs_unfreeze(struct super_block *sb)
+{
+	struct btrfs_root *root = btrfs_sb(sb);
+	mutex_unlock(&root->fs_info->cleaner_mutex);
+	mutex_unlock(&root->fs_info->transaction_kthread_mutex);
+	return 0;
+}
+
+static struct super_operations btrfs_super_ops = {
+	.delete_inode	= btrfs_delete_inode,
+	.put_super	= btrfs_put_super,
+	.write_super	= btrfs_write_super,
+	.sync_fs	= btrfs_sync_fs,
+	.show_options	= generic_show_options,
+	.write_inode	= btrfs_write_inode,
+	.dirty_inode	= btrfs_dirty_inode,
+	.alloc_inode	= btrfs_alloc_inode,
+	.destroy_inode	= btrfs_destroy_inode,
+	.statfs		= btrfs_statfs,
+	.remount_fs	= btrfs_remount,
+	.freeze_fs	= btrfs_freeze,
+	.unfreeze_fs	= btrfs_unfreeze,
+};
+
+static const struct file_operations btrfs_ctl_fops = {
+	.unlocked_ioctl	 = btrfs_control_ioctl,
+	.compat_ioctl = btrfs_control_ioctl,
+	.owner	 = THIS_MODULE,
+};
+
+static struct miscdevice btrfs_misc = {
+	.minor		= MISC_DYNAMIC_MINOR,
+	.name		= "btrfs-control",
+	.fops		= &btrfs_ctl_fops
+};
+
+static int btrfs_interface_init(void)
+{
+	return misc_register(&btrfs_misc);
+}
+
+static void btrfs_interface_exit(void)
+{
+	if (misc_deregister(&btrfs_misc) < 0)
+		printk(KERN_INFO "misc_deregister failed for control device");
+}
+
+static int __init init_btrfs_fs(void)
+{
+	int err;
+
+	err = btrfs_init_sysfs();
+	if (err)
+		return err;
+
+	err = btrfs_init_cachep();
+	if (err)
+		goto free_sysfs;
+
+	err = extent_io_init();
+	if (err)
+		goto free_cachep;
+
+	err = extent_map_init();
+	if (err)
+		goto free_extent_io;
+
+	err = btrfs_interface_init();
+	if (err)
+		goto free_extent_map;
+
+	err = register_filesystem(&btrfs_fs_type);
+	if (err)
+		goto unregister_ioctl;
+
+	printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
+	return 0;
+
+unregister_ioctl:
+	btrfs_interface_exit();
+free_extent_map:
+	extent_map_exit();
+free_extent_io:
+	extent_io_exit();
+free_cachep:
+	btrfs_destroy_cachep();
+free_sysfs:
+	btrfs_exit_sysfs();
+	return err;
+}
+
+static void __exit exit_btrfs_fs(void)
+{
+	btrfs_destroy_cachep();
+	extent_map_exit();
+	extent_io_exit();
+	btrfs_interface_exit();
+	unregister_filesystem(&btrfs_fs_type);
+	btrfs_exit_sysfs();
+	btrfs_cleanup_fs_uuids();
+	btrfs_zlib_exit();
+}
+
+module_init(init_btrfs_fs)
+module_exit(exit_btrfs_fs)
+
+MODULE_LICENSE("GPL");