super.c

linux 内核源代码

					 " with non-standard journal");
		else {
			reiserfs_warning(s,
					 "sh-2012: read_super_block: found unknown "
					 "format \"%u\" of reiserfs with non-standard magic",
					 sb_version(rs));
			return 1;
		}
	} else
		/* s_version of standard format may contain incorrect information,
		   so we just look at the magic string */
		reiserfs_info(s,
			      "found reiserfs format \"%s\" with standard journal\n",
			      is_reiserfs_3_5(rs) ? "3.5" : "3.6");

	s->s_op = &reiserfs_sops;
	s->s_export_op = &reiserfs_export_ops;
#ifdef CONFIG_QUOTA
	s->s_qcop = &reiserfs_qctl_operations;
	s->dq_op = &reiserfs_quota_operations;
#endif

	/* new format is limited by the 32 bit wide i_blocks field, want to
	 ** be one full block below that.
	 */
	s->s_maxbytes = (512LL << 32) - s->s_blocksize;
	return 0;
}

/* after journal replay, reread all bitmap and super blocks */
static int reread_meta_blocks(struct super_block *s)
{
	ll_rw_block(READ, 1, &(SB_BUFFER_WITH_SB(s)));
	wait_on_buffer(SB_BUFFER_WITH_SB(s));
	if (!buffer_uptodate(SB_BUFFER_WITH_SB(s))) {
		reiserfs_warning(s,
				 "reread_meta_blocks, error reading the super");
		return 1;
	}

	return 0;
}

/////////////////////////////////////////////////////
// hash detection stuff

// if root directory is empty - we set default - Yura's - hash and
// warn about it
// FIXME: we look for only one name in a directory. If tea and yura
// bith have the same value - we ask user to send report to the
// mailing list
static __u32 find_hash_out(struct super_block *s)
{
	int retval;
	struct inode *inode;
	struct cpu_key key;
	INITIALIZE_PATH(path);
	struct reiserfs_dir_entry de;
	__u32 hash = DEFAULT_HASH;

	inode = s->s_root->d_inode;

	do {			// Some serious "goto"-hater was there ;)
		u32 teahash, r5hash, yurahash;

		make_cpu_key(&key, inode, ~0, TYPE_DIRENTRY, 3);
		retval = search_by_entry_key(s, &key, &path, &de);
		if (retval == IO_ERROR) {
			pathrelse(&path);
			return UNSET_HASH;
		}
		if (retval == NAME_NOT_FOUND)
			de.de_entry_num--;
		set_de_name_and_namelen(&de);
		if (deh_offset(&(de.de_deh[de.de_entry_num])) == DOT_DOT_OFFSET) {
			/* allow override in this case */
			if (reiserfs_rupasov_hash(s)) {
				hash = YURA_HASH;
			}
			reiserfs_warning(s, "FS seems to be empty, autodetect "
					 "is using the default hash");
			break;
		}
		r5hash = GET_HASH_VALUE(r5_hash(de.de_name, de.de_namelen));
		teahash = GET_HASH_VALUE(keyed_hash(de.de_name, de.de_namelen));
		yurahash = GET_HASH_VALUE(yura_hash(de.de_name, de.de_namelen));
		if (((teahash == r5hash)
		     &&
		     (GET_HASH_VALUE(deh_offset(&(de.de_deh[de.de_entry_num])))
		      == r5hash)) || ((teahash == yurahash)
				      && (yurahash ==
					  GET_HASH_VALUE(deh_offset
							 (&
							  (de.
							   de_deh[de.
								  de_entry_num])))))
		    || ((r5hash == yurahash)
			&& (yurahash ==
			    GET_HASH_VALUE(deh_offset
					   (&(de.de_deh[de.de_entry_num])))))) {
			reiserfs_warning(s,
					 "Unable to automatically detect hash function. "
					 "Please mount with -o hash={tea,rupasov,r5}",
					 reiserfs_bdevname(s));
			hash = UNSET_HASH;
			break;
		}
		if (GET_HASH_VALUE(deh_offset(&(de.de_deh[de.de_entry_num]))) ==
		    yurahash)
			hash = YURA_HASH;
		else if (GET_HASH_VALUE
			 (deh_offset(&(de.de_deh[de.de_entry_num]))) == teahash)
			hash = TEA_HASH;
		else if (GET_HASH_VALUE
			 (deh_offset(&(de.de_deh[de.de_entry_num]))) == r5hash)
			hash = R5_HASH;
		else {
			reiserfs_warning(s, "Unrecognised hash function");
			hash = UNSET_HASH;
		}
	} while (0);

	pathrelse(&path);
	return hash;
}

// finds out which hash names are sorted with
static int what_hash(struct super_block *s)
{
	__u32 code;

	code = sb_hash_function_code(SB_DISK_SUPER_BLOCK(s));

	/* reiserfs_hash_detect() == true if any of the hash mount options
	 ** were used.  We must check them to make sure the user isn't
	 ** using a bad hash value
	 */
	if (code == UNSET_HASH || reiserfs_hash_detect(s))
		code = find_hash_out(s);

	if (code != UNSET_HASH && reiserfs_hash_detect(s)) {
		/* detection has found the hash, and we must check against the 
		 ** mount options 
		 */
		if (reiserfs_rupasov_hash(s) && code != YURA_HASH) {
			reiserfs_warning(s, "Error, %s hash detected, "
					 "unable to force rupasov hash",
					 reiserfs_hashname(code));
			code = UNSET_HASH;
		} else if (reiserfs_tea_hash(s) && code != TEA_HASH) {
			reiserfs_warning(s, "Error, %s hash detected, "
					 "unable to force tea hash",
					 reiserfs_hashname(code));
			code = UNSET_HASH;
		} else if (reiserfs_r5_hash(s) && code != R5_HASH) {
			reiserfs_warning(s, "Error, %s hash detected, "
					 "unable to force r5 hash",
					 reiserfs_hashname(code));
			code = UNSET_HASH;
		}
	} else {
		/* find_hash_out was not called or could not determine the hash */
		if (reiserfs_rupasov_hash(s)) {
			code = YURA_HASH;
		} else if (reiserfs_tea_hash(s)) {
			code = TEA_HASH;
		} else if (reiserfs_r5_hash(s)) {
			code = R5_HASH;
		}
	}

	/* if we are mounted RW, and we have a new valid hash code, update 
	 ** the super
	 */
	if (code != UNSET_HASH &&
	    !(s->s_flags & MS_RDONLY) &&
	    code != sb_hash_function_code(SB_DISK_SUPER_BLOCK(s))) {
		set_sb_hash_function_code(SB_DISK_SUPER_BLOCK(s), code);
	}
	return code;
}

// return pointer to appropriate function
static hashf_t hash_function(struct super_block *s)
{
	switch (what_hash(s)) {
	case TEA_HASH:
		reiserfs_info(s, "Using tea hash to sort names\n");
		return keyed_hash;
	case YURA_HASH:
		reiserfs_info(s, "Using rupasov hash to sort names\n");
		return yura_hash;
	case R5_HASH:
		reiserfs_info(s, "Using r5 hash to sort names\n");
		return r5_hash;
	}
	return NULL;
}

// this is used to set up correct value for old partitions
static int function2code(hashf_t func)
{
	if (func == keyed_hash)
		return TEA_HASH;
	if (func == yura_hash)
		return YURA_HASH;
	if (func == r5_hash)
		return R5_HASH;

	BUG();			// should never happen

	return 0;
}

#define SWARN(silent, s, ...)			\
	if (!(silent))				\
		reiserfs_warning (s, __VA_ARGS__)

static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
{
	struct inode *root_inode;
	struct reiserfs_transaction_handle th;
	int old_format = 0;
	unsigned long blocks;
	unsigned int commit_max_age = 0;
	int jinit_done = 0;
	struct reiserfs_iget_args args;
	struct reiserfs_super_block *rs;
	char *jdev_name;
	struct reiserfs_sb_info *sbi;
	int errval = -EINVAL;

	sbi = kzalloc(sizeof(struct reiserfs_sb_info), GFP_KERNEL);
	if (!sbi) {
		errval = -ENOMEM;
		goto error;
	}
	s->s_fs_info = sbi;
	/* Set default values for options: non-aggressive tails, RO on errors */
	REISERFS_SB(s)->s_mount_opt |= (1 << REISERFS_SMALLTAIL);
	REISERFS_SB(s)->s_mount_opt |= (1 << REISERFS_ERROR_RO);
	/* no preallocation minimum, be smart in
	   reiserfs_file_write instead */
	REISERFS_SB(s)->s_alloc_options.preallocmin = 0;
	/* Preallocate by 16 blocks (17-1) at once */
	REISERFS_SB(s)->s_alloc_options.preallocsize = 17;
#ifdef CONFIG_REISERFS_FS_XATTR
	/* Initialize the rwsem for xattr dir */
	init_rwsem(&REISERFS_SB(s)->xattr_dir_sem);
#endif
	/* setup default block allocator options */
	reiserfs_init_alloc_options(s);

	jdev_name = NULL;
	if (reiserfs_parse_options
	    (s, (char *)data, &(sbi->s_mount_opt), &blocks, &jdev_name,
	     &commit_max_age) == 0) {
		goto error;
	}

	if (blocks) {
		SWARN(silent, s, "jmacd-7: reiserfs_fill_super: resize option "
		      "for remount only");
		goto error;
	}

	/* try old format (undistributed bitmap, super block in 8-th 1k block of a device) */
	if (!read_super_block(s, REISERFS_OLD_DISK_OFFSET_IN_BYTES))
		old_format = 1;
	/* try new format (64-th 1k block), which can contain reiserfs super block */
	else if (read_super_block(s, REISERFS_DISK_OFFSET_IN_BYTES)) {
		SWARN(silent, s,
		      "sh-2021: reiserfs_fill_super: can not find reiserfs on %s",
		      reiserfs_bdevname(s));
		goto error;
	}

	rs = SB_DISK_SUPER_BLOCK(s);
	/* Let's do basic sanity check to verify that underlying device is not
	   smaller than the filesystem. If the check fails then abort and scream,
	   because bad stuff will happen otherwise. */
	if (s->s_bdev && s->s_bdev->bd_inode
	    && i_size_read(s->s_bdev->bd_inode) <
	    sb_block_count(rs) * sb_blocksize(rs)) {
		SWARN(silent, s,
		      "Filesystem on %s cannot be mounted because it is bigger than the device",
		      reiserfs_bdevname(s));
		SWARN(silent, s,
		      "You may need to run fsck or increase size of your LVM partition");
		SWARN(silent, s,
		      "Or may be you forgot to reboot after fdisk when it told you to");
		goto error;
	}

	sbi->s_mount_state = SB_REISERFS_STATE(s);
	sbi->s_mount_state = REISERFS_VALID_FS;

	if ((errval = reiserfs_init_bitmap_cache(s))) {
		SWARN(silent, s,
		      "jmacd-8: reiserfs_fill_super: unable to read bitmap");
		goto error;
	}
	errval = -EINVAL;
#ifdef CONFIG_REISERFS_CHECK
	SWARN(silent, s, "CONFIG_REISERFS_CHECK is set ON");
	SWARN(silent, s, "- it is slow mode for debugging.");
#endif

	/* make data=ordered the default */
	if (!reiserfs_data_log(s) && !reiserfs_data_ordered(s) &&
	    !reiserfs_data_writeback(s)) {
		REISERFS_SB(s)->s_mount_opt |= (1 << REISERFS_DATA_ORDERED);
	}

	if (reiserfs_data_log(s)) {
		reiserfs_info(s, "using journaled data mode\n");
	} else if (reiserfs_data_ordered(s)) {
		reiserfs_info(s, "using ordered data mode\n");
	} else {
		reiserfs_info(s, "using writeback data mode\n");
	}
	if (reiserfs_barrier_flush(s)) {
		printk("reiserfs: using flush barriers\n");
	}
	// set_device_ro(s->s_dev, 1) ;
	if (journal_init(s, jdev_name, old_format, commit_max_age)) {
		SWARN(silent, s,
		      "sh-2022: reiserfs_fill_super: unable to initialize journal space");
		goto error;
	} else {
		jinit_done = 1;	/* once this is set, journal_release must be called
				 ** if we error out of the mount
				 */
	}
	if (reread_meta_blocks(s)) {
		SWARN(silent, s,
		      "jmacd-9: reiserfs_fill_super: unable to reread meta blocks after journal init");
		goto error;
	}

	if (replay_only(s))
		goto error;

	if (bdev_read_only(s->s_bdev) && !(s->s_flags & MS_RDONLY)) {
		SWARN(silent, s,
		      "clm-7000: Detected readonly device, marking FS readonly");
		s->s_flags |= MS_RDONLY;
	}
	args.objectid = REISERFS_ROOT_OBJECTID;
	args.dirid = REISERFS_ROOT_PARENT_OBJECTID;
	root_inode =
	    iget5_locked(s, REISERFS_ROOT_OBJECTID, reiserfs_find_actor,
			 reiserfs_init_locked_inode, (void *)(&args));
	if (!root_inode) {
		SWARN(silent, s,
		      "jmacd-10: reiserfs_fill_super: get root inode failed");
		goto error;
	}

	if (root_inode->i_state & I_NEW) {
		reiserfs_read_locked_inode(root_inode, &args);
		unlock_new_inode(root_inode);
	}

	s->s_root = d_alloc_root(root_inode);
	if (!s->s_root) {
		iput(root_inode);
		goto error;
	}
	// define and initialize hash function
	sbi->s_hash_function = hash_function(s);
	if (sbi->s_hash_function == NULL) {
		dput(s->s_root);
		s->s_root = NULL;
		goto error;
	}

	if (is_reiserfs_3_5(rs)
	    || (is_reiserfs_jr(rs) && SB_VERSION(s) == REISERFS_VERSION_1))
		set_bit(REISERFS_3_5, &(sbi->s_properties));
	else if (old_format)
		set_bit(REISERFS_OLD_FORMAT, &(sbi->s_properties));
	else
		set_bit(REISERFS_3_6, &(sbi->s_properties));

	if (!(s->s_flags & MS_RDONLY)) {

		errval = journal_begin(&th, s, 1);
		if (errval) {
			dput(s->s_root);
			s->s_root = NULL;
			goto error;
		}
		reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);

		set_sb_umount_state(rs, REISERFS_ERROR_FS);
		set_sb_fs_state(rs, 0);

		/* Clear out s_bmap_nr if it would wrap. We can handle this
		 * case, but older revisions can't. This will cause the
		 * file system to fail mount on those older implementations,
		 * avoiding corruption. -jeffm */
		if (bmap_would_wrap(reiserfs_bmap_count(s)) &&
		    sb_bmap_nr(rs) != 0) {
			reiserfs_warning(s, "super-2030: This file system "
					"claims to use %u bitmap blocks in "
					"its super block, but requires %u. "
					"Clearing to zero.", sb_bmap_nr(rs),
					reiserfs_bmap_count(s));

			set_sb_bmap_nr(rs, 0);
		}

		if (old_format_only(s)) {
			/* filesystem of format 3.5 either with standard or non-standard
			   journal */
			if (convert_reiserfs(s)) {
				/* and -o conv is given */
				if (!silent)
					reiserfs_info(s,
						      "converting 3.5 filesystem to the 3.6 format");

				if (is_reiserfs_3_5(rs))
					/* put magic string of 3.6 format. 2.2 will not be able to
					   mount this filesystem anymore */
					memcpy(rs->s_v1.s_magic,
					       reiserfs_3_6_magic_string,
					       sizeof
					       (reiserfs_3_6_magic_string));

				set_sb_version(rs, REISERFS_VERSION_2);
				reiserfs_convert_objectid_map_v1(s);
				set_bit(REISERFS_3_6, &(sbi->s_properties));
				clear_bit(REISERFS_3_5, &(sbi->s_properties));
			} else if (!silent) {
				reiserfs_info(s, "using 3.5.x disk format\n");
			}
		}

		journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
		errval = journal_end(&th, s, 1);
		if (errval) {
			dput(s->s_root);