[net-next-2.6.git] / fs / reiserfs / objectid.c

/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

#include <linux/string.h>
#include <linux/random.h>
#include <linux/time.h>
#include <linux/reiserfs_fs.h>
#include <linux/reiserfs_fs_sb.h>

// find where objectid map starts
#define objectid_map(s,rs) (old_format_only (s) ? \
                         (__le32 *)((struct reiserfs_super_block_v1 *)(rs) + 1) :\
			 (__le32 *)((rs) + 1))

#ifdef CONFIG_REISERFS_CHECK

static void check_objectid_map(struct super_block *s, __le32 * map)
{
	if (le32_to_cpu(map[0]) != 1)
		reiserfs_panic(s, "vs-15010", "map corrupted: %lx",
			       (long unsigned int)le32_to_cpu(map[0]));

	// FIXME: add something else here
}

#else
static void check_objectid_map(struct super_block *s, __le32 * map)
{;
}
#endif

/* When we allocate objectids we allocate the first unused objectid.
   Each sequence of objectids in use (the odd sequences) is followed
   by a sequence of objectids not in use (the even sequences).  We
   only need to record the last objectid in each of these sequences
   (both the odd and even sequences) in order to fully define the
   boundaries of the sequences.  A consequence of allocating the first
   objectid not in use is that under most conditions this scheme is
   extremely compact.  The exception is immediately after a sequence
   of operations which deletes a large number of objects of
   non-sequential objectids, and even then it will become compact
   again as soon as more objects are created.  Note that many
   interesting optimizations of layout could result from complicating
   objectid assignment, but we have deferred making them for now. */

/* get unique object identifier */
__u32 reiserfs_get_unused_objectid(struct reiserfs_transaction_handle *th)
{
	struct super_block *s = th->t_super;
	struct reiserfs_super_block *rs = SB_DISK_SUPER_BLOCK(s);
	__le32 *map = objectid_map(s, rs);
	__u32 unused_objectid;

	BUG_ON(!th->t_trans_id);

	check_objectid_map(s, map);

	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
	/* comment needed -Hans */
	unused_objectid = le32_to_cpu(map[1]);
	if (unused_objectid == U32_MAX) {
		reiserfs_warning(s, "reiserfs-15100", "no more object ids");
		reiserfs_restore_prepared_buffer(s, SB_BUFFER_WITH_SB(s));
		return 0;
	}

	/* This incrementation allocates the first unused objectid. That
	   is to say, the first entry on the objectid map is the first
	   unused objectid, and by incrementing it we use it.  See below
	   where we check to see if we eliminated a sequence of unused
	   objectids.... */
	map[1] = cpu_to_le32(unused_objectid + 1);

	/* Now we check to see if we eliminated the last remaining member of
	   the first even sequence (and can eliminate the sequence by
	   eliminating its last objectid from oids), and can collapse the
	   first two odd sequences into one sequence.  If so, then the net
	   result is to eliminate a pair of objectids from oids.  We do this
	   by shifting the entire map to the left. */
	if (sb_oid_cursize(rs) > 2 && map[1] == map[2]) {
		memmove(map + 1, map + 3,
			(sb_oid_cursize(rs) - 3) * sizeof(__u32));
		set_sb_oid_cursize(rs, sb_oid_cursize(rs) - 2);
	}

	journal_mark_dirty(th, s, SB_BUFFER_WITH_SB(s));
	return unused_objectid;
}

/* makes object identifier unused */
void reiserfs_release_objectid(struct reiserfs_transaction_handle *th,
			       __u32 objectid_to_release)
{
	struct super_block *s = th->t_super;
	struct reiserfs_super_block *rs = SB_DISK_SUPER_BLOCK(s);
	__le32 *map = objectid_map(s, rs);
	int i = 0;

	BUG_ON(!th->t_trans_id);
	//return;
	check_objectid_map(s, map);

	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
	journal_mark_dirty(th, s, SB_BUFFER_WITH_SB(s));

	/* start at the beginning of the objectid map (i = 0) and go to
	   the end of it (i = disk_sb->s_oid_cursize).  Linear search is
	   what we use, though it is possible that binary search would be
	   more efficient after performing lots of deletions (which is
	   when oids is large.)  We only check even i's. */
	while (i < sb_oid_cursize(rs)) {
		if (objectid_to_release == le32_to_cpu(map[i])) {
			/* This incrementation unallocates the objectid. */
			//map[i]++;
			le32_add_cpu(&map[i], 1);

			/* Did we unallocate the last member of an odd sequence, and can shrink oids? */
			if (map[i] == map[i + 1]) {
				/* shrink objectid map */
				memmove(map + i, map + i + 2,
					(sb_oid_cursize(rs) - i -
					 2) * sizeof(__u32));
				//disk_sb->s_oid_cursize -= 2;
				set_sb_oid_cursize(rs, sb_oid_cursize(rs) - 2);

				RFALSE(sb_oid_cursize(rs) < 2 ||
				       sb_oid_cursize(rs) > sb_oid_maxsize(rs),
				       "vs-15005: objectid map corrupted cur_size == %d (max == %d)",
				       sb_oid_cursize(rs), sb_oid_maxsize(rs));
			}
			return;
		}

		if (objectid_to_release > le32_to_cpu(map[i]) &&
		    objectid_to_release < le32_to_cpu(map[i + 1])) {
			/* size of objectid map is not changed */
			if (objectid_to_release + 1 == le32_to_cpu(map[i + 1])) {
				//objectid_map[i+1]--;
				le32_add_cpu(&map[i + 1], -1);
				return;
			}

			/* JDM comparing two little-endian values for equality -- safe */
			if (sb_oid_cursize(rs) == sb_oid_maxsize(rs)) {
				/* objectid map must be expanded, but there is no space */
				PROC_INFO_INC(s, leaked_oid);
				return;
			}

			/* expand the objectid map */
			memmove(map + i + 3, map + i + 1,
				(sb_oid_cursize(rs) - i - 1) * sizeof(__u32));
			map[i + 1] = cpu_to_le32(objectid_to_release);
			map[i + 2] = cpu_to_le32(objectid_to_release + 1);
			set_sb_oid_cursize(rs, sb_oid_cursize(rs) + 2);
			return;
		}
		i += 2;
	}

	reiserfs_error(s, "vs-15011", "tried to free free object id (%lu)",
		       (long unsigned)objectid_to_release);
}

int reiserfs_convert_objectid_map_v1(struct super_block *s)
{
	struct reiserfs_super_block *disk_sb = SB_DISK_SUPER_BLOCK(s);
	int cur_size = sb_oid_cursize(disk_sb);
	int new_size = (s->s_blocksize - SB_SIZE) / sizeof(__u32) / 2 * 2;
	int old_max = sb_oid_maxsize(disk_sb);
	struct reiserfs_super_block_v1 *disk_sb_v1;
	__le32 *objectid_map, *new_objectid_map;
	int i;

	disk_sb_v1 =
	    (struct reiserfs_super_block_v1 *)(SB_BUFFER_WITH_SB(s)->b_data);
	objectid_map = (__le32 *) (disk_sb_v1 + 1);
	new_objectid_map = (__le32 *) (disk_sb + 1);

	if (cur_size > new_size) {
		/* mark everyone used that was listed as free at the end of the objectid
		 ** map
		 */
		objectid_map[new_size - 1] = objectid_map[cur_size - 1];
		set_sb_oid_cursize(disk_sb, new_size);
	}
	/* move the smaller objectid map past the end of the new super */
	for (i = new_size - 1; i >= 0; i--) {
		objectid_map[i + (old_max - new_size)] = objectid_map[i];
	}

	/* set the max size so we don't overflow later */
	set_sb_oid_maxsize(disk_sb, new_size);

	/* Zero out label and generate random UUID */
	memset(disk_sb->s_label, 0, sizeof(disk_sb->s_label));
	generate_random_uuid(disk_sb->s_uuid);

	/* finally, zero out the unused chunk of the new super */
	memset(disk_sb->s_unused, 0, sizeof(disk_sb->s_unused));
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
	3	*/
	4
1da177e4 LT	5	#include <linux/string.h>
	6	#include <linux/random.h>
	7	#include <linux/time.h>
	8	#include <linux/reiserfs_fs.h>
	9	#include <linux/reiserfs_fs_sb.h>
	10
	11	// find where objectid map starts
	12	#define objectid_map(s,rs) (old_format_only (s) ? \
3e8962be AV	13	(__le32 )((struct reiserfs_super_block_v1 )(rs) + 1) :\
3e8962be AV	14	(__le32 *)((rs) + 1))
1da177e4	15
1da177e4 LT	16	#ifdef CONFIG_REISERFS_CHECK
1da177e4 LT	17
bd4c625c	18	static void check_objectid_map(struct super_block s, __le32 map)
1da177e4	19	{
bd4c625c	20	if (le32_to_cpu(map[0]) != 1)
c3a9c210	21	reiserfs_panic(s, "vs-15010", "map corrupted: %lx",
bd4c625c	22	(long unsigned int)le32_to_cpu(map[0]));
1da177e4	23
bd4c625c	24	// FIXME: add something else here
1da177e4 LT	25	}
	26
	27	#else
bd4c625c LT	28	static void check_objectid_map(struct super_block s, __le32 map)
	29	{;
	30	}
1da177e4 LT	31	#endif
1da177e4 LT	32
1da177e4 LT	33	/* When we allocate objectids we allocate the first unused objectid.
	34	Each sequence of objectids in use (the odd sequences) is followed
	35	by a sequence of objectids not in use (the even sequences). We
	36	only need to record the last objectid in each of these sequences
	37	(both the odd and even sequences) in order to fully define the
	38	boundaries of the sequences. A consequence of allocating the first
	39	objectid not in use is that under most conditions this scheme is
	40	extremely compact. The exception is immediately after a sequence
	41	of operations which deletes a large number of objects of
	42	non-sequential objectids, and even then it will become compact
	43	again as soon as more objects are created. Note that many
	44	interesting optimizations of layout could result from complicating
	45	objectid assignment, but we have deferred making them for now. */
	46
1da177e4	47	/* get unique object identifier */
bd4c625c	48	__u32 reiserfs_get_unused_objectid(struct reiserfs_transaction_handle *th)
1da177e4	49	{
bd4c625c LT	50	struct super_block *s = th->t_super;
	51	struct reiserfs_super_block *rs = SB_DISK_SUPER_BLOCK(s);
	52	__le32 *map = objectid_map(s, rs);
	53	__u32 unused_objectid;
	54
	55	BUG_ON(!th->t_trans_id);
	56
	57	check_objectid_map(s, map);
	58
	59	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
	60	/* comment needed -Hans */
	61	unused_objectid = le32_to_cpu(map[1]);
	62	if (unused_objectid == U32_MAX) {
45b03d5e	63	reiserfs_warning(s, "reiserfs-15100", "no more object ids");
bd4c625c LT	64	reiserfs_restore_prepared_buffer(s, SB_BUFFER_WITH_SB(s));
	65	return 0;
	66	}
1da177e4	67
bd4c625c LT	68	/* This incrementation allocates the first unused objectid. That
	69	is to say, the first entry on the objectid map is the first
	70	unused objectid, and by incrementing it we use it. See below
	71	where we check to see if we eliminated a sequence of unused
	72	objectids.... */
	73	map[1] = cpu_to_le32(unused_objectid + 1);
	74
	75	/* Now we check to see if we eliminated the last remaining member of
	76	the first even sequence (and can eliminate the sequence by
	77	eliminating its last objectid from oids), and can collapse the
	78	first two odd sequences into one sequence. If so, then the net
	79	result is to eliminate a pair of objectids from oids. We do this
	80	by shifting the entire map to the left. */
	81	if (sb_oid_cursize(rs) > 2 && map[1] == map[2]) {
	82	memmove(map + 1, map + 3,
	83	(sb_oid_cursize(rs) - 3) * sizeof(__u32));
	84	set_sb_oid_cursize(rs, sb_oid_cursize(rs) - 2);
	85	}
1da177e4	86
bd4c625c LT	87	journal_mark_dirty(th, s, SB_BUFFER_WITH_SB(s));
bd4c625c LT	88	return unused_objectid;
1da177e4 LT	89	}
1da177e4 LT	90
1da177e4	91	/* makes object identifier unused */
bd4c625c LT	92	void reiserfs_release_objectid(struct reiserfs_transaction_handle *th,
bd4c625c LT	93	__u32 objectid_to_release)
1da177e4	94	{
bd4c625c LT	95	struct super_block *s = th->t_super;
	96	struct reiserfs_super_block *rs = SB_DISK_SUPER_BLOCK(s);
	97	__le32 *map = objectid_map(s, rs);
	98	int i = 0;
	99
	100	BUG_ON(!th->t_trans_id);
	101	//return;
	102	check_objectid_map(s, map);
	103
	104	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
	105	journal_mark_dirty(th, s, SB_BUFFER_WITH_SB(s));
	106
	107	/* start at the beginning of the objectid map (i = 0) and go to
	108	the end of it (i = disk_sb->s_oid_cursize). Linear search is
	109	what we use, though it is possible that binary search would be
	110	more efficient after performing lots of deletions (which is
	111	when oids is large.) We only check even i's. */
	112	while (i < sb_oid_cursize(rs)) {
	113	if (objectid_to_release == le32_to_cpu(map[i])) {
	114	/* This incrementation unallocates the objectid. */
	115	//map[i]++;
9e902df6	116	le32_add_cpu(&map[i], 1);
bd4c625c LT	117
	118	/* Did we unallocate the last member of an odd sequence, and can shrink oids? */
	119	if (map[i] == map[i + 1]) {
	120	/* shrink objectid map */
	121	memmove(map + i, map + i + 2,
	122	(sb_oid_cursize(rs) - i -
	123	2) * sizeof(__u32));
	124	//disk_sb->s_oid_cursize -= 2;
	125	set_sb_oid_cursize(rs, sb_oid_cursize(rs) - 2);
	126
	127	RFALSE(sb_oid_cursize(rs) < 2 \|\|
	128	sb_oid_cursize(rs) > sb_oid_maxsize(rs),
	129	"vs-15005: objectid map corrupted cur_size == %d (max == %d)",
	130	sb_oid_cursize(rs), sb_oid_maxsize(rs));
	131	}
	132	return;
	133	}
	134
	135	if (objectid_to_release > le32_to_cpu(map[i]) &&
	136	objectid_to_release < le32_to_cpu(map[i + 1])) {
	137	/* size of objectid map is not changed */
	138	if (objectid_to_release + 1 == le32_to_cpu(map[i + 1])) {
	139	//objectid_map[i+1]--;
9e902df6	140	le32_add_cpu(&map[i + 1], -1);
bd4c625c LT	141	return;
	142	}
	143
	144	/* JDM comparing two little-endian values for equality -- safe */
	145	if (sb_oid_cursize(rs) == sb_oid_maxsize(rs)) {
	146	/* objectid map must be expanded, but there is no space */
	147	PROC_INFO_INC(s, leaked_oid);
	148	return;
	149	}
	150
	151	/* expand the objectid map */
	152	memmove(map + i + 3, map + i + 1,
	153	(sb_oid_cursize(rs) - i - 1) * sizeof(__u32));
	154	map[i + 1] = cpu_to_le32(objectid_to_release);
	155	map[i + 2] = cpu_to_le32(objectid_to_release + 1);
	156	set_sb_oid_cursize(rs, sb_oid_cursize(rs) + 2);
	157	return;
	158	}
	159	i += 2;
1da177e4 LT	160	}
1da177e4 LT	161
0030b645 JM	162	reiserfs_error(s, "vs-15011", "tried to free free object id (%lu)",
0030b645 JM	163	(long unsigned)objectid_to_release);
bd4c625c	164	}
1da177e4	165
bd4c625c LT	166	int reiserfs_convert_objectid_map_v1(struct super_block *s)
	167	{
	168	struct reiserfs_super_block *disk_sb = SB_DISK_SUPER_BLOCK(s);
	169	int cur_size = sb_oid_cursize(disk_sb);
	170	int new_size = (s->s_blocksize - SB_SIZE) / sizeof(__u32) / 2 * 2;
	171	int old_max = sb_oid_maxsize(disk_sb);
	172	struct reiserfs_super_block_v1 *disk_sb_v1;
	173	__le32 objectid_map, new_objectid_map;
	174	int i;
	175
	176	disk_sb_v1 =
	177	(struct reiserfs_super_block_v1 *)(SB_BUFFER_WITH_SB(s)->b_data);
	178	objectid_map = (__le32 *) (disk_sb_v1 + 1);
	179	new_objectid_map = (__le32 *) (disk_sb + 1);
	180
	181	if (cur_size > new_size) {
	182	/* mark everyone used that was listed as free at the end of the objectid
0222e657	183	** map
bd4c625c LT	184	*/
	185	objectid_map[new_size - 1] = objectid_map[cur_size - 1];
	186	set_sb_oid_cursize(disk_sb, new_size);
	187	}
	188	/* move the smaller objectid map past the end of the new super */
	189	for (i = new_size - 1; i >= 0; i--) {
	190	objectid_map[i + (old_max - new_size)] = objectid_map[i];
1da177e4	191	}
1da177e4	192
bd4c625c LT	193	/* set the max size so we don't overflow later */
bd4c625c LT	194	set_sb_oid_maxsize(disk_sb, new_size);
1da177e4	195
bd4c625c LT	196	/* Zero out label and generate random UUID */
	197	memset(disk_sb->s_label, 0, sizeof(disk_sb->s_label));
	198	generate_random_uuid(disk_sb->s_uuid);
1da177e4	199
bd4c625c LT	200	/* finally, zero out the unused chunk of the new super */
	201	memset(disk_sb->s_unused, 0, sizeof(disk_sb->s_unused));
	202	return 0;
1da177e4	203	}