[mirror_ubuntu-hirsute-kernel.git] / fs / reiserfs / resize.c

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

/* 
 * Written by Alexander Zarochentcev.
 *
 * The kernel part of the (on-line) reiserfs resizer.
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/reiserfs_fs.h>
#include <linux/reiserfs_fs_sb.h>
#include <linux/buffer_head.h>

int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
{
	int err = 0;
	struct reiserfs_super_block *sb;
	struct reiserfs_bitmap_info *bitmap;
	struct reiserfs_bitmap_info *info;
	struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s);
	struct buffer_head *bh;
	struct reiserfs_transaction_handle th;
	unsigned int bmap_nr_new, bmap_nr;
	unsigned int block_r_new, block_r;

	struct reiserfs_list_bitmap *jb;
	struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];

	unsigned long int block_count, free_blocks;
	int i;
	int copy_size;

	sb = SB_DISK_SUPER_BLOCK(s);

	if (SB_BLOCK_COUNT(s) >= block_count_new) {
		printk("can\'t shrink filesystem on-line\n");
		return -EINVAL;
	}

	/* check the device size */
	bh = sb_bread(s, block_count_new - 1);
	if (!bh) {
		printk("reiserfs_resize: can\'t read last block\n");
		return -EINVAL;
	}
	bforget(bh);

	/* old disk layout detection; those partitions can be mounted, but
	 * cannot be resized */
	if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size
	    != REISERFS_DISK_OFFSET_IN_BYTES) {
		printk
		    ("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
		return -ENOTSUPP;
	}

	/* count used bits in last bitmap block */
	block_r = SB_BLOCK_COUNT(s) - (SB_BMAP_NR(s) - 1) * s->s_blocksize * 8;

	/* count bitmap blocks in new fs */
	bmap_nr_new = block_count_new / (s->s_blocksize * 8);
	block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8;
	if (block_r_new)
		bmap_nr_new++;
	else
		block_r_new = s->s_blocksize * 8;

	/* save old values */
	block_count = SB_BLOCK_COUNT(s);
	bmap_nr = SB_BMAP_NR(s);

	/* resizing of reiserfs bitmaps (journal and real), if needed */
	if (bmap_nr_new > bmap_nr) {
		/* reallocate journal bitmaps */
		if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) {
			printk
			    ("reiserfs_resize: unable to allocate memory for journal bitmaps\n");
			unlock_super(s);
			return -ENOMEM;
		}
		/* the new journal bitmaps are zero filled, now we copy in the bitmap
		 ** node pointers from the old journal bitmap structs, and then
		 ** transfer the new data structures into the journal struct.
		 **
		 ** using the copy_size var below allows this code to work for
		 ** both shrinking and expanding the FS.
		 */
		copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr;
		copy_size =
		    copy_size * sizeof(struct reiserfs_list_bitmap_node *);
		for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) {
			struct reiserfs_bitmap_node **node_tmp;
			jb = SB_JOURNAL(s)->j_list_bitmap + i;
			memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size);

			/* just in case vfree schedules on us, copy the new
			 ** pointer into the journal struct before freeing the 
			 ** old one
			 */
			node_tmp = jb->bitmaps;
			jb->bitmaps = jbitmap[i].bitmaps;
			vfree(node_tmp);
		}

		/* allocate additional bitmap blocks, reallocate array of bitmap
		 * block pointers */
		bitmap =
		    vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
		if (!bitmap) {
			/* Journal bitmaps are still supersized, but the memory isn't
			 * leaked, so I guess it's ok */
			printk("reiserfs_resize: unable to allocate memory.\n");
			return -ENOMEM;
		}
		memset(bitmap, 0,
		       sizeof(struct reiserfs_bitmap_info) * SB_BMAP_NR(s));
		for (i = 0; i < bmap_nr; i++)
			bitmap[i] = old_bitmap[i];

		/* This doesn't go through the journal, but it doesn't have to.
		 * The changes are still atomic: We're synced up when the journal
		 * transaction begins, and the new bitmaps don't matter if the
		 * transaction fails. */
		for (i = bmap_nr; i < bmap_nr_new; i++) {
			/* don't use read_bitmap_block since it will cache
			 * the uninitialized bitmap */
			bh = sb_bread(s, i * s->s_blocksize * 8);
			memset(bh->b_data, 0, sb_blocksize(sb));
			reiserfs_test_and_set_le_bit(0, bh->b_data);
			reiserfs_cache_bitmap_metadata(s, bh, bitmap + i);

			set_buffer_uptodate(bh);
			mark_buffer_dirty(bh);
			sync_dirty_buffer(bh);
			// update bitmap_info stuff
			bitmap[i].first_zero_hint = 1;
			bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
			brelse(bh);
		}
		/* free old bitmap blocks array */
		SB_AP_BITMAP(s) = bitmap;
		vfree(old_bitmap);
	}

	/* begin transaction, if there was an error, it's fine. Yes, we have
	 * incorrect bitmaps now, but none of it is ever going to touch the
	 * disk anyway. */
	err = journal_begin(&th, s, 10);
	if (err)
		return err;

	/* Extend old last bitmap block - new blocks have been made available */
	info = SB_AP_BITMAP(s) + bmap_nr - 1;
	bh = reiserfs_read_bitmap_block(s, bmap_nr - 1);
	if (!bh) {
		int jerr = journal_end(&th, s, 10);
		if (jerr)
			return jerr;
		return -EIO;
	}

	reiserfs_prepare_for_journal(s, bh, 1);
	for (i = block_r; i < s->s_blocksize * 8; i++)
		reiserfs_test_and_clear_le_bit(i, bh->b_data);
	info->free_count += s->s_blocksize * 8 - block_r;
	if (!info->first_zero_hint)
		info->first_zero_hint = block_r;

	journal_mark_dirty(&th, s, bh);
	brelse(bh);

	/* Correct new last bitmap block - It may not be full */
	info = SB_AP_BITMAP(s) + bmap_nr_new - 1;
	bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1);
	if (!bh) {
		int jerr = journal_end(&th, s, 10);
		if (jerr)
			return jerr;
		return -EIO;
	}

	reiserfs_prepare_for_journal(s, bh, 1);
	for (i = block_r_new; i < s->s_blocksize * 8; i++)
		reiserfs_test_and_set_le_bit(i, bh->b_data);
	journal_mark_dirty(&th, s, bh);
	brelse(bh);

	info->free_count -= s->s_blocksize * 8 - block_r_new;
	/* Extreme case where last bitmap is the only valid block in itself. */
	if (!info->free_count)
		info->first_zero_hint = 0;
	/* update super */
	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
	free_blocks = SB_FREE_BLOCKS(s);
	PUT_SB_FREE_BLOCKS(s,
			   free_blocks + (block_count_new - block_count -
					  (bmap_nr_new - bmap_nr)));
	PUT_SB_BLOCK_COUNT(s, block_count_new);
	PUT_SB_BMAP_NR(s, bmap_nr_new);
	s->s_dirt = 1;

	journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));

	SB_JOURNAL(s)->j_must_wait = 1;
	return journal_end(&th, s, 10);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
	3	*/
bd4c625c	4
1da177e4 LT	5	/*
	6	* Written by Alexander Zarochentcev.
	7	*
	8	* The kernel part of the (on-line) reiserfs resizer.
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/mm.h>
	13	#include <linux/vmalloc.h>
	14	#include <linux/string.h>
	15	#include <linux/errno.h>
	16	#include <linux/reiserfs_fs.h>
	17	#include <linux/reiserfs_fs_sb.h>
	18	#include <linux/buffer_head.h>
	19
bd4c625c	20	int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
1da177e4	21	{
bd4c625c LT	22	int err = 0;
	23	struct reiserfs_super_block *sb;
	24	struct reiserfs_bitmap_info *bitmap;
0b3dc17b	25	struct reiserfs_bitmap_info *info;
1da177e4	26	struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s);
bd4c625c	27	struct buffer_head *bh;
1da177e4 LT	28	struct reiserfs_transaction_handle th;
	29	unsigned int bmap_nr_new, bmap_nr;
	30	unsigned int block_r_new, block_r;
bd4c625c LT	31
bd4c625c LT	32	struct reiserfs_list_bitmap *jb;
1da177e4	33	struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];
bd4c625c	34
1da177e4 LT	35	unsigned long int block_count, free_blocks;
1da177e4 LT	36	int i;
bd4c625c	37	int copy_size;
1da177e4 LT	38
	39	sb = SB_DISK_SUPER_BLOCK(s);
	40
	41	if (SB_BLOCK_COUNT(s) >= block_count_new) {
	42	printk("can\'t shrink filesystem on-line\n");
	43	return -EINVAL;
	44	}
	45
	46	/* check the device size */
	47	bh = sb_bread(s, block_count_new - 1);
	48	if (!bh) {
	49	printk("reiserfs_resize: can\'t read last block\n");
	50	return -EINVAL;
bd4c625c	51	}
1da177e4 LT	52	bforget(bh);
	53
	54	/* old disk layout detection; those partitions can be mounted, but
	55	* cannot be resized */
bd4c625c LT	56	if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size
	57	!= REISERFS_DISK_OFFSET_IN_BYTES) {
	58	printk
	59	("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
1da177e4 LT	60	return -ENOTSUPP;
1da177e4 LT	61	}
bd4c625c	62
1da177e4	63	/* count used bits in last bitmap block */
bd4c625c LT	64	block_r = SB_BLOCK_COUNT(s) - (SB_BMAP_NR(s) - 1) * s->s_blocksize * 8;
bd4c625c LT	65
1da177e4	66	/* count bitmap blocks in new fs */
bd4c625c	67	bmap_nr_new = block_count_new / (s->s_blocksize * 8);
1da177e4	68	block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8;
bd4c625c	69	if (block_r_new)
1da177e4 LT	70	bmap_nr_new++;
	71	else
	72	block_r_new = s->s_blocksize * 8;
	73
	74	/* save old values */
	75	block_count = SB_BLOCK_COUNT(s);
bd4c625c	76	bmap_nr = SB_BMAP_NR(s);
1da177e4 LT	77
1da177e4 LT	78	/* resizing of reiserfs bitmaps (journal and real), if needed */
bd4c625c LT	79	if (bmap_nr_new > bmap_nr) {
	80	/* reallocate journal bitmaps */
	81	if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) {
	82	printk
	83	("reiserfs_resize: unable to allocate memory for journal bitmaps\n");
	84	unlock_super(s);
	85	return -ENOMEM;
	86	}
	87	/* the new journal bitmaps are zero filled, now we copy in the bitmap
	88	** node pointers from the old journal bitmap structs, and then
	89	** transfer the new data structures into the journal struct.
	90	**
	91	** using the copy_size var below allows this code to work for
	92	** both shrinking and expanding the FS.
	93	*/
	94	copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr;
	95	copy_size =
	96	copy_size * sizeof(struct reiserfs_list_bitmap_node *);
	97	for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) {
	98	struct reiserfs_bitmap_node **node_tmp;
	99	jb = SB_JOURNAL(s)->j_list_bitmap + i;
	100	memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size);
	101
	102	/* just in case vfree schedules on us, copy the new
	103	** pointer into the journal struct before freeing the
	104	** old one
	105	*/
	106	node_tmp = jb->bitmaps;
	107	jb->bitmaps = jbitmap[i].bitmaps;
	108	vfree(node_tmp);
	109	}
	110
	111	/* allocate additional bitmap blocks, reallocate array of bitmap
	112	* block pointers */
	113	bitmap =
	114	vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
	115	if (!bitmap) {
	116	/* Journal bitmaps are still supersized, but the memory isn't
	117	* leaked, so I guess it's ok */
	118	printk("reiserfs_resize: unable to allocate memory.\n");
	119	return -ENOMEM;
	120	}
	121	memset(bitmap, 0,
	122	sizeof(struct reiserfs_bitmap_info) * SB_BMAP_NR(s));
	123	for (i = 0; i < bmap_nr; i++)
	124	bitmap[i] = old_bitmap[i];
	125
	126	/* This doesn't go through the journal, but it doesn't have to.
	127	* The changes are still atomic: We're synced up when the journal
	128	* transaction begins, and the new bitmaps don't matter if the
	129	* transaction fails. */
	130	for (i = bmap_nr; i < bmap_nr_new; i++) {
5065227b JM	131	/* don't use read_bitmap_block since it will cache
	132	* the uninitialized bitmap */
	133	bh = sb_bread(s, i * s->s_blocksize * 8);
0b3dc17b JM	134	memset(bh->b_data, 0, sb_blocksize(sb));
0b3dc17b JM	135	reiserfs_test_and_set_le_bit(0, bh->b_data);
6f01046b	136	reiserfs_cache_bitmap_metadata(s, bh, bitmap + i);
0b3dc17b JM	137
	138	set_buffer_uptodate(bh);
	139	mark_buffer_dirty(bh);
	140	sync_dirty_buffer(bh);
bd4c625c LT	141	// update bitmap_info stuff
	142	bitmap[i].first_zero_hint = 1;
	143	bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
0b3dc17b	144	brelse(bh);
bd4c625c LT	145	}
	146	/* free old bitmap blocks array */
	147	SB_AP_BITMAP(s) = bitmap;
	148	vfree(old_bitmap);
1da177e4	149	}
bd4c625c	150
1da177e4 LT	151	/* begin transaction, if there was an error, it's fine. Yes, we have
	152	* incorrect bitmaps now, but none of it is ever going to touch the
	153	* disk anyway. */
	154	err = journal_begin(&th, s, 10);
	155	if (err)
bd4c625c	156	return err;
1da177e4	157
0b3dc17b JM	158	/* Extend old last bitmap block - new blocks have been made available */
0b3dc17b JM	159	info = SB_AP_BITMAP(s) + bmap_nr - 1;
5065227b JM	160	bh = reiserfs_read_bitmap_block(s, bmap_nr - 1);
	161	if (!bh) {
	162	int jerr = journal_end(&th, s, 10);
	163	if (jerr)
	164	return jerr;
	165	return -EIO;
	166	}
0b3dc17b JM	167
0b3dc17b JM	168	reiserfs_prepare_for_journal(s, bh, 1);
1da177e4	169	for (i = block_r; i < s->s_blocksize * 8; i++)
0b3dc17b JM	170	reiserfs_test_and_clear_le_bit(i, bh->b_data);
	171	info->free_count += s->s_blocksize * 8 - block_r;
	172	if (!info->first_zero_hint)
	173	info->first_zero_hint = block_r;
	174
	175	journal_mark_dirty(&th, s, bh);
	176	brelse(bh);
1da177e4	177
0b3dc17b JM	178	/* Correct new last bitmap block - It may not be full */
0b3dc17b JM	179	info = SB_AP_BITMAP(s) + bmap_nr_new - 1;
5065227b JM	180	bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1);
	181	if (!bh) {
	182	int jerr = journal_end(&th, s, 10);
	183	if (jerr)
	184	return jerr;
	185	return -EIO;
	186	}
1da177e4	187
0b3dc17b	188	reiserfs_prepare_for_journal(s, bh, 1);
1da177e4	189	for (i = block_r_new; i < s->s_blocksize * 8; i++)
0b3dc17b JM	190	reiserfs_test_and_set_le_bit(i, bh->b_data);
	191	journal_mark_dirty(&th, s, bh);
	192	brelse(bh);
bd4c625c	193
0b3dc17b	194	info->free_count -= s->s_blocksize * 8 - block_r_new;
1da177e4	195	/* Extreme case where last bitmap is the only valid block in itself. */
0b3dc17b JM	196	if (!info->free_count)
0b3dc17b JM	197	info->first_zero_hint = 0;
bd4c625c LT	198	/* update super */
bd4c625c LT	199	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
1da177e4	200	free_blocks = SB_FREE_BLOCKS(s);
bd4c625c LT	201	PUT_SB_FREE_BLOCKS(s,
	202	free_blocks + (block_count_new - block_count -
	203	(bmap_nr_new - bmap_nr)));
1da177e4 LT	204	PUT_SB_BLOCK_COUNT(s, block_count_new);
	205	PUT_SB_BMAP_NR(s, bmap_nr_new);
	206	s->s_dirt = 1;
	207
	208	journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
bd4c625c	209
1da177e4 LT	210	SB_JOURNAL(s)->j_must_wait = 1;
	211	return journal_end(&th, s, 10);
	212	}