1 files changed, 230 insertions, 0 deletions
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c
new file mode 100644
index 000000000..7b498a0d0
--- /dev/null
+++ b/fs/reiserfs/resize.c
@@ -0,0 +1,230 @@
+/*
+ * 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 "reiserfs.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;
+	int depth;
+
+	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 */
+	depth = reiserfs_write_unlock_nested(s);
+	bh = sb_bread(s, block_count_new - 1);
+	reiserfs_write_lock_nested(s, depth);
+	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) -
+			(reiserfs_bmap_count(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 = reiserfs_bmap_count(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");
+			return -ENOMEM;
+		}
+		/*
+		 * the new journal bitmaps are zero filled, now we copy i
+		 * 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 = min(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 =
+		    vzalloc(array_size(bmap_nr_new,
+				       sizeof(struct reiserfs_bitmap_info)));
+		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;
+		}
+		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++) {
+			int depth;
+			/*
+			 * don't use read_bitmap_block since it will cache
+			 * the uninitialized bitmap
+			 */
+			depth = reiserfs_write_unlock_nested(s);
+			bh = sb_bread(s, i * s->s_blocksize * 8);
+			reiserfs_write_lock_nested(s, depth);
+			if (!bh) {
+				vfree(bitmap);
+				return -EIO;
+			}
+			memset(bh->b_data, 0, sb_blocksize(sb));
+			reiserfs_set_le_bit(0, bh->b_data);
+			reiserfs_cache_bitmap_metadata(s, bh, bitmap + i);
+
+			set_buffer_uptodate(bh);
+			mark_buffer_dirty(bh);
+			depth = reiserfs_write_unlock_nested(s);
+			sync_dirty_buffer(bh);
+			reiserfs_write_lock_nested(s, depth);
+			/* update bitmap_info stuff */
+			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);
+		if (jerr)
+			return jerr;
+		return -EIO;
+	}
+
+	reiserfs_prepare_for_journal(s, bh, 1);
+	for (i = block_r; i < s->s_blocksize * 8; i++)
+		reiserfs_clear_le_bit(i, bh->b_data);
+	info->free_count += s->s_blocksize * 8 - block_r;
+
+	journal_mark_dirty(&th, 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);
+		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_set_le_bit(i, bh->b_data);
+	journal_mark_dirty(&th, bh);
+	brelse(bh);
+
+	info->free_count -= s->s_blocksize * 8 - block_r_new;
+	/* 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_would_wrap(bmap_nr_new) ? : bmap_nr_new);
+
+	journal_mark_dirty(&th, SB_BUFFER_WITH_SB(s));
+
+	SB_JOURNAL(s)->j_must_wait = 1;
+	return journal_end(&th);
+}