1 files changed, 269 insertions, 0 deletions
diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c
new file mode 100644
index 000000000000..dc6a4e4abcdc
--- /dev/null
+++ b/fs/minix/bitmap.c
@@ -0,0 +1,269 @@
+/*
+ *  linux/fs/minix/bitmap.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * Modified for 680x0 by Hamish Macdonald
+ * Fixed for 680x0 by Andreas Schwab
+ */
+
+/* bitmap.c contains the code that handles the inode and block bitmaps */
+
+#include "minix.h"
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <linux/bitops.h>
+
+static int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 };
+
+static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits)
+{
+	unsigned i, j, sum = 0;
+	struct buffer_head *bh;
+  
+	for (i=0; i<numblocks-1; i++) {
+		if (!(bh=map[i])) 
+			return(0);
+		for (j=0; j<BLOCK_SIZE; j++)
+			sum += nibblemap[bh->b_data[j] & 0xf]
+				+ nibblemap[(bh->b_data[j]>>4) & 0xf];
+	}
+
+	if (numblocks==0 || !(bh=map[numblocks-1]))
+		return(0);
+	i = ((numbits-(numblocks-1)*BLOCK_SIZE*8)/16)*2;
+	for (j=0; j<i; j++) {
+		sum += nibblemap[bh->b_data[j] & 0xf]
+			+ nibblemap[(bh->b_data[j]>>4) & 0xf];
+	}
+
+	i = numbits%16;
+	if (i!=0) {
+		i = *(__u16 *)(&bh->b_data[j]) | ~((1<<i) - 1);
+		sum += nibblemap[i & 0xf] + nibblemap[(i>>4) & 0xf];
+		sum += nibblemap[(i>>8) & 0xf] + nibblemap[(i>>12) & 0xf];
+	}
+	return(sum);
+}
+
+void minix_free_block(struct inode * inode, int block)
+{
+	struct super_block * sb = inode->i_sb;
+	struct minix_sb_info * sbi = minix_sb(sb);
+	struct buffer_head * bh;
+	unsigned int bit,zone;
+
+	if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
+		printk("trying to free block not in datazone\n");
+		return;
+	}
+	zone = block - sbi->s_firstdatazone + 1;
+	bit = zone & 8191;
+	zone >>= 13;
+	if (zone >= sbi->s_zmap_blocks) {
+		printk("minix_free_block: nonexistent bitmap buffer\n");
+		return;
+	}
+	bh = sbi->s_zmap[zone];
+	lock_kernel();
+	if (!minix_test_and_clear_bit(bit,bh->b_data))
+		printk("free_block (%s:%d): bit already cleared\n",
+		       sb->s_id, block);
+	unlock_kernel();
+	mark_buffer_dirty(bh);
+	return;
+}
+
+int minix_new_block(struct inode * inode)
+{
+	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
+	int i;
+
+	for (i = 0; i < sbi->s_zmap_blocks; i++) {
+		struct buffer_head *bh = sbi->s_zmap[i];
+		int j;
+
+		lock_kernel();
+		if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192) {
+			minix_set_bit(j,bh->b_data);
+			unlock_kernel();
+			mark_buffer_dirty(bh);
+			j += i*8192 + sbi->s_firstdatazone-1;
+			if (j < sbi->s_firstdatazone || j >= sbi->s_nzones)
+				break;
+			return j;
+		}
+		unlock_kernel();
+	}
+	return 0;
+}
+
+unsigned long minix_count_free_blocks(struct minix_sb_info *sbi)
+{
+	return (count_free(sbi->s_zmap, sbi->s_zmap_blocks,
+		sbi->s_nzones - sbi->s_firstdatazone + 1)
+		<< sbi->s_log_zone_size);
+}
+
+struct minix_inode *
+minix_V1_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
+{
+	int block;
+	struct minix_sb_info *sbi = minix_sb(sb);
+	struct minix_inode *p;
+
+	if (!ino || ino > sbi->s_ninodes) {
+		printk("Bad inode number on dev %s: %ld is out of range\n",
+		       sb->s_id, (long)ino);
+		return NULL;
+	}
+	ino--;
+	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
+		 ino / MINIX_INODES_PER_BLOCK;
+	*bh = sb_bread(sb, block);
+	if (!*bh) {
+		printk("unable to read i-node block\n");
+		return NULL;
+	}
+	p = (void *)(*bh)->b_data;
+	return p + ino % MINIX_INODES_PER_BLOCK;
+}
+
+struct minix2_inode *
+minix_V2_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
+{
+	int block;
+	struct minix_sb_info *sbi = minix_sb(sb);
+	struct minix2_inode *p;
+
+	*bh = NULL;
+	if (!ino || ino > sbi->s_ninodes) {
+		printk("Bad inode number on dev %s: %ld is out of range\n",
+		       sb->s_id, (long)ino);
+		return NULL;
+	}
+	ino--;
+	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
+		 ino / MINIX2_INODES_PER_BLOCK;
+	*bh = sb_bread(sb, block);
+	if (!*bh) {
+		printk("unable to read i-node block\n");
+		return NULL;
+	}
+	p = (void *)(*bh)->b_data;
+	return p + ino % MINIX2_INODES_PER_BLOCK;
+}
+
+/* Clear the link count and mode of a deleted inode on disk. */
+
+static void minix_clear_inode(struct inode *inode)
+{
+	struct buffer_head *bh = NULL;
+
+	if (INODE_VERSION(inode) == MINIX_V1) {
+		struct minix_inode *raw_inode;
+		raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
+		if (raw_inode) {
+			raw_inode->i_nlinks = 0;
+			raw_inode->i_mode = 0;
+		}
+	} else {
+		struct minix2_inode *raw_inode;
+		raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
+		if (raw_inode) {
+			raw_inode->i_nlinks = 0;
+			raw_inode->i_mode = 0;
+		}
+	}
+	if (bh) {
+		mark_buffer_dirty(bh);
+		brelse (bh);
+	}
+}
+
+void minix_free_inode(struct inode * inode)
+{
+	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
+	struct buffer_head * bh;
+	unsigned long ino;
+
+	ino = inode->i_ino;
+	if (ino < 1 || ino > sbi->s_ninodes) {
+		printk("minix_free_inode: inode 0 or nonexistent inode\n");
+		goto out;
+	}
+	if ((ino >> 13) >= sbi->s_imap_blocks) {
+		printk("minix_free_inode: nonexistent imap in superblock\n");
+		goto out;
+	}
+
+	minix_clear_inode(inode);	/* clear on-disk copy */
+
+	bh = sbi->s_imap[ino >> 13];
+	lock_kernel();
+	if (!minix_test_and_clear_bit(ino & 8191, bh->b_data))
+		printk("minix_free_inode: bit %lu already cleared.\n", ino);
+	unlock_kernel();
+	mark_buffer_dirty(bh);
+ out:
+	clear_inode(inode);		/* clear in-memory copy */
+}
+
+struct inode * minix_new_inode(const struct inode * dir, int * error)
+{
+	struct super_block *sb = dir->i_sb;
+	struct minix_sb_info *sbi = minix_sb(sb);
+	struct inode *inode = new_inode(sb);
+	struct buffer_head * bh;
+	int i,j;
+
+	if (!inode) {
+		*error = -ENOMEM;
+		return NULL;
+	}
+	j = 8192;
+	bh = NULL;
+	*error = -ENOSPC;
+	lock_kernel();
+	for (i = 0; i < sbi->s_imap_blocks; i++) {
+		bh = sbi->s_imap[i];
+		if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192)
+			break;
+	}
+	if (!bh || j >= 8192) {
+		unlock_kernel();
+		iput(inode);
+		return NULL;
+	}
+	if (minix_test_and_set_bit(j,bh->b_data)) {	/* shouldn't happen */
+		printk("new_inode: bit already set");
+		unlock_kernel();
+		iput(inode);
+		return NULL;
+	}
+	unlock_kernel();
+	mark_buffer_dirty(bh);
+	j += i*8192;
+	if (!j || j > sbi->s_ninodes) {
+		iput(inode);
+		return NULL;
+	}
+	inode->i_uid = current->fsuid;
+	inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
+	inode->i_ino = j;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+	inode->i_blocks = inode->i_blksize = 0;
+	memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
+	insert_inode_hash(inode);
+	mark_inode_dirty(inode);
+
+	*error = 0;
+	return inode;
+}
+
+unsigned long minix_count_free_inodes(struct minix_sb_info *sbi)
+{
+	return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1);
+}