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-rw-r--r--fs/minix/bitmap.c269
1 files changed, 269 insertions, 0 deletions
diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c
new file mode 100644
index 00000000000..dc6a4e4abcd
--- /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);
+}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-23 18:42:35 +0000