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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/qnx4/bitmap.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/qnx4/bitmap.c')
-rw-r--r--fs/qnx4/bitmap.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/fs/qnx4/bitmap.c b/fs/qnx4/bitmap.c
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+++ b/fs/qnx4/bitmap.c
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+/*
+ * QNX4 file system, Linux implementation.
+ *
+ * Version : 0.2.1
+ *
+ * Using parts of the xiafs filesystem.
+ *
+ * History :
+ *
+ * 28-05-1998 by Richard Frowijn : first release.
+ * 20-06-1998 by Frank Denis : basic optimisations.
+ * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
+ * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
+ */
+
+#include <linux/config.h>
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/qnx4_fs.h>
+#include <linux/stat.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/buffer_head.h>
+#include <linux/bitops.h>
+
+int qnx4_new_block(struct super_block *sb)
+{
+ return 0;
+}
+
+static void count_bits(register const char *bmPart, register int size,
+ int *const tf)
+{
+ char b;
+ int tot = *tf;
+
+ if (size > QNX4_BLOCK_SIZE) {
+ size = QNX4_BLOCK_SIZE;
+ }
+ do {
+ b = *bmPart++;
+ if ((b & 1) == 0)
+ tot++;
+ if ((b & 2) == 0)
+ tot++;
+ if ((b & 4) == 0)
+ tot++;
+ if ((b & 8) == 0)
+ tot++;
+ if ((b & 16) == 0)
+ tot++;
+ if ((b & 32) == 0)
+ tot++;
+ if ((b & 64) == 0)
+ tot++;
+ if ((b & 128) == 0)
+ tot++;
+ size--;
+ } while (size != 0);
+ *tf = tot;
+}
+
+unsigned long qnx4_count_free_blocks(struct super_block *sb)
+{
+ int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
+ int total = 0;
+ int total_free = 0;
+ int offset = 0;
+ int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
+ struct buffer_head *bh;
+
+ while (total < size) {
+ if ((bh = sb_bread(sb, start + offset)) == NULL) {
+ printk("qnx4: I/O error in counting free blocks\n");
+ break;
+ }
+ count_bits(bh->b_data, size - total, &total_free);
+ brelse(bh);
+ total += QNX4_BLOCK_SIZE;
+ offset++;
+ }
+
+ return total_free;
+}
+
+#ifdef CONFIG_QNX4FS_RW
+
+int qnx4_is_free(struct super_block *sb, long block)
+{
+ int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
+ int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
+ struct buffer_head *bh;
+ const char *g;
+ int ret = -EIO;
+
+ start += block / (QNX4_BLOCK_SIZE * 8);
+ QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n",
+ (unsigned long) block, (unsigned long) start));
+ (void) size; /* CHECKME */
+ bh = sb_bread(sb, start);
+ if (bh == NULL) {
+ return -EIO;
+ }
+ g = bh->b_data + (block % QNX4_BLOCK_SIZE);
+ if (((*g) & (1 << (block % 8))) == 0) {
+ QNX4DEBUG(("qnx4: is_free -> block is free\n"));
+ ret = 1;
+ } else {
+ QNX4DEBUG(("qnx4: is_free -> block is busy\n"));
+ ret = 0;
+ }
+ brelse(bh);
+
+ return ret;
+}
+
+int qnx4_set_bitmap(struct super_block *sb, long block, int busy)
+{
+ int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
+ int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
+ struct buffer_head *bh;
+ char *g;
+
+ start += block / (QNX4_BLOCK_SIZE * 8);
+ QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n",
+ (unsigned long) block, (unsigned long) start));
+ (void) size; /* CHECKME */
+ bh = sb_bread(sb, start);
+ if (bh == NULL) {
+ return -EIO;
+ }
+ g = bh->b_data + (block % QNX4_BLOCK_SIZE);
+ if (busy == 0) {
+ (*g) &= ~(1 << (block % 8));
+ } else {
+ (*g) |= (1 << (block % 8));
+ }
+ mark_buffer_dirty(bh);
+ brelse(bh);
+
+ return 0;
+}
+
+static void qnx4_clear_inode(struct inode *inode)
+{
+ struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode);
+ /* What for? */
+ memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname);
+ qnx4_ino->di_size = 0;
+ qnx4_ino->di_num_xtnts = 0;
+ qnx4_ino->di_mode = 0;
+ qnx4_ino->di_status = 0;
+}
+
+void qnx4_free_inode(struct inode *inode)
+{
+ if (inode->i_ino < 1) {
+ printk("free_inode: inode 0 or nonexistent inode\n");
+ return;
+ }
+ qnx4_clear_inode(inode);
+ clear_inode(inode);
+}
+
+#endif