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!

1 files changed, 221 insertions, 0 deletions

diff --git a/fs/hfsplus/bitmap.c b/fs/hfsplus/bitmap.c
new file mode 100644
index 000000000000..c7d316455fa0
--- /dev/null
+++ b/fs/hfsplus/bitmap.c
@@ -0,0 +1,221 @@
+/*
+ *  linux/fs/hfsplus/bitmap.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handling of allocation file
+ */
+
+#include <linux/pagemap.h>
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+#define PAGE_CACHE_BITS	(PAGE_CACHE_SIZE * 8)
+
+int hfsplus_block_allocate(struct super_block *sb, u32 size, u32 offset, u32 *max)
+{
+	struct page *page;
+	struct address_space *mapping;
+	__be32 *pptr, *curr, *end;
+	u32 mask, start, len, n;
+	__be32 val;
+	int i;
+
+	len = *max;
+	if (!len)
+		return size;
+
+	dprint(DBG_BITMAP, "block_allocate: %u,%u,%u\n", size, offset, len);
+	down(&HFSPLUS_SB(sb).alloc_file->i_sem);
+	mapping = HFSPLUS_SB(sb).alloc_file->i_mapping;
+	page = read_cache_page(mapping, offset / PAGE_CACHE_BITS,
+			       (filler_t *)mapping->a_ops->readpage, NULL);
+	pptr = kmap(page);
+	curr = pptr + (offset & (PAGE_CACHE_BITS - 1)) / 32;
+	i = offset % 32;
+	offset &= ~(PAGE_CACHE_BITS - 1);
+	if ((size ^ offset) / PAGE_CACHE_BITS)
+		end = pptr + PAGE_CACHE_BITS / 32;
+	else
+		end = pptr + ((size + 31) & (PAGE_CACHE_BITS - 1)) / 32;
+
+	/* scan the first partial u32 for zero bits */
+	val = *curr;
+	if (~val) {
+		n = be32_to_cpu(val);
+		mask = (1U << 31) >> i;
+		for (; i < 32; mask >>= 1, i++) {
+			if (!(n & mask))
+				goto found;
+		}
+	}
+	curr++;
+
+	/* scan complete u32s for the first zero bit */
+	while (1) {
+		while (curr < end) {
+			val = *curr;
+			if (~val) {
+				n = be32_to_cpu(val);
+				mask = 1 << 31;
+				for (i = 0; i < 32; mask >>= 1, i++) {
+					if (!(n & mask))
+						goto found;
+				}
+			}
+			curr++;
+		}
+		kunmap(page);
+		offset += PAGE_CACHE_BITS;
+		if (offset >= size)
+			break;
+		page = read_cache_page(mapping, offset / PAGE_CACHE_BITS,
+				       (filler_t *)mapping->a_ops->readpage, NULL);
+		curr = pptr = kmap(page);
+		if ((size ^ offset) / PAGE_CACHE_BITS)
+			end = pptr + PAGE_CACHE_BITS / 32;
+		else
+			end = pptr + ((size + 31) & (PAGE_CACHE_BITS - 1)) / 32;
+	}
+	dprint(DBG_BITMAP, "bitmap full\n");
+	start = size;
+	goto out;
+
+found:
+	start = offset + (curr - pptr) * 32 + i;
+	if (start >= size) {
+		dprint(DBG_BITMAP, "bitmap full\n");
+		goto out;
+	}
+	/* do any partial u32 at the start */
+	len = min(size - start, len);
+	while (1) {
+		n |= mask;
+		if (++i >= 32)
+			break;
+		mask >>= 1;
+		if (!--len || n & mask)
+			goto done;
+	}
+	if (!--len)
+		goto done;
+	*curr++ = cpu_to_be32(n);
+	/* do full u32s */
+	while (1) {
+		while (curr < end) {
+			n = be32_to_cpu(*curr);
+			if (len < 32)
+				goto last;
+			if (n) {
+				len = 32;
+				goto last;
+			}
+			*curr++ = cpu_to_be32(0xffffffff);
+			len -= 32;
+		}
+		set_page_dirty(page);
+		kunmap(page);
+		offset += PAGE_CACHE_BITS;
+		page = read_cache_page(mapping, offset / PAGE_CACHE_BITS,
+				       (filler_t *)mapping->a_ops->readpage, NULL);
+		pptr = kmap(page);
+		curr = pptr;
+		end = pptr + PAGE_CACHE_BITS / 32;
+	}
+last:
+	/* do any partial u32 at end */
+	mask = 1U << 31;
+	for (i = 0; i < len; i++) {
+		if (n & mask)
+			break;
+		n |= mask;
+		mask >>= 1;
+	}
+done:
+	*curr = cpu_to_be32(n);
+	set_page_dirty(page);
+	kunmap(page);
+	*max = offset + (curr - pptr) * 32 + i - start;
+	HFSPLUS_SB(sb).free_blocks -= *max;
+	sb->s_dirt = 1;
+	dprint(DBG_BITMAP, "-> %u,%u\n", start, *max);
+out:
+	up(&HFSPLUS_SB(sb).alloc_file->i_sem);
+	return start;
+}
+
+int hfsplus_block_free(struct super_block *sb, u32 offset, u32 count)
+{
+	struct page *page;
+	struct address_space *mapping;
+	__be32 *pptr, *curr, *end;
+	u32 mask, len, pnr;
+	int i;
+
+	/* is there any actual work to be done? */
+	if (!count)
+		return 0;
+
+	dprint(DBG_BITMAP, "block_free: %u,%u\n", offset, count);
+	/* are all of the bits in range? */
+	if ((offset + count) > HFSPLUS_SB(sb).total_blocks)
+		return -2;
+
+	down(&HFSPLUS_SB(sb).alloc_file->i_sem);
+	mapping = HFSPLUS_SB(sb).alloc_file->i_mapping;
+	pnr = offset / PAGE_CACHE_BITS;
+	page = read_cache_page(mapping, pnr, (filler_t *)mapping->a_ops->readpage, NULL);
+	pptr = kmap(page);
+	curr = pptr + (offset & (PAGE_CACHE_BITS - 1)) / 32;
+	end = pptr + PAGE_CACHE_BITS / 32;
+	len = count;
+
+	/* do any partial u32 at the start */
+	i = offset % 32;
+	if (i) {
+		int j = 32 - i;
+		mask = 0xffffffffU << j;
+		if (j > count) {
+			mask |= 0xffffffffU >> (i + count);
+			*curr++ &= cpu_to_be32(mask);
+			goto out;
+		}
+		*curr++ &= cpu_to_be32(mask);
+		count -= j;
+	}
+
+	/* do full u32s */
+	while (1) {
+		while (curr < end) {
+			if (count < 32)
+				goto done;
+			*curr++ = 0;
+			count -= 32;
+		}
+		if (!count)
+			break;
+		set_page_dirty(page);
+		kunmap(page);
+		page = read_cache_page(mapping, ++pnr, (filler_t *)mapping->a_ops->readpage, NULL);
+		pptr = kmap(page);
+		curr = pptr;
+		end = pptr + PAGE_CACHE_BITS / 32;
+	}
+done:
+	/* do any partial u32 at end */
+	if (count) {
+		mask = 0xffffffffU >> count;
+		*curr &= cpu_to_be32(mask);
+	}
+out:
+	set_page_dirty(page);
+	kunmap(page);
+	HFSPLUS_SB(sb).free_blocks += len;
+	sb->s_dirt = 1;
+	up(&HFSPLUS_SB(sb).alloc_file->i_sem);
+
+	return 0;
+}