upload tizen1.0 sourceHEADmaster2.0alpha

1 files changed, 193 insertions, 0 deletions

diff --git a/fs/ntfs/bitmap.c b/fs/ntfs/bitmap.c
new file mode 100644
index 00000000..0809cf87
--- /dev/null
+++ b/fs/ntfs/bitmap.c
@@ -0,0 +1,193 @@
+/*
+ * bitmap.c - NTFS kernel bitmap handling.  Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2004-2005 Anton Altaparmakov
+ *
+ * This program/include file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program/include file is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (in the main directory of the Linux-NTFS
+ * distribution in the file COPYING); if not, write to the Free Software
+ * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifdef NTFS_RW
+
+#include <linux/pagemap.h>
+
+#include "bitmap.h"
+#include "debug.h"
+#include "aops.h"
+#include "ntfs.h"
+
+/**
+ * __ntfs_bitmap_set_bits_in_run - set a run of bits in a bitmap to a value
+ * @vi:			vfs inode describing the bitmap
+ * @start_bit:		first bit to set
+ * @count:		number of bits to set
+ * @value:		value to set the bits to (i.e. 0 or 1)
+ * @is_rollback:	if 'true' this is a rollback operation
+ *
+ * Set @count bits starting at bit @start_bit in the bitmap described by the
+ * vfs inode @vi to @value, where @value is either 0 or 1.
+ *
+ * @is_rollback should always be 'false', it is for internal use to rollback
+ * errors.  You probably want to use ntfs_bitmap_set_bits_in_run() instead.
+ *
+ * Return 0 on success and -errno on error.
+ */
+int __ntfs_bitmap_set_bits_in_run(struct inode *vi, const s64 start_bit,
+		const s64 count, const u8 value, const bool is_rollback)
+{
+	s64 cnt = count;
+	pgoff_t index, end_index;
+	struct address_space *mapping;
+	struct page *page;
+	u8 *kaddr;
+	int pos, len;
+	u8 bit;
+
+	BUG_ON(!vi);
+	ntfs_debug("Entering for i_ino 0x%lx, start_bit 0x%llx, count 0x%llx, "
+			"value %u.%s", vi->i_ino, (unsigned long long)start_bit,
+			(unsigned long long)cnt, (unsigned int)value,
+			is_rollback ? " (rollback)" : "");
+	BUG_ON(start_bit < 0);
+	BUG_ON(cnt < 0);
+	BUG_ON(value > 1);
+	/*
+	 * Calculate the indices for the pages containing the first and last
+	 * bits, i.e. @start_bit and @start_bit + @cnt - 1, respectively.
+	 */
+	index = start_bit >> (3 + PAGE_CACHE_SHIFT);
+	end_index = (start_bit + cnt - 1) >> (3 + PAGE_CACHE_SHIFT);
+
+	/* Get the page containing the first bit (@start_bit). */
+	mapping = vi->i_mapping;
+	page = ntfs_map_page(mapping, index);
+	if (IS_ERR(page)) {
+		if (!is_rollback)
+			ntfs_error(vi->i_sb, "Failed to map first page (error "
+					"%li), aborting.", PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+	kaddr = page_address(page);
+
+	/* Set @pos to the position of the byte containing @start_bit. */
+	pos = (start_bit >> 3) & ~PAGE_CACHE_MASK;
+
+	/* Calculate the position of @start_bit in the first byte. */
+	bit = start_bit & 7;
+
+	/* If the first byte is partial, modify the appropriate bits in it. */
+	if (bit) {
+		u8 *byte = kaddr + pos;
+		while ((bit & 7) && cnt) {
+			cnt--;
+			if (value)
+				*byte |= 1 << bit++;
+			else
+				*byte &= ~(1 << bit++);
+		}
+		/* If we are done, unmap the page and return success. */
+		if (!cnt)
+			goto done;
+
+		/* Update @pos to the new position. */
+		pos++;
+	}
+	/*
+	 * Depending on @value, modify all remaining whole bytes in the page up
+	 * to @cnt.
+	 */
+	len = min_t(s64, cnt >> 3, PAGE_CACHE_SIZE - pos);
+	memset(kaddr + pos, value ? 0xff : 0, len);
+	cnt -= len << 3;
+
+	/* Update @len to point to the first not-done byte in the page. */
+	if (cnt < 8)
+		len += pos;
+
+	/* If we are not in the last page, deal with all subsequent pages. */
+	while (index < end_index) {
+		BUG_ON(cnt <= 0);
+
+		/* Update @index and get the next page. */
+		flush_dcache_page(page);
+		set_page_dirty(page);
+		ntfs_unmap_page(page);
+		page = ntfs_map_page(mapping, ++index);
+		if (IS_ERR(page))
+			goto rollback;
+		kaddr = page_address(page);
+		/*
+		 * Depending on @value, modify all remaining whole bytes in the
+		 * page up to @cnt.
+		 */
+		len = min_t(s64, cnt >> 3, PAGE_CACHE_SIZE);
+		memset(kaddr, value ? 0xff : 0, len);
+		cnt -= len << 3;
+	}
+	/*
+	 * The currently mapped page is the last one.  If the last byte is
+	 * partial, modify the appropriate bits in it.  Note, @len is the
+	 * position of the last byte inside the page.
+	 */
+	if (cnt) {
+		u8 *byte;
+
+		BUG_ON(cnt > 7);
+
+		bit = cnt;
+		byte = kaddr + len;
+		while (bit--) {
+			if (value)
+				*byte |= 1 << bit;
+			else
+				*byte &= ~(1 << bit);
+		}
+	}
+done:
+	/* We are done.  Unmap the page and return success. */
+	flush_dcache_page(page);
+	set_page_dirty(page);
+	ntfs_unmap_page(page);
+	ntfs_debug("Done.");
+	return 0;
+rollback:
+	/*
+	 * Current state:
+	 *	- no pages are mapped
+	 *	- @count - @cnt is the number of bits that have been modified
+	 */
+	if (is_rollback)
+		return PTR_ERR(page);
+	if (count != cnt)
+		pos = __ntfs_bitmap_set_bits_in_run(vi, start_bit, count - cnt,
+				value ? 0 : 1, true);
+	else
+		pos = 0;
+	if (!pos) {
+		/* Rollback was successful. */
+		ntfs_error(vi->i_sb, "Failed to map subsequent page (error "
+				"%li), aborting.", PTR_ERR(page));
+	} else {
+		/* Rollback failed. */
+		ntfs_error(vi->i_sb, "Failed to map subsequent page (error "
+				"%li) and rollback failed (error %i).  "
+				"Aborting and leaving inconsistent metadata.  "
+				"Unmount and run chkdsk.", PTR_ERR(page), pos);
+		NVolSetErrors(NTFS_SB(vi->i_sb));
+	}
+	return PTR_ERR(page);
+}
+
+#endif /* NTFS_RW */