NTFS: Implement support for sector sizes above 512 bytes (up to the maximum

      supported by NTFS which is 4096 bytes).

1 files changed, 99 insertions, 52 deletions

diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index e9c0d80..489f704 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -1,7 +1,7 @@
 /*
  * super.c - NTFS kernel super block handling. Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2005 Anton Altaparmakov
+ * Copyright (c) 2001-2006 Anton Altaparmakov
  * Copyright (c) 2001,2002 Richard Russon
  *
  * This program/include file is free software; you can redistribute it and/or
@@ -22,6 +22,7 @@
 
 #include <linux/stddef.h>
 #include <linux/init.h>
+#include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/blkdev.h>	/* For bdev_hardsect_size(). */
@@ -641,7 +642,7 @@ static struct buffer_head *read_ntfs_boot_sector(struct super_block *sb,
 {
 	const char *read_err_str = "Unable to read %s boot sector.";
 	struct buffer_head *bh_primary, *bh_backup;
-	long nr_blocks = NTFS_SB(sb)->nr_blocks;
+	sector_t nr_blocks = NTFS_SB(sb)->nr_blocks;
 
 	/* Try to read primary boot sector. */
 	if ((bh_primary = sb_bread(sb, 0))) {
@@ -688,13 +689,18 @@ hotfix_primary_boot_sector:
 		/*
 		 * If we managed to read sector zero and the volume is not
 		 * read-only, copy the found, valid backup boot sector to the
-		 * primary boot sector.
+		 * primary boot sector.  Note we only copy the actual boot
+		 * sector structure, not the actual whole device sector as that
+		 * may be bigger and would potentially damage the $Boot system
+		 * file (FIXME: Would be nice to know if the backup boot sector
+		 * on a large sector device contains the whole boot loader or
+		 * just the first 512 bytes).
 		 */
 		if (!(sb->s_flags & MS_RDONLY)) {
 			ntfs_warning(sb, "Hot-fix: Recovering invalid primary "
 					"boot sector from backup copy.");
 			memcpy(bh_primary->b_data, bh_backup->b_data,
-					sb->s_blocksize);
+					NTFS_BLOCK_SIZE);
 			mark_buffer_dirty(bh_primary);
 			sync_dirty_buffer(bh_primary);
 			if (buffer_uptodate(bh_primary)) {
@@ -733,9 +739,13 @@ static BOOL parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
 			vol->sector_size);
 	ntfs_debug("vol->sector_size_bits = %i (0x%x)", vol->sector_size_bits,
 			vol->sector_size_bits);
-	if (vol->sector_size != vol->sb->s_blocksize)
-		ntfs_warning(vol->sb, "The boot sector indicates a sector size "
-				"different from the device sector size.");
+	if (vol->sector_size < vol->sb->s_blocksize) {
+		ntfs_error(vol->sb, "Sector size (%i) is smaller than the "
+				"device block size (%lu).  This is not "
+				"supported.  Sorry.", vol->sector_size,
+				vol->sb->s_blocksize);
+		return FALSE;
+	}
 	ntfs_debug("sectors_per_cluster = 0x%x", b->bpb.sectors_per_cluster);
 	sectors_per_cluster_bits = ffs(b->bpb.sectors_per_cluster) - 1;
 	ntfs_debug("sectors_per_cluster_bits = 0x%x",
@@ -748,16 +758,11 @@ static BOOL parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
 	ntfs_debug("vol->cluster_size = %i (0x%x)", vol->cluster_size,
 			vol->cluster_size);
 	ntfs_debug("vol->cluster_size_mask = 0x%x", vol->cluster_size_mask);
-	ntfs_debug("vol->cluster_size_bits = %i (0x%x)",
-			vol->cluster_size_bits, vol->cluster_size_bits);
-	if (vol->sector_size > vol->cluster_size) {
-		ntfs_error(vol->sb, "Sector sizes above the cluster size are "
-				"not supported.  Sorry.");
-		return FALSE;
-	}
-	if (vol->sb->s_blocksize > vol->cluster_size) {
-		ntfs_error(vol->sb, "Cluster sizes smaller than the device "
-				"sector size are not supported.  Sorry.");
+	ntfs_debug("vol->cluster_size_bits = %i", vol->cluster_size_bits);
+	if (vol->cluster_size < vol->sector_size) {
+		ntfs_error(vol->sb, "Cluster size (%i) is smaller than the "
+				"sector size (%i).  This is not supported.  "
+				"Sorry.", vol->cluster_size, vol->sector_size);
 		return FALSE;
 	}
 	clusters_per_mft_record = b->clusters_per_mft_record;
@@ -786,11 +791,18 @@ static BOOL parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
 	 * we store $MFT/$DATA, the table of mft records in the page cache.
 	 */
 	if (vol->mft_record_size > PAGE_CACHE_SIZE) {
-		ntfs_error(vol->sb, "Mft record size %i (0x%x) exceeds the "
-				"page cache size on your system %lu (0x%lx).  "
+		ntfs_error(vol->sb, "Mft record size (%i) exceeds the "
+				"PAGE_CACHE_SIZE on your system (%lu).  "
 				"This is not supported.  Sorry.",
-				vol->mft_record_size, vol->mft_record_size,
-				PAGE_CACHE_SIZE, PAGE_CACHE_SIZE);
+				vol->mft_record_size, PAGE_CACHE_SIZE);
+		return FALSE;
+	}
+	/* We cannot support mft record sizes below the sector size. */
+	if (vol->mft_record_size < vol->sector_size) {
+		ntfs_error(vol->sb, "Mft record size (%i) is smaller than the "
+				"sector size (%i).  This is not supported.  "
+				"Sorry.", vol->mft_record_size,
+				vol->sector_size);
 		return FALSE;
 	}
 	clusters_per_index_record = b->clusters_per_index_record;
@@ -816,6 +828,14 @@ static BOOL parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
 	ntfs_debug("vol->index_record_size_bits = %i (0x%x)",
 			vol->index_record_size_bits,
 			vol->index_record_size_bits);
+	/* We cannot support index record sizes below the sector size. */
+	if (vol->index_record_size < vol->sector_size) {
+		ntfs_error(vol->sb, "Index record size (%i) is smaller than "
+				"the sector size (%i).  This is not "
+				"supported.  Sorry.", vol->index_record_size,
+				vol->sector_size);
+		return FALSE;
+	}
 	/*
 	 * Get the size of the volume in clusters and check for 64-bit-ness.
 	 * Windows currently only uses 32 bits to save the clusters so we do
@@ -845,15 +865,18 @@ static BOOL parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
 	}
 	ll = sle64_to_cpu(b->mft_lcn);
 	if (ll >= vol->nr_clusters) {
-		ntfs_error(vol->sb, "MFT LCN is beyond end of volume.  Weird.");
+		ntfs_error(vol->sb, "MFT LCN (%lli, 0x%llx) is beyond end of "
+				"volume.  Weird.", (unsigned long long)ll,
+				(unsigned long long)ll);
 		return FALSE;
 	}
 	vol->mft_lcn = ll;
 	ntfs_debug("vol->mft_lcn = 0x%llx", (long long)vol->mft_lcn);
 	ll = sle64_to_cpu(b->mftmirr_lcn);
 	if (ll >= vol->nr_clusters) {
-		ntfs_error(vol->sb, "MFTMirr LCN is beyond end of volume.  "
-				"Weird.");
+		ntfs_error(vol->sb, "MFTMirr LCN (%lli, 0x%llx) is beyond end "
+				"of volume.  Weird.", (unsigned long long)ll,
+				(unsigned long long)ll);
 		return FALSE;
 	}
 	vol->mftmirr_lcn = ll;
@@ -2685,7 +2708,7 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
 	ntfs_volume *vol;
 	struct buffer_head *bh;
 	struct inode *tmp_ino;
-	int result;
+	int blocksize, result;
 
 	ntfs_debug("Entering.");
 #ifndef NTFS_RW
@@ -2724,60 +2747,85 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
 	if (!parse_options(vol, (char*)opt))
 		goto err_out_now;
 
+	/* We support sector sizes up to the PAGE_CACHE_SIZE. */
+	if (bdev_hardsect_size(sb->s_bdev) > PAGE_CACHE_SIZE) {
+		if (!silent)
+			ntfs_error(sb, "Device has unsupported sector size "
+					"(%i).  The maximum supported sector "
+					"size on this architecture is %lu "
+					"bytes.",
+					bdev_hardsect_size(sb->s_bdev),
+					PAGE_CACHE_SIZE);
+		goto err_out_now;
+	}
 	/*
-	 * TODO: Fail safety check. In the future we should really be able to
-	 * cope with this being the case, but for now just bail out.
+	 * Setup the device access block size to NTFS_BLOCK_SIZE or the hard
+	 * sector size, whichever is bigger.
 	 */
-	if (bdev_hardsect_size(sb->s_bdev) > NTFS_BLOCK_SIZE) {
+	blocksize = sb_min_blocksize(sb, NTFS_BLOCK_SIZE);
+	if (blocksize < NTFS_BLOCK_SIZE) {
 		if (!silent)
-			ntfs_error(sb, "Device has unsupported hardsect_size.");
+			ntfs_error(sb, "Unable to set device block size.");
 		goto err_out_now;
 	}
-
-	/* Setup the device access block size to NTFS_BLOCK_SIZE. */
-	if (sb_set_blocksize(sb, NTFS_BLOCK_SIZE) != NTFS_BLOCK_SIZE) {
+	BUG_ON(blocksize != sb->s_blocksize);
+	ntfs_debug("Set device block size to %i bytes (block size bits %i).",
+			blocksize, sb->s_blocksize_bits);
+	/* Determine the size of the device in units of block_size bytes. */
+	if (!i_size_read(sb->s_bdev->bd_inode)) {
 		if (!silent)
-			ntfs_error(sb, "Unable to set block size.");
+			ntfs_error(sb, "Unable to determine device size.");
 		goto err_out_now;
 	}
-
-	/* Get the size of the device in units of NTFS_BLOCK_SIZE bytes. */
 	vol->nr_blocks = i_size_read(sb->s_bdev->bd_inode) >>
-			NTFS_BLOCK_SIZE_BITS;
-
+			sb->s_blocksize_bits;
 	/* Read the boot sector and return unlocked buffer head to it. */
 	if (!(bh = read_ntfs_boot_sector(sb, silent))) {
 		if (!silent)
 			ntfs_error(sb, "Not an NTFS volume.");
 		goto err_out_now;
 	}
-
 	/*
-	 * Extract the data from the boot sector and setup the ntfs super block
+	 * Extract the data from the boot sector and setup the ntfs volume
 	 * using it.
 	 */
 	result = parse_ntfs_boot_sector(vol, (NTFS_BOOT_SECTOR*)bh->b_data);
-
-	/* Initialize the cluster and mft allocators. */
-	ntfs_setup_allocators(vol);
-
 	brelse(bh);
-
 	if (!result) {
 		if (!silent)
 			ntfs_error(sb, "Unsupported NTFS filesystem.");
 		goto err_out_now;
 	}
-
 	/*
-	 * TODO: When we start coping with sector sizes different from
-	 * NTFS_BLOCK_SIZE, we now probably need to set the blocksize of the
-	 * device (probably to NTFS_BLOCK_SIZE).
+	 * If the boot sector indicates a sector size bigger than the current
+	 * device block size, switch the device block size to the sector size.
+	 * TODO: It may be possible to support this case even when the set
+	 * below fails, we would just be breaking up the i/o for each sector
+	 * into multiple blocks for i/o purposes but otherwise it should just
+	 * work.  However it is safer to leave disabled until someone hits this
+	 * error message and then we can get them to try it without the setting
+	 * so we know for sure that it works.
 	 */
-
+	if (vol->sector_size > blocksize) {
+		blocksize = sb_set_blocksize(sb, vol->sector_size);
+		if (blocksize != vol->sector_size) {
+			if (!silent)
+				ntfs_error(sb, "Unable to set device block "
+						"size to sector size (%i).",
+						vol->sector_size);
+			goto err_out_now;
+		}
+		BUG_ON(blocksize != sb->s_blocksize);
+		vol->nr_blocks = i_size_read(sb->s_bdev->bd_inode) >>
+				sb->s_blocksize_bits;
+		ntfs_debug("Changed device block size to %i bytes (block size "
+				"bits %i) to match volume sector size.",
+				blocksize, sb->s_blocksize_bits);
+	}
+	/* Initialize the cluster and mft allocators. */
+	ntfs_setup_allocators(vol);
 	/* Setup remaining fields in the super block. */
 	sb->s_magic = NTFS_SB_MAGIC;
-
 	/*
 	 * Ntfs allows 63 bits for the file size, i.e. correct would be:
 	 *	sb->s_maxbytes = ~0ULL >> 1;
@@ -2787,9 +2835,8 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
 	 * without overflowing the index or to 2^63 - 1, whichever is smaller.
 	 */
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
-
+	/* Ntfs measures time in 100ns intervals. */
 	sb->s_time_gran = 100;
-
 	/*
 	 * Now load the metadata required for the page cache and our address
 	 * space operations to function. We do this by setting up a specialised