Add a patch to fix Intel E100 wake-on-lan problems.

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.31 / patches.fixes / udf-faster_anchor_detection.patch

From: Jan Kara <jack@suse.cz>
Subject: [PATCH] udf: Try anchor in block 256 first
References: bnc#467174
Patch-mainline: 2.6.30

Anchor block can be located at several places on the medium. Two of the
locations are relative to media end which is problematic to detect. Also
some drives report some block as last but are not able to read it or any
block nearby before it. So let's first try block 256 and if it is all fine,
don't look at other possible locations of anchor blocks to avoid IO errors.
This change required a larger reorganization of code but the new code is
hopefully more readable and definitely shorter.

Signed-off-by: Jan Kara <jack@suse.cz>

diff -rupX /home/jack/.kerndiffexclude linux-2.6.27-SLE11_BRANCH/fs/udf/super.c linux-2.6.27-SLE11_BRANCH-1-udf_anchor_detection//fs/udf/super.c
--- linux-2.6.27-SLE11_BRANCH/fs/udf/super.c	2008-10-10 00:13:53.000000000 +0200
+++ linux-2.6.27-SLE11_BRANCH-1-udf_anchor_detection/fs/udf/super.c	2009-03-19 16:44:56.000000000 +0100
@@ -83,10 +83,7 @@ static int udf_fill_super(struct super_b
 static void udf_put_super(struct super_block *);
 static void udf_write_super(struct super_block *);
 static int udf_remount_fs(struct super_block *, int *, char *);
-static int udf_check_valid(struct super_block *, int, int);
-static int udf_vrs(struct super_block *sb, int silent);
 static void udf_load_logicalvolint(struct super_block *, kernel_extent_ad);
-static void udf_find_anchor(struct super_block *);
 static int udf_find_fileset(struct super_block *, kernel_lb_addr *,
 			    kernel_lb_addr *);
 static void udf_load_fileset(struct super_block *, struct buffer_head *,
@@ -286,14 +283,8 @@ static int udf_show_options(struct seq_f
 		seq_printf(seq, ",session=%u", sbi->s_session);
 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_LASTBLOCK_SET))
 		seq_printf(seq, ",lastblock=%u", sbi->s_last_block);
-	/*
-	 * s_anchor[2] could be zeroed out in case there is no anchor
-	 * in the specified block, but then the "anchor=N" option
-	 * originally given by the user wasn't effective, so it's OK
-	 * if we don't show it.
-	 */
-	if (sbi->s_anchor[2] != 0)
-		seq_printf(seq, ",anchor=%u", sbi->s_anchor[2]);
+	if (sbi->s_anchor != 0)
+		seq_printf(seq, ",anchor=%u", sbi->s_anchor);
 	/*
 	 * volume, partition, fileset and rootdir seem to be ignored
 	 * currently
@@ -585,22 +576,19 @@ static int udf_remount_fs(struct super_b
 	return 0;
 }
 
-static int udf_vrs(struct super_block *sb, int silent)
+/* Check Volume Structure Descriptors (ECMA 167 2/9.1) */
+/* We also check any "CD-ROM Volume Descriptor Set" (ECMA 167 2/8.3.1) */
+static loff_t udf_check_vsd(struct super_block *sb)
 {
 	struct volStructDesc *vsd = NULL;
 	loff_t sector = 32768;
 	int sectorsize;
 	struct buffer_head *bh = NULL;
-	int iso9660 = 0;
 	int nsr02 = 0;
 	int nsr03 = 0;
 	struct udf_sb_info *sbi;
 
-	/* Block size must be a multiple of 512 */
-	if (sb->s_blocksize & 511)
-		return 0;
 	sbi = UDF_SB(sb);
-
 	if (sb->s_blocksize < sizeof(struct volStructDesc))
 		sectorsize = sizeof(struct volStructDesc);
 	else
@@ -627,7 +615,6 @@ static int udf_vrs(struct super_block *s
 			break;
 		} else if (!strncmp(vsd->stdIdent, VSD_STD_ID_CD001,
 				    VSD_STD_ID_LEN)) {
-			iso9660 = sector;
 			switch (vsd->structType) {
 			case 0:
 				udf_debug("ISO9660 Boot Record found\n");
@@ -679,136 +666,6 @@ static int udf_vrs(struct super_block *s
 		return 0;
 }
 
-/*
- * Check whether there is an anchor block in the given block
- */
-static int udf_check_anchor_block(struct super_block *sb, sector_t block)
-{
-	struct buffer_head *bh;
-	uint16_t ident;
-
-	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV) &&
-	    udf_fixed_to_variable(block) >=
-	    sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits)
-		return 0;
-
-	bh = udf_read_tagged(sb, block, block, &ident);
-	if (!bh)
-		return 0;
-	brelse(bh);
-
-	return ident == TAG_IDENT_AVDP;
-}
-
-/* Search for an anchor volume descriptor pointer */
-static sector_t udf_scan_anchors(struct super_block *sb, sector_t lastblock)
-{
-	sector_t last[6];
-	int i;
-	struct udf_sb_info *sbi = UDF_SB(sb);
-
-	last[0] = lastblock;
-	last[1] = last[0] - 1;
-	last[2] = last[0] + 1;
-	last[3] = last[0] - 2;
-	last[4] = last[0] - 150;
-	last[5] = last[0] - 152;
-
-	/*  according to spec, anchor is in either:
-	 *     block 256
-	 *     lastblock-256
-	 *     lastblock
-	 *  however, if the disc isn't closed, it could be 512 */
-
-	for (i = 0; i < ARRAY_SIZE(last); i++) {
-		if (last[i] < 0)
-			continue;
-		if (last[i] >= sb->s_bdev->bd_inode->i_size >>
-				sb->s_blocksize_bits)
-			continue;
-
-		if (udf_check_anchor_block(sb, last[i])) {
-			sbi->s_anchor[0] = last[i];
-			sbi->s_anchor[1] = last[i] - 256;
-			return last[i];
-		}
-
-		if (last[i] < 256)
-			continue;
-
-		if (udf_check_anchor_block(sb, last[i] - 256)) {
-			sbi->s_anchor[1] = last[i] - 256;
-			return last[i];
-		}
-	}
-
-	if (udf_check_anchor_block(sb, sbi->s_session + 256)) {
-		sbi->s_anchor[0] = sbi->s_session + 256;
-		return last[0];
-	}
-	if (udf_check_anchor_block(sb, sbi->s_session + 512)) {
-		sbi->s_anchor[0] = sbi->s_session + 512;
-		return last[0];
-	}
-	return 0;
-}
-
-/*
- * Find an anchor volume descriptor. The function expects sbi->s_lastblock to
- * be the last block on the media.
- *
- * Return 1 if not found, 0 if ok
- *
- */
-static void udf_find_anchor(struct super_block *sb)
-{
-	sector_t lastblock;
-	struct buffer_head *bh = NULL;
-	uint16_t ident;
-	int i;
-	struct udf_sb_info *sbi = UDF_SB(sb);
-
-	lastblock = udf_scan_anchors(sb, sbi->s_last_block);
-	if (lastblock)
-		goto check_anchor;
-
-	/* No anchor found? Try VARCONV conversion of block numbers */
-	UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
-	/* Firstly, we try to not convert number of the last block */
-	lastblock = udf_scan_anchors(sb,
-				udf_variable_to_fixed(sbi->s_last_block));
-	if (lastblock)
-		goto check_anchor;
-
-	/* Secondly, we try with converted number of the last block */
-	lastblock = udf_scan_anchors(sb, sbi->s_last_block);
-	if (!lastblock) {
-		/* VARCONV didn't help. Clear it. */
-		UDF_CLEAR_FLAG(sb, UDF_FLAG_VARCONV);
-	}
-
-check_anchor:
-	/*
-	 * Check located anchors and the anchor block supplied via
-	 * mount options
-	 */
-	for (i = 0; i < ARRAY_SIZE(sbi->s_anchor); i++) {
-		if (!sbi->s_anchor[i])
-			continue;
-		bh = udf_read_tagged(sb, sbi->s_anchor[i],
-					sbi->s_anchor[i], &ident);
-		if (!bh)
-			sbi->s_anchor[i] = 0;
-		else {
-			brelse(bh);
-			if (ident != TAG_IDENT_AVDP)
-				sbi->s_anchor[i] = 0;
-		}
-	}
-
-	sbi->s_last_block = lastblock;
-}
-
 static int udf_find_fileset(struct super_block *sb,
 			    kernel_lb_addr *fileset,
 			    kernel_lb_addr *root)
@@ -1655,86 +1512,201 @@ static noinline int udf_process_sequence
 	return 0;
 }
 
+static int udf_load_sequence(struct super_block *sb, struct buffer_head *bh,
+			     kernel_lb_addr *fileset)
+{
+	struct anchorVolDescPtr *anchor;
+	long main_s, main_e, reserve_s, reserve_e;
+	struct udf_sb_info *sbi;
+
+	sbi = UDF_SB(sb);
+	anchor = (struct anchorVolDescPtr *)bh->b_data;
+
+	/* Locate the main sequence */
+	main_s = le32_to_cpu(anchor->mainVolDescSeqExt.extLocation);
+	main_e = le32_to_cpu(anchor->mainVolDescSeqExt.extLength);
+	main_e = main_e >> sb->s_blocksize_bits;
+	main_e += main_s;
+
+	/* Locate the reserve sequence */
+	reserve_s = le32_to_cpu(anchor->reserveVolDescSeqExt.extLocation);
+	reserve_e = le32_to_cpu(anchor->reserveVolDescSeqExt.extLength);
+	reserve_e = reserve_e >> sb->s_blocksize_bits;
+	reserve_e += reserve_s;
+
+	/* Process the main & reserve sequences */
+	/* responsible for finding the PartitionDesc(s) */
+	if (!udf_process_sequence(sb, main_s, main_e, fileset))
+		return 1;
+	return !udf_process_sequence(sb, reserve_s, reserve_e, fileset);
+}
+
 /*
- * udf_check_valid()
+ * Check whether there is an anchor block in the given block and
+ * load Volume Descriptor Sequence if so.
  */
-static int udf_check_valid(struct super_block *sb, int novrs, int silent)
+static int udf_check_anchor_block(struct super_block *sb, sector_t block,
+				  kernel_lb_addr *fileset)
 {
-	long block;
-	struct udf_sb_info *sbi = UDF_SB(sb);
+	struct buffer_head *bh;
+	uint16_t ident;
+	int ret;
 
-	if (novrs) {
-		udf_debug("Validity check skipped because of novrs option\n");
+	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV) &&
+	    udf_fixed_to_variable(block) >=
+	    sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits)
+		return 0;
+
+	bh = udf_read_tagged(sb, block, block, &ident);
+	if (!bh)
+		return 0;
+	if (ident != TAG_IDENT_AVDP) {
+		brelse(bh);
 		return 0;
 	}
-	/* Check that it is NSR02 compliant */
-	/* Process any "CD-ROM Volume Descriptor Set" (ECMA 167 2/8.3.1) */
-	block = udf_vrs(sb, silent);
-	if (block == -1)
-		udf_debug("Failed to read byte 32768. Assuming open "
-			  "disc. Skipping validity check\n");
-	if (block && !sbi->s_last_block)
-		sbi->s_last_block = udf_get_last_block(sb);
-	return !block;
+	ret = udf_load_sequence(sb, bh, fileset);
+	brelse(bh);
+	return ret;
 }
 
-static int udf_load_sequence(struct super_block *sb, kernel_lb_addr *fileset)
+/* Search for an anchor volume descriptor pointer */
+static sector_t udf_scan_anchors(struct super_block *sb, sector_t lastblock,
+				 kernel_lb_addr *fileset)
 {
-	struct anchorVolDescPtr *anchor;
-	uint16_t ident;
-	struct buffer_head *bh;
-	long main_s, main_e, reserve_s, reserve_e;
+	sector_t last[6];
 	int i;
-	struct udf_sb_info *sbi;
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	int last_count = 0;
 
-	if (!sb)
-		return 1;
-	sbi = UDF_SB(sb);
+	/* First try user provided anchor */
+	if (sbi->s_anchor) {
+		if (udf_check_anchor_block(sb, sbi->s_anchor, fileset))
+			return lastblock;
+	}
+	/*
+	 * according to spec, anchor is in either:
+	 *     block 256
+	 *     lastblock-256
+	 *     lastblock
+	 *  however, if the disc isn't closed, it could be 512.
+	 */
+	if (udf_check_anchor_block(sb, sbi->s_session + 256, fileset))
+		return lastblock;
+	/*
+	 * The trouble is which block is the last one. Drives often misreport
+	 * this so we try various possibilities.
+	 */
+	last[last_count++] = lastblock;
+	if (lastblock >= 1)
+		last[last_count++] = lastblock - 1;
+	last[last_count++] = lastblock + 1;
+	if (lastblock >= 2)
+		last[last_count++] = lastblock - 2;
+	if (lastblock >= 150)
+		last[last_count++] = lastblock - 150;
+	if (lastblock >= 152)
+		last[last_count++] = lastblock - 152;
 
-	for (i = 0; i < ARRAY_SIZE(sbi->s_anchor); i++) {
-		if (!sbi->s_anchor[i])
+	for (i = 0; i < last_count; i++) {
+		if (last[i] >= sb->s_bdev->bd_inode->i_size >>
+				sb->s_blocksize_bits)
 			continue;
-
-		bh = udf_read_tagged(sb, sbi->s_anchor[i], sbi->s_anchor[i],
-				     &ident);
-		if (!bh)
+		if (udf_check_anchor_block(sb, last[i], fileset))
+			return last[i];
+		if (last[i] < 256)
 			continue;
+		if (udf_check_anchor_block(sb, last[i] - 256, fileset))
+			return last[i];
+	}
+
+	/* Finally try block 512 in case media is open */
+	if (udf_check_anchor_block(sb, sbi->s_session + 512, fileset))
+		return last[0];
+	return 0;
+}
 
-		anchor = (struct anchorVolDescPtr *)bh->b_data;
+/*
+ * Find an anchor volume descriptor and load Volume Descriptor Sequence from
+ * area specified by it. The function expects sbi->s_lastblock to be the last
+ * block on the media.
+ *
+ * Return 1 if ok, 0 if not found.
+ *
+ */
+static int udf_find_anchor(struct super_block *sb,
+			   kernel_lb_addr *fileset)
+{
+	sector_t lastblock;
+	struct udf_sb_info *sbi = UDF_SB(sb);
 
-		/* Locate the main sequence */
-		main_s = le32_to_cpu(anchor->mainVolDescSeqExt.extLocation);
-		main_e = le32_to_cpu(anchor->mainVolDescSeqExt.extLength);
-		main_e = main_e >> sb->s_blocksize_bits;
-		main_e += main_s;
-
-		/* Locate the reserve sequence */
-		reserve_s = le32_to_cpu(
-				anchor->reserveVolDescSeqExt.extLocation);
-		reserve_e = le32_to_cpu(
-				anchor->reserveVolDescSeqExt.extLength);
-		reserve_e = reserve_e >> sb->s_blocksize_bits;
-		reserve_e += reserve_s;
+	lastblock = udf_scan_anchors(sb, sbi->s_last_block, fileset);
+	if (lastblock)
+		goto out;
 
-		brelse(bh);
+	/* No anchor found? Try VARCONV conversion of block numbers */
+	UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
+	/* Firstly, we try to not convert number of the last block */
+	lastblock = udf_scan_anchors(sb,
+				udf_variable_to_fixed(sbi->s_last_block),
+				fileset);
+	if (lastblock)
+		goto out;
 
-		/* Process the main & reserve sequences */
-		/* responsible for finding the PartitionDesc(s) */
-		if (!(udf_process_sequence(sb, main_s, main_e,
-					   fileset) &&
-		      udf_process_sequence(sb, reserve_s, reserve_e,
-					   fileset)))
-			break;
+	/* Secondly, we try with converted number of the last block */
+	lastblock = udf_scan_anchors(sb, sbi->s_last_block, fileset);
+	if (!lastblock) {
+		/* VARCONV didn't help. Clear it. */
+		UDF_CLEAR_FLAG(sb, UDF_FLAG_VARCONV);
+		return 0;
 	}
+out:
+	sbi->s_last_block = lastblock;
+	return 1;
+}
 
-	if (i == ARRAY_SIZE(sbi->s_anchor)) {
-		udf_debug("No Anchor block found\n");
-		return 1;
+/*
+ * Check Volume Structure Descriptor, find Anchor block and load Volume
+ * Descriptor Sequence
+ */
+static int udf_load_vrs(struct super_block *sb, struct udf_options *uopt,
+			int silent, kernel_lb_addr *fileset)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	loff_t nsr_off;
+
+	if (!sb_set_blocksize(sb, uopt->blocksize)) {
+		if (!silent)
+			printk(KERN_WARNING "UDF-fs: Bad block size\n");
+		return 0;
+	}
+	sbi->s_last_block = uopt->lastblock;
+	if (!uopt->novrs) {
+		/* Check that it is NSR02 compliant */
+		nsr_off = udf_check_vsd(sb);
+		if (!nsr_off) {
+			if (!silent)
+				printk(KERN_WARNING "UDF-fs: No VRS found\n");
+			return 0;
+		}
+		if (nsr_off == -1)
+			udf_debug("Failed to read byte 32768. Assuming open "
+				  "disc. Skipping validity check\n");
+		if (!sbi->s_last_block)
+			sbi->s_last_block = udf_get_last_block(sb);
+	} else {
+		udf_debug("Validity check skipped because of novrs option\n");
 	}
-	udf_debug("Using anchor in block %d\n", sbi->s_anchor[i]);
 
-	return 0;
+	/* Look for anchor block and load Volume Descriptor Sequence */
+	sbi->s_anchor = uopt->anchor;
+	if (!udf_find_anchor(sb, fileset)) {
+		if (!silent)
+			printk(KERN_WARNING "UDF-fs: No anchor found\n");
+		return 0;
+	}
+	return 1;
 }
+  
 
 static void udf_open_lvid(struct super_block *sb)
 {
@@ -1908,18 +1880,6 @@ static int udf_fill_super(struct super_b
 
 	udf_debug("Multi-session=%d\n", sbi->s_session);
 
-	sbi->s_last_block = uopt.lastblock;
-	sbi->s_anchor[0] = sbi->s_anchor[1] = 0;
-	sbi->s_anchor[2] = uopt.anchor;
-
-	if (udf_check_valid(sb, uopt.novrs, silent)) {
-		/* read volume recognition sequences */
-		printk(KERN_WARNING "UDF-fs: No VRS found\n");
-		goto error_out;
-	}
-
-	udf_find_anchor(sb);
-
 	/* Fill in the rest of the superblock */
 	sb->s_op = &udf_sb_ops;
 	sb->s_export_op = &udf_export_ops;
@@ -1928,7 +1888,7 @@ static int udf_fill_super(struct super_b
 	sb->s_magic = UDF_SUPER_MAGIC;
 	sb->s_time_gran = 1000;
 
-	if (udf_load_sequence(sb, &fileset)) {
+	if (!udf_load_vrs(sb, &uopt, silent, &fileset)) {
 		printk(KERN_WARNING "UDF-fs: No partition found (1)\n");
 		goto error_out;
 	}
diff -rupX /home/jack/.kerndiffexclude linux-2.6.27-SLE11_BRANCH/fs/udf/udf_sb.h linux-2.6.27-SLE11_BRANCH-1-udf_anchor_detection//fs/udf/udf_sb.h
--- linux-2.6.27-SLE11_BRANCH/fs/udf/udf_sb.h	2008-10-10 00:13:53.000000000 +0200
+++ linux-2.6.27-SLE11_BRANCH-1-udf_anchor_detection/fs/udf/udf_sb.h	2009-03-19 16:33:24.000000000 +0100
@@ -114,7 +114,7 @@ struct udf_sb_info {
 
 	/* Sector headers */
 	__s32			s_session;
-	__u32			s_anchor[3];
+	__u32			s_anchor;
 	__u32			s_last_block;
 
 	struct buffer_head	*s_lvid_bh;