Patchwork [36/54] libext2fs: Block group checksum should use metadata_csum algorithm

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Submitter Darrick J. Wong
Date March 7, 2012, 12:01 a.m.
Message ID <20120307000136.11945.24146.stgit@elm3b70.beaverton.ibm.com>
Download mbox | patch
Permalink /patch/145093/
State Deferred
Delegated to: Theodore Ts'o
Headers show

Comments

Darrick J. Wong - March 7, 2012, 12:01 a.m.
Change the block group algorithm to use the same algorithm as the rest of the
metadata_csum.  This mostly involves providing a helper function to tell if
group descriptors should have checksums set or verified, and modifying the gdt
checksum code to use the correct algorithm.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
 debugfs/debugfs.c        |    3 +-
 lib/ext2fs/alloc.c       |    6 +---
 lib/ext2fs/alloc_stats.c |    3 +-
 lib/ext2fs/csum.c        |   67 ++++++++++++++++++++++++++++------------------
 lib/ext2fs/ext2fs.h      |    6 ++++
 lib/ext2fs/initialize.c  |    3 +-
 lib/ext2fs/inode.c       |    9 ++----
 lib/ext2fs/openfs.c      |    3 +-
 lib/ext2fs/rw_bitmaps.c  |   12 +++-----
 misc/dumpe2fs.c          |    4 +--
 resize/resize2fs.c       |   12 +++-----
 11 files changed, 66 insertions(+), 62 deletions(-)



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Patch

diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index 36dd730..2e46cd5 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -357,8 +357,7 @@  void do_show_super_stats(int argc, char *argv[])
 		return;
 	}
 
-	gdt_csum = EXT2_HAS_RO_COMPAT_FEATURE(current_fs->super,
-					      EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
+	gdt_csum = ext2fs_has_group_desc_csum(current_fs);
 	for (i = 0; i < current_fs->group_desc_count; i++) {
 		fprintf(out, " Group %2d: block bitmap at %llu, "
 		        "inode bitmap at %llu, "
diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
index 948a0ec..e62ed68 100644
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -36,8 +36,7 @@  static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map,
 	blk64_t		blk, super_blk, old_desc_blk, new_desc_blk;
 	int		old_desc_blocks;
 
-	if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
+	if (!ext2fs_has_group_desc_csum(fs) ||
 	    !(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)))
 		return;
 
@@ -83,8 +82,7 @@  static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
 {
 	ext2_ino_t	i, ino;
 
-	if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
+	if (!ext2fs_has_group_desc_csum(fs) ||
 	    !(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT)))
 		return;
 
diff --git a/lib/ext2fs/alloc_stats.c b/lib/ext2fs/alloc_stats.c
index adec363..4229084 100644
--- a/lib/ext2fs/alloc_stats.c
+++ b/lib/ext2fs/alloc_stats.c
@@ -38,8 +38,7 @@  void ext2fs_inode_alloc_stats2(ext2_filsys fs, ext2_ino_t ino,
 	/* We don't strictly need to be clearing the uninit flag if inuse < 0
 	 * (i.e. freeing inodes) but it also means something is bad. */
 	ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
-	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+	if (ext2fs_has_group_desc_csum(fs)) {
 		ext2_ino_t first_unused_inode =	fs->super->s_inodes_per_group -
 			ext2fs_bg_itable_unused(fs, group) +
 			group * fs->super->s_inodes_per_group + 1;
diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c
index 11a24f0..d4f98e0 100644
--- a/lib/ext2fs/csum.c
+++ b/lib/ext2fs/csum.c
@@ -696,39 +696,56 @@  STATIC __u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group)
 
 	desc = ext2fs_group_desc(fs, fs->group_desc, group);
 
-	if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
-		size_t offset = offsetof(struct ext2_group_desc, bg_checksum);
-
 #ifdef WORDS_BIGENDIAN
-		struct ext4_group_desc swabdesc;
+	struct ext4_group_desc swabdesc;
 
-		/* Have to swab back to little-endian to do the checksum */
-		memcpy(&swabdesc, desc, size);
-		ext2fs_swap_group_desc2(fs,
-					(struct ext2_group_desc *) &swabdesc);
-		desc = (struct ext2_group_desc *) &swabdesc;
+	/* Have to swab back to little-endian to do the checksum */
+	memcpy(&swabdesc, desc, size);
+	ext2fs_swap_group_desc2(fs,
+				(struct ext2_group_desc *) &swabdesc);
+	desc = (struct ext2_group_desc *) &swabdesc;
 
-		group = ext2fs_swab32(group);
+	group = ext2fs_swab32(group);
 #endif
-		crc = ext2fs_crc16(~0, fs->super->s_uuid,
-				   sizeof(fs->super->s_uuid));
-		crc = ext2fs_crc16(crc, &group, sizeof(group));
-		crc = ext2fs_crc16(crc, desc, offset);
-		offset += sizeof(desc->bg_checksum); /* skip checksum */
-		/* for checksum of struct ext4_group_desc do the rest...*/
-		if (offset < size) {
-			crc = ext2fs_crc16(crc, (char *)desc + offset,
-					   size - offset);
-		}
+
+	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+		/* new metadata csum code */
+		__u16 old_crc;
+		__u32 crc32;
+
+		old_crc = desc->bg_checksum;
+		desc->bg_checksum = 0;
+		crc32 = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&group,
+					 sizeof(group));
+		crc32 = ext2fs_crc32c_le(crc32, (unsigned char *)desc,
+					 size);
+		desc->bg_checksum = old_crc;
+
+		crc = crc32 & 0xFFFF;
+		goto out;
 	}
 
+	/* old crc16 code */
+	size_t offset = offsetof(struct ext2_group_desc, bg_checksum);
+	crc = ext2fs_crc16(~0, fs->super->s_uuid,
+			   sizeof(fs->super->s_uuid));
+	crc = ext2fs_crc16(crc, &group, sizeof(group));
+	crc = ext2fs_crc16(crc, desc, offset);
+	offset += sizeof(desc->bg_checksum); /* skip checksum */
+	/* for checksum of struct ext4_group_desc do the rest...*/
+	if (offset < size) {
+		crc = ext2fs_crc16(crc, (char *)desc + offset,
+				   size - offset);
+	}
+
+out:
 	return crc;
 }
 
 int ext2fs_group_desc_csum_verify(ext2_filsys fs, dgrp_t group)
 {
-	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+	if (ext2fs_has_group_desc_csum(fs) &&
 	    (ext2fs_bg_checksum(fs, group) !=
 	     ext2fs_group_desc_csum(fs, group)))
 		return 0;
@@ -738,8 +755,7 @@  int ext2fs_group_desc_csum_verify(ext2_filsys fs, dgrp_t group)
 
 void ext2fs_group_desc_csum_set(ext2_filsys fs, dgrp_t group)
 {
-	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+	if (!ext2fs_has_group_desc_csum(fs))
 		return;
 
 	/* ext2fs_bg_checksum_set() sets the actual checksum field but
@@ -773,8 +789,7 @@  errcode_t ext2fs_set_gdt_csum(ext2_filsys fs)
 	if (!fs->inode_map)
 		return EXT2_ET_NO_INODE_BITMAP;
 
-	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+	if (!ext2fs_has_group_desc_csum(fs))
 		return 0;
 
 	for (i = 0; i < fs->group_desc_count; i++) {
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 9574525..eeac04d 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -642,6 +642,12 @@  typedef struct stat ext2fs_struct_stat;
 /*
  * function prototypes
  */
+static inline int ext2fs_has_group_desc_csum(ext2_filsys fs)
+{
+	return EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+			EXT4_FEATURE_RO_COMPAT_GDT_CSUM |
+			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
+}
 
 /* alloc.c */
 extern errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir, int mode,
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index a63ea18..a22cab4 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -435,8 +435,7 @@  ipg_retry:
 	 * bitmaps will be accounted for when allocated).
 	 */
 	free_blocks = 0;
-	csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					       EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
+	csum_flag = ext2fs_has_group_desc_csum(fs);
 	for (i = 0; i < fs->group_desc_count; i++) {
 		/*
 		 * Don't set the BLOCK_UNINIT group for the last group
diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c
index 74703c5..3e6d853 100644
--- a/lib/ext2fs/inode.c
+++ b/lib/ext2fs/inode.c
@@ -157,8 +157,7 @@  errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
 						     scan->current_group);
 	scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
 	scan->blocks_left = scan->fs->inode_blocks_per_group;
-	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+	if (ext2fs_has_group_desc_csum(fs)) {
 		scan->inodes_left -=
 			ext2fs_bg_itable_unused(fs, scan->current_group);
 		scan->blocks_left =
@@ -183,8 +182,7 @@  errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
 	}
 	if (scan->fs->badblocks && scan->fs->badblocks->num)
 		scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
-	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+	if (ext2fs_has_group_desc_csum(fs))
 		scan->scan_flags |= EXT2_SF_DO_LAZY;
 	*ret_scan = scan;
 	return 0;
@@ -250,8 +248,7 @@  static errcode_t get_next_blockgroup(ext2_inode_scan scan)
 	scan->bytes_left = 0;
 	scan->inodes_left = EXT2_INODES_PER_GROUP(fs->super);
 	scan->blocks_left = fs->inode_blocks_per_group;
-	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+	if (ext2fs_has_group_desc_csum(fs)) {
 		scan->inodes_left -=
 			ext2fs_bg_itable_unused(fs, scan->current_group);
 		scan->blocks_left =
diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index d2b64f4..2dc9b94 100644
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -382,8 +382,7 @@  errcode_t ext2fs_open2(const char *name, const char *io_options,
 	 * If recovery is from backup superblock, Clear _UNININT flags &
 	 * reset bg_itable_unused to zero
 	 */
-	if (superblock > 1 && EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+	if (superblock > 1 && ext2fs_has_group_desc_csum(fs)) {
 		dgrp_t group;
 
 		for (group = 0; group < fs->group_desc_count; group++) {
diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c
index a5097c1..18e18aa 100644
--- a/lib/ext2fs/rw_bitmaps.c
+++ b/lib/ext2fs/rw_bitmaps.c
@@ -36,7 +36,7 @@  static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 	unsigned int	nbits;
 	errcode_t	retval;
 	char		*block_buf = NULL, *inode_buf = NULL;
-	int		csum_flag = 0;
+	int		csum_flag;
 	blk64_t		blk;
 	blk64_t		blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
 	ext2_ino_t	ino_itr = 1;
@@ -46,9 +46,7 @@  static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 	if (!(fs->flags & EXT2_FLAG_RW))
 		return EXT2_ET_RO_FILSYS;
 
-	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
-		csum_flag = 1;
+	csum_flag = ext2fs_has_group_desc_csum(fs);
 
 	inode_nbytes = block_nbytes = 0;
 	if (do_block) {
@@ -168,7 +166,7 @@  static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 	errcode_t retval;
 	int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
 	int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
-	int csum_flag = 0;
+	int csum_flag;
 	int do_image = fs->flags & EXT2_FLAG_IMAGE_FILE;
 	unsigned int	cnt;
 	blk64_t	blk;
@@ -181,9 +179,7 @@  static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 
 	fs->write_bitmaps = ext2fs_write_bitmaps;
 
-	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
-		csum_flag = 1;
+	csum_flag = ext2fs_has_group_desc_csum(fs);
 
 	retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
 	if (retval)
diff --git a/misc/dumpe2fs.c b/misc/dumpe2fs.c
index 23dec30..40398a7 100644
--- a/misc/dumpe2fs.c
+++ b/misc/dumpe2fs.c
@@ -114,7 +114,7 @@  static void print_bg_opts(ext2_filsys fs, dgrp_t i)
 {
 	int first = 1, bg_flags = 0;
 
-	if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM)
+	if (ext2fs_has_group_desc_csum(fs))
 		bg_flags = ext2fs_bg_flags(fs, i);
 
 	print_bg_opt(bg_flags, EXT2_BG_INODE_UNINIT, "INODE_UNINIT",
@@ -190,7 +190,7 @@  static void list_desc (ext2_filsys fs)
 		print_range(first_block, last_block);
 		fputs(")", stdout);
 		print_bg_opts(fs, i);
-		if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM)
+		if (ext2fs_has_group_desc_csum(fs))
 			printf(_("  Checksum 0x%04x, unused inodes %u\n"),
 			       ext2fs_bg_checksum(fs, i),
 			       ext2fs_bg_itable_unused(fs, i));
diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index dc2805d..8a02ff4 100644
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -191,8 +191,7 @@  static void fix_uninit_block_bitmaps(ext2_filsys fs)
 	int		old_desc_blocks;
 	dgrp_t		g;
 
-	if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
+	if (!ext2fs_has_group_desc_csum(fs))
 		return;
 
 	for (g=0; g < fs->group_desc_count; g++) {
@@ -482,8 +481,7 @@  retry:
 	group_block = fs->super->s_first_data_block +
 		old_fs->group_desc_count * fs->super->s_blocks_per_group;
 
-	csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					       EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
+	csum_flag = ext2fs_has_group_desc_csum(fs);
 	adj = old_fs->group_desc_count;
 	max_group = fs->group_desc_count - adj;
 	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
@@ -743,8 +741,7 @@  static void mark_fs_metablock(ext2_resize_t rfs,
 	} else if (IS_INODE_TB(fs, group, blk)) {
 		ext2fs_inode_table_loc_set(fs, group, 0);
 		rfs->needed_blocks++;
-	} else if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					      EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+	} else if (ext2fs_has_group_desc_csum(fs) &&
 		   (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 		/*
 		 * If the block bitmap is uninitialized, which means
@@ -804,8 +801,7 @@  static errcode_t blocks_to_move(ext2_resize_t rfs)
 	for (blk = ext2fs_blocks_count(fs->super);
 	     blk < ext2fs_blocks_count(old_fs->super); blk++) {
 		g = ext2fs_group_of_blk2(fs, blk);
-		if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
-					       EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+		if (ext2fs_has_group_desc_csum(fs) &&
 		    ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 			/*
 			 * The block bitmap is uninitialized, so skip