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5e1dbd5bc

Denys Vlasenko

2009-10-20

FAILED Duration: 30s

Subject

mkfs_ext2: another update by Vladimir

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No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

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Commit Diff GitHub →

util-linux/mkfs_ext2.c +95 -52 util-linux/mkfs_ext2_test.sh +31 -37

util-linux/mkfs_ext2.c+95 -52

@@ -75,8 +75,8 @@ static unsigned int_log2(unsigned arg)
	}

	// taken from mkfs_minix.c. libbb candidate?
-	// why "uint64_t size"? we never use it for anything >32 bits
-	static uint32_t div_roundup(uint64_t size, uint32_t n)
+	// "uint32_t size", since we never use it for anything >32 bits
+	static uint32_t div_roundup(uint32_t size, uint32_t n)
	{
	// Overflow-resistant
	uint32_t res = size / n;
@@ -176,12 +176,15 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	unsigned blocksize, blocksize_log2;
	unsigned reserved_percent = 5;
	unsigned long long kilobytes;
-	uint32_t nblocks, nblocks_full, nreserved;
+	uint32_t nblocks, nblocks_full;
+	uint32_t nreserved;
	uint32_t ngroups;
	uint32_t bytes_per_inode;
	uint32_t first_block;
	uint32_t inodes_per_group;
-	uint32_t gdtsz, itsz;
+	uint32_t group_desc_blocks;
+	uint32_t inode_table_blocks;
+	uint32_t lost_and_found_blocks;
	time_t timestamp;
	unsigned opts;
	const char *label = "";
@@ -245,6 +248,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	) {
	bb_error_msg_and_die("blocksize %u is bad", blocksize);
	}
+	if ((int32_t)bytes_per_inode < blocksize)
+	bb_error_msg_and_die("-%c is bad", 'i');
	// number of bits in one block, i.e. 8*blocksize
	#define blocks_per_group (8 * blocksize)
	first_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
@@ -266,7 +271,6 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	// How many reserved blocks?
	if (reserved_percent > 50)
	bb_error_msg_and_die("-%c is bad", 'm');
-	//nreserved = div_roundup((uint64_t) nblocks * reserved_percent, 100);
	nreserved = (uint64_t)nblocks * reserved_percent / 100;

	// N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
@@ -279,10 +283,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	retry:
	// N.B. a block group can have no more than blocks_per_group blocks
	ngroups = div_roundup(nblocks - first_block, blocks_per_group);
-	if (0 == ngroups)
-	bb_error_msg_and_die("ngroups");

-	gdtsz = div_roundup(ngroups, blocksize / sizeof(*gd));
+	group_desc_blocks = div_roundup(ngroups, blocksize / sizeof(*gd));
	// TODO: reserved blocks must be marked as such in the bitmaps,
	// or resulting filesystem is corrupt
	if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
@@ -294,15 +296,15 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	* We set it at 1024x the current filesystem size, or
	* the upper block count limit (2^32), whichever is lower.
	*/
-	uint32_t rgdtsz = 0xFFFFFFFF; // maximum block number
-	if (nblocks < rgdtsz / 1024)
-	rgdtsz = nblocks * 1024;
-	rgdtsz = div_roundup(rgdtsz - first_block, blocks_per_group);
-	rgdtsz = div_roundup(rgdtsz, blocksize / sizeof(*gd)) - gdtsz;
-	if (rgdtsz > blocksize / sizeof(uint32_t))
-	rgdtsz = blocksize / sizeof(uint32_t);
-	//TODO: STORE_LE(sb->s_reserved_gdt_blocks, rgdtsz);
-	gdtsz += rgdtsz;
+	uint32_t reserved_group_desc_blocks = 0xFFFFFFFF; // maximum block number
+	if (nblocks < reserved_group_desc_blocks / 1024)
+	reserved_group_desc_blocks = nblocks * 1024;
+	reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks - first_block, blocks_per_group);
+	reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks, blocksize / sizeof(*gd)) - group_desc_blocks;
+	if (reserved_group_desc_blocks > blocksize / sizeof(uint32_t))
+	reserved_group_desc_blocks = blocksize / sizeof(uint32_t);
+	//TODO: STORE_LE(sb->s_reserved_gdt_blocks, reserved_group_desc_blocks);
+	group_desc_blocks += reserved_group_desc_blocks;
	}

	{
@@ -324,13 +326,25 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	inodes_per_group = (div_roundup(inodes_per_group * sizeof(inode), blocksize) blocksize) / sizeof(*inode);
	// make sure the number of inodes per group is a multiple of 8
	inodes_per_group &= ~7;
-	itsz = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
+	inode_table_blocks = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
+
+	// to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
+	// and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
+	/* Or e2fsprogs comment verbatim (what does it mean?):
+	* Ensure that lost+found is at least 2 blocks, so we always
+	* test large empty blocks for big-block filesystems. */
+	lost_and_found_blocks = MIN(EXT2_NDIR_BLOCKS, 16 >> (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE));

	// the last group needs more attention: isn't it too small for possible overhead?
-	overhead = (has_super(ngroups - 1) ? (1/sb/ + gdtsz) : 0) + 1/bbmp/ + 1/ibmp/ + itsz;
+	overhead = (has_super(ngroups - 1) ? (1/sb/ + group_desc_blocks) : 0) + 1/bbmp/ + 1/ibmp/ + inode_table_blocks;
	remainder = (nblocks - first_block) % blocks_per_group;
-	if ((1 == ngroups) && remainder && (remainder < overhead))
-	bb_error_msg_and_die("way small device");
+	////can't happen, nblocks >= 60 guarantees this
+	////if ((1 == ngroups)
+	//// && remainder
+	//// && (remainder < overhead + 1/* "/" */ + lost_and_found_blocks)
+	////) {
+	//// bb_error_msg_and_die("way small device");
+	////}
	// Standard mke2fs uses 50. Looks like a bug in our calculation
	// of "remainder" or "overhead" - we don't match standard mke2fs
	// when we transition from one group to two groups
@@ -363,7 +377,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	, inodes_per_group * ngroups, nblocks
	, nreserved, reserved_percent
	, first_block
-	, gdtsz * (blocksize / sizeof(gd)) blocks_per_group
+	, group_desc_blocks * (blocksize / sizeof(gd)) blocks_per_group
	, ngroups
	, blocks_per_group, blocks_per_group
	, inodes_per_group
@@ -382,9 +396,11 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	}
	bb_putchar('\n');

-	// dry run? -> we are done
-	if (opts & OPT_n)
-	goto done;
+	if (opts & OPT_n) {
+	if (ENABLE_FEATURE_CLEAN_UP)
+	close(fd);
+	return EXIT_SUCCESS;
+	}

	// TODO: 3/5 refuse if mounted
	// TODO: 4/5 compat options
@@ -395,7 +411,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	// TODO: 3/5 dir_index?

	// fill the superblock
-	sb = xzalloc(blocksize);
+	sb = xzalloc(1024);
	STORE_LE(sb->s_rev_level, 1); // revision 1 filesystem
	STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
	STORE_LE(sb->s_inode_size, sizeof(*inode));
@@ -444,49 +460,61 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	* don't check all the filesystems at the same time. We use a
	* kludgy hack of using the UUID to derive a random jitter value.
	*/
-	STORE_LE(sb->s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT
+	STORE_LE(sb->s_max_mnt_count,
+	EXT2_DFL_MAX_MNT_COUNT
	+ (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));

	// write the label
	safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));

-	// fill group descriptors
-	gd = xzalloc(gdtsz * blocksize);
+	// calculate filesystem skeleton structures
+	gd = xzalloc(group_desc_blocks * blocksize);
	buf = xmalloc(blocksize);
	sb->s_free_blocks_count = 0;
	for (i = 0, pos = first_block, n = nblocks - first_block;
	i < ngroups;
	i++, pos += blocks_per_group, n -= blocks_per_group
	) {
-	uint32_t overhead = pos + (has_super(i) ? (1/sb/ + gdtsz) : 0);
-	uint32_t fb;
+	uint32_t overhead = pos + (has_super(i) ? (1/sb/ + group_desc_blocks) : 0);
+	uint32_t free_blocks;
+	// fill group descriptors
	STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
	STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
	STORE_LE(gd[i].bg_inode_table, overhead + 2);
-	overhead = overhead - pos + 1/bbmp/ + 1/ibmp/ + itsz;
+	overhead = overhead - pos + 1/bbmp/ + 1/ibmp/ + inode_table_blocks;
	gd[i].bg_free_inodes_count = inodes_per_group;
	//STORE_LE(gd[i].bg_used_dirs_count, 0);
-	// N.B. both root and lost+found dirs are within the first block group, thus +2
+	// N.B. both "/" and "/lost+found" are within the first block group
+	// "/" occupies 1 block, "/lost+found" occupies lost_and_found_blocks...
	if (0 == i) {
-	overhead += 2;
+	// ... thus increased overhead for the first block group ...
+	overhead += 1 + lost_and_found_blocks;
+	// ... and 2 used directories
	STORE_LE(gd[i].bg_used_dirs_count, 2);
+	// well known reserved inodes belong to the first block too
	gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
	}

+	// cache free block count of the group
+	free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
+
	// mark preallocated blocks as allocated
-	fb = (n < blocks_per_group ? n : blocks_per_group) - overhead;
-	//bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (fb + overhead));
+	//bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
	allocate(buf, blocksize,
+	// reserve "overhead" blocks
	overhead,
-	blocks_per_group - (fb + overhead)
+	// mark unused trailing blocks
+	blocks_per_group - (free_blocks + overhead)
	);
	// dump block bitmap
	PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
-	STORE_LE(gd[i].bg_free_blocks_count, fb);
+	STORE_LE(gd[i].bg_free_blocks_count, free_blocks);

	// mark preallocated inodes as allocated
	allocate(buf, blocksize,
+	// mark reserved inodes
	inodes_per_group - gd[i].bg_free_inodes_count,
+	// mark unused trailing inodes
	blocks_per_group - inodes_per_group
	);
	// dump inode bitmap
@@ -496,7 +524,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);

	// count overall free blocks
-	sb->s_free_blocks_count += fb;
+	sb->s_free_blocks_count += free_blocks;
	}
	STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);

@@ -506,8 +534,10 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	// dump superblock and group descriptors and their backups
	if (has_super(i)) {
	// N.B. 1024 byte blocks are special
-	PUT(((uint64_t)pos * blocksize) + ((0 == i && 0 == first_block) ? 1024 : 0), sb, 1024);//blocksize);
-	PUT(((uint64_t)pos * blocksize) + blocksize, gd, gdtsz * blocksize);
+	PUT(((uint64_t)pos * blocksize) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
+	sb, 1024);
+	PUT(((uint64_t)pos * blocksize) + blocksize,
+	gd, group_desc_blocks * blocksize);
	}
	}

@@ -516,8 +546,9 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
	// zero inode tables
	for (i = 0; i < ngroups; ++i)
-	for (n = 0; n < itsz; ++n)
-	PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize, buf, blocksize);
+	for (n = 0; n < inode_table_blocks; ++n)
+	PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize,
+	buf, blocksize);

	// prepare directory inode
	inode = (struct ext2_inode *)buf;
@@ -526,21 +557,34 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	STORE_LE(inode->i_atime, timestamp);
	STORE_LE(inode->i_ctime, timestamp);
	STORE_LE(inode->i_size, blocksize);
-	// N.B. inode->i_blocks stores the number of 512 byte data blocks. Why on Earth?!
+	// inode->i_blocks stores the number of 512 byte data blocks
+	// (512, because it goes directly to struct stat without scaling)
	STORE_LE(inode->i_blocks, blocksize / 512);

	// dump root dir inode
	STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
-	STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + itsz);
-	PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * sizeof(inode), buf, sizeof(inode));
+	STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks);
+	PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * sizeof(*inode),
+	buf, sizeof(*inode));

	// dump lost+found dir inode
	STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
-	STORE_LE(inode->i_block[0], inode->i_block[0]+1); // use next block
-	PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(inode), buf, sizeof(inode));
+	STORE_LE(inode->i_size, lost_and_found_blocks * blocksize);
+	STORE_LE(inode->i_blocks, (lost_and_found_blocks * blocksize) / 512);
+	n = FETCH_LE32(inode->i_block[0]) + 1;
+	for (i = 0; i < lost_and_found_blocks; ++i)
+	STORE_LE(inode->i_block[i], i + n); // use next block
+	//bb_info_msg("LAST BLOCK USED[%u]", i + n);
+	PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode),
+	buf, sizeof(*inode));
+
+	// zero the blocks for "/lost+found"
+	memset(buf, 0, blocksize);
+	for (i = 1; i < lost_and_found_blocks; ++i)
+	PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
+	buf, blocksize);

	// dump directories
-	memset(buf, 0, blocksize);
	dir = (struct ext2_dir *)buf;

	// dump lost+found dir block
@@ -554,7 +598,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	STORE_LE(dir->name_len2, 2);
	STORE_LE(dir->file_type2, EXT2_FT_DIR);
	dir->name2[0] = '.'; dir->name2[1] = '.';
-	PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + itsz + 1) * blocksize, buf, blocksize);
+	PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1) * blocksize, buf, blocksize);

	// dump root dir block
	STORE_LE(dir->inode1, EXT2_ROOT_INO);
@@ -564,9 +608,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
	STORE_LE(dir->name_len3, 10);
	STORE_LE(dir->file_type3, EXT2_FT_DIR);
	strcpy(dir->name3, "lost+found");
-	PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + itsz + 0) * blocksize, buf, blocksize);
+	PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 0) * blocksize, buf, blocksize);

-	done:
	// cleanup
	if (ENABLE_FEATURE_CLEAN_UP) {
	free(buf);

util-linux/mkfs_ext2_test.sh+31 -37

@@ -7,9 +7,6 @@ gen_image() { # params: mke2fs_invocation image_name
	>$2
	dd seek=$((kilobytes-1)) bs=1K count=1 </dev/zero of=$2 >/dev/null 2>&1 \|\| exit 1
	$1 -F $2 $kilobytes >$2.raw_out 2>&1 \|\| return 1
-
-	#off \| sed 's/inodes, [0-9]* blocks/inodes, N blocks/' \
-
	cat $2.raw_out \
	\| grep -v '^mke2fs [0-9]\.[0-9]\.[0-9]* ' \
	\| grep -v '^Maximum filesystem' \
@@ -55,54 +52,51 @@ done

	# Transition from one block group to two
	# fails in [8378..8410] range
-	kilobytes=$((8*1024 - 20))
+	kilobytes=$((1 * 8*1024 - 50))
	while true; do
	test_mke2fs #\|\| exit 1
	: $((kilobytes++))
-	test $kilobytes = $((8*1024 + 300)) && break
+	test $kilobytes = $((1 * 8*1024 + 300)) && break
	done

-	# Transition from two block groups to three
+	# Transition from 2 block groups to 3
	# works
-	kilobytes=$((16*1024 - 40))
+	kilobytes=$((2 * 8*1024 - 50))
	while true; do
	test_mke2fs \|\| exit 1
	: $((kilobytes++))
-	test $kilobytes = $((16*1024 + 500)) && break
+	test $kilobytes = $((2 * 8*1024 + 400)) && break
	done
-	exit
-
-	# Specific sizes with known differences:
-
-	# -6240 inodes, 24908 blocks
-	# +6240 inodes, 24577 blocks
-	# -4 block group
-	# +3 block group
-	# -1560 inodes per group
-	# +2080 inodes per group
-	kilobytes=24908 test_mke2fs

-	# -304 inodes, N blocks
-	# +152 inodes, N blocks
-	# -304 inodes per group
-	# +152 inodes per group
-	kilobytes=1218 test_mke2fs
-
-	# -14464 inodes, N blocks
-	# +14448 inodes, N blocks
-	# -8 block group
-	# +7 block group
-	# -1808 inodes per group
-	# +2064 inodes per group
-	kilobytes=57696 test_mke2fs
+	# Transition from 3 block groups to 4
+	# fails in [24825..24922] range
+	kilobytes=$((3 * 8*1024 - 50))
+	while true; do
+	test_mke2fs #\|\| exit 1
+	: $((kilobytes++))
+	test $kilobytes = $((3 * 8*1024 + 500)) && break
+	done

-	# -warning: 239 blocks unused.
-	# +warning: 242 blocks unused.
-	kilobytes=49395 test_mke2fs
+	# Transition from 4 block groups to 5
+	# works
+	kilobytes=$((4 * 8*1024 - 50))
+	while true; do
+	test_mke2fs \|\| exit 1
+	: $((kilobytes++))
+	test $kilobytes = $((4 * 8*1024 + 600)) && break
+	done

-	## This size results in "warning: 75 blocks unused"
-	#kilobytes=98380 test_mke2fs
+	# Transition from 5 block groups to 6
+	# fails in [41230..41391] range
+	kilobytes=$((5 * 8*1024 - 50))
+	while true; do
+	test_mke2fs #\|\| exit 1
+	: $((kilobytes++))
+	test $kilobytes = $((5 * 8*1024 + 700)) && break
+	done
+	exit

+	# Random sizes
	while true; do
	kilobytes=$(( (RANDOM*RANDOM) % 1000000 + 60))
	test_mke2fs \|\| exit 1