mkfs_ext2: compat fixes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
author: Denys Vlasenko <vda.linux@googlemail.com> 2009-10-20 00:06:03 +0200
committer: Denys Vlasenko <vda.linux@googlemail.com> 2009-10-20 00:06:03 +0200
commit: 05647b55512d0fec74fe6d69553a773e852674df (patch)
tree: e12249ce2de19cfc4280f2850574958202eb8d9c /util-linux/mkfs_ext2.c
parent: 3ef4f77620a9f5f9a7c1247e29ea9c14e07b8a30 (diff)
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1 files changed, 197 insertions, 190 deletions
diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c
index 38654ef04..d0ebc1dd9 100644
--- a/util-linux/mkfs_ext2.c
+++ b/util-linux/mkfs_ext2.c
@@ -10,6 +10,10 @@
 #include "libbb.h"
 #include <linux/fs.h>
 #include <linux/ext2_fs.h>
+#include <sys/user.h> /* PAGE_SIZE */
+#ifndef PAGE_SIZE
+# define PAGE_SIZE 4096
+#endif
 #include "volume_id/volume_id_internal.h"
 #define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
@@ -26,8 +30,8 @@
 //#define LINUX_S_IFWHT                  0160000
 //#define EXT2_FEATURE_INCOMPAT_WHITEOUT 0x0020
-// storage helper
+// storage helpers
-void BUG_unsupported_field_size(void);
+char BUG_wrong_field_size(void);
 #define STORE_LE(field, value) \
 do { \
        if (sizeof(field) == 4) \
@@ -37,9 +41,12 @@ do { \
        else if (sizeof(field) == 1) \
                field = (value); \
        else \
-                BUG_unsupported_field_size(); \
+                BUG_wrong_field_size(); \
 } while (0)
+#define FETCH_LE32(field) \
+        (sizeof(field) == 4 ? cpu_to_le32(field) : BUG_wrong_field_size())
 // All fields are little-endian
 struct ext2_dir {
        uint32_t inode1;
@@ -68,10 +75,10 @@ static unsigned int_log2(unsigned arg)
 }
 // taken from mkfs_minix.c. libbb candidate?
-static unsigned div_roundup(uint32_t size, uint32_t n)
+static unsigned div_roundup(uint64_t size, uint32_t n)
 {
        // Overflow-resistant
-        uint32_t res = size / n;
+        uint64_t res = size / n;
        if (res * n != size)
                res++;
        return res;
@@ -83,8 +90,8 @@ static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32
        memset(bitmap, 0, blocksize);
        i = start / 8;
        memset(bitmap, 0xFF, i);
-        bitmap[i] = 0xFF >> (8-(start&7));
+        bitmap[i] = 0xFF >> (8 - (start & 7));
-//bb_info_msg("ALLOC: [%u][%u][%u]: [%u]:=[%x]", blocksize, start, end, blocksize - end/8 - 1, (uint8_t)(0xFF << (8-(end&7))));
+//bb_info_msg("ALLOC: [%u][%u][%u]: [%u-%u]:=[%x],[%x]", blocksize, start, end, start/8, blocksize - end/8 - 1, 0xFF >> (8 - (start & 7)), (uint8_t)(0xFF << (8-(end&7))));
        i = end / 8;
        bitmap[blocksize - i - 1] = 0xFF << (8 - (end & 7));
        memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
@@ -167,15 +174,15 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
        unsigned blocksize, blocksize_log2;
        unsigned nreserved = 5;
        unsigned long long kilobytes;
-        uint32_t nblocks;
+        uint32_t nblocks, nblocks_full;
        uint32_t ngroups;
        uint32_t bytes_per_inode;
        uint32_t first_data_block;
-        uint32_t ninodes_per_group;
+        uint32_t inodes_per_group;
        uint32_t gdtsz, itsz;
        time_t timestamp;
        unsigned opts;
-        const char *label;
+        const char *label = "";
        struct stat st;
        struct ext2_super_block *sb; // superblock
        struct ext2_group_desc *gd; // group descriptors
@@ -245,145 +252,85 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
        nblocks = kilobytes;
        if (nblocks != kilobytes)
                bb_error_msg_and_die("block count doesn't fit in 32 bits");
+#define kilobytes kilobytes_unused_after_this
+        if (blocksize < PAGE_SIZE)
+                nblocks &= ~((PAGE_SIZE / blocksize)-1);
+        // N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
+        nblocks_full = nblocks;
+ retry:
        if (nblocks < 8)
                bb_error_msg_and_die("need >= 8 blocks");
-#define kilobytes kilobytes_unused_after_this
        // number of bits in one block, i.e. 8*blocksize
 #define blocks_per_group (8 * blocksize)
-/* e2fsprogs-1.41.9
-        overhead = 2 + fs->inode_blocks_per_group;
-        if (has_super(fs->group_desc_count - 1))
-                overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
-        rem = (nblocks - first_data_block) % blocks_per_group);
-        if ((fs->group_desc_count == 1) && rem && (rem < overhead)) {
-                retval = EXT2_ET_TOOSMALL;
-                goto cleanup;
-        }
-        if (rem && (rem < overhead+50)) {
-                nblocks -= rem;
-                goto retry;
-        }
-*/
        // N.B. a block group can have no more than blocks_per_group blocks
        first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
        ngroups = div_roundup(nblocks - first_data_block, blocks_per_group);
        if (0 == ngroups)
                bb_error_msg_and_die("ngroups");
-        {
+        gdtsz = div_roundup(ngroups, blocksize / sizeof(*gd));
-                // ninodes is the total number of inodes (files) in the file system
+        // TODO: reserved blocks must be marked as such in the bitmaps,
-                uint32_t ninodes = nblocks / (bytes_per_inode >> blocksize_log2);
+        // or resulting filesystem is corrupt
-                if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
-                        ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
-                ninodes_per_group = div_roundup(ninodes, ngroups);
-                // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
-                if (ninodes_per_group < 16)
-                        ninodes_per_group = 16;
-        }
-        // TODO: 5?/5 WE MUST NOT DEPEND ON WHETHER DEVICE IS /dev/zero 'ed OR NOT
-        // TODO: 3/5 refuse if mounted
-        // TODO: 4/5 compat options
-        // TODO: 1/5 sanity checks
-        // TODO: 0/5 more verbose error messages
-        // TODO: 0/5 info printing
-        // TODO: 2/5 bigendianness! Spot where it comes to play! sb->, gd->
-        // TODO: 2/5 reserved GDT: how to mark but not allocate?
-        // TODO: 3/5 dir_index?
-        // fill the superblock
-        sb = xzalloc(blocksize);
-        sb->s_rev_level = 1; // revision 1 filesystem
-        sb->s_magic = EXT2_SUPER_MAGIC;
-        sb->s_inode_size = sizeof(*inode);
-        sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
-        sb->s_log_block_size = sb->s_log_frag_size = blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE;
-        // first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
-        // the first block available for data is 1, otherwise 0
-        sb->s_first_data_block = first_data_block; // 0 or 1
-        // block and inode bitmaps occupy no more than one block, so maximum number of blocks is
-        sb->s_blocks_per_group = sb->s_frags_per_group = blocks_per_group;
-        timestamp = time(NULL);
-        sb->s_mkfs_time = sb->s_wtime = sb->s_lastcheck = timestamp;
-        sb->s_state = 1;
-        sb->s_creator_os = EXT2_OS_LINUX;
-        sb->s_checkinterval = 24*60*60 * 180; // 180 days
-        sb->s_errors = EXT2_ERRORS_DEFAULT;
-        sb->s_feature_compat = EXT2_FEATURE_COMPAT_SUPP
-                | (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
-                | (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
-                ;
-        // e2fsprogs-1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
-        sb->s_feature_incompat = EXT2_FEATURE_INCOMPAT_FILETYPE;// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
-        sb->s_feature_ro_compat = EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
-        sb->s_flags = EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX;
-        generate_uuid(sb->s_uuid);
-        if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
-                sb->s_def_hash_version = EXT2_HASH_HALF_MD4;
-                generate_uuid((uint8_t *)sb->s_hash_seed);
-        }
-        /*
-         * From e2fsprogs: add "jitter" to the superblock's check interval so that we
-         * 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.
-         */
-        sb->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT
-                + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT);
-        sb->s_blocks_count = nblocks;
-        // reserve blocks for superuser
-        sb->s_r_blocks_count = ((uint64_t) nblocks * nreserved) / 100;
-        gdtsz = div_roundup(ngroups, EXT2_DESC_PER_BLOCK(sb));
-        /*
-         * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
-         * filesystem growth.
-         * The absolute maximum number of GDT blocks we can reserve is determined by
-         * the number of block pointers that can fit into a single block.
-         */
-        /* We set it at 1024x the current filesystem size, or
-         * the upper block count limit (2^32), whichever is lower.
-         */
        if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
+                /*
+                 * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
+                 * filesystem growth.
+                 * The absolute maximum number of GDT blocks we can reserve is determined by
+                 * the number of block pointers that can fit into a single block.
+                 * 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_data_block, blocks_per_group);
-                rgdtsz = div_roundup(rgdtsz, EXT2_DESC_PER_BLOCK(sb)) - gdtsz;
+                rgdtsz = div_roundup(rgdtsz, blocksize / sizeof(*gd)) - gdtsz;
-                if (rgdtsz > EXT2_ADDR_PER_BLOCK(sb))
+                if (rgdtsz > blocksize / sizeof(uint32_t))
-                        rgdtsz = EXT2_ADDR_PER_BLOCK(sb);
+                        rgdtsz = blocksize / sizeof(uint32_t);
-                STORE_LE(sb->s_reserved_gdt_blocks, rgdtsz);
+                //TODO: STORE_LE(sb->s_reserved_gdt_blocks, rgdtsz);
                gdtsz += rgdtsz;
        }
-        // N.B. a block group can have no more than 8*blocksize inodes
+        {
-        if (ninodes_per_group > blocks_per_group)
+                // N.B. e2fsprogs does as follows!
-                ninodes_per_group = blocks_per_group;
+                // ninodes is the total number of inodes (files) in the file system
-        // adjust inodes per group so they completely fill the inode table blocks in the descriptor
+                uint32_t ninodes = nblocks_full / (blocksize >= 4096 ? 1 : 4096 / blocksize);
-        ninodes_per_group = (div_roundup(ninodes_per_group * EXT2_INODE_SIZE(sb), blocksize) << blocksize_log2) / EXT2_INODE_SIZE(sb);
+                uint32_t overhead, remainder;
-        // make sure the number of inodes per group is a multiple of 8
+                if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
-        ninodes_per_group &= ~7;
+                        ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
-        sb->s_inodes_per_group = ninodes_per_group;// = div_roundup(ninodes_per_group * sb->s_inode_size, blocksize);
+                inodes_per_group = div_roundup(ninodes, ngroups);
-        // total ninodes
+                // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
-        sb->s_inodes_count = ninodes_per_group * ngroups;
+                if (inodes_per_group < 16)
+                        inodes_per_group = 16;
-        itsz = ninodes_per_group * sb->s_inode_size / blocksize;
-        sb->s_free_inodes_count = sb->s_inodes_count - EXT2_GOOD_OLD_FIRST_INO;
+                // N.B. a block group can have no more than 8*blocksize inodes
+                if (inodes_per_group > blocks_per_group)
-        // write the label, if any
+                        inodes_per_group = blocks_per_group;
-        if (opts & OPT_L)
+                // adjust inodes per group so they completely fill the inode table blocks in the descriptor
-                safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
+                inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) << blocksize_log2) / sizeof(*inode);
+                // make sure the number of inodes per group is a multiple of 8
-#if 1
+                inodes_per_group &= ~7;
-/*      if (fs_param.s_blocks_count != s->s_blocks_count)
+                itsz = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
-                fprintf(stderr, _("warning: %u blocks unused.\n\n"),
-                       fs_param.s_blocks_count - s->s_blocks_count);
+                // the last block needs more attention: doesn't it too small for possible overhead?
-*/
+                overhead = (has_super(ngroups - 1) ? (1/*sb*/ + gdtsz) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
+                remainder = (nblocks - first_data_block) % blocks_per_group;
+                if ((1 == ngroups) && remainder && (remainder < overhead))
+                        bb_error_msg_and_die("way small device");
+                if (remainder && (remainder < overhead + 50)) {
+//bb_info_msg("CHOP[%u]", remainder);
+                        nblocks -= remainder;
+                        goto retry;
+                }
+        }
+        // print info
+        if (nblocks_full - nblocks)
+                printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
        printf(
                "Filesystem label=%s\n"
                "OS type: Linux\n"
@@ -396,16 +343,17 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
                "%u block groups\n"
                "%u blocks per group, %u fragments per group\n"
                "%u inodes per group"
-                , (char *)sb->s_volume_name
+                , label
-                , blocksize, sb->s_log_block_size
+                , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
-                , blocksize, sb->s_log_block_size
+                , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
-                , sb->s_inodes_count, sb->s_blocks_count
+                , inodes_per_group * ngroups, nblocks
-                , sb->s_r_blocks_count, nreserved
+                //, div_roundup((uint64_t) nblocks * nreserved, 100), nreserved
+                , (unsigned)((uint64_t) nblocks_full * nreserved / 100), nreserved
                , first_data_block
-                , gdtsz * EXT2_DESC_PER_BLOCK(sb) * blocks_per_group
+                , gdtsz * (blocksize / sizeof(*gd)) * blocks_per_group
                , ngroups
                , blocks_per_group, blocks_per_group
-                , ninodes_per_group
+                , inodes_per_group
        );
        {
                const char *fmt = "\nSuperblock backups stored on blocks:\n"
@@ -420,84 +368,149 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
                }
        }
        bb_putchar('\n');
-#endif
+        // dry run? -> we are done
        if (opts & OPT_n)
                goto done;
+        // TODO: 3/5 refuse if mounted
+        // TODO: 4/5 compat options
+        // TODO: 1/5 sanity checks
+        // TODO: 0/5 more verbose error messages
+        // TODO: 4/5 bigendianness: recheck, wait for ARM reporters
+        // TODO: 2/5 reserved GDT: how to mark but not allocate?
+        // TODO: 3/5 dir_index?
+        // fill the superblock
+        sb = xzalloc(blocksize);
+        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));
+        STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
+        STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
+        STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
+        // first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
+        // the first block available for data is 1, otherwise 0
+        STORE_LE(sb->s_first_data_block, first_data_block); // 0 or 1
+        // block and inode bitmaps occupy no more than one block, so maximum number of blocks is
+        STORE_LE(sb->s_blocks_per_group, blocks_per_group);
+        STORE_LE(sb->s_frags_per_group, blocks_per_group);
+        // blocks
+        STORE_LE(sb->s_blocks_count, nblocks);
+        // reserve blocks for superuser
+        STORE_LE(sb->s_r_blocks_count, (uint32_t)((uint64_t) nblocks_full * nreserved / 100));
+        // ninodes
+        STORE_LE(sb->s_inodes_per_group, inodes_per_group);
+        STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
+        STORE_LE(sb->s_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
+        // timestamps
+        timestamp = time(NULL);
+        STORE_LE(sb->s_mkfs_time, timestamp);
+        STORE_LE(sb->s_wtime, timestamp);
+        STORE_LE(sb->s_lastcheck, timestamp);
+        // misc
+        STORE_LE(sb->s_state, 1); // TODO: what's 1?
+        STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
+        STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
+        STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
+        STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
+                | (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
+                | (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
+        );
+        // e2fsprogs-1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
+        STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
+        STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
+        STORE_LE(sb->s_flags, EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
+        generate_uuid(sb->s_uuid);
+        if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
+                STORE_LE(sb->s_def_hash_version, EXT2_HASH_HALF_MD4);
+                generate_uuid((uint8_t *)sb->s_hash_seed);
+        }
+        /*
+         * From e2fsprogs: add "jitter" to the superblock's check interval so that we
+         * 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
+                + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
+        // write the label, if any
+        if (label) //opts & OPT_L)
+                safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
        // fill group descriptors
        gd = xzalloc(gdtsz * blocksize);
+        buf = xmalloc(blocksize);
        sb->s_free_blocks_count = 0;
-        for (i = 0, pos = first_data_block, n = nblocks;
+        for (i = 0, pos = first_data_block, n = nblocks - first_data_block;
                i < ngroups;
                i++, pos += blocks_per_group, n -= blocks_per_group
        ) {
                uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + gdtsz) : 0);
-                gd[i].bg_block_bitmap = overhead + 0;
+                uint32_t fb;
-                gd[i].bg_inode_bitmap = overhead + 1;
+                STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
-                gd[i].bg_inode_table  = overhead + 2;
+                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;
-                gd[i].bg_free_inodes_count = ninodes_per_group;
+                gd[i].bg_free_inodes_count = inodes_per_group;
-                //gd[i].bg_used_dirs_count = 0;
+                //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
                if (0 == i) {
                        overhead += 2;
-                        gd[i].bg_used_dirs_count = 2;
+                        STORE_LE(gd[i].bg_used_dirs_count, 2);
                        gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
                }
-                // N.B. the following is pure heuristics!
+//              // N.B. the following is pure heuristics!
-                // Likely to cope with 1024-byte blocks, when first block is for boot sectors
+//              // Likely to cope with 1024-byte blocks, when first block is for boot sectors
-                if (ngroups-1 == i) {
+//              if (ngroups-1 == i) {
-                        overhead += first_data_block;
+//                      n -= first_data_block;
-                }
+//              }
-                gd[i].bg_free_blocks_count = (n < blocks_per_group ? n : blocks_per_group) - overhead;
-                sb->s_free_blocks_count += gd[i].bg_free_blocks_count;
+                // 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));
+                allocate(buf, blocksize,
+                        overhead,
+                        blocks_per_group - (fb + 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);
+                // mark preallocated inodes as allocated
+                allocate(buf, blocksize,
+                        inodes_per_group - gd[i].bg_free_inodes_count,
+                        blocks_per_group - inodes_per_group
+                );
+                // dump inode bitmap
+                //PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
+                //but it's right after block bitmap, so we can just:
+                xwrite(fd, buf, blocksize);
+                STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
+                // count overall free blocks
+                sb->s_free_blocks_count += fb;
        }
        STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
        // dump filesystem skeleton structures
 //      printf("Writing superblocks and filesystem accounting information: ");
-        buf = xmalloc(blocksize);
        for (i = 0, pos = first_data_block; i < ngroups; i++, pos += blocks_per_group) {
-                uint32_t overhead = has_super(i) ? (1/*sb*/ + gdtsz) : 0;
-                uint32_t start;
-                uint32_t end;
                // dump superblock and group descriptors and their backups
-                if (overhead) { // N.B. in fact, we want (has_super(i)) condition, but it is equal to (overhead != 0) and is cheaper
+                if (has_super(i)) {
                        // N.B. 1024 byte blocks are special
                        PUT(((uint64_t)pos << blocksize_log2) + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, 1024);//blocksize);
                        PUT(((uint64_t)pos << blocksize_log2) + blocksize, gd, gdtsz * blocksize);
                }
-                start = overhead + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
-                if (i == 0)
-                        start += 2; // for "/" and "/lost+found"
-                end = blocks_per_group - (start + gd[i].bg_free_blocks_count);
-                // mark preallocated blocks as allocated
-                allocate(buf, blocksize, start, end);
-                // dump block bitmap
-                PUT((uint64_t)(pos + overhead) * blocksize, buf, blocksize);
-                // mark preallocated inodes as allocated
-                allocate(buf, blocksize,
-                        ninodes_per_group - gd[i].bg_free_inodes_count,
-                        blocks_per_group - ninodes_per_group
-                );
-                // dump inode bitmap
-                //PUT((uint64_t)(pos + overhead + 1) * blocksize, buf, blocksize);
-                //but it's right after block bitmap, so we can just:
-                xwrite(fd, buf, blocksize);
        }
        // zero boot sectors
        memset(buf, 0, blocksize);
-        PUT(0, buf, 1024); // N.B. 1024 <= blocksize
+        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)(gd[i].bg_inode_table + n) * blocksize, buf, blocksize);
+                        PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize, buf, blocksize);
        // prepare directory inode
        inode = (struct ext2_inode *)buf;
@@ -511,13 +524,13 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
        // dump root dir inode
        STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
-        STORE_LE(inode->i_block[0], gd[0].bg_inode_table + itsz);
+        STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + itsz);
-        PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
+        PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (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 //= gd[0].bg_inode_table + itsz + 1;
+        STORE_LE(inode->i_block[0], inode->i_block[0]+1); // use next block
-        PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
+        PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
        // dump directories
        memset(buf, 0, blocksize);
@@ -534,7 +547,7 @@ 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)(gd[0].bg_inode_table + itsz + 1) * blocksize, buf, blocksize);
+        PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + itsz + 1) * blocksize, buf, blocksize);
        // dump root dir block
        STORE_LE(dir->inode1, EXT2_ROOT_INO);
@@ -544,13 +557,7 @@ 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)(gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize);
+        PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + itsz + 0) * blocksize, buf, blocksize);
-//      bb_info_msg("done\n"
-//              "This filesystem will be automatically checked every %u mounts or\n"
-//              "180 days, whichever comes first. Use tune2fs -c or -i to override.",
-//              sb->s_max_mnt_count
-//      );
 done:
        // cleanup
author	Denys Vlasenko <vda.linux@googlemail.com>	2009-10-20 00:06:03 +0200
committer	Denys Vlasenko <vda.linux@googlemail.com>	2009-10-20 00:06:03 +0200
commit	05647b55512d0fec74fe6d69553a773e852674df (patch)
tree	e12249ce2de19cfc4280f2850574958202eb8d9c /util-linux/mkfs_ext2.c
parent	3ef4f77620a9f5f9a7c1247e29ea9c14e07b8a30 (diff)
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