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genext2fs.c
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genext2fs.c
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/* vi: set sw=8 ts=8: */
// genext2fs.c
//
// ext2 filesystem generator for embedded systems
// Copyright (C) 2000 Xavier Bestel <[email protected]>
//
// Please direct support requests to https://github.com/bestouff/genext2fs/issues
//
// 'du' portions taken from coreutils/du.c in busybox:
// Copyright (C) 1999,2000 by Lineo, inc. and John Beppu
// Copyright (C) 1999,2000,2001 by John Beppu <[email protected]>
// Copyright (C) 2002 Edward Betts <[email protected]>
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; version
// 2 of the License.
//
// Changes:
// 3 Jun 2000 Initial release
// 6 Jun 2000 Bugfix: fs size multiple of 8
// Bugfix: fill blocks with inodes
// 14 Jun 2000 Bugfix: bad chdir() with -d option
// Bugfix: removed size=8n constraint
// Changed -d file to -f file
// Added -e option
// 22 Jun 2000 Changed types for 64bits archs
// 24 Jun 2000 Added endianness swap
// Bugfix: bad dir name lookup
// 03 Aug 2000 Bugfix: ind. blocks endian swap
// 09 Aug 2000 Bugfix: symlinks endian swap
// 01 Sep 2000 Bugfix: getopt returns int, not char [email protected]
// 10 Sep 2000 Bugfix: device nodes endianness [email protected]
// Bugfix: getcwd values for Solaris [email protected]
// Bugfix: ANSI scanf for non-GNU C [email protected]
// 28 Jun 2001 Bugfix: getcwd differs for Solaris/GNU [email protected]
// 8 Mar 2002 Bugfix: endianness swap of x-indirects
// 23 Mar 2002 Bugfix: test for IFCHR or IFBLK was flawed
// 10 Oct 2002 Added comments,makefile targets, [email protected]
// endianess swap assert check.
// Copyright (C) 2002 Ixia communications
// 12 Oct 2002 Added support for triple indirection [email protected]
// Copyright (C) 2002 Ixia communications
// 14 Oct 2002 Added support for groups [email protected]
// Copyright (C) 2002 Ixia communications
// 5 Jan 2003 Bugfixes: reserved inodes should be set [email protected]
// only in the first group; directory names
// need to be null padded at the end; and
// number of blocks per group should be a
// multiple of 8. Updated md5 values.
// 6 Jan 2003 Erik Andersen <[email protected]> added
// mkfs.jffs2 compatible device table support,
// along with -q, -P, -U
/*
* Allow fseeko/off_t to be 64-bit offsets to allow filesystems and
* individual files >2GB.
*/
#define _FILE_OFFSET_BITS 64
#include <config.h>
#include <stdio.h>
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#if MAJOR_IN_MKDEV
# include <sys/mkdev.h>
#elif MAJOR_IN_SYSMACROS
# include <sys/sysmacros.h>
#endif
#if HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#if STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# if HAVE_STDLIB_H
# include <stdlib.h>
# endif
# if HAVE_STDDEF_H
# include <stddef.h>
# endif
#endif
#if HAVE_STRING_H
# if !STDC_HEADERS && HAVE_MEMORY_H
# include <memory.h>
# endif
# include <string.h>
#endif
#if HAVE_STRINGS_H
# include <strings.h>
#endif
#if HAVE_INTTYPES_H
# include <inttypes.h>
#else
# if HAVE_STDINT_H
# include <stdint.h>
# endif
#endif
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#if HAVE_DIRENT_H
# include <dirent.h>
#else
# define dirent direct
# if HAVE_SYS_NDIR_H
# include <sys/ndir.h>
# endif
# if HAVE_SYS_DIR_H
# include <sys/dir.h>
# endif
# if HAVE_NDIR_H
# include <ndir.h>
# endif
#endif
#if HAVE_LIBGEN_H
# include <libgen.h>
#endif
#include <stdarg.h>
#include <assert.h>
#include <time.h>
#include <ctype.h>
#include <errno.h>
#if HAVE_FCNTL_H
# include <fcntl.h>
#endif
#if HAVE_GETOPT_H
# include <getopt.h>
#endif
#if HAVE_LIMITS_H
# include <limits.h>
#endif
#include "cache.h"
struct stats {
unsigned long nblocks;
unsigned long ninodes;
};
// block size
static int blocksize = 1024;
#define SUPERBLOCK_OFFSET 1024
#define SUPERBLOCK_SIZE 1024
#define BLOCKSIZE blocksize
#define BLOCKS_PER_GROUP 8192
#define INODES_PER_GROUP 8192
/* Percentage of blocks that are reserved.*/
#define RESERVED_BLOCKS 5/100
#define MAX_RESERVED_BLOCKS 25/100
/* The default value for s_creator_os. */
#if defined(__linux__) && defined(EXT2_OS_LINUX)
#define CREATOR_OS EXT2_OS_LINUX
#define CREATOR_OS_NAME "linux"
#else
#if defined(__GNU__) && defined(EXT2_OS_HURD)
#define CREATOR_OS EXT2_OS_HURD
#define CREATOR_OS_NAME "hurd"
#else
#if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
#define CREATOR_OS EXT2_OS_FREEBSD
#define CREATOR_OS_NAME "freebsd"
#else
#if defined(LITES) && defined(EXT2_OS_LITES)
#define CREATOR_OS EXT2_OS_LITES
#define CREATOR_OS_NAME "lites"
#else
#define CREATOR_OS EXT2_OS_LINUX /* by default */
#define CREATOR_OS_NAME "linux"
#endif /* defined(LITES) && defined(EXT2_OS_LITES) */
#endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */
#endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */
#endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */
// inode block size (why is it != BLOCKSIZE ?!?)
/* The field i_blocks in the ext2 inode stores the number of data blocks
but in terms of 512 bytes. That is what INODE_BLOCKSIZE represents.
INOBLK is the number of such blocks in an actual disk block */
#define INODE_BLOCKSIZE 512
#define INOBLK (BLOCKSIZE / INODE_BLOCKSIZE)
// reserved inodes
#define EXT2_BAD_INO 1 // Bad blocks inode
#define EXT2_ROOT_INO 2 // Root inode
#define EXT2_ACL_IDX_INO 3 // ACL inode
#define EXT2_ACL_DATA_INO 4 // ACL inode
#define EXT2_BOOT_LOADER_INO 5 // Boot loader inode
#define EXT2_UNDEL_DIR_INO 6 // Undelete directory inode
#define EXT2_FIRST_INO 11 // First non reserved inode
// magic number for ext2
#define EXT2_MAGIC_NUMBER 0xEF53
// direct/indirect block addresses
#define EXT2_NDIR_BLOCKS 11 // direct blocks
#define EXT2_IND_BLOCK 12 // indirect block
#define EXT2_DIND_BLOCK 13 // double indirect block
#define EXT2_TIND_BLOCK 14 // triple indirect block
#define EXT2_INIT_BLOCK 0xFFFFFFFF // just initialized (not really a block address)
// codes for operating systems
#define EXT2_OS_LINUX 0
#define EXT2_OS_HURD 1
#define EXT2_OS_MASIX 2
#define EXT2_OS_FREEBSD 3
#define EXT2_OS_LITES 4
// end of a block walk
#define WALK_END 0xFFFFFFFE
// file modes
#define FM_IFMT 0170000 // format mask
#define FM_IFSOCK 0140000 // socket
#define FM_IFLNK 0120000 // symbolic link
#define FM_IFREG 0100000 // regular file
#define FM_IFBLK 0060000 // block device
#define FM_IFDIR 0040000 // directory
#define FM_IFCHR 0020000 // character device
#define FM_IFIFO 0010000 // fifo
#define FM_IMASK 0007777 // *all* perms mask for everything below
#define FM_ISUID 0004000 // SUID
#define FM_ISGID 0002000 // SGID
#define FM_ISVTX 0001000 // sticky bit
#define FM_IRWXU 0000700 // entire "user" mask
#define FM_IRUSR 0000400 // read
#define FM_IWUSR 0000200 // write
#define FM_IXUSR 0000100 // execute
#define FM_IRWXG 0000070 // entire "group" mask
#define FM_IRGRP 0000040 // read
#define FM_IWGRP 0000020 // write
#define FM_IXGRP 0000010 // execute
#define FM_IRWXO 0000007 // entire "other" mask
#define FM_IROTH 0000004 // read
#define FM_IWOTH 0000002 // write
#define FM_IXOTH 0000001 // execute
/* Defines for accessing group details */
// Number of groups in the filesystem
#define GRP_NBGROUPS(fs) \
(((fs)->sb->s_blocks_count - fs->sb->s_first_data_block + \
(fs)->sb->s_blocks_per_group - 1) / (fs)->sb->s_blocks_per_group)
// Get group block bitmap (bbm) given the group number
#define GRP_GET_GROUP_BBM(fs,grp,bi) (get_blk((fs),(grp)->bg_block_bitmap,(bi)))
#define GRP_PUT_GROUP_BBM(bi) ( put_blk((bi)) )
// Get group inode bitmap (ibm) given the group number
#define GRP_GET_GROUP_IBM(fs,grp,bi) (get_blk((fs), (grp)->bg_inode_bitmap,(bi)))
#define GRP_PUT_GROUP_IBM(bi) ( put_blk((bi)) )
// Given an inode number find the group it belongs to
#define GRP_GROUP_OF_INODE(fs,nod) ( ((nod)-1) / (fs)->sb->s_inodes_per_group)
//Given an inode number get the inode bitmap that covers it
#define GRP_GET_INODE_BITMAP(fs,nod,bi,gi) \
( GRP_GET_GROUP_IBM((fs),get_gd(fs,GRP_GROUP_OF_INODE((fs),(nod)),gi),bi) )
#define GRP_PUT_INODE_BITMAP(bi,gi) \
( GRP_PUT_GROUP_IBM((bi)),put_gd((gi)) )
//Given an inode number find its offset within the inode bitmap that covers it
#define GRP_IBM_OFFSET(fs,nod) \
( (nod) - GRP_GROUP_OF_INODE((fs),(nod))*(fs)->sb->s_inodes_per_group )
// Given a block number find the group it belongs to
#define GRP_GROUP_OF_BLOCK(fs,blk) ( ((blk)-1) / (fs)->sb->s_blocks_per_group)
//Given a block number get/put the block bitmap that covers it
#define GRP_GET_BLOCK_BITMAP(fs,blk,bi,gi) \
( GRP_GET_GROUP_BBM((fs),get_gd(fs,GRP_GROUP_OF_BLOCK((fs),(blk)),(gi)),(bi)) )
#define GRP_PUT_BLOCK_BITMAP(bi,gi) \
( GRP_PUT_GROUP_BBM((bi)),put_gd((gi)) )
//Given a block number find its offset within the block bitmap that covers it
#define GRP_BBM_OFFSET(fs,blk) \
( (blk) - GRP_GROUP_OF_BLOCK((fs),(blk))*(fs)->sb->s_blocks_per_group )
// used types
typedef signed char int8;
typedef unsigned char uint8;
typedef signed short int16;
typedef unsigned short uint16;
typedef signed int int32;
typedef unsigned int uint32;
// the GNU C library has a wonderful scanf("%as", string) which will
// allocate the string with the right size, good to avoid buffer
// overruns. the following macros use it if available or use a
// hacky workaround
// moreover it will define a snprintf() like a sprintf(), i.e.
// without the buffer overrun checking, to work around bugs in
// older solaris. Note that this is still not very portable, in that
// the return value cannot be trusted.
#if 0 // SCANF_CAN_MALLOC
// C99 define "a" for floating point, so you can have runtime surprise
// according the library versions
# define SCANF_PREFIX "a"
# define SCANF_STRING(s) (&s)
#else
# define SCANF_PREFIX "511"
# define SCANF_STRING(s) (s = malloc(512))
#endif /* SCANF_CAN_MALLOC */
#if PREFER_PORTABLE_SNPRINTF
static inline int
portable_snprintf(char *str, size_t n, const char *fmt, ...)
{
int ret;
va_list ap;
va_start(ap, fmt);
ret = vsprintf(str, fmt, ap);
va_end(ap);
return ret;
}
# define SNPRINTF portable_snprintf
#else
# define SNPRINTF snprintf
#endif /* PREFER_PORTABLE_SNPRINTF */
#if !HAVE_GETLINE
// getline() replacement for Darwin and Solaris etc.
// This code uses backward seeks (unless rchunk is set to 1) which can't work
// on pipes etc. However, add2fs_from_file() only calls getline() for
// regular files, so a larger rchunk and backward seeks are okay.
ssize_t
getdelim(char **lineptr, size_t *n, int delim, FILE *stream)
{
char *p; // reads stored here
size_t const rchunk = 512; // number of bytes to read
size_t const mchunk = 512; // number of extra bytes to malloc
size_t m = rchunk + 1; // initial buffer size
if (*lineptr) {
if (*n < m) {
*lineptr = (char*)realloc(*lineptr, m);
if (!*lineptr) return -1;
*n = m;
}
} else {
*lineptr = (char*)malloc(m);
if (!*lineptr) return -1;
*n = m;
}
m = 0; // record length including seperator
do {
size_t i; // number of bytes read etc
size_t j = 0; // number of bytes searched
p = *lineptr + m;
i = fread(p, 1, rchunk, stream);
if (i < rchunk && ferror(stream))
return -1;
while (j < i) {
++j;
if (*p++ == (char)delim) {
*p = '\0';
if (j != i) {
if (fseek(stream, j - i, SEEK_CUR))
return -1;
if (feof(stream))
clearerr(stream);
}
m += j;
return m;
}
}
m += j;
if (feof(stream)) {
if (m) return m;
if (!i) return -1;
}
// allocate space for next read plus possible null terminator
i = ((m + (rchunk + 1 > mchunk ? rchunk + 1 : mchunk) +
mchunk - 1) / mchunk) * mchunk;
if (i != *n) {
*lineptr = (char*)realloc(*lineptr, i);
if (!*lineptr) return -1;
*n = i;
}
} while (1);
}
#define getline(a,b,c) getdelim(a,b,'\n',c)
#endif /* HAVE_GETLINE */
// Convert a numerical string to a float, and multiply the result by an
// IEC or SI multiplier if provided; supported multipliers are Ki, Mi, Gi, k, M
// and G.
float
SI_atof(const char *nptr)
{
float f = 0;
float m = 1;
char *suffixptr;
#if HAVE_STRTOF
f = strtof(nptr, &suffixptr);
#else
f = (float)strtod(nptr, &suffixptr);
#endif /* HAVE_STRTOF */
if (*suffixptr) {
if (!strcmp(suffixptr, "Ki"))
m = 1 << 10;
else if (!strcmp(suffixptr, "Mi"))
m = 1 << 20;
else if (!strcmp(suffixptr, "Gi"))
m = 1 << 30;
else if (!strcmp(suffixptr, "k"))
m = 1000;
else if (!strcmp(suffixptr, "M"))
m = 1000 * 1000;
else if (!strcmp(suffixptr, "G"))
m = 1000 * 1000 * 1000;
}
return f * m;
}
// endianness swap
static inline uint16
swab16(uint16 val)
{
return (val >> 8) | (val << 8);
}
static inline uint32
swab32(uint32 val)
{
return ((val>>24) | ((val>>8)&0xFF00) |
((val<<8)&0xFF0000) | (val<<24));
}
static inline int
is_blk_empty(uint8 *b)
{
uint32 i;
uint32 *v = (uint32 *) b;
for(i = 0; i < BLOCKSIZE / 4; i++)
if (*v++)
return 0;
return 1;
}
// on-disk structures
// this trick makes me declare things only once
// (once for the structures, once for the endianness swap)
#define superblock_decl \
udecl32(s_inodes_count) /* Count of inodes in the filesystem */ \
udecl32(s_blocks_count) /* Count of blocks in the filesystem */ \
udecl32(s_r_blocks_count) /* Count of the number of reserved blocks */ \
udecl32(s_free_blocks_count) /* Count of the number of free blocks */ \
udecl32(s_free_inodes_count) /* Count of the number of free inodes */ \
udecl32(s_first_data_block) /* The first block which contains data */ \
udecl32(s_log_block_size) /* Indicator of the block size */ \
decl32(s_log_frag_size) /* Indicator of the size of the fragments */ \
udecl32(s_blocks_per_group) /* Count of the number of blocks in each block group */ \
udecl32(s_frags_per_group) /* Count of the number of fragments in each block group */ \
udecl32(s_inodes_per_group) /* Count of the number of inodes in each block group */ \
udecl32(s_mtime) /* The time that the filesystem was last mounted */ \
udecl32(s_wtime) /* The time that the filesystem was last written to */ \
udecl16(s_mnt_count) /* The number of times the file system has been mounted */ \
decl16(s_max_mnt_count) /* The number of times the file system can be mounted */ \
udecl16(s_magic) /* Magic number indicating ex2fs */ \
udecl16(s_state) /* Flags indicating the current state of the filesystem */ \
udecl16(s_errors) /* Flags indicating the procedures for error reporting */ \
udecl16(s_minor_rev_level) /* The minor revision level of the filesystem */ \
udecl32(s_lastcheck) /* The time that the filesystem was last checked */ \
udecl32(s_checkinterval) /* The maximum time permissable between checks */ \
udecl32(s_creator_os) /* Indicator of which OS created the filesystem */ \
udecl32(s_rev_level) /* The revision level of the filesystem */ \
udecl16(s_def_resuid) /* The default uid for reserved blocks */ \
udecl16(s_def_resgid) /* The default gid for reserved blocks */ \
/* rev 1 version fields start here */ \
udecl32(s_first_ino) /* First non-reserved inode */ \
udecl16(s_inode_size) /* size of inode structure */ \
udecl16(s_block_group_nr) /* block group # of this superblock */ \
udecl32(s_feature_compat) /* compatible feature set */ \
udecl32(s_feature_incompat) /* incompatible feature set */ \
udecl32(s_feature_ro_compat) /* readonly-compatible feature set */ \
utdecl8(s_uuid,16) /* 128-bit uuid for volume */ \
utdecl8(s_volume_name,16) /* volume name */ \
utdecl8(s_last_mounted,64) /* directory where last mounted */ \
udecl32(s_algorithm_usage_bitmap) /* For compression */
#define EXT2_GOOD_OLD_FIRST_INO 11
#define EXT2_GOOD_OLD_INODE_SIZE 128
#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
#define groupdescriptor_decl \
udecl32(bg_block_bitmap) /* Block number of the block bitmap */ \
udecl32(bg_inode_bitmap) /* Block number of the inode bitmap */ \
udecl32(bg_inode_table) /* Block number of the inode table */ \
udecl16(bg_free_blocks_count) /* Free blocks in the group */ \
udecl16(bg_free_inodes_count) /* Free inodes in the group */ \
udecl16(bg_used_dirs_count) /* Number of directories in the group */ \
udecl16(bg_pad)
#define inode_decl \
udecl16(i_mode) /* Entry type and file mode */ \
udecl16(i_uid) /* User id */ \
udecl32(i_size) /* File/dir size in bytes */ \
udecl32(i_atime) /* Last access time */ \
udecl32(i_ctime) /* Creation time */ \
udecl32(i_mtime) /* Last modification time */ \
udecl32(i_dtime) /* Deletion time */ \
udecl16(i_gid) /* Group id */ \
udecl16(i_links_count) /* Number of (hard) links to this inode */ \
udecl32(i_blocks) /* Number of blocks used (1 block = 512 bytes) */ \
udecl32(i_flags) /* ??? */ \
udecl32(i_reserved1) \
utdecl32(i_block,15) /* Blocks table */ \
udecl32(i_version) /* ??? */ \
udecl32(i_file_acl) /* File access control list */ \
udecl32(i_dir_acl) /* Directory access control list */ \
udecl32(i_faddr) /* Fragment address */ \
udecl8(i_frag) /* Fragments count*/ \
udecl8(i_fsize) /* Fragment size */ \
udecl16(i_pad1)
#define directory_decl \
udecl32(d_inode) /* Inode entry */ \
udecl16(d_rec_len) /* Total size on record */ \
udecl16(d_name_len) /* Size of entry name */
#define decl8(x) int8 x;
#define udecl8(x) uint8 x;
#define utdecl8(x,n) uint8 x[n];
#define decl16(x) int16 x;
#define udecl16(x) uint16 x;
#define decl32(x) int32 x;
#define udecl32(x) uint32 x;
#define utdecl32(x,n) uint32 x[n];
typedef struct
{
superblock_decl
uint32 s_reserved[205]; // Reserved
} superblock;
typedef struct
{
groupdescriptor_decl
uint32 bg_reserved[3];
} groupdescriptor;
typedef struct
{
inode_decl
uint32 i_reserved2[2];
} inode;
typedef struct
{
directory_decl
} directory;
typedef uint8 *block;
/* blockwalker fields:
The blockwalker is used to access all the blocks of a file (including
the indirection blocks) through repeated calls to walk_bw.
bpdir -> index into the inode->i_block[]. Indicates level of indirection.
bnum -> total number of blocks so far accessed. including indirection
blocks.
bpind,bpdind,bptind -> index into indirection blocks.
bpind, bpdind, bptind do *NOT* index into single, double and triple
indirect blocks resp. as you might expect from their names. Instead
they are in order the 1st, 2nd & 3rd index to be used
As an example..
To access data block number 70000:
bpdir: 15 (we are doing triple indirection)
bpind: 0 ( index into the triple indirection block)
bpdind: 16 ( index into the double indirection block)
bptind: 99 ( index into the single indirection block)
70000 = 12 + 256 + 256*256 + 16*256 + 100 (indexing starts from zero)
So,for double indirection bpind will index into the double indirection
block and bpdind into the single indirection block. For single indirection
only bpind will be used.
*/
typedef struct
{
uint32 bnum;
uint32 bpdir;
uint32 bpind;
uint32 bpdind;
uint32 bptind;
} blockwalker;
#define HDLINK_CNT 16
struct hdlink_s
{
uint32 src_inode;
uint32 dst_nod;
};
struct hdlinks_s
{
int32 count;
struct hdlink_s *hdl;
};
/* Filesystem structure that support groups */
typedef struct
{
FILE *f;
superblock *sb;
int swapit;
int32 hdlink_cnt;
struct hdlinks_s hdlinks;
int holes;
listcache blks;
listcache gds;
listcache inodes;
listcache blkmaps;
} filesystem;
// now the endianness swap
#undef decl8
#undef udecl8
#undef utdecl8
#undef decl16
#undef udecl16
#undef decl32
#undef udecl32
#undef utdecl32
#define decl8(x)
#define udecl8(x)
#define utdecl8(x,n)
#define decl16(x) this->x = swab16(this->x);
#define udecl16(x) this->x = swab16(this->x);
#define decl32(x) this->x = swab32(this->x);
#define udecl32(x) this->x = swab32(this->x);
#define utdecl32(x,n) { int i; for(i=0; i<n; i++) this->x[i] = swab32(this->x[i]); }
static void
swap_sb(superblock *sb)
{
#define this sb
superblock_decl
#undef this
}
static void
swap_gd(groupdescriptor *gd)
{
#define this gd
groupdescriptor_decl
#undef this
}
static void
swap_nod(inode *nod)
{
#define this nod
inode_decl
#undef this
}
static void
swap_dir(directory *dir)
{
#define this dir
directory_decl
#undef this
}
static void
swap_block(block b)
{
int i;
uint32 *blk = (uint32*)b;
for(i = 0; i < BLOCKSIZE/4; i++)
blk[i] = swab32(blk[i]);
}
#undef decl8
#undef udecl8
#undef utdecl8
#undef decl16
#undef udecl16
#undef decl32
#undef udecl32
#undef utdecl32
static char * app_name;
static const char *const memory_exhausted = "memory exhausted";
// error (un)handling
static void
verror_msg(const char *s, va_list p)
{
fflush(stdout);
fprintf(stderr, "%s: ", app_name);
vfprintf(stderr, s, p);
}
static void
error_msg(const char *s, ...)
{
va_list p;
va_start(p, s);
verror_msg(s, p);
va_end(p);
putc('\n', stderr);
}
static void
error_msg_and_die(const char *s, ...)
{
va_list p;
va_start(p, s);
verror_msg(s, p);
va_end(p);
putc('\n', stderr);
exit(EXIT_FAILURE);
}
static void
vperror_msg(const char *s, va_list p)
{
int err = errno;
if (s == 0)
s = "";
verror_msg(s, p);
if (*s)
s = ": ";
fprintf(stderr, "%s%s\n", s, strerror(err));
}
static void
perror_msg_and_die(const char *s, ...)
{
va_list p;
va_start(p, s);
vperror_msg(s, p);
va_end(p);
exit(EXIT_FAILURE);
}
static FILE *
xfopen(const char *path, const char *mode)
{
FILE *fp;
if ((fp = fopen(path, mode)) == NULL)
perror_msg_and_die("%s", path);
return fp;
}
static char *
xstrdup(const char *s)
{
char *t;
if (s == NULL)
return NULL;
t = strdup(s);
if (t == NULL)
error_msg_and_die(memory_exhausted);
return t;
}
int
is_hardlink(filesystem *fs, ino_t inode)
{
int i;
for(i = 0; i < fs->hdlinks.count; i++) {
if(fs->hdlinks.hdl[i].src_inode == inode)
return i;
}
return -1;
}
// printf helper macro
#define plural(a) (a), ((a) == 1) ? "" : "s"
// temporary working block
static inline uint8 *
get_workblk(void)
{
unsigned char* b=calloc(1,BLOCKSIZE);
if (!b)
error_msg_and_die("get_workblk() failed, out of memory");
return b;
}
static inline void
free_workblk(block b)
{
free(b);
}
/* Rounds qty upto a multiple of siz. siz should be a power of 2 */
static inline uint32
rndup(uint32 qty, uint32 siz)
{
return (qty + (siz - 1)) & ~(siz - 1);
}
// check if something is allocated in the bitmap
static inline uint32
allocated(block b, uint32 item)
{
return b[(item-1) / 8] & (1 << ((item-1) % 8));
}
// Used by get_blk/put_blk to hold information about a block owned
// by the user.
typedef struct
{
cache_link link;
filesystem *fs;
uint32 blk;
uint8 *b;
uint32 usecount;
} blk_info;
#define MAX_FREE_CACHE_BLOCKS 100
static uint32
blk_elem_val(cache_link *elem)
{
blk_info *bi = container_of(elem, blk_info, link);
return bi->blk;
}
static void
blk_freed(cache_link *elem)
{
blk_info *bi = container_of(elem, blk_info, link);
if (fseeko(bi->fs->f, ((off_t) bi->blk) * BLOCKSIZE, SEEK_SET))
perror_msg_and_die("fseek");
if (fwrite(bi->b, BLOCKSIZE, 1, bi->fs->f) != 1)
perror_msg_and_die("get_blk: write");
free(bi->b);
free(bi);
}
// Return a given block from a filesystem. Make sure to call
// put_blk when you are done with it.
static inline uint8 *
get_blk(filesystem *fs, uint32 blk, blk_info **rbi)
{
cache_link *curr;
blk_info *bi;
if (blk >= fs->sb->s_blocks_count)
error_msg_and_die("Internal error, block out of range");
curr = cache_find(&fs->blks, blk);
if (curr) {
bi = container_of(curr, blk_info, link);
bi->usecount++;
goto out;
}
bi = malloc(sizeof(*bi));
if (!bi)
error_msg_and_die("get_blk: out of memory");
bi->fs = fs;
bi->blk = blk;
bi->usecount = 1;
bi->b = malloc(BLOCKSIZE);
if (!bi->b)
error_msg_and_die("get_blk: out of memory");
cache_add(&fs->blks, &bi->link);
if (fseeko(fs->f, ((off_t) blk) * BLOCKSIZE, SEEK_SET))
perror_msg_and_die("fseek");
if (fread(bi->b, BLOCKSIZE, 1, fs->f) != 1) {
if (ferror(fs->f))
perror_msg_and_die("fread");
memset(bi->b, 0, BLOCKSIZE);
}
out:
*rbi = bi;
return bi->b;
}
static inline void
put_blk(blk_info *bi)
{
if (bi->usecount == 0)
error_msg_and_die("Internal error: put_blk usecount zero");
bi->usecount--;
if (bi->usecount == 0)
/* Free happens in the cache code */
cache_item_set_unused(&bi->fs->blks, &bi->link);
}
typedef struct
{
cache_link link;
filesystem *fs;
int gds;
blk_info *bi;
groupdescriptor *gd;
uint32 usecount;
} gd_info;
#define MAX_FREE_CACHE_GDS 100
static uint32
gd_elem_val(cache_link *elem)
{
gd_info *gi = container_of(elem, gd_info, link);
return gi->gds;
}
static void
gd_freed(cache_link *elem)
{
gd_info *gi = container_of(elem, gd_info, link);
if (gi->fs->swapit)
swap_gd(gi->gd);
put_blk(gi->bi);
free(gi);
}
#define GDS_START ((SUPERBLOCK_OFFSET + SUPERBLOCK_SIZE + BLOCKSIZE - 1) / BLOCKSIZE)
#define GDS_PER_BLOCK (BLOCKSIZE / sizeof(groupdescriptor))
// the group descriptors are aligned on the block size
static inline groupdescriptor *
get_gd(filesystem *fs, uint32 no, gd_info **rgi)
{
uint32 gdblk;
uint32 offset;
gd_info *gi;
cache_link *curr;
curr = cache_find(&fs->gds, no);
if (curr) {
gi = container_of(curr, gd_info, link);
gi->usecount++;
goto out;
}
gi = malloc(sizeof(*gi));
if (!gi)
error_msg_and_die("get_gd: out of memory");