| /* |
| * GRUB -- GRand Unified Bootloader |
| * Copyright (C) 1996 Erich Boleyn <erich@uruk.org> |
| * |
| * 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; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| |
| #include "shared.h" |
| |
| #ifdef E2DEBUG |
| #include "pc_slice.h" |
| #else |
| #include "filesys.h" |
| #endif |
| |
| static int mapblock1, mapblock2; |
| |
| /* sizes are always in bytes, BLOCK values are always in DEV_BSIZE (sectors) */ |
| #define DEV_BSIZE 512 |
| |
| /* include/linux/fs.h */ |
| #define BLOCK_SIZE 1024 /* initial block size for superblock read */ |
| /* made up, defaults to 1 but can be passed via mount_opts */ |
| #define WHICH_SUPER 1 |
| /* kind of from fs/ext2/super.c */ |
| #define SBLOCK (WHICH_SUPER * BLOCK_SIZE / DEV_BSIZE) /* = 2 */ |
| |
| /* include/asm-i386/types.h */ |
| typedef __signed__ char __s8; |
| typedef unsigned char __u8; |
| typedef __signed__ short __s16; |
| typedef unsigned short __u16; |
| typedef __signed__ int __s32; |
| typedef unsigned int __u32; |
| |
| /* |
| * Constants relative to the data blocks, from ext2_fs.h |
| */ |
| #define EXT2_NDIR_BLOCKS 12 |
| #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS |
| #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1) |
| #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1) |
| #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1) |
| |
| /* include/linux/ext2_fs.h */ |
| struct ext2_super_block { |
| __u32 s_inodes_count; /* Inodes count */ |
| __u32 s_blocks_count; /* Blocks count */ |
| __u32 s_r_blocks_count; /* Reserved blocks count */ |
| __u32 s_free_blocks_count; /* Free blocks count */ |
| __u32 s_free_inodes_count; /* Free inodes count */ |
| __u32 s_first_data_block; /* First Data Block */ |
| __u32 s_log_block_size; /* Block size */ |
| __s32 s_log_frag_size; /* Fragment size */ |
| __u32 s_blocks_per_group; /* # Blocks per group */ |
| __u32 s_frags_per_group; /* # Fragments per group */ |
| __u32 s_inodes_per_group; /* # Inodes per group */ |
| __u32 s_mtime; /* Mount time */ |
| __u32 s_wtime; /* Write time */ |
| __u16 s_mnt_count; /* Mount count */ |
| __s16 s_max_mnt_count; /* Maximal mount count */ |
| __u16 s_magic; /* Magic signature */ |
| __u16 s_state; /* File system state */ |
| __u16 s_errors; /* Behaviour when detecting errors */ |
| __u16 s_pad; |
| __u32 s_lastcheck; /* time of last check */ |
| __u32 s_checkinterval; /* max. time between checks */ |
| __u32 s_creator_os; /* OS */ |
| __u32 s_rev_level; /* Revision level */ |
| __u16 s_def_resuid; /* Default uid for reserved blocks */ |
| __u16 s_def_resgid; /* Default gid for reserved blocks */ |
| __u32 s_reserved[235]; /* Padding to the end of the block */ |
| }; |
| |
| struct ext2_group_desc |
| { |
| __u32 bg_block_bitmap; /* Blocks bitmap block */ |
| __u32 bg_inode_bitmap; /* Inodes bitmap block */ |
| __u32 bg_inode_table; /* Inodes table block */ |
| __u16 bg_free_blocks_count; /* Free blocks count */ |
| __u16 bg_free_inodes_count; /* Free inodes count */ |
| __u16 bg_used_dirs_count; /* Directories count */ |
| __u16 bg_pad; |
| __u32 bg_reserved[3]; |
| }; |
| |
| struct ext2_inode { |
| __u16 i_mode; /* File mode */ |
| __u16 i_uid; /* Owner Uid */ |
| __u32 i_size; /* 4: Size in bytes */ |
| __u32 i_atime; /* Access time */ |
| __u32 i_ctime; /* 12: Creation time */ |
| __u32 i_mtime; /* Modification time */ |
| __u32 i_dtime; /* 20: Deletion Time */ |
| __u16 i_gid; /* Group Id */ |
| __u16 i_links_count; /* 24: Links count */ |
| __u32 i_blocks; /* Blocks count */ |
| __u32 i_flags; /* 32: File flags */ |
| union { |
| struct { |
| __u32 l_i_reserved1; |
| } linux1; |
| struct { |
| __u32 h_i_translator; |
| } hurd1; |
| struct { |
| __u32 m_i_reserved1; |
| } masix1; |
| } osd1; /* OS dependent 1 */ |
| __u32 i_block[EXT2_N_BLOCKS];/* 40: Pointers to blocks */ |
| __u32 i_version; /* File version (for NFS) */ |
| __u32 i_file_acl; /* File ACL */ |
| __u32 i_dir_acl; /* Directory ACL */ |
| __u32 i_faddr; /* Fragment address */ |
| union { |
| struct { |
| __u8 l_i_frag; /* Fragment number */ |
| __u8 l_i_fsize; /* Fragment size */ |
| __u16 i_pad1; |
| __u32 l_i_reserved2[2]; |
| } linux2; |
| struct { |
| __u8 h_i_frag; /* Fragment number */ |
| __u8 h_i_fsize; /* Fragment size */ |
| __u16 h_i_mode_high; |
| __u16 h_i_uid_high; |
| __u16 h_i_gid_high; |
| __u32 h_i_author; |
| } hurd2; |
| struct { |
| __u8 m_i_frag; /* Fragment number */ |
| __u8 m_i_fsize; /* Fragment size */ |
| __u16 m_pad1; |
| __u32 m_i_reserved2[2]; |
| } masix2; |
| } osd2; /* OS dependent 2 */ |
| }; |
| |
| /* linux/limits.h */ |
| #define NAME_MAX 255 /* # chars in a file name */ |
| |
| /* linux/posix_type.h */ |
| typedef long off_t; |
| |
| /* linux/ext2fs.h */ |
| #define EXT2_NAME_LEN 255 |
| struct ext2_dir_entry { |
| __u32 inode; /* Inode number */ |
| __u16 rec_len; /* Directory entry length */ |
| __u16 name_len; /* Name length */ |
| char name[EXT2_NAME_LEN]; /* File name */ |
| }; |
| |
| /* linux/ext2fs.h */ |
| /* |
| * EXT2_DIR_PAD defines the directory entries boundaries |
| * |
| * NOTE: It must be a multiple of 4 |
| */ |
| #define EXT2_DIR_PAD 4 |
| #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1) |
| #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \ |
| ~EXT2_DIR_ROUND) |
| |
| |
| /* ext2/super.c */ |
| #define log2(n) ffz(~(n)) |
| |
| #define EXT2_SUPER_MAGIC 0xEF53 /* include/linux/ext2_fs.h */ |
| #define EXT2_ROOT_INO 2 /* include/linux/ext2_fs.h */ |
| |
| /* made up, these are pointers into FSYS_BUF */ |
| /* read once, always stays there: */ |
| #define SUPERBLOCK \ |
| ((struct ext2_super_block *)(FSYS_BUF)) |
| #define GROUP_DESC \ |
| ((struct ext2_group_desc *) \ |
| ((int)SUPERBLOCK + sizeof(struct ext2_super_block))) |
| #define INODE \ |
| ((struct ext2_inode *)((int)GROUP_DESC + EXT2_BLOCK_SIZE(SUPERBLOCK))) |
| #define DATABLOCK1 \ |
| ((int)((int)INODE + sizeof(struct ext2_inode))) |
| #define DATABLOCK2 \ |
| ((int)((int)DATABLOCK1 + EXT2_BLOCK_SIZE(SUPERBLOCK))) |
| |
| /* linux/ext2_fs.h */ |
| #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32)) |
| #define EXT2_ADDR_PER_BLOCK_BITS(s) (log2(EXT2_ADDR_PER_BLOCK(s))) |
| |
| /* linux/ext2_fs.h */ |
| #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10) |
| /* kind of from ext2/super.c */ |
| #define EXT2_BLOCK_SIZE(s) (1 << EXT2_BLOCK_SIZE_BITS(s)) |
| /* linux/ext2fs.h */ |
| #define EXT2_DESC_PER_BLOCK(s) \ |
| (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc)) |
| /* linux/stat.h */ |
| #define S_IFMT 00170000 |
| #define S_IFREG 0100000 |
| #define S_IFDIR 0040000 |
| #define S_ISREG(m) (((m) & S_IFMT) == S_IFREG) |
| #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) |
| |
| /* include/asm-i386/bitops.h */ |
| /* |
| * ffz = Find First Zero in word. Undefined if no zero exists, |
| * so code should check against ~0UL first.. |
| */ |
| __inline__ unsigned long ffz(unsigned long word) |
| { |
| __asm__("bsfl %1,%0" |
| :"=r" (word) |
| :"r" (~word)); |
| return word; |
| } |
| |
| /* check filesystem types and read superblock into memory buffer */ |
| int |
| ext2fs_mount(void) |
| { |
| int retval = 1; |
| |
| if ( (((current_drive & 0x80) || (current_slice != 0)) |
| && (current_slice != PC_SLICE_TYPE_EXT2FS) |
| && (current_slice != (PC_SLICE_TYPE_BSD | (FS_OTHER<<8)))) |
| || part_length < (SBLOCK + (sizeof(struct ext2_super_block)/DEV_BSIZE)) |
| || !devread(SBLOCK, 0, sizeof(struct ext2_super_block), (int)SUPERBLOCK) |
| || SUPERBLOCK->s_magic != EXT2_SUPER_MAGIC) |
| retval = 0; |
| |
| return retval; |
| } |
| |
| /* not part of the interface |
| takes a file system block number and reads it into area pointed |
| to by buffer */ |
| int |
| ext2_rdfsb (int fsblock, int buffer) { |
| #ifdef E2DEBUG |
| printf("fsblock %d buffer %d\n", fsblock, buffer); |
| #endif /* E2DEBUG */ |
| return devread(fsblock * EXT2_BLOCK_SIZE(SUPERBLOCK) / DEV_BSIZE, 0, |
| EXT2_BLOCK_SIZE(SUPERBLOCK), (int)buffer); |
| } |
| |
| /* from |
| ext2/inode.c:ext2_bmap() |
| */ |
| /* not part of interface |
| maps "logical block" (the file offset div blocksize) into |
| "physical blocks" (the location in the file system) via an inode */ |
| int |
| ext2fs_block_map(int logical_block) |
| { |
| |
| #ifdef E2DEBUG |
| unsigned char * i; |
| for (i = (unsigned char *)INODE; |
| i < ((unsigned char *)INODE + sizeof(struct ext2_inode)); |
| i++) { |
| printf("%c", "0123456789abcdef"[*i >> 4]); |
| printf("%c", "0123456789abcdef"[*i % 16]); |
| if (!((i + 1 - (unsigned char *)INODE) % 16)) { printf("\n"); } |
| else { printf(" "); } |
| } |
| printf("logical block %d\n", logical_block); |
| #endif /* E2DEBUG */ |
| |
| /* if it is directly pointed to by the inode, return that physical addr */ |
| if (logical_block < EXT2_NDIR_BLOCKS) { |
| #ifdef E2DEBUG |
| printf ("returning %d\n", (unsigned char *)(INODE->i_block[logical_block])); |
| printf ("returning %d\n", INODE->i_block[logical_block]); |
| #endif /* E2DEBUG */ |
| return INODE->i_block[logical_block]; |
| } |
| /* else */ |
| logical_block -= EXT2_NDIR_BLOCKS; |
| /* try the indirect block */ |
| if (logical_block < EXT2_ADDR_PER_BLOCK(SUPERBLOCK)) { |
| if ( mapblock1 != 1 |
| && !ext2_rdfsb(INODE->i_block[EXT2_IND_BLOCK], DATABLOCK1)) { |
| errnum = ERR_FSYS_CORRUPT; |
| return -1; |
| } |
| mapblock1 = 1; |
| return ((__u32 *)DATABLOCK1)[logical_block]; |
| } |
| /* else */ |
| logical_block -= EXT2_ADDR_PER_BLOCK(SUPERBLOCK); |
| /* now try the double indirect block */ |
| if (logical_block < (1 << (EXT2_ADDR_PER_BLOCK_BITS(SUPERBLOCK) * 2))) { |
| int bnum; |
| if ( mapblock1 != 2 |
| && !ext2_rdfsb(INODE->i_block[EXT2_DIND_BLOCK], DATABLOCK1)) { |
| errnum = ERR_FSYS_CORRUPT; |
| return -1; |
| } |
| mapblock1 = 2; |
| if ( (bnum = (((__u32 *)DATABLOCK1) |
| [logical_block >> EXT2_ADDR_PER_BLOCK_BITS(SUPERBLOCK)])) |
| != mapblock2 |
| && !ext2_rdfsb(bnum, DATABLOCK2)) { |
| errnum = ERR_FSYS_CORRUPT; |
| return -1; |
| } |
| mapblock2 = bnum; |
| return ((__u32 *)DATABLOCK2) |
| [logical_block & (EXT2_ADDR_PER_BLOCK(SUPERBLOCK) - 1)]; |
| } |
| /* else */ |
| mapblock2 = -1; |
| logical_block -= (1 << (EXT2_ADDR_PER_BLOCK_BITS(SUPERBLOCK) * 2)); |
| if ( mapblock1 != 3 |
| && !ext2_rdfsb(INODE->i_block[EXT2_TIND_BLOCK], DATABLOCK1)) { |
| errnum = ERR_FSYS_CORRUPT; |
| return -1; |
| } |
| mapblock1 = 3; |
| if (!ext2_rdfsb(((__u32 *)DATABLOCK1) |
| [logical_block >> (EXT2_ADDR_PER_BLOCK_BITS(SUPERBLOCK)*2)], |
| DATABLOCK2)) { |
| errnum = ERR_FSYS_CORRUPT; |
| return -1; |
| } |
| if (!ext2_rdfsb(((__u32 *)DATABLOCK2) |
| [(logical_block >> EXT2_ADDR_PER_BLOCK_BITS(SUPERBLOCK)) |
| & (EXT2_ADDR_PER_BLOCK(SUPERBLOCK) - 1)], |
| DATABLOCK2)) { |
| errnum = ERR_FSYS_CORRUPT; |
| return -1; |
| } |
| return ((__u32 *)DATABLOCK2) |
| [logical_block & (EXT2_ADDR_PER_BLOCK(SUPERBLOCK)-1)]; |
| } |
| |
| /* preconditions: all preconds of ext2fs_block_map */ |
| int |
| ext2fs_read(int addr, int len) |
| { |
| int logical_block; |
| int offset; |
| int map; |
| int ret = 0; |
| int size = 0; |
| |
| #ifdef E2DEBUG |
| unsigned char * i; |
| for (i = (unsigned char *)INODE; |
| i < ((unsigned char *)INODE + sizeof(struct ext2_inode)); |
| i++) { |
| printf("%c", "0123456789abcdef"[*i >> 4]); |
| printf("%c", "0123456789abcdef"[*i % 16]); |
| if (!((i + 1 - (unsigned char *)INODE) % 16)) { printf("\n"); } |
| else { printf(" "); } |
| } |
| #endif /* E2DEBUG */ |
| while(len > 0) { |
| /* find the (logical) block component of our location */ |
| logical_block = filepos >> EXT2_BLOCK_SIZE_BITS(SUPERBLOCK); |
| offset = filepos & (EXT2_BLOCK_SIZE(SUPERBLOCK) - 1); |
| map = ext2fs_block_map(logical_block); |
| #ifdef E2DEBUG |
| printf("map=%d\n", map); |
| #endif /* E2DEBUG */ |
| if (map < 0) |
| break; |
| |
| size = EXT2_BLOCK_SIZE(SUPERBLOCK); |
| size -= offset; |
| if (size > len) |
| size = len; |
| |
| #ifndef NO_FANCY_STUFF |
| debug_fs_func = debug_fs; |
| #endif /* NO_FANCY_STUFF */ |
| |
| devread(map * EXT2_BLOCK_SIZE(SUPERBLOCK) / DEV_BSIZE, |
| offset, size, addr); |
| |
| #ifndef NO_FANCY_STUFF |
| debug_fs_func = NULL; |
| #endif /* NO_FANCY_STUFF */ |
| |
| addr += size; |
| len -= size; |
| filepos += size; |
| ret += size; |
| } |
| |
| if (errnum) |
| ret = 0; |
| |
| return ret; |
| } |
| |
| |
| /* Based on: |
| def_blk_fops points to |
| blkdev_open, which calls (I think): |
| sys_open() |
| do_open() |
| open_namei() |
| dir_namei() which accesses current->fs->root |
| fs->root was set during original mount: |
| (something)... which calls (I think): |
| ext2_read_super() |
| iget() |
| __iget() |
| read_inode() |
| ext2_read_inode() |
| uses desc_per_block_bits, which is set in ext2_read_super() |
| also uses group descriptors loaded during ext2_read_super() |
| lookup() |
| ext2_lookup() |
| ext2_find_entry() |
| ext2_getblk() |
| |
| */ |
| |
| /* preconditions: ext2fs_mount already executed, therefore supblk in buffer |
| * known as SUPERBLOCK |
| * returns: 0 if error, nonzero iff we were able to find the file successfully |
| * postconditions: on a nonzero return, buffer known as INODE contains the |
| * inode of the file we were trying to look up |
| * side effects: messes up GROUP_DESC buffer area |
| */ |
| int |
| ext2fs_dir(char *dirname) |
| { |
| int current_ino = EXT2_ROOT_INO; /* start at the root */ |
| int group_id; /* which group the inode is in */ |
| int group_desc; /* fs pointer to that group */ |
| int desc; /* index within that group */ |
| int ino_blk; /* fs pointer of the inode's information */ |
| int str_chk; /* used to hold the results of a string compare */ |
| struct ext2_group_desc * gdp; |
| struct ext2_inode * raw_inode; /* inode info corresponding to current_ino */ |
| |
| char *rest; |
| char ch; /* temp char holder */ |
| |
| int off; /* offset within block of directory entry (off mod blocksize) */ |
| int loc; /* location within a directory */ |
| int blk; /* which data blk within dir entry (off div blocksize) */ |
| long map; /* fs pointer of a particular block from dir entry */ |
| struct ext2_dir_entry *dp; /* pointer to directory entry */ |
| #ifdef E2DEBUG |
| unsigned char *i; |
| #endif E2DEBUG |
| |
| /* loop invariants: |
| current_ino = inode to lookup |
| dirname = pointer to filename component we are cur looking up within |
| the directory known pointed to by current_ino (if any) |
| */ |
| |
| while (1) { |
| #ifdef E2DEBUG |
| printf("inode %d\n", current_ino); |
| printf("dirname=%s\n", dirname); |
| #endif /* E2DEBUG */ |
| |
| /* look up an inode */ |
| group_id = (current_ino - 1) / (SUPERBLOCK->s_inodes_per_group); |
| group_desc = group_id >> log2(EXT2_DESC_PER_BLOCK(SUPERBLOCK)); |
| desc = group_id & (EXT2_DESC_PER_BLOCK(SUPERBLOCK) - 1); |
| #ifdef E2DEBUG |
| printf("ipg=%d, dpb=%d\n", SUPERBLOCK->s_inodes_per_group, |
| EXT2_DESC_PER_BLOCK(SUPERBLOCK)); |
| printf("group_id=%d group_desc=%d desc=%d\n", group_id, group_desc, desc); |
| #endif /* E2DEBUG */ |
| if (!ext2_rdfsb((WHICH_SUPER + group_desc + 1), (int)GROUP_DESC)) { |
| return 0; |
| } |
| gdp = GROUP_DESC; |
| ino_blk = gdp[desc].bg_inode_table + |
| (((current_ino - 1) % (SUPERBLOCK->s_inodes_per_group)) |
| >> log2(EXT2_BLOCK_SIZE(SUPERBLOCK) / sizeof(struct ext2_inode))); |
| #ifdef E2DEBUG |
| printf("inode table fsblock=%d\n", ino_blk); |
| #endif /* E2DEBUG */ |
| if (!ext2_rdfsb(ino_blk, (int)INODE)) { |
| return 0; |
| } |
| |
| /* reset indirect blocks! */ |
| mapblock2 = mapblock1 = -1; |
| |
| raw_inode = INODE + |
| ((current_ino - 1) |
| & (EXT2_BLOCK_SIZE(SUPERBLOCK) / sizeof(struct ext2_inode) - 1)); |
| #ifdef E2DEBUG |
| printf("ipb=%d, sizeof(inode)=%d\n", |
| (EXT2_BLOCK_SIZE(SUPERBLOCK) / sizeof(struct ext2_inode)), |
| sizeof(struct ext2_inode)); |
| printf("inode=%x, raw_inode=%x\n", INODE, raw_inode); |
| printf("offset into inode table block=%d\n", (int)raw_inode - (int)INODE); |
| for (i = (unsigned char *)INODE; i <= (unsigned char *)raw_inode; i++) { |
| printf("%c", "0123456789abcdef"[*i >> 4]); |
| printf("%c", "0123456789abcdef"[*i % 16]); |
| if (!((i + 1 - (unsigned char *)INODE) % 16)) { printf("\n"); } |
| else { printf(" "); } |
| } |
| printf("first word=%x\n", *((int *)raw_inode)); |
| #endif /* E2DEBUG */ |
| |
| /* copy inode to fixed location */ |
| bcopy((void *)raw_inode, (void *)INODE, sizeof(struct ext2_inode)); |
| |
| #ifdef E2DEBUG |
| printf("first word=%x\n", *((int *)INODE)); |
| #endif /* E2DEBUG */ |
| |
| /* if end of filename, INODE points to the file's inode */ |
| if (!*dirname || isspace(*dirname)) |
| { |
| if (!S_ISREG(INODE->i_mode)) |
| { |
| errnum = ERR_BAD_FILETYPE; |
| return 0; |
| } |
| |
| filemax = (INODE->i_size); |
| return 1; |
| } |
| |
| /* else we have to traverse a directory */ |
| |
| /* skip over slashes */ |
| while (*dirname == '/') |
| dirname++; |
| |
| /* if this isn't a directory of sufficient size to hold our file, abort */ |
| if (!(INODE->i_size) || !S_ISDIR(INODE->i_mode)) |
| { |
| errnum = ERR_BAD_FILETYPE; |
| return 0; |
| } |
| |
| /* skip to next slash or end of filename (space) */ |
| for (rest = dirname; (ch = *rest) && !isspace(ch) && ch != '/'; rest++) ; |
| |
| /* look through this directory and find the next filename component */ |
| /* invariant: rest points to slash after the next filename component */ |
| *rest = 0; |
| loc = 0; |
| |
| do { |
| |
| #ifdef E2DEBUG |
| printf("dirname=%s, rest=%s, loc=%d\n", dirname, rest, loc); |
| #endif /* E2DEBUG */ |
| |
| /* if our location/byte offset into the directory exceeds the size, |
| give up */ |
| if (loc >= INODE->i_size) { |
| if (print_possibilities < 0) { |
| putchar('\n'); |
| } |
| else { |
| errnum = ERR_FILE_NOT_FOUND; |
| *rest = ch; |
| } |
| return (print_possibilities < 0); |
| } |
| |
| /* else, find the (logical) block component of our location */ |
| blk = loc >> EXT2_BLOCK_SIZE_BITS(SUPERBLOCK); |
| |
| /* now we know which logical block of the directory entry we are looking |
| for, now we have to translate that to the physical (fs) block on |
| the disk */ |
| map = ext2fs_block_map(blk); |
| #ifdef E2DEBUG |
| printf("fs block=%d\n", map); |
| #endif /* E2DEBUG */ |
| mapblock2 = -1; |
| if ((map < 0) || !ext2_rdfsb(map, DATABLOCK2)) { |
| errnum = ERR_FSYS_CORRUPT; |
| *rest = ch; |
| return 0; |
| } |
| off = loc & (EXT2_BLOCK_SIZE(SUPERBLOCK) - 1); |
| dp = (struct ext2_dir_entry *)(DATABLOCK2 + off); |
| /* advance loc prematurely to next on-disk directory entry */ |
| loc += dp->rec_len; |
| |
| /* NOTE: ext2fs filenames are NOT null-terminated */ |
| |
| #ifdef E2DEBUG |
| printf("directory entry ino=%d\n", dp->inode); |
| if (dp->inode) |
| printf("entry=%s\n", dp->name); |
| #endif /* E2DEBUG */ |
| |
| if (dp->inode) |
| { |
| int saved_c = dp->name[dp->name_len]; |
| |
| dp->name[dp->name_len] = 0; |
| str_chk = strcmp(dirname, dp->name); |
| |
| if (print_possibilities && ch != '/' |
| && (!*dirname || str_chk <= 0)) |
| { |
| if (print_possibilities > 0) |
| print_possibilities = -print_possibilities; |
| printf(" %s", dp->name); |
| } |
| |
| dp->name[dp->name_len] = saved_c; |
| } |
| |
| } while (!dp->inode || (str_chk || (print_possibilities && ch != '/')) ); |
| |
| current_ino = dp->inode; |
| *(dirname = rest) = ch; |
| } |
| /* never get here */ |
| } |