diff options
Diffstat (limited to 'src/stream/fs/ext2fs.c')
| -rw-r--r-- | src/stream/fs/ext2fs.c | 793 |
1 files changed, 793 insertions, 0 deletions
diff --git a/src/stream/fs/ext2fs.c b/src/stream/fs/ext2fs.c new file mode 100644 index 0000000000..e57a9f1915 --- /dev/null +++ b/src/stream/fs/ext2fs.c @@ -0,0 +1,793 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 1999, 2001 Free Software Foundation, Inc. + * + * 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 <console/console.h> +#include <fs/fs.h> +#include <string.h> +#include <arch/byteorder.h> + +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 linux_off_t; + +/* linux/ext2fs.h */ +#define EXT2_NAME_LEN 255 +struct ext2_dir_entry + { + __u32 inode; /* Inode number */ + __u16 rec_len; /* Directory entry length */ + __u8 name_len; /* Name length */ + __u8 file_type; + 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 */ +#define PATH_MAX 1024 /* include/linux/limits.h */ +#define MAX_LINK_COUNT 5 /* number of symbolic links to follow */ + +/* 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) (le32_to_cpu((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_IFLNK 0120000 +#define S_IFREG 0100000 +#define S_IFDIR 0040000 +#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK) +#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.. + */ +#ifndef PPC +static __inline__ unsigned long +ffz (unsigned long word) +{ + __asm__ ("bsfl %1,%0" +: "=r" (word) +: "r" (~word)); + return word; +} +#else /* !PPC */ +static __inline__ unsigned long + __ilog2(unsigned long x) +{ + unsigned long lz; + + asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); + return 31 - lz; +} +static __inline__ unsigned long +ffz(unsigned long x) +{ + if ((x = ~x) == 0) + return 32; + return __ilog2(x & -x); +} +#endif + +/* 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_LINUX_RAID) + && (! IS_PC_SLICE_TYPE_BSD_WITH_FS (current_slice, FS_EXT2FS)) + && (! IS_PC_SLICE_TYPE_BSD_WITH_FS (current_slice, FS_OTHER))) + || part_length < (SBLOCK + (sizeof (struct ext2_super_block) / DEV_BSIZE)) + || !devread (SBLOCK, 0, sizeof (struct ext2_super_block), + (char *) SUPERBLOCK) + || le16_to_cpu(SUPERBLOCK->s_magic) != EXT2_SUPER_MAGIC) + retval = 0; + + return retval; +} + +/* Takes a file system block number and reads it into BUFFER. */ +static int +ext2_rdfsb (int fsblock, int buffer) +{ +#ifdef E2DEBUG + printk_debug ("fsblock %d buffer %d\n", fsblock, buffer); +#endif /* E2DEBUG */ + return devread (fsblock * (EXT2_BLOCK_SIZE (SUPERBLOCK) / DEV_BSIZE), 0, + EXT2_BLOCK_SIZE (SUPERBLOCK), (char *) buffer); +} + +/* from + ext2/inode.c:ext2_bmap() +*/ +/* Maps LOGICAL_BLOCK (the file offset divided by the blocksize) into + a physical block (the location in the file system) via an inode. */ +static 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++) + { + printk_debug ("%c", "0123456789abcdef"[*i >> 4]); + printk_debug ("%c", "0123456789abcdef"[*i % 16]); + if (!((i + 1 - (unsigned char *) INODE) % 16)) + { + printk_debug ("\n"); + } + else + { + printk_debug (" "); + } + } + printk_debug ("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 + printk_debug ("returning %d\n", (unsigned char *) (le32_to_cpu(INODE->i_block[logical_block]))); + printk_debug ("returning %d\n", le32_to_cpu(INODE->i_block[logical_block])); +#endif /* E2DEBUG */ + return le32_to_cpu(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 (le32_to_cpu(INODE->i_block[EXT2_IND_BLOCK]), DATABLOCK1)) + { + errnum = ERR_FSYS_CORRUPT; + return -1; + } + mapblock1 = 1; + return le32_to_cpu(((__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 (le32_to_cpu(INODE->i_block[EXT2_DIND_BLOCK]), DATABLOCK1)) + { + errnum = ERR_FSYS_CORRUPT; + return -1; + } + mapblock1 = 2; + if ((bnum = le32_to_cpu(((__u32 *) DATABLOCK1) + [logical_block >> EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK)])) + != mapblock2 + && !ext2_rdfsb (bnum, DATABLOCK2)) + { + errnum = ERR_FSYS_CORRUPT; + return -1; + } + mapblock2 = bnum; + return le32_to_cpu(((__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 (le32_to_cpu(INODE->i_block[EXT2_TIND_BLOCK]), DATABLOCK1)) + { + errnum = ERR_FSYS_CORRUPT; + return -1; + } + mapblock1 = 3; + if (!ext2_rdfsb (le32_to_cpu(((__u32 *) DATABLOCK1) + [logical_block >> (EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK) + * 2)]), + DATABLOCK2)) + { + errnum = ERR_FSYS_CORRUPT; + return -1; + } + if (!ext2_rdfsb (le32_to_cpu(((__u32 *) DATABLOCK2) + [(logical_block >> EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK)) + & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)]), + DATABLOCK2)) + { + errnum = ERR_FSYS_CORRUPT; + return -1; + } + return le32_to_cpu(((__u32 *) DATABLOCK2) + [logical_block & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)]); +} + +/* preconditions: all preconds of ext2fs_block_map */ +int +ext2fs_read (char *buf, int len) +{ + int logical_block; + int offset; + int map; + int ret = 0; + int size = 0; + +#ifdef E2DEBUG + static char hexdigit[] = "0123456789abcdef"; + unsigned char *i; + for (i = (unsigned char *) INODE; + i < ((unsigned char *) INODE + sizeof (struct ext2_inode)); + i++) + { + printk_debug ("%c", hexdigit[*i >> 4]); + printk_debug ("%c", hexdigit[*i % 16]); + if (!((i + 1 - (unsigned char *) INODE) % 16)) + { + printk_debug ("\n"); + } + else + { + printk_debug (" "); + } + } +#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 + printk_debug ("map=%d\n", map); +#endif /* E2DEBUG */ + if (map < 0) + break; + + size = EXT2_BLOCK_SIZE (SUPERBLOCK); + size -= offset; + if (size > len) + size = len; + + disk_read_func = disk_read_hook; + + devread (map * (EXT2_BLOCK_SIZE (SUPERBLOCK) / DEV_BSIZE), + offset, size, buf); + + disk_read_func = 0; + + buf += 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 updir_ino = current_ino; /* the parent of the current directory */ + 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 = 0; /* 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 linkbuf[PATH_MAX]; /* buffer for following symbolic links */ + int link_count = 0; + + 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 + printk_debug ("inode %d\n", current_ino); + printk_debug ("dirname=%s\n", dirname); +#endif /* E2DEBUG */ + + /* look up an inode */ + group_id = (current_ino - 1) / le32_to_cpu(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 + printk_debug ("ipg=%d, dpb=%d\n", le32_to_cpu(SUPERBLOCK->s_inodes_per_group), + EXT2_DESC_PER_BLOCK (SUPERBLOCK)); + printk_debug ("group_id=%d group_desc=%d desc=%d\n", group_id, group_desc, desc); +#endif /* E2DEBUG */ + if (!ext2_rdfsb ( + (WHICH_SUPER + group_desc + le32_to_cpu(SUPERBLOCK->s_first_data_block)), + (int) GROUP_DESC)) + { + return 0; + } + gdp = GROUP_DESC; + ino_blk = le32_to_cpu(gdp[desc].bg_inode_table) + + (((current_ino - 1) % le32_to_cpu(SUPERBLOCK->s_inodes_per_group)) + >> log2 (EXT2_BLOCK_SIZE (SUPERBLOCK) / sizeof (struct ext2_inode))); +#ifdef E2DEBUG + printk_debug ("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 + printk_debug ("ipb=%d, sizeof(inode)=%d\n", + (EXT2_BLOCK_SIZE (SUPERBLOCK) / sizeof (struct ext2_inode)), + sizeof (struct ext2_inode)); + printk_debug ("inode=%x, raw_inode=%x\n", INODE, raw_inode); + printk_debug ("offset into inode table block=%d\n", (int) raw_inode - (int) INODE); + for (i = (unsigned char *) INODE; i <= (unsigned char *) raw_inode; + i++) + { + printk_debug ("%c", "0123456789abcdef"[*i >> 4]); + printk_debug ("%c", "0123456789abcdef"[*i % 16]); + if (!((i + 1 - (unsigned char *) INODE) % 16)) + { + printk_debug ("\n"); + } + else + { + printk_debug (" "); + } + } + printk_debug ("first word=%x\n", *((int *) raw_inode)); +#endif /* E2DEBUG */ + + /* copy inode to fixed location */ + memmove ((void *) INODE, (void *) raw_inode, sizeof (struct ext2_inode)); + +#ifdef E2DEBUG + printk_debug ("first word=%x\n", *((int *) INODE)); +#endif /* E2DEBUG */ + + /* If we've got a symbolic link, then chase it. */ + if (S_ISLNK (le16_to_cpu(INODE->i_mode))) + { + int len; + if (++link_count > MAX_LINK_COUNT) + { + errnum = ERR_SYMLINK_LOOP; + return 0; + } + + /* Find out how long our remaining name is. */ + len = 0; + while (dirname[len] && !isspace (dirname[len])) + len++; + + /* Get the symlink size. */ + filemax = le32_to_cpu(INODE->i_size); + if (filemax + len > sizeof (linkbuf) - 2) + { + errnum = ERR_FILELENGTH; + return 0; + } + + if (len) + { + /* Copy the remaining name to the end of the symlink data. + Note that DIRNAME and LINKBUF may overlap! */ + memmove (linkbuf + filemax, dirname, len); + } + linkbuf[filemax + len] = '\0'; + + /* Read the symlink data. */ + if (le32_to_cpu(INODE->i_blocks)) + { + /* Read the necessary blocks, and reset the file pointer. */ + len = file_read (linkbuf, filemax); + filepos = 0; + if (!len) + return 0; + } + else + { + /* Copy the data directly from the inode. */ + len = filemax; + memmove (linkbuf, (char *) INODE->i_block, len); + } + +#ifdef E2DEBUG + printk_debug ("symlink=%s\n", linkbuf); +#endif + + dirname = linkbuf; + if (*dirname == '/') + { + /* It's an absolute link, so look it up in root. */ + current_ino = EXT2_ROOT_INO; + updir_ino = current_ino; + } + else + { + /* Relative, so look it up in our parent directory. */ + current_ino = updir_ino; + } + + /* Try again using the new name. */ + continue; + } + + /* if end of filename, INODE points to the file's inode */ + if (!*dirname || isspace (*dirname)) + { + if (!S_ISREG (le16_to_cpu(INODE->i_mode))) + { + errnum = ERR_BAD_FILETYPE; + return 0; + } + + filemax = le32_to_cpu(INODE->i_size); + return 1; + } + + /* else we have to traverse a directory */ + updir_ino = current_ino; + + /* skip over slashes */ + while (*dirname == '/') + dirname++; + + /* if this isn't a directory of sufficient size to hold our file, abort */ + if (!(le32_to_cpu(INODE->i_size)) || !S_ISDIR (le16_to_cpu(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 + printk_debug ("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 >= le32_to_cpu(INODE->i_size)) + { + if (print_possibilities < 0) + { +# if 0 + putchar ('\n'); +# endif + } + 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); + + /* 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 + printk_debug ("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 += le16_to_cpu(dp->rec_len); + + /* NOTE: ext2fs filenames are NOT null-terminated */ + +#ifdef E2DEBUG + printk_debug ("directory entry ino=%d\n", le32_to_cpu(dp->inode)); + if (le32_to_cpu(dp->inode)) + printk_debug ("entry=%s\n", dp->name); +#endif /* E2DEBUG */ + + if (le32_to_cpu(dp->inode)) + { + int saved_c = dp->name[dp->name_len]; + + dp->name[dp->name_len] = 0; + str_chk = substring (dirname, dp->name); + +# ifndef STAGE1_5 + if (print_possibilities && ch != '/' + && (!*dirname || str_chk <= 0)) + { + if (print_possibilities > 0) + print_possibilities = -print_possibilities; + print_a_completion (dp->name); + } +# endif + + dp->name[dp->name_len] = saved_c; + } + + } + while (!le32_to_cpu(dp->inode) || (str_chk || (print_possibilities && ch != '/'))); + + current_ino = le32_to_cpu(dp->inode); + *(dirname = rest) = ch; + } + /* never get here */ +} |