--- /dev/null
+/*
+ * 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., 51 Franklin Street - Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#ifdef FSYS_EXT2FS
+
+#include "config.h"
+#include "shared.h"
+#include "filesys.h"
+#include "libc/byteorder.h"
+
+#ifdef CONFIG_DEBUG_EXT2FS
+#define E2DEBUG
+#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/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 */
+ };
+
+/* ext2/super.c */
+#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 *) \
+ ((char *)SUPERBLOCK + sizeof(struct ext2_super_block)))
+#define INODE \
+ ((struct ext2_inode *)((char *)GROUP_DESC + EXT2_BLOCK_SIZE(SUPERBLOCK)))
+#define DATABLOCK1 \
+ ((char *)((char *)INODE + sizeof(struct ext2_inode)))
+#define DATABLOCK2 \
+ ((char *)((char *)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)
+
+#ifdef E2DEBUG
+void
+dump_super(struct ext2_super_block *s)
+{
+ printf(" superblock 0x%x:\n", s);
+ printf(" inodes=%d\n", __le32_to_cpu(s->s_inodes_count));
+ printf(" blocks=%d\n", __le32_to_cpu(s->s_blocks_count));
+ printf(" reserved=%d\n", __le32_to_cpu(s->s_r_blocks_count));
+ printf(" i_free=%d\n", __le32_to_cpu(s->s_free_inodes_count));
+ printf(" b_free=%d\n", __le32_to_cpu(s->s_free_blocks_count));
+ printf(" first=%d\n", __le32_to_cpu(s->s_first_data_block));
+ printf(" log_b_size=%d, b_size=%d\n", __le32_to_cpu(s->s_log_block_size), EXT2_BLOCK_SIZE(s));
+ printf(" log_f_size=%d\n", __le32_to_cpu(s->s_log_frag_size));
+ printf(" bpg=%d\n", __le32_to_cpu(s->s_blocks_per_group));
+ printf(" fpg=%d\n", __le32_to_cpu(s->s_frags_per_group));
+ printf(" ipg=%d\n", __le32_to_cpu(s->s_inodes_per_group));
+}
+
+void
+dump_group_desc(struct ext2_group_desc *g)
+{
+ printf(" group_desc 0x%x:\n", g);
+ printf(" b_bmap block=%d\n", __le32_to_cpu(g->bg_block_bitmap));
+ printf(" i_bmap block=%d\n", __le32_to_cpu(g->bg_inode_bitmap));
+ printf(" i_tab block=%d\n", __le32_to_cpu(g->bg_inode_table));
+ printf(" free_blks=%d\n", __le16_to_cpu(g->bg_free_blocks_count));
+ printf(" free_inodes=%d\n", __le16_to_cpu(g->bg_free_inodes_count));
+ printf(" used_dirs=%d\n", __le16_to_cpu(g->bg_used_dirs_count));
+}
+
+void
+dump_inode(struct ext2_inode *i)
+{
+ printf(" inode 0x%x:\n", i);
+ printf(" mode=%o\n", __le16_to_cpu(i->i_mode));
+ printf(" uid=%d\n", __le16_to_cpu(i->i_uid));
+ printf(" gid=%d\n", __le16_to_cpu(i->i_gid));
+ printf(" size=%d\n", __le32_to_cpu(i->i_size));
+ printf(" atime=%d\n", __le32_to_cpu(i->i_atime));
+ printf(" ctime=%d\n", __le32_to_cpu(i->i_ctime));
+ printf(" mtime=%d\n", __le32_to_cpu(i->i_mtime));
+ printf(" dtime=%d\n", __le32_to_cpu(i->i_dtime));
+ printf(" links=%d\n", __le16_to_cpu(i->i_links_count));
+ printf(" blocks=%d\n", __le32_to_cpu(i->i_blocks));
+ printf(" flags=%d\n", __le32_to_cpu(i->i_flags));
+}
+
+void
+dump_inode_data(unsigned char *inode, int len)
+{
+ static char hexdigit[] = "0123456789abcdef";
+ unsigned char *i;
+ for (i = inode;
+ i < (inode + len);
+ i++)
+ {
+ printf ("%c", hexdigit[*i >> 4]);
+ printf ("%c", hexdigit[*i % 16]);
+ if (!((i + 1 - inode) % 16))
+ {
+ printf ("\n");
+ }
+ else
+ {
+ printf (" ");
+ }
+ }
+}
+#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, char * buffer)
+{
+#ifdef E2DEBUG
+ printf ("ext2_rdfsb: fsblock %d, devblock %d, size %d\n", fsblock,
+ fsblock * (EXT2_BLOCK_SIZE (SUPERBLOCK) / DEV_BSIZE),
+ EXT2_BLOCK_SIZE (SUPERBLOCK));
+#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
+ printf ("ext2fs_block_map(%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 ("ext2fs_block_map: 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
+ printf("ext2fs_read(0x%x, %d)\n", buf, len);
+ dump_inode(INODE);
+ dump_inode_data((unsigned char *)INODE, sizeof (struct ext2_inode));
+#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;
+
+ disk_read_func = disk_read_hook;
+
+ devread (map * (EXT2_BLOCK_SIZE (SUPERBLOCK) / DEV_BSIZE),
+ offset, size, buf);
+
+ disk_read_func = NULL;
+
+ 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 */
+
+ /* 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)
+ */
+
+#ifdef E2DEBUG
+ printf("****** ext2fs_dir(%s)\n", dirname);
+ dump_super(SUPERBLOCK);
+#endif /* E2DEBUG */
+
+ while (1)
+ {
+#ifdef E2DEBUG
+ printf ("ext2fs_dir: inode %d\n", current_ino);
+ printf ("ext2fs_dir: 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
+ printf ("ext2fs_dir: ipg=%d, dpb=%d\n", __le32_to_cpu(SUPERBLOCK->s_inodes_per_group),
+ EXT2_DESC_PER_BLOCK (SUPERBLOCK));
+ printf ("ext2fs_dir: 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)),
+ (char*) GROUP_DESC))
+ {
+ return 0;
+ }
+
+#ifdef E2DEBUG
+ dump_group_desc(GROUP_DESC);
+#endif /* E2DEBUG */
+
+ 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
+ printf ("ext2fs_dir: itab_blk=%d, i_in_grp=%d, log2=%d\n",
+ __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)));
+ printf ("ext2fs_dir: inode table fsblock=%d\n", ino_blk);
+#endif /* E2DEBUG */
+ if (!ext2_rdfsb (ino_blk, (char *)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 ("ext2fs_dir: ipb=%d, sizeof(inode)=%d\n",
+ (EXT2_BLOCK_SIZE (SUPERBLOCK) / sizeof (struct ext2_inode)),
+ sizeof (struct ext2_inode));
+ printf ("ext2fs_dir: inode=%x, raw_inode=%x\n", INODE, raw_inode);
+ printf ("ext2fs_dir: offset into inode table block=%d\n", (int) raw_inode - (int) INODE);
+ dump_inode(raw_inode);
+ dump_inode_data((unsigned char *)INODE, EXT2_BLOCK_SIZE(SUPERBLOCK));
+ printf ("ext2fs_dir: 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
+ dump_inode(INODE);
+ printf ("ext2fs_dir: 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
+ printf ("ext2fs_dir: 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
+ printf ("ext2fs_dir: 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
+ printf ("ext2fs_dir: 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
+ printf ("ext2fs_dir: directory entry ino=%d\n", __le32_to_cpu(dp->inode));
+ if (__le32_to_cpu(dp->inode))
+ printf ("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 */
+}
+
+#endif /* FSYS_EXT2_FS */
Code Review / kvmfornfv.git / blobdiff