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e2fsprogs/e2fsck/pass2.c

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/*
* pass2.c --- check directory structure
*
* Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*
* Pass 2 of e2fsck iterates through all active directory inodes, and
* applies to following tests to each directory entry in the directory
* blocks in the inodes:
*
* - The length of the directory entry (rec_len) should be at
* least 8 bytes, and no more than the remaining space
* left in the directory block.
* - The length of the name in the directory entry (name_len)
* should be less than (rec_len - 8).
* - The inode number in the directory entry should be within
* legal bounds.
* - The inode number should refer to a in-use inode.
* - The first entry should be '.', and its inode should be
* the inode of the directory.
* - The second entry should be '..'.
*
* To minimize disk seek time, the directory blocks are processed in
* sorted order of block numbers.
*
* Pass 2 also collects the following information:
* - The inode numbers of the subdirectories for each directory.
*
* Pass 2 relies on the following information from previous passes:
* - The directory information collected in pass 1.
* - The inode_used_map bitmap
* - The inode_bad_map bitmap
* - The inode_dir_map bitmap
*
* Pass 2 frees the following data structures
* - The inode_bad_map bitmap
*/
#include "et/com_err.h"
#include "e2fsck.h"
#include "problem.h"
/*
* Keeps track of how many times an inode is referenced.
*/
ext2_icount_t inode_count = 0;
static void deallocate_inode(ext2_filsys fs, ino_t ino,
char* block_buf);
static int process_bad_inode(ext2_filsys fs, ino_t dir, ino_t ino);
static int check_dir_block(ext2_filsys fs,
struct ext2_db_entry *dir_blocks_info,
void *private);
static int allocate_dir_block(ext2_filsys fs,
struct ext2_db_entry *dir_blocks_info,
char *buf, struct problem_context *pctx);
static int update_dir_block(ext2_filsys fs,
blk_t *block_nr,
int blockcnt,
void *private);
struct check_dir_struct {
char *buf;
struct problem_context pctx;
};
void pass2(ext2_filsys fs)
{
char *buf;
struct resource_track rtrack;
struct dir_info *dir;
errcode_t retval;
ino_t size;
struct check_dir_struct cd;
init_resource_track(&rtrack);
#ifdef MTRACE
mtrace_print("Pass 2");
#endif
if (!preen)
printf("Pass 2: Checking directory structure\n");
size = ext2fs_get_icount_size(inode_link_info) + 10;
retval = ext2fs_create_icount(fs, EXT2_ICOUNT_OPT_INCREMENT,
size, &inode_count);
if (retval) {
com_err("ext2fs_create_icount", retval,
"while creating inode_count");
fatal_error(0);
}
buf = allocate_memory(fs->blocksize, "directory scan buffer");
/*
* Set up the parent pointer for the root directory, if
* present. (If the root directory is not present, we will
* create it in pass 3.)
*/
dir = get_dir_info(EXT2_ROOT_INO);
if (dir)
dir->parent = EXT2_ROOT_INO;
cd.buf = buf;
clear_problem_context(&cd.pctx);
retval = ext2fs_dblist_iterate(fs->dblist, check_dir_block, &cd);
free(buf);
ext2fs_free_dblist(fs->dblist);
if (inode_bad_map) {
ext2fs_free_inode_bitmap(inode_bad_map);
inode_bad_map = 0;
}
if (tflag > 1) {
printf("Pass 2: ");
print_resource_track(&rtrack);
}
}
/*
* Make sure the first entry in the directory is '.', and that the
* directory entry is sane.
*/
static int check_dot(ext2_filsys fs,
struct ext2_dir_entry *dirent,
ino_t ino, struct problem_context *pctx)
{
struct ext2_dir_entry *nextdir;
int status = 0;
int created = 0;
int new_len;
int problem = 0;
if (!dirent->inode)
problem = PR_2_MISSING_DOT;
else if ((dirent->name_len != 1) ||
(dirent->name[0] != '.'))
problem = PR_2_1ST_NOT_DOT;
else if (dirent->name[1] != '\0')
problem = PR_2_DOT_NULL_TERM;
if (problem) {
if (fix_problem(fs, problem, pctx)) {
if (dirent->rec_len < 12)
dirent->rec_len = 12;
dirent->inode = ino;
dirent->name_len = 1;
dirent->name[0] = '.';
dirent->name[1] = '\0';
status = 1;
created = 1;
}
}
if (dirent->inode != ino) {
if (fix_problem(fs, PR_2_BAD_INODE_DOT, pctx)) {
dirent->inode = ino;
status = 1;
}
}
if (dirent->rec_len > 12) {
new_len = dirent->rec_len - 12;
if (new_len > 12) {
preenhalt(fs);
if (created ||
ask("Directory entry for '.' is big. Split", 1)) {
nextdir = (struct ext2_dir_entry *)
((char *) dirent + 12);
dirent->rec_len = 12;
nextdir->rec_len = new_len;
nextdir->inode = 0;
nextdir->name_len = 0;
status = 1;
}
}
}
return status;
}
/*
* Make sure the second entry in the directory is '..', and that the
* directory entry is sane. We do not check the inode number of '..'
* here; this gets done in pass 3.
*/
static int check_dotdot(ext2_filsys fs,
struct ext2_dir_entry *dirent,
struct dir_info *dir, struct problem_context *pctx)
{
int problem = 0;
if (!dirent->inode)
problem = PR_2_MISSING_DOT_DOT;
else if ((dirent->name_len != 2) ||
(dirent->name[0] != '.') ||
(dirent->name[1] != '.'))
problem = PR_2_2ND_NOT_DOT_DOT;
else if (dirent->name[2] != '\0')
problem = PR_2_DOT_DOT_NULL_TERM;
if (problem) {
if (fix_problem(fs, problem, pctx)) {
if (dirent->rec_len < 12)
dirent->rec_len = 12;
/*
* Note: we don't have the parent inode just
* yet, so we will fill it in with the root
* inode. This will get fixed in pass 3.
*/
dirent->inode = EXT2_ROOT_INO;
dirent->name_len = 2;
dirent->name[0] = '.';
dirent->name[1] = '.';
dirent->name[2] = '\0';
return 1;
}
return 0;
}
dir->dotdot = dirent->inode;
return 0;
}
/*
* Check to make sure a directory entry doesn't contain any illegal
* characters.
*/
static int check_name(ext2_filsys fs,
struct ext2_dir_entry *dirent,
ino_t dir_ino, struct problem_context *pctx)
{
int i;
int fixup = -1;
int ret = 0;
for ( i = 0; i < dirent->name_len; i++) {
if (dirent->name[i] == '/' || dirent->name[i] == '\0') {
if (fixup < 0) {
fixup = fix_problem(fs, PR_2_BAD_NAME, pctx);
}
if (fixup) {
dirent->name[i] = '.';
ret = 1;
}
}
}
return ret;
}
static int check_dir_block(ext2_filsys fs,
struct ext2_db_entry *db,
void *private)
{
struct dir_info *subdir, *dir;
struct ext2_dir_entry *dirent;
int offset = 0;
int dir_modified = 0;
errcode_t retval;
int dot_state;
blk_t block_nr = db->blk;
ino_t ino = db->ino;
__u16 links;
struct check_dir_struct *cd = private;
char *buf = cd->buf;
/*
* Make sure the inode is still in use (could have been
* deleted in the duplicate/bad blocks pass.
*/
if (!(ext2fs_test_inode_bitmap(inode_used_map, ino)))
return 0;
cd->pctx.ino = ino;
cd->pctx.blk = block_nr;
cd->pctx.blkcount = db->blockcnt;
cd->pctx.ino2 = 0;
cd->pctx.dirent = 0;
cd->pctx.num = 0;
if (db->blk == 0) {
if (allocate_dir_block(fs, db, buf, &cd->pctx))
return 0;
block_nr = db->blk;
}
if (db->blockcnt)
dot_state = 2;
else
dot_state = 0;
#if 0
printf("In process_dir_block block %lu, #%d, inode %lu\n", block_nr,
db->blockcnt, ino);
#endif
retval = ext2fs_read_dir_block(fs, block_nr, buf);
if (retval) {
com_err(program_name, retval,
"while reading directory block %d", block_nr);
}
do {
dot_state++;
dirent = (struct ext2_dir_entry *) (buf + offset);
cd->pctx.dirent = dirent;
cd->pctx.num = offset;
if (((offset + dirent->rec_len) > fs->blocksize) ||
(dirent->rec_len < 8) ||
((dirent->rec_len % 4) != 0) ||
((dirent->name_len+8) > dirent->rec_len)) {
if (fix_problem(fs, PR_2_DIR_CORRUPTED, &cd->pctx)) {
dirent->rec_len = fs->blocksize - offset;
dirent->name_len = 0;
dirent->inode = 0;
dir_modified++;
} else
return DIRENT_ABORT;
}
if (dirent->name_len > EXT2_NAME_LEN) {
if (fix_problem(fs, PR_2_FILENAME_LONG, &cd->pctx)) {
dirent->name_len = EXT2_NAME_LEN;
dir_modified++;
}
}
if (dot_state == 1) {
if (check_dot(fs, dirent, ino, &cd->pctx))
dir_modified++;
} else if (dot_state == 2) {
dir = get_dir_info(ino);
if (!dir) {
printf("Internal error: couldn't find dir_info for %lu\n",
ino);
fatal_error(0);
}
if (check_dotdot(fs, dirent, dir, &cd->pctx))
dir_modified++;
} else if (dirent->inode == ino) {
if (fix_problem(fs, PR_2_LINK_DOT, &cd->pctx)) {
dirent->inode = 0;
dir_modified++;
goto next;
}
}
if (!dirent->inode)
goto next;
if (check_name(fs, dirent, ino, &cd->pctx))
dir_modified++;
/*
* Make sure the inode listed is a legal one.
*/
if (((dirent->inode != EXT2_ROOT_INO) &&
(dirent->inode < EXT2_FIRST_INODE(fs->super))) ||
(dirent->inode > fs->super->s_inodes_count)) {
if (fix_problem(fs, PR_2_BAD_INO, &cd->pctx)) {
dirent->inode = 0;
dir_modified++;
goto next;
}
}
/*
* If the inode is unused, offer to clear it.
*/
if (!(ext2fs_test_inode_bitmap(inode_used_map,
dirent->inode))) {
if (fix_problem(fs, PR_2_UNUSED_INODE, &cd->pctx)) {
dirent->inode = 0;
dir_modified++;
goto next;
}
}
/*
* If the inode is in a bad block, offer to clear it.
*/
if (inode_bb_map &&
(ext2fs_test_inode_bitmap(inode_bb_map,
dirent->inode))) {
if (fix_problem(fs, PR_2_BB_INODE, &cd->pctx)) {
dirent->inode = 0;
dir_modified++;
goto next;
}
}
/*
* If the inode was marked as having bad fields in
* pass1, process it and offer to fix/clear it.
* (We wait until now so that we can display the
* pathname to the user.)
*/
if (inode_bad_map &&
ext2fs_test_inode_bitmap(inode_bad_map,
dirent->inode)) {
if (process_bad_inode(fs, ino, dirent->inode)) {
dirent->inode = 0;
dir_modified++;
goto next;
}
}
/*
* Don't allow links to the root directory. We check
* this specially to make sure we catch this error
* case even if the root directory hasn't been created
* yet.
*/
if ((dot_state > 2) && (dirent->inode == EXT2_ROOT_INO)) {
if (fix_problem(fs, PR_2_LINK_ROOT, &cd->pctx)) {
dirent->inode = 0;
dir_modified++;
goto next;
}
}
/*
* If this is a directory, then mark its parent in its
* dir_info structure. If the parent field is already
* filled in, then this directory has more than one
* hard link. We assume the first link is correct,
* and ask the user if he/she wants to clear this one.
*/
if ((dot_state > 2) &&
(ext2fs_test_inode_bitmap(inode_dir_map,
dirent->inode))) {
subdir = get_dir_info(dirent->inode);
if (!subdir) {
printf("INTERNAL ERROR: missing dir %u\n",
dirent->inode);
fatal_error(0);
}
if (subdir->parent) {
cd->pctx.ino2 = subdir->parent;
if (fix_problem(fs, PR_2_LINK_DIR,
&cd->pctx)) {
dirent->inode = 0;
dir_modified++;
goto next;
}
cd->pctx.ino2 = 0;
} else
subdir->parent = ino;
}
ext2fs_icount_increment(inode_count, dirent->inode, &links);
if (links > 1)
fs_links_count++;
fs_total_count++;
next:
offset += dirent->rec_len;
} while (offset < fs->blocksize);
#if 0
printf("\n");
#endif
if (offset != fs->blocksize) {
printf("Final rec_len is %d, should be %d\n",
dirent->rec_len,
dirent->rec_len - fs->blocksize + offset);
}
if (dir_modified) {
retval = ext2fs_write_dir_block(fs, block_nr, buf);
if (retval) {
com_err(program_name, retval,
"while writing directory block %d", block_nr);
}
ext2fs_mark_changed(fs);
}
return 0;
}
/*
* This function is called to deallocate a block, and is an interator
* functioned called by deallocate inode via ext2fs_iterate_block().
*/
static int deallocate_inode_block(ext2_filsys fs,
blk_t *block_nr,
int blockcnt,
void *private)
{
if (!*block_nr)
return 0;
ext2fs_unmark_block_bitmap(block_found_map, *block_nr);
ext2fs_unmark_block_bitmap(fs->block_map, *block_nr);
return 0;
}
/*
* This fuction deallocates an inode
*/
static void deallocate_inode(ext2_filsys fs, ino_t ino,
char* block_buf)
{
errcode_t retval;
struct ext2_inode inode;
ext2fs_icount_store(inode_link_info, ino, 0);
e2fsck_read_inode(fs, ino, &inode, "deallocate_inode");
inode.i_links_count = 0;
inode.i_dtime = time(0);
e2fsck_write_inode(fs, ino, &inode, "deallocate_inode");
/*
* Fix up the bitmaps...
*/
read_bitmaps(fs);
ext2fs_unmark_inode_bitmap(inode_used_map, ino);
ext2fs_unmark_inode_bitmap(inode_dir_map, ino);
if (inode_bad_map)
ext2fs_unmark_inode_bitmap(inode_bad_map, ino);
ext2fs_unmark_inode_bitmap(fs->inode_map, ino);
ext2fs_mark_ib_dirty(fs);
if (!ext2fs_inode_has_valid_blocks(&inode))
return;
ext2fs_mark_bb_dirty(fs);
retval = ext2fs_block_iterate(fs, ino, 0, block_buf,
deallocate_inode_block, 0);
if (retval)
com_err("deallocate_inode", retval,
"while calling ext2fs_block_iterate for inode %d",
ino);
}
static int process_bad_inode(ext2_filsys fs, ino_t dir, ino_t ino)
{
struct ext2_inode inode;
int inode_modified = 0;
unsigned char *frag, *fsize;
struct problem_context pctx;
e2fsck_read_inode(fs, ino, &inode, "process_bad_inode");
clear_problem_context(&pctx);
pctx.ino = ino;
pctx.dir = dir;
pctx.inode = &inode;
if (!LINUX_S_ISDIR(inode.i_mode) && !LINUX_S_ISREG(inode.i_mode) &&
!LINUX_S_ISCHR(inode.i_mode) && !LINUX_S_ISBLK(inode.i_mode) &&
!LINUX_S_ISLNK(inode.i_mode) && !LINUX_S_ISFIFO(inode.i_mode) &&
!(LINUX_S_ISSOCK(inode.i_mode))) {
if (fix_problem(fs, PR_2_BAD_MODE, &pctx)) {
deallocate_inode(fs, ino, 0);
return 1;
}
}
if (inode.i_faddr &&
fix_problem(fs, PR_2_FADDR_ZERO, &pctx)) {
inode.i_faddr = 0;
inode_modified++;
}
switch (fs->super->s_creator_os) {
case EXT2_OS_LINUX:
frag = &inode.osd2.linux2.l_i_frag;
fsize = &inode.osd2.linux2.l_i_fsize;
break;
case EXT2_OS_HURD:
frag = &inode.osd2.hurd2.h_i_frag;
fsize = &inode.osd2.hurd2.h_i_fsize;
break;
case EXT2_OS_MASIX:
frag = &inode.osd2.masix2.m_i_frag;
fsize = &inode.osd2.masix2.m_i_fsize;
break;
default:
frag = fsize = 0;
}
if (frag && *frag) {
pctx.num = *frag;
if (fix_problem(fs, PR_2_FRAG_ZERO, &pctx)) {
*frag = 0;
inode_modified++;
}
pctx.num = 0;
}
if (fsize && *fsize) {
pctx.num = *fsize;
if (fix_problem(fs, PR_2_FSIZE_ZERO, &pctx)) {
*fsize = 0;
inode_modified++;
}
pctx.num = 0;
}
if (inode.i_file_acl &&
fix_problem(fs, PR_2_FILE_ACL_ZERO, &pctx)) {
inode.i_file_acl = 0;
inode_modified++;
}
if (inode.i_dir_acl &&
fix_problem(fs, PR_2_DIR_ACL_ZERO, &pctx)) {
inode.i_dir_acl = 0;
inode_modified++;
}
if (inode_modified)
e2fsck_write_inode(fs, ino, &inode, "process_bad_inode");
return 0;
}
/*
* allocate_dir_block --- this function allocates a new directory
* block for a particular inode; this is done if a directory has
* a "hole" in it, or if a directory has a illegal block number
* that was zeroed out and now needs to be replaced.
*/
static int allocate_dir_block(ext2_filsys fs,
struct ext2_db_entry *db,
char *buf, struct problem_context *pctx)
{
blk_t blk;
char *block;
struct ext2_inode inode;
errcode_t retval;
if (fix_problem(fs, PR_2_DIRECTORY_HOLE, pctx) == 0)
return 1;
/*
* Read the inode and block bitmaps in; we'll be messing with
* them.
*/
read_bitmaps(fs);
/*
* First, find a free block
*/
retval = ext2fs_new_block(fs, 0, block_found_map, &blk);
if (retval) {
com_err("allocate_dir_block", retval,
"while trying to fill a hole in a directory inode");
return 1;
}
ext2fs_mark_block_bitmap(block_found_map, blk);
ext2fs_mark_block_bitmap(fs->block_map, blk);
ext2fs_mark_bb_dirty(fs);
/*
* Now let's create the actual data block for the inode
*/
if (db->blockcnt)
retval = ext2fs_new_dir_block(fs, 0, 0, &block);
else
retval = ext2fs_new_dir_block(fs, db->ino, EXT2_ROOT_INO,
&block);
if (retval) {
com_err("allocate_dir_block", retval,
"while creating new directory block");
return 1;
}
retval = ext2fs_write_dir_block(fs, blk, block);
free(block);
if (retval) {
com_err("allocate_dir_block", retval,
"while writing an empty directory block");
return 1;
}
/*
* Update the inode block count
*/
e2fsck_read_inode(fs, db->ino, &inode, "allocate_dir_block");
inode.i_blocks += fs->blocksize / 512;
if (inode.i_size < (db->blockcnt+1) * fs->blocksize)
inode.i_size = (db->blockcnt+1) * fs->blocksize;
e2fsck_write_inode(fs, db->ino, &inode, "allocate_dir_block");
/*
* Finally, update the block pointers for the inode
*/
db->blk = blk;
retval = ext2fs_block_iterate(fs, db->ino, BLOCK_FLAG_HOLE,
0, update_dir_block, db);
if (retval) {
com_err("allocate_dir_block", retval,
"while calling ext2fs_block_iterate");
return 1;
}
return 0;
}
/*
* This is a helper function for allocate_dir_block().
*/
static int update_dir_block(ext2_filsys fs,
blk_t *block_nr,
int blockcnt,
void *private)
{
struct ext2_db_entry *db = private;
if (db->blockcnt == blockcnt) {
*block_nr = db->blk;
return BLOCK_CHANGED;
}
return 0;
}
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