blob: 2f97aa4cb1bcc0f5446372788c37ba625578a133 [file] [log] [blame]
/*
* pass3.c -- pass #3 of e2fsck: Check for directory connectivity
*
* 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 #3 assures that all directories are connected to the
* filesystem tree, using the following algorithm:
*
* First, the root directory is checked to make sure it exists; if
* not, e2fsck will offer to create a new one. It is then marked as
* "done".
*
* Then, pass3 interates over all directory inodes; for each directory
* it attempts to trace up the filesystem tree, using dirinfo.parent
* until it reaches a directory which has been marked "done". If it
* can not do so, then the directory must be disconnected, and e2fsck
* will offer to reconnect it to /lost+found. While it is chasing
* parent pointers up the filesystem tree, if pass3 sees a directory
* twice, then it has detected a filesystem loop, and it will again
* offer to reconnect the directory to /lost+found in to break the
* filesystem loop.
*
* Pass 3 also contains the subroutine, reconnect_file() to reconnect
* inodes to /lost+found; this subroutine is also used by pass 4.
* reconnect_file() calls get_lost_and_found(), which is responsible
* for creating /lost+found if it does not exist.
*
* Pass 3 frees the following data structures:
* - The dirinfo directory information cache.
*/
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include "et/com_err.h"
#include "e2fsck.h"
#include "problem.h"
static void check_root(ext2_filsys fs);
static void check_directory(ext2_filsys fs, struct dir_info *dir,
struct problem_context *pctx);
static ino_t get_lost_and_found(ext2_filsys fs);
static void fix_dotdot(ext2_filsys fs, struct dir_info *dir, ino_t parent);
static errcode_t adjust_inode_count(ext2_filsys fs, ino_t ino, int adj);
static errcode_t expand_directory(ext2_filsys fs, ino_t dir);
static ino_t lost_and_found = 0;
static int bad_lost_and_found = 0;
static ext2fs_inode_bitmap inode_loop_detect;
static ext2fs_inode_bitmap inode_done_map;
void pass3(ext2_filsys fs)
{
int i;
errcode_t retval;
struct resource_track rtrack;
struct problem_context pctx;
struct dir_info *dir;
init_resource_track(&rtrack);
#ifdef MTRACE
mtrace_print("Pass 3");
#endif
if (!preen)
printf("Pass 3: Checking directory connectivity\n");
/*
* Allocate some bitmaps to do loop detection.
*/
retval = ext2fs_allocate_inode_bitmap(fs,
"inode loop detection bitmap",
&inode_loop_detect);
if (retval) {
com_err("ext2fs_allocate_inode_bitmap", retval,
"while allocating inode_loop_detect");
fatal_error(0);
}
retval = ext2fs_allocate_inode_bitmap(fs, "inode done bitmap",
&inode_done_map);
if (retval) {
com_err("ext2fs_allocate_inode_bitmap", retval,
"while allocating inode_done_map");
fatal_error(0);
}
if (tflag) {
printf("Peak memory: ");
print_resource_track(&global_rtrack);
}
check_root(fs);
ext2fs_mark_inode_bitmap(inode_done_map, EXT2_ROOT_INO);
clear_problem_context(&pctx);
for (i=0; (dir = dir_info_iter(&i)) != 0;) {
if (ext2fs_test_inode_bitmap(inode_dir_map, dir->ino))
check_directory(fs, dir, &pctx);
}
free_dir_info(fs);
ext2fs_free_inode_bitmap(inode_loop_detect);
ext2fs_free_inode_bitmap(inode_done_map);
if (tflag > 1) {
printf("Pass 3: ");
print_resource_track(&rtrack);
}
}
/*
* This makes sure the root inode is present; if not, we ask if the
* user wants us to create it. Not creating it is a fatal error.
*/
static void check_root(ext2_filsys fs)
{
blk_t blk;
errcode_t retval;
struct ext2_inode inode;
char * block;
if (ext2fs_test_inode_bitmap(inode_used_map, EXT2_ROOT_INO)) {
/*
* If the root inode is a directory, die here. The
* user must have answered 'no' in pass1 when we
* offered to clear it.
*/
if (!(ext2fs_test_inode_bitmap(inode_dir_map, EXT2_ROOT_INO)))
fatal_error("Root inode not directory");
return;
}
if (!fix_problem(fs, PR_3_NO_ROOT_INODE, 0))
fatal_error("Cannot proceed without a root inode.");
read_bitmaps(fs);
/*
* First, find a free block
*/
retval = ext2fs_new_block(fs, 0, block_found_map, &blk);
if (retval) {
com_err("ext2fs_new_block", retval,
"while trying to create root directory");
fatal_error(0);
}
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
*/
retval = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO,
&block);
if (retval) {
com_err("ext2fs_new_dir_block", retval,
"while creating new root directory");
fatal_error(0);
}
retval = ext2fs_write_dir_block(fs, blk, block);
if (retval) {
com_err("ext2fs_write_dir_block", retval,
"while writing the root directory block");
fatal_error(0);
}
free(block);
/*
* Set up the inode structure
*/
memset(&inode, 0, sizeof(inode));
inode.i_mode = 040755;
inode.i_size = fs->blocksize;
inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
inode.i_links_count = 2;
inode.i_blocks = fs->blocksize / 512;
inode.i_block[0] = blk;
/*
* Write out the inode.
*/
retval = ext2fs_write_inode(fs, EXT2_ROOT_INO, &inode);
if (retval) {
com_err("ext2fs_write_inode", retval,
"While trying to create /lost+found");
fatal_error(0);
}
/*
* Miscellaneous bookkeeping...
*/
add_dir_info(fs, EXT2_ROOT_INO, EXT2_ROOT_INO);
ext2fs_icount_store(inode_count, EXT2_ROOT_INO, 2);
ext2fs_icount_store(inode_link_info, EXT2_ROOT_INO, 2);
ext2fs_mark_inode_bitmap(inode_used_map, EXT2_ROOT_INO);
ext2fs_mark_inode_bitmap(inode_dir_map, EXT2_ROOT_INO);
ext2fs_mark_inode_bitmap(fs->inode_map, EXT2_ROOT_INO);
ext2fs_mark_ib_dirty(fs);
}
/*
* This subroutine is responsible for making sure that a particular
* directory is connected to the root; if it isn't we trace it up as
* far as we can go, and then offer to connect the resulting parent to
* the lost+found. We have to do loop detection; if we ever discover
* a loop, we treat that as a disconnected directory and offer to
* reparent it to lost+found.
*/
static void check_directory(ext2_filsys fs, struct dir_info *dir,
struct problem_context *pctx)
{
struct dir_info *p = dir;
ext2fs_clear_inode_bitmap(inode_loop_detect);
while (p) {
/*
* If we find a parent which we've already checked,
* then stop; we know it's either already connected to
* the directory tree, or it isn't but the user has
* already told us he doesn't want us to reconnect the
* disconnected subtree.
*/
if (ext2fs_test_inode_bitmap(inode_done_map, p->ino))
goto check_dot_dot;
/*
* Mark this inode as being "done"; by the time we
* return from this function, the inode we either be
* verified as being connected to the directory tree,
* or we will have offered to reconnect this to
* lost+found.
*/
ext2fs_mark_inode_bitmap(inode_done_map, p->ino);
/*
* If this directory doesn't have a parent, or we've
* seen the parent once already, then offer to
* reparent it to lost+found
*/
if (!p->parent ||
(ext2fs_test_inode_bitmap(inode_loop_detect,
p->parent)))
break;
ext2fs_mark_inode_bitmap(inode_loop_detect,
p->parent);
p = get_dir_info(p->parent);
}
/*
* If we've reached here, we've hit a detached directory
* inode; offer to reconnect it to lost+found.
*/
pctx->ino = p->ino;
if (fix_problem(fs, PR_3_UNCONNECTED_DIR, pctx)) {
if (reconnect_file(fs, p->ino))
ext2fs_unmark_valid(fs);
else {
p->parent = lost_and_found;
fix_dotdot(fs, p, lost_and_found);
}
}
/*
* Make sure that .. and the parent directory are the same;
* offer to fix it if not.
*/
check_dot_dot:
if (dir->parent != dir->dotdot) {
pctx->ino = dir->ino;
pctx->ino2 = dir->dotdot;
pctx->dir = dir->parent;
if (fix_problem(fs, PR_3_BAD_DOT_DOT, pctx))
fix_dotdot(fs, dir, dir->parent);
}
}
/*
* This routine gets the lost_and_found inode, making it a directory
* if necessary
*/
ino_t get_lost_and_found(ext2_filsys fs)
{
ino_t ino;
blk_t blk;
errcode_t retval;
struct ext2_inode inode;
char * block;
const char name[] = "lost+found";
retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
sizeof(name)-1, 0, &ino);
if (!retval)
return ino;
if (retval != ENOENT)
printf("Error while trying to find /lost+found: %s",
error_message(retval));
if (!fix_problem(fs, PR_3_NO_LF_DIR, 0))
return 0;
/*
* 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("ext2fs_new_block", retval,
"while trying to create /lost+found directory");
return 0;
}
ext2fs_mark_block_bitmap(block_found_map, blk);
ext2fs_mark_block_bitmap(fs->block_map, blk);
ext2fs_mark_bb_dirty(fs);
/*
* Next find a free inode.
*/
retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040755, inode_used_map,
&ino);
if (retval) {
com_err("ext2fs_new_inode", retval,
"while trying to create /lost+found directory");
return 0;
}
ext2fs_mark_inode_bitmap(inode_used_map, ino);
ext2fs_mark_inode_bitmap(inode_dir_map, ino);
ext2fs_mark_inode_bitmap(fs->inode_map, ino);
ext2fs_mark_ib_dirty(fs);
/*
* Now let's create the actual data block for the inode
*/
retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
if (retval) {
com_err("ext2fs_new_dir_block", retval,
"while creating new directory block");
return 0;
}
retval = ext2fs_write_dir_block(fs, blk, block);
free(block);
if (retval) {
com_err("ext2fs_write_dir_block", retval,
"while writing the directory block for /lost+found");
return 0;
}
/*
* Set up the inode structure
*/
memset(&inode, 0, sizeof(inode));
inode.i_mode = 040755;
inode.i_size = fs->blocksize;
inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
inode.i_links_count = 2;
inode.i_blocks = fs->blocksize / 512;
inode.i_block[0] = blk;
/*
* Next, write out the inode.
*/
retval = ext2fs_write_inode(fs, ino, &inode);
if (retval) {
com_err("ext2fs_write_inode", retval,
"While trying to create /lost+found");
return 0;
}
/*
* Finally, create the directory link
*/
retval = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, 0);
if (retval) {
com_err("ext2fs_link", retval, "While creating /lost+found");
return 0;
}
/*
* Miscellaneous bookkeeping that needs to be kept straight.
*/
add_dir_info(fs, ino, EXT2_ROOT_INO);
adjust_inode_count(fs, EXT2_ROOT_INO, +1);
ext2fs_icount_store(inode_count, ino, 2);
ext2fs_icount_store(inode_link_info, ino, 2);
#if 0
printf("/lost+found created; inode #%lu\n", ino);
#endif
return ino;
}
/*
* This routine will connect a file to lost+found
*/
int reconnect_file(ext2_filsys fs, ino_t inode)
{
errcode_t retval;
char name[80];
if (bad_lost_and_found) {
printf("Bad or nonexistent /lost+found. Cannot reconnect.\n");
return 1;
}
if (!lost_and_found) {
lost_and_found = get_lost_and_found(fs);
if (!lost_and_found) {
printf("Bad or nonexistent /lost+found. Cannot reconnect.\n");
bad_lost_and_found++;
return 1;
}
}
sprintf(name, "#%lu", inode);
retval = ext2fs_link(fs, lost_and_found, name, inode, 0);
if (retval == EXT2_ET_DIR_NO_SPACE) {
if (!fix_problem(fs, PR_3_EXPAND_LF_DIR, 0))
return 1;
retval = expand_directory(fs, lost_and_found);
if (retval) {
printf("Could not expand /lost+found: %s\n",
error_message(retval));
return 1;
}
retval = ext2fs_link(fs, lost_and_found, name, inode, 0);
}
if (retval) {
printf("Could not reconnect %lu: %s\n", inode,
error_message(retval));
return 1;
}
adjust_inode_count(fs, inode, +1);
return 0;
}
/*
* Utility routine to adjust the inode counts on an inode.
*/
static errcode_t adjust_inode_count(ext2_filsys fs, ino_t ino, int adj)
{
errcode_t retval;
struct ext2_inode inode;
if (!ino)
return 0;
retval = ext2fs_read_inode(fs, ino, &inode);
if (retval)
return retval;
#if 0
printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
inode.i_links_count);
#endif
inode.i_links_count += adj;
if (adj == 1) {
ext2fs_icount_increment(inode_count, ino, 0);
ext2fs_icount_increment(inode_link_info, ino, 0);
} else {
ext2fs_icount_decrement(inode_count, ino, 0);
ext2fs_icount_decrement(inode_link_info, ino, 0);
}
retval = ext2fs_write_inode(fs, ino, &inode);
if (retval)
return retval;
return 0;
}
/*
* Fix parent --- this routine fixes up the parent of a directory.
*/
struct fix_dotdot_struct {
ext2_filsys fs;
ino_t parent;
int done;
};
static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
int offset,
int blocksize,
char *buf,
void *private)
{
struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) private;
errcode_t retval;
if (dirent->name_len != 2)
return 0;
if (strncmp(dirent->name, "..", 2))
return 0;
retval = adjust_inode_count(fp->fs, dirent->inode, -1);
if (retval)
printf("Error while adjusting inode count on inode %u\n",
dirent->inode);
retval = adjust_inode_count(fp->fs, fp->parent, 1);
if (retval)
printf("Error while adjusting inode count on inode %lu\n",
fp->parent);
dirent->inode = fp->parent;
fp->done++;
return DIRENT_ABORT | DIRENT_CHANGED;
}
static void fix_dotdot(ext2_filsys fs, struct dir_info *dir, ino_t parent)
{
errcode_t retval;
struct fix_dotdot_struct fp;
fp.fs = fs;
fp.parent = parent;
fp.done = 0;
#if 0
printf("Fixing '..' of inode %lu to be %lu...\n", dir->ino, parent);
#endif
retval = ext2fs_dir_iterate(fs, dir->ino, DIRENT_FLAG_INCLUDE_EMPTY,
0, fix_dotdot_proc, &fp);
if (retval || !fp.done) {
printf("Couldn't fix parent of inode %lu: %s\n\n",
dir->ino, retval ? error_message(retval) :
"Couldn't find parent direntory entry");
ext2fs_unmark_valid(fs);
}
dir->dotdot = parent;
return;
}
/*
* These routines are responsible for expanding a /lost+found if it is
* too small.
*/
struct expand_dir_struct {
int done;
errcode_t err;
};
static int expand_dir_proc(ext2_filsys fs,
blk_t *blocknr,
int blockcnt,
void *private)
{
struct expand_dir_struct *es = (struct expand_dir_struct *) private;
blk_t new_blk;
static blk_t last_blk = 0;
char *block;
errcode_t retval;
if (*blocknr) {
last_blk = *blocknr;
return 0;
}
retval = ext2fs_new_block(fs, last_blk, block_found_map, &new_blk);
if (retval) {
es->err = retval;
return BLOCK_ABORT;
}
if (blockcnt > 0) {
retval = ext2fs_new_dir_block(fs, 0, 0, &block);
if (retval) {
es->err = retval;
return BLOCK_ABORT;
}
es->done = 1;
} else {
block = malloc(fs->blocksize);
if (!block) {
es->err = ENOMEM;
return BLOCK_ABORT;
}
memset(block, 0, fs->blocksize);
}
retval = ext2fs_write_dir_block(fs, new_blk, block);
if (retval) {
es->err = retval;
return BLOCK_ABORT;
}
free(block);
*blocknr = new_blk;
ext2fs_mark_block_bitmap(block_found_map, new_blk);
ext2fs_mark_block_bitmap(fs->block_map, new_blk);
ext2fs_mark_bb_dirty(fs);
if (es->done)
return (BLOCK_CHANGED | BLOCK_ABORT);
else
return BLOCK_CHANGED;
}
static errcode_t expand_directory(ext2_filsys fs, ino_t dir)
{
errcode_t retval;
struct expand_dir_struct es;
struct ext2_inode inode;
if (!(fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
retval = ext2fs_check_directory(fs, dir);
if (retval)
return retval;
es.done = 0;
es.err = 0;
retval = ext2fs_block_iterate(fs, dir, BLOCK_FLAG_APPEND,
0, expand_dir_proc, &es);
if (es.err)
return es.err;
if (!es.done)
return EXT2_ET_EXPAND_DIR_ERR;
/*
* Update the size and block count fields in the inode.
*/
retval = ext2fs_read_inode(fs, dir, &inode);
if (retval)
return retval;
inode.i_size += fs->blocksize;
inode.i_blocks += fs->blocksize / 512;
e2fsck_write_inode(fs, dir, &inode, "expand_directory");
return 0;
}