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libjio/libjio/check.c  view on Meta::CPAN

/*
 * Recovery functions
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <sys/mman.h>

#include "libjio.h"
#include "common.h"
#include "journal.h"
#include "trans.h"


/** Remove the journal directory (if it's clean).
 *
 * @param name path to the file
 * @param jdir path to the journal directory
 * @returns 0 on success, < 0 on error
 */
static int jfsck_cleanup(const char *name, const char *jdir)
{
	char tfile[PATH_MAX*3];
	DIR *dir;
	struct dirent *dent;

	dir = opendir(jdir);
	if (dir == NULL && errno == ENOENT)
		/* it doesn't exist, so it's clean */
		return 0;
	else if (dir == NULL)
		return -1;

	for (errno = 0, dent = readdir(dir); dent != NULL;
			errno = 0, dent = readdir(dir)) {
		/* We only care about files we know, and ignore everything
		 * else. Note that transactions should have been removed by
		 * jfsck(), we will not do it to prevent accidental misuse */
		if (strcmp(dent->d_name, "lock"))
			continue;

		/* build the full path to the transaction file */
		memset(tfile, 0, PATH_MAX * 3);
		strcat(tfile, jdir);
		strcat(tfile, "/");
		strcat(tfile, dent->d_name);

		if (strlen(tfile) > PATH_MAX) {
			closedir(dir);
			return -1;
		}

		if (unlink(tfile) != 0) {
			closedir(dir);
			return -1;
		}
	}

	if (errno) {
		closedir(dir);
		return -1;
	}

	if (closedir(dir) != 0)
		return -1;

	if (rmdir(jdir) != 0)
		return -1;

	return 0;
}

/* Check the journal and fix the incomplete transactions */
enum jfsck_return jfsck(const char *name, const char *jdir,
		struct jfsck_result *res, unsigned int flags)
{
	int tfd, rv, i, ret;
	unsigned int maxtid;
	char jlockfile[PATH_MAX], tname[PATH_MAX], brokenname[PATH_MAX];
	struct stat sinfo;
	struct jfs fs;
	struct jtrans *curts;
	struct operation *tmpop;
	DIR *dir;
	struct dirent *dent;
	unsigned char *map;
	off_t filelen, lr;

	tfd = -1;
	filelen = 0;
	dir = NULL;
	fs.fd = -1;
	fs.jfd = -1;
	fs.jdir = NULL;
	fs.jdirfd = -1;
	fs.jmap = MAP_FAILED;
	map = NULL;
	ret = 0;

	res->total = 0;
	res->invalid = 0;
	res->in_progress = 0;
	res->broken = 0;
	res->corrupt = 0;
	res->reapplied = 0;

	fs.fd = open(name, O_RDWR | O_SYNC);
	if (fs.fd < 0) {
		ret = J_EIO;
		if (errno == ENOENT)
			ret = J_ENOENT;
		goto exit;
	}

	fs.name = (char *) name;

	/* Locking the whole file protect us from concurrent runs, but it's
	 * not to be trusted nor assumed (lingering transactions break it): it
	 * just helps prevent some accidents. */
	lr = plockf(fs.fd, F_LOCKW, 0, 0);
	if (lr == -1) {
		/* In the future, we may want to differentiate this case from
		 * a normal I/O error. */
		ret = J_EIO;
		goto exit;
	}

	if (jdir == NULL) {
		fs.jdir = (char *) malloc(PATH_MAX);
		if (fs.jdir == NULL) {
			ret = J_ENOMEM;
			goto exit;
		}

		if (!get_jdir(name, fs.jdir)) {
			ret = J_ENOMEM;
			goto exit;
		}
	} else {
		fs.jdir = strdup(jdir);
		if (fs.jdir == NULL) {
			ret = J_ENOMEM;
			goto exit;
		}
	}

	rv = lstat(fs.jdir, &sinfo);
	if (rv < 0) {
		ret = J_EIO;
		if (errno == ENOENT)
			ret = J_ENOJOURNAL;
		goto exit;
	}
	if (!S_ISDIR(sinfo.st_mode)) {
		ret = J_ENOJOURNAL;
		goto exit;
	}

	fs.jdirfd = open(fs.jdir, O_RDONLY);
	if (fs.jdirfd < 0) {
		ret = J_EIO;
		if (errno == ENOENT)
			ret = J_ENOJOURNAL;
		goto exit;
	}

	/* open the lock file, which is only used to complete the jfs
	 * structure */
	snprintf(jlockfile, PATH_MAX, "%s/%s", fs.jdir, "lock");
	rv = open(jlockfile, O_RDWR | O_CREAT, 0600);
	if (rv < 0) {
		ret = J_EIO;
		if (errno == ENOENT)
			ret = J_ENOJOURNAL;
		goto exit;
	}
	fs.jfd = rv;

	fs.jmap = (unsigned int *) mmap(NULL, sizeof(unsigned int),