store_dir_diskd.c

一个功能非常全面的代理服务器源代码程序,

    if (fd < 0) {
	debug(50, 1) ("%s: %s\n", swaplog_path, xstrerror());
	fatal("storeDiskdDirCloseTmpSwapLog: Failed to open swap log.");
    }
    safe_free(swaplog_path);
    safe_free(new_path);
    diskdinfo->swaplog_fd = fd;
    debug(47, 3) ("Cache Dir #%d log opened on FD %d\n", sd->index, fd);
}

static void
storeSwapLogDataFree(void *s)
{
    memFree(s, MEM_SWAP_LOG_DATA);
}

static void
storeDiskdWriteSwapLogheader(int fd)
{
    storeSwapLogHeader *hdr = memAllocate(MEM_SWAP_LOG_DATA);
    hdr->op = SWAP_LOG_VERSION;
    hdr->version = 1;
    hdr->record_size = sizeof(storeSwapLogData);
    /* The header size is a full log record to keep some level of backward
     * compatibility even if the actual header is smaller
     */
    file_write(fd,
	-1,
	hdr,
	sizeof(storeSwapLogData),
	NULL,
	NULL,
	(FREE *) storeSwapLogDataFree);
}

static FILE *
storeDiskdDirOpenTmpSwapLog(SwapDir * sd, int *clean_flag, int *zero_flag)
{
    diskdinfo_t *diskdinfo = sd->fsdata;
    char *swaplog_path = xstrdup(storeDiskdDirSwapLogFile(sd, NULL));
    char *clean_path = xstrdup(storeDiskdDirSwapLogFile(sd, ".last-clean"));
    char *new_path = xstrdup(storeDiskdDirSwapLogFile(sd, ".new"));
    struct stat log_sb;
    struct stat clean_sb;
    FILE *fp;
    int fd;
    if (stat(swaplog_path, &log_sb) < 0) {
	debug(47, 1) ("Cache Dir #%d: No log file\n", sd->index);
	safe_free(swaplog_path);
	safe_free(clean_path);
	safe_free(new_path);
	return NULL;
    }
    *zero_flag = log_sb.st_size == 0 ? 1 : 0;
    /* close the existing write-only FD */
    if (diskdinfo->swaplog_fd >= 0)
	file_close(diskdinfo->swaplog_fd);
    /* open a write-only FD for the new log */
    fd = file_open(new_path, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY);
    if (fd < 0) {
	debug(50, 1) ("%s: %s\n", new_path, xstrerror());
	fatal("storeDirOpenTmpSwapLog: Failed to open swap log.");
    }
    diskdinfo->swaplog_fd = fd;
    storeDiskdWriteSwapLogheader(fd);
    /* open a read-only stream of the old log */
    fp = fopen(swaplog_path, "rb");
    if (fp == NULL) {
	debug(50, 0) ("%s: %s\n", swaplog_path, xstrerror());
	fatal("Failed to open swap log for reading");
    }
    memset(&clean_sb, '\0', sizeof(struct stat));
    if (stat(clean_path, &clean_sb) < 0)
	*clean_flag = 0;
    else if (clean_sb.st_mtime < log_sb.st_mtime)
	*clean_flag = 0;
    else
	*clean_flag = 1;
    safeunlink(clean_path, 1);
    safe_free(swaplog_path);
    safe_free(clean_path);
    safe_free(new_path);
    return fp;
}

struct _clean_state {
    char *cur;
    char *new;
    char *cln;
    char *outbuf;
    int outbuf_offset;
    int fd;
    RemovalPolicyWalker *walker;
};

#define CLEAN_BUF_SZ 16384
/*
 * Begin the process to write clean cache state.  For DISKD this means
 * opening some log files and allocating write buffers.  Return 0 if
 * we succeed, and assign the 'func' and 'data' return pointers.
 */
static int
storeDiskdDirWriteCleanStart(SwapDir * sd)
{
    struct _clean_state *state = xcalloc(1, sizeof(*state));
#if HAVE_FCHMOD
    struct stat sb;
#endif
    sd->log.clean.write = NULL;
    sd->log.clean.state = NULL;
    state->new = xstrdup(storeDiskdDirSwapLogFile(sd, ".clean"));
    state->cur = xstrdup(storeDiskdDirSwapLogFile(sd, NULL));
    state->cln = xstrdup(storeDiskdDirSwapLogFile(sd, ".last-clean"));
    state->outbuf = xcalloc(CLEAN_BUF_SZ, 1);
    state->outbuf_offset = 0;
    state->walker = sd->repl->WalkInit(sd->repl);
    unlink(state->cln);
    state->fd = file_open(state->new, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY);
    if (state->fd < 0) {
	xfree(state->new);
	xfree(state->cur);
	xfree(state->cln);
	xfree(state);
	return -1;
    }
    debug(20, 3) ("storeDirWriteCleanLogs: opened %s, FD %d\n",
	state->new, state->fd);
    storeDiskdWriteSwapLogheader(state->fd);
#if HAVE_FCHMOD
    if (stat(state->cur, &sb) == 0)
	fchmod(state->fd, sb.st_mode);
#endif
    sd->log.clean.write = storeDiskdDirWriteCleanEntry;
    sd->log.clean.state = state;
    return 0;
}

/*
 * Get the next entry that is a candidate for clean log writing
 */
const StoreEntry *
storeDiskdDirCleanLogNextEntry(SwapDir * sd)
{
    const StoreEntry *entry = NULL;
    struct _clean_state *state = sd->log.clean.state;
    if (state->walker)
	entry = state->walker->Next(state->walker);
    return entry;
}

/*
 * "write" an entry to the clean log file.
 */
static void
storeDiskdDirWriteCleanEntry(SwapDir * sd, const StoreEntry * e)
{
    storeSwapLogData s;
    static size_t ss = sizeof(storeSwapLogData);
    struct _clean_state *state = sd->log.clean.state;
    memset(&s, '\0', ss);
    s.op = (char) SWAP_LOG_ADD;
    s.swap_filen = e->swap_filen;
    s.timestamp = e->timestamp;
    s.lastref = e->lastref;
    s.expires = e->expires;
    s.lastmod = e->lastmod;
    s.swap_file_sz = e->swap_file_sz;
    s.refcount = e->refcount;
    s.flags = e->flags;
    xmemcpy(&s.key, e->hash.key, MD5_DIGEST_CHARS);
    xmemcpy(state->outbuf + state->outbuf_offset, &s, ss);
    state->outbuf_offset += ss;
    /* buffered write */
    if (state->outbuf_offset + ss > CLEAN_BUF_SZ) {
	if (FD_WRITE_METHOD(state->fd, state->outbuf, state->outbuf_offset) < 0) {
	    debug(50, 0) ("storeDirWriteCleanLogs: %s: write: %s\n",
		state->new, xstrerror());
	    debug(20, 0) ("storeDirWriteCleanLogs: Current swap logfile not replaced.\n");
	    file_close(state->fd);
	    state->fd = -1;
	    unlink(state->new);
	    safe_free(state);
	    sd->log.clean.state = NULL;
	    sd->log.clean.write = NULL;
	    return;
	}
	state->outbuf_offset = 0;
    }
}

static void
storeDiskdDirWriteCleanDone(SwapDir * sd)
{
    struct _clean_state *state = sd->log.clean.state;
    if (NULL == state)
	return;
    if (state->fd < 0)
	return;
    state->walker->Done(state->walker);
    if (FD_WRITE_METHOD(state->fd, state->outbuf, state->outbuf_offset) < 0) {
	debug(50, 0) ("storeDirWriteCleanLogs: %s: write: %s\n",
	    state->new, xstrerror());
	debug(20, 0) ("storeDirWriteCleanLogs: Current swap logfile "
	    "not replaced.\n");
	file_close(state->fd);
	state->fd = -1;
	unlink(state->new);
    }
    safe_free(state->outbuf);
    /*
     * You can't rename open files on Microsoft "operating systems"
     * so we have to close before renaming.
     */
    storeDiskdDirCloseSwapLog(sd);
    /* rename */
    if (state->fd >= 0) {
#ifdef _SQUID_OS2_
	file_close(state->fd);
	state->fd = -1;
#endif
	xrename(state->new, state->cur);
    }
    /* touch a timestamp file if we're not still validating */
    if (store_dirs_rebuilding)
	(void) 0;
    else if (state->fd < 0)
	(void) 0;
    else
	file_close(file_open(state->cln, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY));
    /* close */
    safe_free(state->cur);
    safe_free(state->new);
    safe_free(state->cln);
    if (state->fd >= 0)
	file_close(state->fd);
    state->fd = -1;
    safe_free(state);
    sd->log.clean.state = NULL;
    sd->log.clean.write = NULL;
}

static void
storeDiskdDirSwapLog(const SwapDir * sd, const StoreEntry * e, int op)
{
    diskdinfo_t *diskdinfo = sd->fsdata;
    storeSwapLogData *s = memAllocate(MEM_SWAP_LOG_DATA);
    s->op = (char) op;
    s->swap_filen = e->swap_filen;
    s->timestamp = e->timestamp;
    s->lastref = e->lastref;
    s->expires = e->expires;
    s->lastmod = e->lastmod;
    s->swap_file_sz = e->swap_file_sz;
    s->refcount = e->refcount;
    s->flags = e->flags;
    xmemcpy(s->key, e->hash.key, MD5_DIGEST_CHARS);
    file_write(diskdinfo->swaplog_fd,
	-1,
	s,
	sizeof(storeSwapLogData),
	NULL,
	NULL,
	(FREE *) storeSwapLogDataFree);
}

static void
storeDiskdDirNewfs(SwapDir * sd)
{
    debug(47, 3) ("Creating swap space in %s\n", sd->path);
    storeDiskdDirCreateDirectory(sd->path, 0);
    storeDiskdDirCreateSwapSubDirs(sd);
}

static int
rev_int_sort(const void *A, const void *B)
{
    const int *i1 = A;
    const int *i2 = B;
    return *i2 - *i1;
}

static int
storeDiskdDirClean(int swap_index)
{
    DIR *dp = NULL;
    struct dirent *de = NULL;
    LOCAL_ARRAY(char, p1, MAXPATHLEN + 1);
    LOCAL_ARRAY(char, p2, MAXPATHLEN + 1);
#if USE_TRUNCATE
    struct stat sb;
#endif
    int files[20];
    int swapfileno;
    int fn;			/* same as swapfileno, but with dirn bits set */
    int n = 0;
    int k = 0;
    int N0, N1, N2;
    int D0, D1, D2;
    SwapDir *SD;
    diskdinfo_t *diskdinfo;
    N0 = n_diskd_dirs;
    D0 = diskd_dir_index[swap_index % N0];
    SD = &Config.cacheSwap.swapDirs[D0];
    diskdinfo = SD->fsdata;
    N1 = diskdinfo->l1;
    D1 = (swap_index / N0) % N1;
    N2 = diskdinfo->l2;
    D2 = ((swap_index / N0) / N1) % N2;
    snprintf(p1, SQUID_MAXPATHLEN, "%s/%02X/%02X",
	Config.cacheSwap.swapDirs[D0].path, D1, D2);
    debug(36, 3) ("storeDirClean: Cleaning directory %s\n", p1);
    dp = opendir(p1);
    if (dp == NULL) {
	if (errno == ENOENT) {
	    debug(36, 0) ("storeDirClean: WARNING: Creating %s\n", p1);
	    if (mkdir(p1, 0777) == 0)
		return 0;
	}
	debug(50, 0) ("storeDirClean: %s: %s\n", p1, xstrerror());
	safeunlink(p1, 1);
	return 0;
    }
    while ((de = readdir(dp)) != NULL && k < 20) {
	if (sscanf(de->d_name, "%X", &swapfileno) != 1)
	    continue;
	fn = swapfileno;	/* XXX should remove this cruft ! */
	if (storeDiskdDirValidFileno(SD, fn, 1))
	    if (storeDiskdDirMapBitTest(SD, fn))
		if (storeDiskdFilenoBelongsHere(fn, D0, D1, D2))
		    continue;
#if USE_TRUNCATE
	if (!stat(de->d_name, &sb))
	    if (sb.st_size == 0)
		continue;
#endif
	files[k++] = swapfileno;
    }
    closedir(dp);
    if (k == 0)
	return 0;
    qsort(files, k, sizeof(int), rev_int_sort);
    if (k > 10)
	k = 10;
    for (n = 0; n < k; n++) {
	debug(36, 3) ("storeDirClean: Cleaning file %08X\n", files[n]);
	snprintf(p2, MAXPATHLEN + 1, "%s/%08X", p1, files[n]);
#if USE_TRUNCATE
	truncate(p2, 0);
#else
	safeunlink(p2, 0);
#endif
	statCounter.swap.files_cleaned++;
    }
    debug(36, 3) ("Cleaned %d unused files from %s\n", k, p1);
    return k;
}

static void
storeDiskdDirCleanEvent(void *unused)
{
    static int swap_index = 0;
    int i;
    int j = 0;
    int n = 0;
    /*
     * Assert that there are DISKD cache_dirs configured, otherwise
     * we should never be called.
     */
    assert(n_diskd_dirs);
    if (NULL == diskd_dir_index) {
	SwapDir *sd;
	diskdinfo_t *diskdinfo;
	/*
	 * Initialize the little array that translates DISKD cache_dir
	 * number into the Config.cacheSwap.swapDirs array index.
	 */
	diskd_dir_index = xcalloc(n_diskd_dirs, sizeof(*diskd_dir_index));
	for (i = 0, n = 0; i < Config.cacheSwap.n_configured; i++) {
	    sd = &Config.cacheSwap.swapDirs[i];
	    if (!storeDiskdDirIs(sd))
		continue;
	    diskd_dir_index[n++] = i;
	    diskdinfo = sd->fsdata;
	    j += (diskdinfo->l1 * diskdinfo->l2);
	}
	assert(n == n_diskd_dirs);
	/*
	 * Start the storeDiskdDirClean() swap_index with a random
	 * value.  j equals the total number of DISKD level 2
	 * swap directories
	 */
	swap_index = (int) (squid_random() % j);
    }
    if (0 == store_dirs_rebuilding) {
	n = storeDiskdDirClean(swap_index);
	swap_index++;
    }
    eventAdd("storeDirClean", storeDiskdDirCleanEvent, NULL,
	15.0 * exp(-0.25 * n), 1);
}

static int
storeDiskdDirIs(SwapDir * sd)
{
    if (strncmp(sd->type, "diskd", 3) == 0)
	return 1;
    return 0;
}

/*
 * Does swapfile number 'fn' belong in cachedir #F0,
 * level1 dir #F1, level2 dir #F2?
 */
static int
storeDiskdFilenoBelongsHere(int fn, int F0, int F1, int F2)
{
    int D1, D2;
    int L1, L2;
    int filn = fn;
    diskdinfo_t *diskdinfo;
    assert(F0 < Config.cacheSwap.n_configured);
    diskdinfo = Config.cacheSwap.swapDirs[F0].fsdata;
    L1 = diskdinfo->l1;
    L2 = diskdinfo->l2;
    D1 = ((filn / L2) / L2) % L1;
    if (F1 != D1)
	return 0;
    D2 = (filn / L2) % L2;
    if (F2 != D2)
	return 0;
    return 1;
}

int