Signed-off-by: Thomas Schoebel-Theuer <[email protected]>
---
drivers/staging/mars/xio_bricks/lib_log.c | 505 ++++++++++++++++++++++++++++++
include/linux/xio/lib_log.h | 329 +++++++++++++++++++
2 files changed, 834 insertions(+)
create mode 100644 drivers/staging/mars/xio_bricks/lib_log.c
create mode 100644 include/linux/xio/lib_log.h
diff --git a/drivers/staging/mars/xio_bricks/lib_log.c
b/drivers/staging/mars/xio_bricks/lib_log.c
new file mode 100644
index 0000000..a8382e5
--- /dev/null
+++ b/drivers/staging/mars/xio_bricks/lib_log.c
@@ -0,0 +1,505 @@
+/*
+ * MARS Long Distance Replication Software
+ *
+ * Copyright (C) 2010-2014 Thomas Schoebel-Theuer
+ * Copyright (C) 2011-2014 1&1 Internet AG
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+
+#include <linux/xio/lib_log.h>
+
+atomic_t global_aio_flying = ATOMIC_INIT(0);
+
+void exit_logst(struct log_status *logst)
+{
+ int count;
+
+ log_flush(logst);
+
+ /* TODO: replace by event */
+ count = 0;
+ while (atomic_read(&logst->aio_flying) > 0) {
+ if (!count++)
+ XIO_DBG("waiting for IO terminating...");
+ brick_msleep(500);
+ }
+ if (logst->read_aio) {
+ XIO_DBG("putting read_aio\n");
+ GENERIC_INPUT_CALL(logst->input, aio_put, logst->read_aio);
+ logst->read_aio = NULL;
+ }
+ if (logst->log_aio) {
+ XIO_DBG("putting log_aio\n");
+ GENERIC_INPUT_CALL(logst->input, aio_put, logst->log_aio);
+ logst->log_aio = NULL;
+ }
+}
+
+void init_logst(struct log_status *logst, struct xio_input *input, loff_t
start_pos, loff_t end_pos)
+{
+ exit_logst(logst);
+
+ memset(logst, 0, sizeof(struct log_status));
+
+ logst->input = input;
+ logst->brick = input->brick;
+ logst->start_pos = start_pos;
+ logst->log_pos = start_pos;
+ logst->end_pos = end_pos;
+ init_waitqueue_head(&logst->event);
+}
+
+#define XIO_LOG_CB_MAX 32
+
+struct log_cb_info {
+ struct aio_object *aio;
+ struct log_status *logst;
+ struct semaphore mutex;
+ atomic_t refcount;
+ int nr_cb;
+ void (*endios[XIO_LOG_CB_MAX])(void *private, int error);
+ void *privates[XIO_LOG_CB_MAX];
+};
+
+static
+void put_log_cb_info(struct log_cb_info *cb_info)
+{
+ if (atomic_dec_and_test(&cb_info->refcount))
+ brick_mem_free(cb_info);
+}
+
+static
+void _do_callbacks(struct log_cb_info *cb_info, int error)
+{
+ int i;
+
+ down(&cb_info->mutex);
+ for (i = 0; i < cb_info->nr_cb; i++) {
+ void (*end_fn)(void *private, int error);
+
+ end_fn = cb_info->endios[i];
+ cb_info->endios[i] = NULL;
+ if (end_fn)
+ end_fn(cb_info->privates[i], error);
+ }
+ up(&cb_info->mutex);
+}
+
+static
+void log_write_endio(struct generic_callback *cb)
+{
+ struct log_cb_info *cb_info = cb->cb_private;
+ struct log_status *logst;
+
+ LAST_CALLBACK(cb);
+ CHECK_PTR(cb_info, err);
+
+ logst = cb_info->logst;
+ CHECK_PTR(logst, done);
+
+ _do_callbacks(cb_info, cb->cb_error);
+
+done:
+ put_log_cb_info(cb_info);
+ atomic_dec(&logst->aio_flying);
+ atomic_dec(&global_aio_flying);
+ if (logst->signal_event)
+ wake_up_interruptible(logst->signal_event);
+
+ goto out_return;
+err:
+ XIO_FAT("internal pointer corruption\n");
+out_return:;
+}
+
+void log_flush(struct log_status *logst)
+{
+ struct aio_object *aio = logst->log_aio;
+ struct log_cb_info *cb_info;
+ int align_size;
+ int gap;
+
+ if (!aio || !logst->count)
+ goto out_return;
+ gap = 0;
+ align_size = (logst->align_size / PAGE_SIZE) * PAGE_SIZE;
+ if (align_size > 0) {
+ /* round up to next alignment border */
+ int align_offset = logst->offset & (align_size-1);
+
+ if (align_offset > 0) {
+ int restlen = aio->io_len - logst->offset;
+
+ gap = align_size - align_offset;
+ if (unlikely(gap > restlen))
+ gap = restlen;
+ }
+ }
+ if (gap > 0) {
+ /* don't leak information from kernelspace */
+ memset(aio->io_data + logst->offset, 0, gap);
+ logst->offset += gap;
+ }
+ aio->io_len = logst->offset;
+ memcpy(&logst->log_pos_stamp, &logst->tmp_pos_stamp,
sizeof(logst->log_pos_stamp));
+
+ cb_info = logst->private;
+ logst->private = NULL;
+ SETUP_CALLBACK(aio, log_write_endio, cb_info);
+ cb_info->logst = logst;
+ aio->io_rw = 1;
+
+ atomic_inc(&logst->aio_flying);
+ atomic_inc(&global_aio_flying);
+
+ GENERIC_INPUT_CALL(logst->input, aio_io, aio);
+ GENERIC_INPUT_CALL(logst->input, aio_put, aio);
+
+ logst->log_pos += logst->offset;
+ logst->offset = 0;
+ logst->count = 0;
+ logst->log_aio = NULL;
+
+ put_log_cb_info(cb_info);
+out_return:;
+}
+
+void *log_reserve(struct log_status *logst, struct log_header *lh)
+{
+ struct log_cb_info *cb_info = logst->private;
+ struct aio_object *aio;
+ void *data;
+
+ short total_len = lh->l_len + OVERHEAD;
+ int offset;
+ int status;
+
+ if (unlikely(lh->l_len <= 0 || lh->l_len > logst->max_size)) {
+ XIO_ERR("trying to write %d bytes, max allowed = %d\n",
lh->l_len, logst->max_size);
+ goto err;
+ }
+
+ aio = logst->log_aio;
+ if ((aio && total_len > aio->io_len - logst->offset)
+ || !cb_info || cb_info->nr_cb >= XIO_LOG_CB_MAX) {
+ log_flush(logst);
+ }
+
+ aio = logst->log_aio;
+ if (!aio) {
+ if (unlikely(logst->private)) {
+ XIO_ERR("oops\n");
+ brick_mem_free(logst->private);
+ }
+ logst->private = brick_zmem_alloc(sizeof(struct log_cb_info));
+ cb_info = logst->private;
+ sema_init(&cb_info->mutex, 1);
+ atomic_set(&cb_info->refcount, 2);
+
+ aio = xio_alloc_aio(logst->brick);
+ cb_info->aio = aio;
+
+ aio->io_pos = logst->log_pos;
+ aio->io_len = logst->chunk_size ? logst->chunk_size : total_len;
+ aio->io_may_write = WRITE;
+ aio->io_prio = logst->io_prio;
+
+ for (;;) {
+ status = GENERIC_INPUT_CALL(logst->input, aio_get, aio);
+ if (likely(status >= 0))
+ break;
+ if (status != -ENOMEM && status != -EAGAIN) {
+ XIO_ERR("aio_get() failed, status = %d\n",
status);
+ goto err_free;
+ }
+ brick_msleep(100);
+ }
+
+ if (unlikely(aio->io_len < total_len)) {
+ XIO_ERR("io_len = %d total_len = %d\n", aio->io_len,
total_len);
+ goto put;
+ }
+
+ logst->offset = 0;
+ logst->log_aio = aio;
+ }
+
+ offset = logst->offset;
+ data = aio->io_data;
+ DATA_PUT(data, offset, START_MAGIC);
+ DATA_PUT(data, offset, (char)FORMAT_VERSION);
+ logst->validflag_offset = offset;
+ DATA_PUT(data, offset, (char)0); /* valid_flag */
+ DATA_PUT(data, offset, total_len); /* start of next header */
+ DATA_PUT(data, offset, lh->l_stamp.tv_sec);
+ DATA_PUT(data, offset, lh->l_stamp.tv_nsec);
+ DATA_PUT(data, offset, lh->l_pos);
+ logst->reallen_offset = offset;
+ DATA_PUT(data, offset, lh->l_len);
+ DATA_PUT(data, offset, (short)0); /* spare */
+ DATA_PUT(data, offset, (int)0); /* spare */
+ DATA_PUT(data, offset, lh->l_code);
+ DATA_PUT(data, offset, (short)0); /* spare */
+
+ /* remember the last timestamp */
+ memcpy(&logst->tmp_pos_stamp, &lh->l_stamp,
sizeof(logst->tmp_pos_stamp));
+
+ logst->payload_offset = offset;
+ logst->payload_len = lh->l_len;
+
+ return data + offset;
+
+put:
+ GENERIC_INPUT_CALL(logst->input, aio_put, aio);
+ logst->log_aio = NULL;
+ return NULL;
+
+err_free:
+ obj_free(aio);
+ if (logst->private) {
+ /* TODO: if callbacks are already registered, call them here
with some error code */
+ brick_mem_free(logst->private);
+ logst->private = NULL;
+ }
+err:
+ return NULL;
+}
+
+bool log_finalize(struct log_status *logst, int len, void (*endio)(void
*private, int error), void *private)
+{
+ struct aio_object *aio = logst->log_aio;
+ struct log_cb_info *cb_info = logst->private;
+ struct timespec now;
+ void *data;
+ int offset;
+ int restlen;
+ int nr_cb;
+ int crc;
+ bool ok = false;
+
+ CHECK_PTR(aio, err);
+
+ if (unlikely(len > logst->payload_len)) {
+ XIO_ERR("trying to write more than reserved (%d > %d)\n", len,
logst->payload_len);
+ goto err;
+ }
+ restlen = aio->io_len - logst->offset;
+ if (unlikely(len + END_OVERHEAD > restlen)) {
+ XIO_ERR("trying to write more than available (%d > %d)\n", len,
(int)(restlen - END_OVERHEAD));
+ goto err;
+ }
+ if (unlikely(!cb_info || cb_info->nr_cb >= XIO_LOG_CB_MAX)) {
+ XIO_ERR("too many endio() calls\n");
+ goto err;
+ }
+
+ data = aio->io_data;
+
+ crc = 0;
+ if (logst->do_crc) {
+ unsigned char checksum[xio_digest_size];
+
+ xio_digest(checksum, data + logst->payload_offset, len);
+ crc = *(int *)checksum;
+ }
+
+ /* Correct the length in the header.
+ */
+ offset = logst->reallen_offset;
+ DATA_PUT(data, offset, (short)len);
+
+ /* Write the trailer.
+ */
+ offset = logst->payload_offset + len;
+ DATA_PUT(data, offset, END_MAGIC);
+ DATA_PUT(data, offset, crc);
+ DATA_PUT(data, offset, (char)1); /* valid_flag copy */
+ DATA_PUT(data, offset, (char)0); /* spare */
+ DATA_PUT(data, offset, (short)0); /* spare */
+ DATA_PUT(data, offset, logst->seq_nr + 1);
+ get_lamport(&now); /* when the log entry was ready. */
+ DATA_PUT(data, offset, now.tv_sec);
+ DATA_PUT(data, offset, now.tv_nsec);
+
+ if (unlikely(offset > aio->io_len)) {
+ XIO_FAT("length calculation was wrong: %d > %d\n", offset,
aio->io_len);
+ goto err;
+ }
+ logst->offset = offset;
+
+ /* This must come last. In case of incomplete
+ * or even overlapping disk transfers, this indicates
+ * the completeness / integrity of the payload at
+ * the time of starting the transfer.
+ */
+ offset = logst->validflag_offset;
+ DATA_PUT(data, offset, (char)1);
+
+ nr_cb = cb_info->nr_cb++;
+ cb_info->endios[nr_cb] = endio;
+ cb_info->privates[nr_cb] = private;
+
+ /* report success */
+ logst->seq_nr++;
+ logst->count++;
+ ok = true;
+
+err:
+ return ok;
+}
+
+static
+void log_read_endio(struct generic_callback *cb)
+{
+ struct log_status *logst = cb->cb_private;
+
+ LAST_CALLBACK(cb);
+ CHECK_PTR(logst, err);
+ logst->error_code = cb->cb_error;
+ logst->got = true;
+ wake_up_interruptible(&logst->event);
+ goto out_return;
+err:
+ XIO_FAT("internal pointer corruption\n");
+out_return:;
+}
+
+int log_read(struct log_status *logst, bool sloppy, struct log_header *lh,
void **payload, int *payload_len)
+{
+ struct aio_object *aio;
+ int old_offset;
+ int status;
+
+restart:
+ status = 0;
+ aio = logst->read_aio;
+ if (!aio || logst->do_free) {
+ loff_t this_len;
+
+ if (aio) {
+ GENERIC_INPUT_CALL(logst->input, aio_put, aio);
+ logst->read_aio = NULL;
+ logst->log_pos += logst->offset;
+ logst->offset = 0;
+ }
+
+ this_len = logst->end_pos - logst->log_pos;
+ if (this_len > logst->chunk_size) {
+ this_len = logst->chunk_size;
+ } else if (unlikely(this_len <= 0)) {
+ XIO_ERR("tried bad IO len %lld, start_pos = %lld
log_pos = %lld end_pos = %lld\n",
+ this_len,
+ logst->start_pos,
+ logst->log_pos,
+ logst->end_pos);
+ status = -EOVERFLOW;
+ goto done;
+ }
+
+ aio = xio_alloc_aio(logst->brick);
+ aio->io_pos = logst->log_pos;
+ aio->io_len = this_len;
+ aio->io_prio = logst->io_prio;
+
+ status = GENERIC_INPUT_CALL(logst->input, aio_get, aio);
+ if (unlikely(status < 0)) {
+ if (status != -ENODATA)
+ XIO_ERR("aio_get() failed, status = %d\n",
status);
+ goto done_free;
+ }
+ if (unlikely(aio->io_len <= OVERHEAD)) { /* EOF */
+ status = 0;
+ goto done_put;
+ }
+
+ SETUP_CALLBACK(aio, log_read_endio, logst);
+ aio->io_rw = READ;
+ logst->offset = 0;
+ logst->got = false;
+ logst->do_free = false;
+
+ GENERIC_INPUT_CALL(logst->input, aio_io, aio);
+
+ wait_event_interruptible_timeout(logst->event, logst->got, 60 *
HZ);
+ status = -ETIME;
+ if (!logst->got)
+ goto done_put;
+ status = logst->error_code;
+ if (status < 0)
+ goto done_put;
+ logst->read_aio = aio;
+ }
+
+ status = log_scan(aio->io_data + logst->offset,
+ aio->io_len - logst->offset,
+ aio->io_pos,
+ logst->offset,
+ sloppy,
+ lh,
+ payload,
+ payload_len,
+ &logst->seq_nr);
+
+ if (unlikely(status == 0)) {
+ XIO_ERR("bad logfile scan\n");
+ status = -EINVAL;
+ }
+ if (unlikely(status < 0))
+ goto done_put;
+
+ /* memoize success */
+ logst->offset += status;
+ if (logst->offset + (logst->max_size + OVERHEAD) * 2 >= aio->io_len)
+ logst->do_free = true;
+
+done:
+ if (status == -ENODATA) {
+ /* indicate EOF */
+ status = 0;
+ }
+ return status;
+
+done_put:
+ old_offset = logst->offset;
+ if (aio) {
+ GENERIC_INPUT_CALL(logst->input, aio_put, aio);
+ logst->read_aio = NULL;
+ logst->log_pos += logst->offset;
+ logst->offset = 0;
+ }
+ if (status == -EAGAIN && old_offset > 0)
+ goto restart;
+ goto done;
+
+done_free:
+ obj_free(aio);
+ logst->read_aio = NULL;
+ goto done;
+
+}
+
+/***************** module init stuff ************************/
+
+int __init init_log_format(void)
+{
+ XIO_INF("init_log_format()\n");
+ return 0;
+}
+
+void exit_log_format(void)
+{
+ XIO_INF("exit_log_format()\n");
+}
diff --git a/include/linux/xio/lib_log.h b/include/linux/xio/lib_log.h
new file mode 100644
index 0000000..62bd45a
--- /dev/null
+++ b/include/linux/xio/lib_log.h
@@ -0,0 +1,329 @@
+/*
+ * MARS Long Distance Replication Software
+ *
+ * Copyright (C) 2010-2014 Thomas Schoebel-Theuer
+ * Copyright (C) 2011-2014 1&1 Internet AG
+ *
+ * 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.
+ */
+
+/* Definitions for logfile format.
+ *
+ * This is meant for sharing between different transaction logger variants,
+ * and/or for sharing with userspace tools (e.g. logfile analyzers).
+ * TODO: factor out some remaining kernelspace issues.
+ */
+
+#ifndef LIB_LOG_H
+#define LIB_LOG_H
+
+#ifdef __KERNEL__
+#include <linux/xio/xio.h>
+
+extern atomic_t global_aio_flying;
+#endif
+
+/* The following structure is memory-only.
+ * Transfers to disk are indirectly via the
+ * format conversion functions below.
+ * The advantage is that even newer disk formats can be parsed
+ * by old code (of course, not all information / features will be
+ * available then).
+ */
+#define log_header log_header_v1
+
+struct log_header_v1 {
+ struct timespec l_stamp;
+ struct timespec l_written;
+ loff_t l_pos;
+
+ short l_len;
+ short l_code;
+ unsigned int l_seq_nr;
+ int l_crc;
+};
+
+#define FORMAT_VERSION 1 /* version of disk format, currently
there is no other one */
+
+#define CODE_UNKNOWN 0
+#define CODE_WRITE_NEW 1
+#define CODE_WRITE_OLD 2
+
+#define START_MAGIC 0xa8f7e908d9177957ll
+#define END_MAGIC 0x74941fb74ab5726dll
+
+#define START_OVERHEAD \
+ ( \
+ sizeof(START_MAGIC) + \
+ sizeof(char) + \
+ sizeof(char) + \
+ sizeof(short) + \
+ sizeof(struct timespec) + \
+ sizeof(loff_t) + \
+ sizeof(int) + \
+ sizeof(int) + \
+ sizeof(short) + \
+ sizeof(short) + \
+ 0 \
+ )
+
+#define END_OVERHEAD \
+ ( \
+ sizeof(END_MAGIC) + \
+ sizeof(int) + \
+ sizeof(char) + \
+ 3 + 4 /*spare*/ + \
+ sizeof(struct timespec) + \
+ 0 \
+ )
+
+#define OVERHEAD (START_OVERHEAD + END_OVERHEAD)
+
+/* TODO: make this bytesex-aware. */
+#define DATA_PUT(data, offset, val) \
+ do { \
+ *((typeof(val) *)((data)+offset)) = val; \
+ offset += sizeof(val); \
+ } while (0)
+
+#define DATA_GET(data, offset, val) \
+ do { \
+ val = *((typeof(val) *)((data)+offset)); \
+ offset += sizeof(val); \
+ } while (0)
+
+#define SCAN_TXT \
+"at file_pos = %lld file_offset = %d scan_offset = %d (%lld) test_offset = %d
(%lld) restlen = %d: "
+#define SCAN_PAR \
+file_pos, file_offset, offset, file_pos + file_offset + offset, i, file_pos +
file_offset + i, restlen
+
+static inline
+int log_scan(void *buf,
+ int len,
+ loff_t file_pos,
+ int file_offset,
+ bool sloppy,
+ struct log_header *lh,
+ void **payload,
+ int *payload_len,
+ unsigned int *seq_nr)
+{
+ bool dirty = false;
+ int offset;
+ int i;
+
+ *payload = NULL;
+ *payload_len = 0;
+
+ for (i = 0; i < len && i <= len - OVERHEAD; i += sizeof(long)) {
+ long long start_magic;
+ char format_version;
+ char valid_flag;
+
+ short total_len;
+ long long end_magic;
+ char valid_copy;
+
+ int restlen = 0;
+ int found_offset;
+
+ offset = i;
+ if (unlikely(i > 0 && !sloppy)) {
+ XIO_ERR(SCAN_TXT "detected a hole / bad data\n",
SCAN_PAR);
+ return -EBADMSG;
+ }
+
+ DATA_GET(buf, offset, start_magic);
+ if (unlikely(start_magic != START_MAGIC)) {
+ if (start_magic != 0)
+ dirty = true;
+ continue;
+ }
+
+ restlen = len - i;
+ if (unlikely(restlen < START_OVERHEAD)) {
+ XIO_WRN(SCAN_TXT "magic found, but restlen is too
small\n", SCAN_PAR);
+ return -EAGAIN;
+ }
+
+ DATA_GET(buf, offset, format_version);
+ if (unlikely(format_version != FORMAT_VERSION)) {
+ XIO_ERR(SCAN_TXT "found unknown data format %d\n",
SCAN_PAR, (int)format_version);
+ return -EBADMSG;
+ }
+ DATA_GET(buf, offset, valid_flag);
+ if (unlikely(!valid_flag)) {
+ XIO_WRN(SCAN_TXT "data is explicitly marked invalid
(was there a short write?)\n", SCAN_PAR);
+ continue;
+ }
+ DATA_GET(buf, offset, total_len);
+ if (unlikely(total_len > restlen)) {
+ XIO_WRN(SCAN_TXT "total_len = %d but available data
restlen = %d. Was the logfile truncated?\n",
+ SCAN_PAR,
+ total_len,
+ restlen);
+ return -EAGAIN;
+ }
+
+ memset(lh, 0, sizeof(struct log_header));
+
+ DATA_GET(buf, offset, lh->l_stamp.tv_sec);
+ DATA_GET(buf, offset, lh->l_stamp.tv_nsec);
+ DATA_GET(buf, offset, lh->l_pos);
+ DATA_GET(buf, offset, lh->l_len);
+ offset += 2; /* skip spare */
+ offset += 4; /* skip spare */
+ DATA_GET(buf, offset, lh->l_code);
+ offset += 2; /* skip spare */
+
+ found_offset = offset;
+ offset += lh->l_len;
+
+ restlen = len - offset;
+ if (unlikely(restlen < END_OVERHEAD)) {
+ XIO_WRN(SCAN_TXT "restlen %d is too small\n", SCAN_PAR,
restlen);
+ return -EAGAIN;
+ }
+
+ DATA_GET(buf, offset, end_magic);
+ if (unlikely(end_magic != END_MAGIC)) {
+ XIO_WRN(SCAN_TXT "bad end_magic 0x%llx, is the logfile
truncated?\n", SCAN_PAR, end_magic);
+ return -EBADMSG;
+ }
+ DATA_GET(buf, offset, lh->l_crc);
+ DATA_GET(buf, offset, valid_copy);
+
+ if (unlikely(valid_copy != 1)) {
+ XIO_WRN(SCAN_TXT "found data marked as uncompleted /
invalid, len = %d, valid_flag = %d\n",
+ SCAN_PAR,
+ lh->l_len,
+ (int)valid_copy);
+ return -EBADMSG;
+ }
+
+ /* skip spares */
+ offset += 3;
+
+ DATA_GET(buf, offset, lh->l_seq_nr);
+ DATA_GET(buf, offset, lh->l_written.tv_sec);
+ DATA_GET(buf, offset, lh->l_written.tv_nsec);
+
+ if (unlikely(lh->l_seq_nr > *seq_nr + 1 && lh->l_seq_nr &&
*seq_nr)) {
+ XIO_ERR(SCAN_TXT "record sequence number %u mismatch,
expected was %u\n",
+ SCAN_PAR,
+ lh->l_seq_nr,
+ *seq_nr + 1);
+ return -EBADMSG;
+ } else if (unlikely(lh->l_seq_nr != *seq_nr + 1 && lh->l_seq_nr
&& *seq_nr)) {
+ XIO_WRN(SCAN_TXT "record sequence number %u mismatch,
expected was %u\n",
+ SCAN_PAR,
+ lh->l_seq_nr,
+ *seq_nr + 1);
+ }
+ *seq_nr = lh->l_seq_nr;
+
+ if (lh->l_crc) {
+ unsigned char checksum[xio_digest_size];
+
+ xio_digest(checksum, buf + found_offset, lh->l_len);
+ if (unlikely(*(int *)checksum != lh->l_crc)) {
+ XIO_ERR(SCAN_TXT "data checksumming mismatch,
length = %d\n", SCAN_PAR, lh->l_len);
+ return -EBADMSG;
+ }
+ }
+
+ /* last check */
+ if (unlikely(total_len != offset - i)) {
+ XIO_ERR(SCAN_TXT "internal size mismatch: %d != %d\n",
SCAN_PAR, total_len, offset - i);
+ return -EBADMSG;
+ }
+
+ /* Success... */
+ *payload = buf + found_offset;
+ *payload_len = lh->l_len;
+
+ /* don't cry when nullbytes have been skipped */
+ if (i > 0 && dirty)
+ XIO_WRN(SCAN_TXT "skipped %d dirty bytes to find valid
data\n", SCAN_PAR, i);
+
+ return offset;
+ }
+
+ XIO_ERR("could not find any useful data within len=%d bytes\n", len);
+ return -EAGAIN;
+}
+
+/**************************************************************************/
+
+#ifdef __KERNEL__
+
+/* Bookkeeping status between calls
+ */
+struct log_status {
+ /* interfacing */
+ wait_queue_head_t *signal_event;
+ /* tunables */
+ loff_t start_pos;
+ loff_t end_pos;
+
+ int align_size; /* alignment between requests */
+ int chunk_size; /* must be at least 8K (better 64k) */
+ int max_size; /* max payload length */
+ int io_prio;
+ bool do_crc;
+
+ /* informational */
+ atomic_t aio_flying;
+ int count;
+ loff_t log_pos;
+ struct timespec log_pos_stamp;
+
+ /* internal */
+ struct timespec tmp_pos_stamp;
+ struct xio_input *input;
+ struct xio_brick *brick;
+ struct xio_info info;
+ int offset;
+ int validflag_offset;
+ int reallen_offset;
+ int payload_offset;
+ int payload_len;
+ unsigned int seq_nr;
+ struct aio_object *log_aio;
+ struct aio_object *read_aio;
+
+ wait_queue_head_t event;
+ int error_code;
+ bool got;
+ bool do_free;
+ void *private;
+};
+
+void init_logst(struct log_status *logst, struct xio_input *input, loff_t
start_pos, loff_t end_pos);
+void exit_logst(struct log_status *logst);
+
+void log_flush(struct log_status *logst);
+
+void *log_reserve(struct log_status *logst, struct log_header *lh);
+
+bool log_finalize(struct log_status *logst, int len, void (*endio)(void
*private, int error), void *private);
+
+int log_read(struct log_status *logst, bool sloppy, struct log_header *lh,
void **payload, int *payload_len);
+
+/***********************************************************************/
+
+/* init */
+
+extern int init_log_format(void);
+extern void exit_log_format(void);
+
+#endif
+#endif
--
2.6.4
--
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