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srb_driver.c
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/*
* Copyright (C) 2014 SCALITY SA - http://www.scality.com
*
* This file is part of ScalityRestBlock.
*
* ScalityRestBlock 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 3 of the License, or
* (at your option) any later version.
*
* ScalityRestBlock 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.
*
* You should have received a copy of the GNU General Public License
* along with ScalityRestBlock. If not, see <http://www.gnu.org/licenses/>.
*
*/
// Linux Kernel/LKM headers: module.h is needed by all modules and
// kernel.h is needed for KERN_INFO.
#include <linux/module.h> // included for all kernel modules
#include <linux/kernel.h> // included for KERN_INFO
#include <linux/moduleparam.h> // included for LKM parameters
#include <linux/init.h> // included for __init and __exit macros
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/vmalloc.h> // for vmalloc()
#include <linux/kthread.h>
#include <linux/version.h>
#include <linux/string.h>
#include "srb.h"
// LKM information
MODULE_AUTHOR("Laurent Meyer <[email protected]>");
MODULE_AUTHOR("David Pineau <[email protected]>");
MODULE_DESCRIPTION("Block Device Driver for REST-based storage");
MODULE_LICENSE("GPL");
MODULE_VERSION(DEV_REL_VERSION);
static srb_device_t devtab[DEV_MAX];
static srb_server_t *servers = NULL;
static DEFINE_SPINLOCK(devtab_lock);
/* Module parameters (LKM parameters)
*/
unsigned short srb_log = SRB_LOG_LEVEL_DFLT;
unsigned short req_timeout = SRB_REQ_TIMEOUT_DFLT;
unsigned short nb_req_retries = SRB_NB_REQ_RETRIES_DFLT;
unsigned short server_conn_timeout = SRB_CONN_TIMEOUT_DFLT;
unsigned int thread_pool_size = SRB_THREAD_POOL_SIZE_DFLT;
MODULE_PARM_DESC(debug, "Global log level for ScalityRestBlock LKM");
module_param_named(debug, srb_log, ushort, 0644);
MODULE_PARM_DESC(req_timeout, "Global timeout for request");
module_param(req_timeout, ushort, 0644);
MODULE_PARM_DESC(nb_req_retries, "Global number of retries for request");
module_param(nb_req_retries, ushort, 0644);
MODULE_PARM_DESC(server_conn_timeout, "Global timeout for connection to server(s)");
module_param(server_conn_timeout, ushort, 0644);
MODULE_PARM_DESC(thread_pool_size, "Size of the thread pool");
module_param(thread_pool_size, uint, 0444);
/* XXX: Request mapping
*/
static char *req_code_to_str(int code)
{
switch (code) {
case READ: return "READ"; break;
case WRITE: return "WRITE"; break;
case WRITE_FLUSH: return "WRITE_FLUSH"; break;
case WRITE_FUA: return "WRITE_FUA"; break;
case WRITE_FLUSH_FUA: return "WRITE_FLUSH_FUA"; break;
default: return "UNKNOWN";
}
}
static int req_flags_to_str(int flags, char *buff)
{
//char buff[128];
int size = 0;
buff[0] = '\0';
// detect common flags
if (flags == REQ_COMMON_MASK) {
strncpy(buff, "REQ_COMMON_MASK", 15);
buff[16] = '\0';
return 16;
}
if (flags == REQ_FAILFAST_MASK) {
strncpy(buff, "REQ_FAILFAST_MASK", 17);
buff[18] = '\0';
return 18;
}
if (flags == REQ_NOMERGE_FLAGS) {
strncpy(buff, "REQ_NOMERGE_FLAGS", 17);
buff[18] = '\0';
return 18;
}
if (flags & REQ_WRITE) {
strncpy(&buff[size], "REQ_WRITE|", 10);
size += 10;
}
if (flags & REQ_FAILFAST_DEV) {
strncpy(&buff[size], "REQ_FAILFAST_DEV|", 17);
size += 17;
}
if (flags & REQ_FAILFAST_TRANSPORT) {
strncpy(&buff[size], "REQ_FAILFAST_TRANSPORT|", 23);
size += 23;
}
if (flags & REQ_FAILFAST_DRIVER) {
strncpy(&buff[size], "REQ_FAILFAST_DRIVER|", 20);
size += 20;
}
if (flags & REQ_SYNC) {
strncpy(&buff[size], "REQ_SYNC|", 9);
size += 9;
}
if (flags & REQ_META) {
strncpy(&buff[size], "REQ_META|", 9);
size += 9;
}
if (flags & REQ_PRIO) {
strncpy(&buff[size], "REQ_PRIO|", 9);
size += 9;
}
if (flags & REQ_DISCARD) {
strncpy(&buff[size], "REQ_DISCARD|", 13);
size += 13;
}
if (flags & REQ_WRITE_SAME) {
strncpy(&buff[size], "REQ_WRITE_SAME|", 16);
size += 16;
}
if (flags & REQ_NOIDLE) {
strncpy(&buff[size], "REQ_NOIDLE|", 11);
size += 11;
}
if (flags & REQ_RAHEAD) {
strncpy(&buff[size], "REQ_RAHEAD|", 11);
size += 11;
}
if (flags & REQ_THROTTLED) {
strncpy(&buff[size], "REQ_THROTTLED|", 14);
size += 14;
}
if (flags & REQ_SORTED) {
strncpy(&buff[size], "REQ_SORTED|", 11);
size += 11;
}
if (flags & REQ_SOFTBARRIER) {
strncpy(&buff[size], "REQ_SOFTBARRIER|", 16);
size += 16;
}
if (flags & REQ_FUA) {
strncpy(&buff[size], "REQ_FUA|", 8);
size += 8;
}
if (flags & REQ_NOMERGE) {
strncpy(&buff[size], "REQ_NOMERGE|", 12);
size += 12;
}
if (flags & REQ_STARTED) {
strncpy(&buff[size], "REQ_STARTED|", 12);
size += 12;
}
if (flags & REQ_DONTPREP) {
strncpy(&buff[size], "REQ_DONTPREP|", 13);
size += 13;
}
if (flags & REQ_QUEUED) {
strncpy(&buff[size], "REQ_QUEUED|", 11);
size += 11;
}
if (flags & REQ_ELVPRIV) {
strncpy(&buff[size], "REQ_ELVPRIV|", 12);
size += 12;
}
if (flags & REQ_FAILED) {
strncpy(&buff[size], "REQ_FAILED|", 11);
size += 11;
}
if (flags & REQ_QUIET) {
strncpy(&buff[size], "REQ_QUIET|", 10);
size += 10;
}
if (flags & REQ_PREEMPT) {
strncpy(&buff[size], "REQ_PREEMPT|", 12);
size += 12;
}
if (flags & REQ_ALLOCED) {
strncpy(&buff[size], "REQ_ALLOCED|", 12);
size += 12;
}
if (flags & REQ_COPY_USER) {
strncpy(&buff[size], "REQ_COPY_USER|", 14);
size += 14;
}
if (flags & REQ_FLUSH) {
strncpy(&buff[size], "REQ_FLUSH|", 10);
size += 10;
}
if (flags & REQ_FLUSH_SEQ) {
strncpy(&buff[size], "REQ_FLUSH_SEQ|", 14);
size += 14;
}
if (flags & REQ_IO_STAT) {
strncpy(&buff[size], "REQ_IO_STAT|", 12);
size += 12;
}
if (flags & REQ_MIXED_MERGE) {
strncpy(&buff[size], "REQ_MIXED_MERGE|", 16);
size += 16;
}
if (flags & REQ_SECURE) {
strncpy(&buff[size], "REQ_SECURE|", 11);
size += 11;
}
#ifdef REQ_KERNEL /* Gone in 3.18 */
if (flags & REQ_KERNEL) {
strncpy(&buff[size], "REQ_KERNEL|", 11);
size += 11;
}
#endif
if (flags & REQ_PM) {
strncpy(&buff[size], "REQ_PM|", 7);
size += 7;
}
#ifdef REQ_END /* appears in 3.6.10 in linux/blk_types.h */
if (flags & REQ_END) {
strncpy(&buff[size], "REQ_END|", 8);
size += 8;
}
#endif
if (size != 0)
buff[size-1] = '\0';
return size;
}
/*
* Handle an I/O request.
*/
static int srb_xfer_scl(struct srb_device_s *dev,
struct srb_cdmi_desc_s *desc,
struct request *req)
{
int ret = 0;
struct timeval tv_start;
struct timeval tv_end;
SRBDEV_LOG_DEBUG(dev, "CDMI request %p (%s) with cdmi_desc %p",
req, req_code_to_str(rq_data_dir(req)), desc);
if (SRB_DEBUG <= dev->debug.level)
do_gettimeofday(&tv_start);
if (rq_data_dir(req) == WRITE) {
ret = srb_cdmi_putrange(&dev->debug,
desc,
blk_rq_pos(req) * 512ULL,
blk_rq_sectors(req) * 512ULL);
}
else {
ret = srb_cdmi_getrange(&dev->debug,
desc,
blk_rq_pos(req) * 512ULL,
blk_rq_sectors(req) * 512ULL);
}
if (SRB_DEBUG <= dev->debug.level) {
do_gettimeofday(&tv_end);
SRBDEV_LOG_DEBUG(dev, "Request took %ldms",
(tv_end.tv_sec - tv_start.tv_sec)*1000 +
(tv_end.tv_usec - tv_start.tv_usec)/1000);
}
if (ret) {
SRBDEV_LOG_ERR(dev, "CDMI Request using scatterlist failed"
" with IO error: %d", ret);
return -EIO;
}
return ret;
}
/*
* Free internal disk
*/
static int srb_free_disk(struct srb_device_s *dev)
{
struct gendisk *disk = NULL;
disk = dev->disk;
if (!disk) {
SRBDEV_LOG_ERR(dev, "Disk is not available anymore (%s)", dev->name);
return -EINVAL;
}
dev->disk = NULL;
/* free disk */
if (disk->flags & GENHD_FL_UP) {
del_gendisk(disk);
if (disk->queue)
blk_cleanup_queue(disk->queue);
}
put_disk(disk);
return 0;
}
/*
* Thread for srb
*/
static int srb_thread(void *data)
{
struct srb_device_s *dev;
struct request *req;
unsigned long flags;
int th_id;
int th_ret = 0;
char buff[256];
struct req_iterator iter;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0)
struct bio_vec *bvec;
#else
struct bio_vec bvec;
#endif
struct srb_cdmi_desc_s *cdmi_desc;
SRBDEV_LOG_DEBUG(((struct srb_device_s *)data), "Thread started with device %p", data);
dev = data;
/* Init thread specific values */
spin_lock(&devtab_lock);
th_id = dev->nb_threads;
dev->nb_threads++;
spin_unlock(&devtab_lock);
set_user_nice(current, -20);
while (!kthread_should_stop() || !list_empty(&dev->waiting_queue)) {
/* wait for something to do */
wait_event_interruptible(dev->waiting_wq,
kthread_should_stop() ||
!list_empty(&dev->waiting_queue));
/* TODO: improve kthread termination, otherwise calling we can not
terminate a kthread calling kthread_stop() */
/* if (kthread_should_stop()) {
printk(KERN_INFO "srb_thread: immediate kthread exit\n");
do_exit(0);
} */
spin_lock_irqsave(&dev->waiting_lock, flags);
/* extract request */
if (list_empty(&dev->waiting_queue)) {
spin_unlock_irqrestore(&dev->waiting_lock, flags);
continue;
}
req = list_entry(dev->waiting_queue.next, struct request,
queuelist);
list_del_init(&req->queuelist);
spin_unlock_irqrestore(&dev->waiting_lock, flags);
if (blk_rq_sectors(req) == 0) {
blk_end_request_all(req, 0);
continue;
}
req_flags_to_str(req->cmd_flags, buff);
SRBDEV_LOG_DEBUG(dev, "thread %d: New REQ of type %s (%d) flags: %s (%llu)",
th_id, req_code_to_str(rq_data_dir(req)), rq_data_dir(req), buff,
(unsigned long long)req->cmd_flags);
if (req->cmd_flags & REQ_FLUSH) {
SRBDEV_LOG_DEBUG(dev, "DEBUG CMD REQ_FLUSH\n");
}
/* XXX: Use iterator instead of internal function (cf linux/blkdev.h)
* __rq_for_each_bio(bio, req) {
*/
rq_for_each_segment(bvec, req, iter) {
if (iter.bio->bi_rw & REQ_FLUSH) {
SRBDEV_LOG_DEBUG(dev, "DEBUG VR BIO REQ_FLUSH\n");
}
}
/* Create scatterlist */
cdmi_desc = dev->thread_cdmi_desc[th_id];
sg_init_table(dev->thread_cdmi_desc[th_id]->sgl, DEV_NB_PHYS_SEGS);
dev->thread_cdmi_desc[th_id]->sgl_size = blk_rq_map_sg(dev->q, req, dev->thread_cdmi_desc[th_id]->sgl);
SRBDEV_LOG_DEBUG(dev, "scatter_list size %d [nb_seg = %d,"
" sector = %lu, nr_sectors=%u w=%d]",
DEV_NB_PHYS_SEGS,
dev->thread_cdmi_desc[th_id]->sgl_size,
blk_rq_pos(req), blk_rq_sectors(req),
rq_data_dir(req) == WRITE);
/* Call scatter function */
th_ret = srb_xfer_scl(dev, dev->thread_cdmi_desc[th_id], req);
SRBDEV_LOG_DEBUG(dev, "thread %d: REQ done with returned code %d",
th_id, th_ret);
if (th_ret < 0) {
blk_end_request_all(req, -EIO);
} else {
blk_end_request_all(req, 0);
}
}
return 0;
}
static void srb_rq_fn(struct request_queue *q)
{
struct srb_device_s *dev = q->queuedata;
struct request *req;
unsigned long flags;
while ((req = blk_fetch_request(q)) != NULL) {
if (req->cmd_type != REQ_TYPE_FS) {
SRBDEV_LOG_DEBUG(dev, "Skip non-CMD request");
__blk_end_request_all(req, -EIO);
continue;
}
spin_lock_irqsave(&dev->waiting_lock, flags);
list_add_tail(&req->queuelist, &dev->waiting_queue);
spin_unlock_irqrestore(&dev->waiting_lock, flags);
wake_up_nr(&dev->waiting_wq, 1);
}
}
static int srb_open(struct block_device *bdev, fmode_t mode)
{
srb_device_t *dev = (srb_device_t*)bdev->bd_disk->private_data;
int ret = 0;
SRBDEV_LOG_INFO(dev, "Opening device (%s)", bdev->bd_disk->disk_name);
/* Need to check if a detach command is in progress for this
device*/
spin_lock(&devtab_lock);
if (dev->state == DEV_IN_USE) {
SRBDEV_LOG_INFO(dev,
"Tried to open device (%s) while a detach command is in progress",
bdev->bd_disk->disk_name);
ret = -ENOENT;
goto out;
}
dev->users++;
out:
spin_unlock(&devtab_lock);
return ret;
}
/*
* After linux kernel v3.10, this function stops returning anything
* (becomes void). For simplicity, we currently don't support earlier kernels.
*/
static void srb_release(struct gendisk *disk, fmode_t mode)
{
srb_device_t *dev;
dev = disk->private_data;
SRBDEV_LOG_INFO(dev, "Releasing device (%s)", disk->disk_name);
spin_lock(&devtab_lock);
dev->users--;
spin_unlock(&devtab_lock);
}
static const struct block_device_operations srb_fops =
{
.owner = THIS_MODULE,
.open = srb_open,
.release = srb_release,
};
static int srb_init_disk(struct srb_device_s *dev)
{
struct gendisk *disk = NULL;
struct request_queue *q;
int i;
int ret = 0;
SRB_LOG_INFO(srb_log, "srb_init_disk: initializing disk for device: %s", dev->name);
/* Check for existing device nodes */
if (blk_lookup_devt(dev->name, 0)) {
SRB_LOG_ERR(srb_log, "Device already exists: %s", dev->name);
return -EINVAL;
}
/* create gendisk info */
disk = alloc_disk(DEV_MINORS);
if (!disk) {
SRB_LOG_WARN(srb_log, "srb_init_disk: unable to allocate memory for disk for device: %s",
dev->name);
return -ENOMEM;
}
SRB_LOG_DEBUG(srb_log, "Creating new disk: %p", disk);
strcpy(disk->disk_name, dev->name);
disk->major = dev->major;
disk->first_minor = 0;
disk->fops = &srb_fops;
disk->private_data = dev;
/* init rq */
q = blk_init_queue(srb_rq_fn, &dev->rq_lock);
if (!q) {
SRB_LOG_WARN(srb_log, "srb_init_disk: unable to init block queue for device: %p, disk: %p",
dev, disk);
srb_free_disk(dev);
return -ENOMEM;
}
blk_queue_max_hw_sectors(q, DEV_NB_PHYS_SEGS);
q->queuedata = dev;
dev->disk = disk;
dev->q = disk->queue = q;
dev->nb_threads = 0;
//blk_queue_flush(q, REQ_FLUSH | REQ_FUA);
//blk_queue_max_phys_segments(q, DEV_NB_PHYS_SEGS);
//TODO: Enable flush and bio (Issue #21)
//blk_queue_flush(q, REQ_FLUSH);
for (i = 0; i < thread_pool_size; i++) {
//if ((ret = srb_cdmi_connect(&dev->debug, &dev->thread_cdmi_desc[i]))) {
if ((ret = srb_cdmi_connect(&dev->debug, dev->thread_cdmi_desc[i]))) {
SRB_LOG_ERR(srb_log, "Unable to connect to CDMI endpoint: %d",
ret);
srb_free_disk(dev);
return -EIO;
}
}
/* Caution: be sure to call this before spawning threads */
ret = srb_cdmi_getsize(&dev->debug, dev->thread_cdmi_desc[0], &dev->disk_size);
if (ret != 0) {
SRB_LOG_ERR(srb_log, "Could not retrieve volume size.");
srb_free_disk(dev);
return ret;
}
set_capacity(disk, dev->disk_size / 512ULL);
for (i = 0; i < thread_pool_size; i++) {
dev->thread[i] = kthread_create(srb_thread, dev, "%s",
dev->disk->disk_name);
if (IS_ERR(dev->thread[i])) {
SRB_LOG_ERR(srb_log, "Unable to create worker thread (id %d)", i);
dev->thread[i] = NULL;
srb_free_disk(dev);
goto err_kthread;
}
wake_up_process(dev->thread[i]);
}
add_disk(disk);
SRBDEV_LOG_INFO(dev, "Attached volume %s of size 0x%llx",
disk->disk_name, (unsigned long long)dev->disk_size);
return 0;
err_kthread:
for (i = 0; i < thread_pool_size; i++) {
if (dev->thread[i] != NULL)
kthread_stop(dev->thread[i]);
}
return -EIO;
}
#define device_free_slot(X) ((X)->name[0] == 0)
/* This function gets the next free slot in device tab (devtab)
** and sets its name and id.
** Note : all the remaining fields states are undefived, it is
** the caller responsability to set them.
*/
static int srb_device_new(const char *devname, srb_device_t *dev)
{
int ret = -EINVAL;
int i;
SRB_LOG_INFO(srb_log, "srb_device_new: creating new device %s"
" with %d threads", devname, thread_pool_size);
if (NULL == dev) {
ret = -EINVAL;
goto out;
}
if (NULL == devname || strlen(devname) >= DISK_NAME_LEN) {
SRB_LOG_ERR(srb_log, "srb_device_new: "
"Invalid (or too long) device name '%s'",
devname == NULL ? "" : devname);
ret = -EINVAL;
goto out;
}
/* Lock table to protect against concurrent devices
* creation
*/
dev->debug.name = &dev->name[0];
dev->debug.level = srb_log;
dev->users = 0;
strncpy(dev->name, devname, strlen(devname));
/* XXX: dynamic allocation of thread pool and cdmi connection pool
* NB: The memory allocation for the thread is an array of pointer
* whereas the allocation for the cdmi connection pool is an array
* of cdmi connection structure
*/
dev->thread_cdmi_desc = vmalloc(thread_pool_size * sizeof(struct srb_cdmi_desc_s *));
if (dev->thread_cdmi_desc == NULL) {
SRB_LOG_CRIT(srb_log, "srb_device_new: Unable to allocate memory for CDMI struct pointer");
ret = -ENOMEM;
goto err_mem;
}
for (i = 0; i < thread_pool_size; i++) {
dev->thread_cdmi_desc[i] = vmalloc(sizeof(struct srb_cdmi_desc_s));
if (dev->thread_cdmi_desc[i] == NULL) {
SRB_LOG_CRIT(srb_log, "srb_device_new: Unable to allocate memory for CDMI struct, step %d", i);
ret = -ENOMEM;
goto err_mem;
}
}
dev->thread = vmalloc(thread_pool_size * sizeof(struct task_struct *));
if (dev->thread == NULL) {
SRB_LOG_CRIT(srb_log, "srb_device_new: Unable to allocate memory for kernel thread struct");
ret = -ENOMEM;
goto err_mem;
}
return 0;
err_mem:
if (NULL != dev && NULL != dev->thread_cdmi_desc) {
for (i = 0; i < thread_pool_size; i++) {
if (dev->thread_cdmi_desc[i])
vfree(dev->thread_cdmi_desc[i]);
}
vfree(dev->thread_cdmi_desc);
}
out:
return ret;
}
/* This helper marks the given device slot as empty
** CAUTION: the devab lock must be held
*/
static void __srb_device_free(srb_device_t *dev)
{
SRB_LOG_INFO(srb_log, "__srb_device_free: freeing device: %s", dev->name);
memset(dev->name, 0, DISK_NAME_LEN);
dev->major = 0;
dev->id = -1;
}
static void srb_device_free(srb_device_t *dev)
{
int i = 0;
SRB_LOG_INFO(srb_log, "srb_device_free: freeing device: %s", dev->name);
__srb_device_free(dev);
if (dev->thread_cdmi_desc) {
for (i = 0; i < thread_pool_size; i++) {
if (dev->thread_cdmi_desc[i])
{
srb_cdmi_disconnect(&dev->debug,
dev->thread_cdmi_desc[i]);
vfree(dev->thread_cdmi_desc[i]);
}
}
vfree(dev->thread_cdmi_desc);
}
if (dev->thread)
vfree(dev->thread);
}
static int _srb_reconstruct_url(char *url, char *name,
const char *baseurl, const char *basepath,
const char *filename)
{
int urllen = 0;
int namelen = 0;
int seplen = 0;
SRB_LOG_DEBUG(srb_log, "_srb_reconstruct_url: construction of URL with url: %s, name: %s, baseurl: %s, basepath: %p, filename: %s",
url, name, baseurl, basepath, filename);
urllen = strlen(baseurl);
if (baseurl[urllen - 1] != '/')
seplen = 1;
if (seplen)
{
urllen = snprintf(url, SRB_URL_SIZE, "%s/%s", baseurl, filename);
namelen = snprintf(name, SRB_URL_SIZE, "%s/%s", basepath, filename);
}
else
{
urllen = snprintf(url, SRB_URL_SIZE, "%s%s", baseurl, filename);
namelen = snprintf(name, SRB_URL_SIZE, "%s%s", basepath, filename);
}
if (urllen >= SRB_URL_SIZE || namelen >= SRB_URL_SIZE)
return -EINVAL;
return 0;
}
static int __srb_device_detach(srb_device_t *dev)
{
int i;
int ret = 0;
SRB_LOG_DEBUG(srb_log, "detaching device (%p)", dev);
if (!dev) {
SRB_LOG_WARN(srb_log, "__srb_device_detach: empty device");
return -EINVAL;
}
SRBDEV_LOG_DEBUG(dev, "Detaching device (%s)", dev->name);
if (dev->users > 0) {
SRBDEV_LOG_ERR(dev, "Unable to remove, device still opened (#users: %d)", dev->users);
return -EBUSY;
}
if (!dev->disk) {
SRBDEV_LOG_ERR(dev, "Device %s is not available anymore", dev->name);
return -EINVAL;
}
SRBDEV_LOG_INFO(dev, "Stopping device's background processes");
for (i = 0; i < thread_pool_size; i++) {
if (dev->thread[i])
kthread_stop(dev->thread[i]);
}
/* free disk */
ret = srb_free_disk(dev);
if (0 != ret) {
SRBDEV_LOG_WARN(dev, "Failed to remove device: %d", ret);
}
SRB_LOG_INFO(srb_log, "Unregistering device from BLOCK Subsystem");
/* Remove device */
unregister_blkdev(dev->major, DEV_NAME);
/* Mark slot as empty */
if (NULL != dev)
srb_device_free(dev);
return 0;
}
static int _srb_detach_devices(void)
{
int ret;
int i = 0;
int errcount = 0;
int dev_in_use[DEV_MAX];
SRB_LOG_INFO(srb_log, "_srb_detach_devices: detaching devices");
/* mark all device that are not used */
spin_lock(&devtab_lock);
for (i = 0; i < DEV_MAX; ++i) {
dev_in_use[i] = 0;
if (!device_free_slot(&devtab[i])) {
if (devtab[i].state == DEV_IN_USE) {
dev_in_use[i] = 1;
} else {
devtab[i].state = DEV_IN_USE;
dev_in_use[i] = 2;
}
}
}
spin_unlock(&devtab_lock);
/* detach all marked devices */
for (i = 0; i < DEV_MAX; ++i) {
if (2 == dev_in_use[i]) {
ret = __srb_device_detach(&devtab[i]);
if (ret != 0) {
SRBDEV_LOG_ERR(&devtab[i],
"Cannot remove device %s for volume %s"
" on module unload: %i",
devtab[i].name,
devtab[i].thread_cdmi_desc ?
devtab[i].thread_cdmi_desc[0]->filename
: "NULL",
ret);
errcount++;
}
}
}
/* mark all device that are not used */
spin_lock(&devtab_lock);
for (i = 0; i < DEV_MAX; ++i) {
if (2 == dev_in_use[i]) {
devtab[i].state = DEV_UNUSED;
}
}
spin_unlock(&devtab_lock);
return errcount;
}
static void _srb_server_free(srb_server_t *server)
{
SRB_LOG_DEBUG(srb_log, "_srb_server_free: deleting server url %s (%p)", server->cdmi_desc.url, server);
if (server) {
server->next = NULL;
vfree(server);
server = NULL;
}
}
static int _srb_server_new(srb_debug_t *dbg, const char *url, srb_server_t **server)
{
srb_server_t *new = NULL;
int ret = 0;
SRB_LOG_DEBUG(dbg->level, "_srb_server_new: creating server with url: %s, servers: %p", url, *server);
new = vmalloc(sizeof(struct srb_server_s));
if (new == NULL) {
SRB_LOG_ERR(dbg->level, "Cannot allocate memory to add a new server.");
ret = -ENOMEM;
goto end;
}
memset(new, 0, sizeof(struct srb_server_s));
ret = srb_cdmi_init(dbg, &new->cdmi_desc, url);
if (ret != 0) {
SRB_LOG_ERR(dbg->level, "Could not initialize server descriptor (parse URL).");
goto end;
}
if (server) {
new->next = NULL;
*server = new;
}
return 0;
end:
_srb_server_free(new);
return ret;
}
/*
* XXX NOTE XXX: #13 This function picks only one server that has enough free
* space in the URL buffer to append the filename.
*/
static int _srb_server_pick(const char *filename, struct srb_cdmi_desc_s *pick)
{
char url[SRB_URL_SIZE];
char name[SRB_URL_SIZE];
int ret;
int found = 0;
srb_server_t *server = NULL;
SRB_LOG_DEBUG(srb_log, "_srb_server_pick: picking server with filename: %s, with CDMI pick %p", filename, pick);
spin_lock(&devtab_lock);
server = servers;
while (server != NULL) {
SRB_LOG_INFO(srb_log, "Browsing server: %s", server->cdmi_desc.url);
ret = _srb_reconstruct_url(url, name,
server->cdmi_desc.url,
server->cdmi_desc.filename,
filename);
SRB_LOG_INFO(srb_log, "Dewb reconstruct url yielded %s, %i", url, ret);
if (ret == 0) {
memcpy(pick, &server->cdmi_desc, sizeof(struct srb_cdmi_desc_s));
strncpy(pick->url, url, SRB_URL_SIZE);
strncpy(pick->filename, name, SRB_URL_SIZE);
SRB_LOG_INFO(srb_log, "Copied into pick: url=%s, name=%s", pick->url, pick->filename);
found = 1;
break ;
}
server = server->next;
}
spin_unlock(&devtab_lock);
SRB_LOG_INFO(srb_log, "Browsed all servers");
if (!found) {
SRB_LOG_ERR(srb_log, "Could not match any server for filename %s", filename);
// No such device or adress seems to match 'missing server'
ret = -ENXIO;
goto end;
}
ret = 0;
end:
return ret;
}
/* XXX: Respect ISO C90
* Fix compilation warning: ISO C90 forbids mixed declarations and code
* Fix design: only create new server if not found in the list
*/
int srb_server_add(const char *url)
{
int ret = 0;
int found = 0;
srb_server_t *cur = NULL;
srb_server_t *last = NULL;
srb_server_t *new = NULL;
srb_debug_t debug;
SRB_LOG_INFO(srb_log, "srb_server_add: adding server %s", url);
debug.name = "<Server-Url-Adder>";
debug.level = srb_log;
if (strlen(url) >= SRB_URL_SIZE) {
SRB_LOG_ERR(srb_log, "Url too big: '%s'", url);
ret = -EINVAL;
goto err_out_dev;
}
ret = _srb_server_new(&debug, url, &new);
if (ret != 0)
goto err_out_dev;
spin_lock(&devtab_lock);
cur = servers;
while (cur != NULL) {
if (strcmp(url, cur->cdmi_desc.url) == 0) {
found = 1;
break;
}
last = cur;
cur = cur->next;
}
if (found == 0) {
if (last != NULL)
last->next = new;
else
servers = new;
new = NULL;
}
spin_unlock(&devtab_lock);
if (found)
_srb_server_free(new);
return 0;
err_out_dev:
return ret;
}
static int _locked_server_remove(const char *url)
{
int ret = 0;
int i;
int found = 0;
srb_server_t *cur = NULL;
srb_server_t *prev = NULL;
cur = servers;