![Linus Torvalds](/assets/img/avatar_default.png)
Pull block core updates from Jens Axboe: - Major bit is Kents prep work for immutable bio vecs. - Stable candidate fix for a scheduling-while-atomic in the queue bypass operation. - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging discard bios. - Tejuns changes to convert the writeback thread pool to the generic workqueue mechanism. - Runtime PM framework, SCSI patches exists on top of these in James' tree. - A few random fixes. * 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits) relay: move remove_buf_file inside relay_close_buf partitions/efi.c: replace useless kzalloc's by kmalloc's fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read() block: fix max discard sectors limit blkcg: fix "scheduling while atomic" in blk_queue_bypass_start Documentation: cfq-iosched: update documentation help for cfq tunables writeback: expose the bdi_wq workqueue writeback: replace custom worker pool implementation with unbound workqueue writeback: remove unused bdi_pending_list aoe: Fix unitialized var usage bio-integrity: Add explicit field for owner of bip_buf block: Add an explicit bio flag for bios that own their bvec block: Add bio_alloc_pages() block: Convert some code to bio_for_each_segment_all() block: Add bio_for_each_segment_all() bounce: Refactor __blk_queue_bounce to not use bi_io_vec raid1: use bio_copy_data() pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage pktcdvd: use bio_copy_data() block: Add bio_copy_data() ...
1084 lines
26 KiB
C
1084 lines
26 KiB
C
/*
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* dcssblk.c -- the S/390 block driver for dcss memory
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*
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* Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer
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*/
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#define KMSG_COMPONENT "dcssblk"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/ctype.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/completion.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <asm/extmem.h>
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#include <asm/io.h>
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#define DCSSBLK_NAME "dcssblk"
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#define DCSSBLK_MINORS_PER_DISK 1
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#define DCSSBLK_PARM_LEN 400
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#define DCSS_BUS_ID_SIZE 20
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static int dcssblk_open(struct block_device *bdev, fmode_t mode);
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static void dcssblk_release(struct gendisk *disk, fmode_t mode);
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static void dcssblk_make_request(struct request_queue *q, struct bio *bio);
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static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
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void **kaddr, unsigned long *pfn);
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static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
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static int dcssblk_major;
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static const struct block_device_operations dcssblk_devops = {
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.owner = THIS_MODULE,
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.open = dcssblk_open,
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.release = dcssblk_release,
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.direct_access = dcssblk_direct_access,
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};
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struct dcssblk_dev_info {
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struct list_head lh;
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struct device dev;
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char segment_name[DCSS_BUS_ID_SIZE];
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atomic_t use_count;
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struct gendisk *gd;
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unsigned long start;
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unsigned long end;
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int segment_type;
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unsigned char save_pending;
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unsigned char is_shared;
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struct request_queue *dcssblk_queue;
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int num_of_segments;
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struct list_head seg_list;
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};
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struct segment_info {
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struct list_head lh;
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char segment_name[DCSS_BUS_ID_SIZE];
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unsigned long start;
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unsigned long end;
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int segment_type;
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};
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static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf,
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size_t count);
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static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf,
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size_t count);
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static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store);
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static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store);
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static struct device *dcssblk_root_dev;
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static LIST_HEAD(dcssblk_devices);
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static struct rw_semaphore dcssblk_devices_sem;
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/*
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* release function for segment device.
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*/
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static void
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dcssblk_release_segment(struct device *dev)
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{
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struct dcssblk_dev_info *dev_info;
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struct segment_info *entry, *temp;
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dev_info = container_of(dev, struct dcssblk_dev_info, dev);
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list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) {
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list_del(&entry->lh);
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kfree(entry);
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}
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kfree(dev_info);
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module_put(THIS_MODULE);
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}
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/*
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* get a minor number. needs to be called with
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* down_write(&dcssblk_devices_sem) and the
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* device needs to be enqueued before the semaphore is
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* freed.
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*/
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static int
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dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info)
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{
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int minor, found;
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struct dcssblk_dev_info *entry;
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if (dev_info == NULL)
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return -EINVAL;
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for (minor = 0; minor < (1<<MINORBITS); minor++) {
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found = 0;
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// test if minor available
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list_for_each_entry(entry, &dcssblk_devices, lh)
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if (minor == entry->gd->first_minor)
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found++;
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if (!found) break; // got unused minor
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}
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if (found)
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return -EBUSY;
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dev_info->gd->first_minor = minor;
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return 0;
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}
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/*
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* get the struct dcssblk_dev_info from dcssblk_devices
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* for the given name.
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* down_read(&dcssblk_devices_sem) must be held.
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*/
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static struct dcssblk_dev_info *
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dcssblk_get_device_by_name(char *name)
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{
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struct dcssblk_dev_info *entry;
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list_for_each_entry(entry, &dcssblk_devices, lh) {
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if (!strcmp(name, entry->segment_name)) {
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return entry;
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}
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}
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return NULL;
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}
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/*
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* get the struct segment_info from seg_list
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* for the given name.
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* down_read(&dcssblk_devices_sem) must be held.
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*/
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static struct segment_info *
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dcssblk_get_segment_by_name(char *name)
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{
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struct dcssblk_dev_info *dev_info;
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struct segment_info *entry;
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list_for_each_entry(dev_info, &dcssblk_devices, lh) {
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list_for_each_entry(entry, &dev_info->seg_list, lh) {
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if (!strcmp(name, entry->segment_name))
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return entry;
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}
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}
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return NULL;
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}
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/*
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* get the highest address of the multi-segment block.
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*/
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static unsigned long
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dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info)
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{
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unsigned long highest_addr;
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struct segment_info *entry;
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highest_addr = 0;
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list_for_each_entry(entry, &dev_info->seg_list, lh) {
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if (highest_addr < entry->end)
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highest_addr = entry->end;
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}
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return highest_addr;
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}
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/*
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* get the lowest address of the multi-segment block.
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*/
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static unsigned long
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dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info)
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{
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int set_first;
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unsigned long lowest_addr;
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struct segment_info *entry;
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set_first = 0;
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lowest_addr = 0;
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list_for_each_entry(entry, &dev_info->seg_list, lh) {
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if (set_first == 0) {
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lowest_addr = entry->start;
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set_first = 1;
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} else {
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if (lowest_addr > entry->start)
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lowest_addr = entry->start;
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}
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}
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return lowest_addr;
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}
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/*
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* Check continuity of segments.
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*/
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static int
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dcssblk_is_continuous(struct dcssblk_dev_info *dev_info)
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{
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int i, j, rc;
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struct segment_info *sort_list, *entry, temp;
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if (dev_info->num_of_segments <= 1)
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return 0;
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sort_list = kzalloc(
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sizeof(struct segment_info) * dev_info->num_of_segments,
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GFP_KERNEL);
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if (sort_list == NULL)
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return -ENOMEM;
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i = 0;
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list_for_each_entry(entry, &dev_info->seg_list, lh) {
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memcpy(&sort_list[i], entry, sizeof(struct segment_info));
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i++;
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}
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/* sort segments */
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for (i = 0; i < dev_info->num_of_segments; i++)
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for (j = 0; j < dev_info->num_of_segments; j++)
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if (sort_list[j].start > sort_list[i].start) {
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memcpy(&temp, &sort_list[i],
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sizeof(struct segment_info));
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memcpy(&sort_list[i], &sort_list[j],
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sizeof(struct segment_info));
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memcpy(&sort_list[j], &temp,
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sizeof(struct segment_info));
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}
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/* check continuity */
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for (i = 0; i < dev_info->num_of_segments - 1; i++) {
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if ((sort_list[i].end + 1) != sort_list[i+1].start) {
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pr_err("Adjacent DCSSs %s and %s are not "
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"contiguous\n", sort_list[i].segment_name,
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sort_list[i+1].segment_name);
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rc = -EINVAL;
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goto out;
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}
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/* EN and EW are allowed in a block device */
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if (sort_list[i].segment_type != sort_list[i+1].segment_type) {
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if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) ||
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(sort_list[i].segment_type == SEG_TYPE_ER) ||
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!(sort_list[i+1].segment_type &
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SEGMENT_EXCLUSIVE) ||
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(sort_list[i+1].segment_type == SEG_TYPE_ER)) {
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pr_err("DCSS %s and DCSS %s have "
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"incompatible types\n",
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sort_list[i].segment_name,
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sort_list[i+1].segment_name);
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rc = -EINVAL;
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goto out;
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}
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}
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}
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rc = 0;
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out:
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kfree(sort_list);
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return rc;
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}
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/*
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* Load a segment
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*/
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static int
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dcssblk_load_segment(char *name, struct segment_info **seg_info)
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{
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int rc;
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/* already loaded? */
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down_read(&dcssblk_devices_sem);
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*seg_info = dcssblk_get_segment_by_name(name);
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up_read(&dcssblk_devices_sem);
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if (*seg_info != NULL)
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return -EEXIST;
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/* get a struct segment_info */
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*seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL);
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if (*seg_info == NULL)
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return -ENOMEM;
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strcpy((*seg_info)->segment_name, name);
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/* load the segment */
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rc = segment_load(name, SEGMENT_SHARED,
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&(*seg_info)->start, &(*seg_info)->end);
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if (rc < 0) {
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segment_warning(rc, (*seg_info)->segment_name);
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kfree(*seg_info);
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} else {
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INIT_LIST_HEAD(&(*seg_info)->lh);
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(*seg_info)->segment_type = rc;
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}
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return rc;
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}
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static void dcssblk_unregister_callback(struct device *dev)
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{
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device_unregister(dev);
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put_device(dev);
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}
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/*
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* device attribute for switching shared/nonshared (exclusive)
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* operation (show + store)
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*/
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static ssize_t
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dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct dcssblk_dev_info *dev_info;
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dev_info = container_of(dev, struct dcssblk_dev_info, dev);
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return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n");
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}
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static ssize_t
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dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
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{
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struct dcssblk_dev_info *dev_info;
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struct segment_info *entry, *temp;
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int rc;
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if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
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return -EINVAL;
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down_write(&dcssblk_devices_sem);
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dev_info = container_of(dev, struct dcssblk_dev_info, dev);
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if (atomic_read(&dev_info->use_count)) {
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rc = -EBUSY;
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goto out;
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}
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if (inbuf[0] == '1') {
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/* reload segments in shared mode */
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list_for_each_entry(entry, &dev_info->seg_list, lh) {
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rc = segment_modify_shared(entry->segment_name,
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SEGMENT_SHARED);
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if (rc < 0) {
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BUG_ON(rc == -EINVAL);
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if (rc != -EAGAIN)
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goto removeseg;
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}
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}
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dev_info->is_shared = 1;
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switch (dev_info->segment_type) {
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case SEG_TYPE_SR:
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case SEG_TYPE_ER:
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case SEG_TYPE_SC:
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set_disk_ro(dev_info->gd, 1);
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}
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} else if (inbuf[0] == '0') {
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/* reload segments in exclusive mode */
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if (dev_info->segment_type == SEG_TYPE_SC) {
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pr_err("DCSS %s is of type SC and cannot be "
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"loaded as exclusive-writable\n",
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dev_info->segment_name);
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rc = -EINVAL;
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goto out;
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}
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list_for_each_entry(entry, &dev_info->seg_list, lh) {
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rc = segment_modify_shared(entry->segment_name,
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SEGMENT_EXCLUSIVE);
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if (rc < 0) {
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BUG_ON(rc == -EINVAL);
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if (rc != -EAGAIN)
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goto removeseg;
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}
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}
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dev_info->is_shared = 0;
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set_disk_ro(dev_info->gd, 0);
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} else {
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rc = -EINVAL;
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goto out;
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}
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rc = count;
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goto out;
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removeseg:
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pr_err("DCSS device %s is removed after a failed access mode "
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"change\n", dev_info->segment_name);
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temp = entry;
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list_for_each_entry(entry, &dev_info->seg_list, lh) {
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if (entry != temp)
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segment_unload(entry->segment_name);
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}
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list_del(&dev_info->lh);
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del_gendisk(dev_info->gd);
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blk_cleanup_queue(dev_info->dcssblk_queue);
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dev_info->gd->queue = NULL;
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put_disk(dev_info->gd);
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rc = device_schedule_callback(dev, dcssblk_unregister_callback);
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out:
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up_write(&dcssblk_devices_sem);
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return rc;
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}
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static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show,
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dcssblk_shared_store);
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|
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/*
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* device attribute for save operation on current copy
|
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* of the segment. If the segment is busy, saving will
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* become pending until it gets released, which can be
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* undone by storing a non-true value to this entry.
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* (show + store)
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*/
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static ssize_t
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dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf)
|
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{
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struct dcssblk_dev_info *dev_info;
|
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|
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dev_info = container_of(dev, struct dcssblk_dev_info, dev);
|
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return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n");
|
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}
|
|
|
|
static ssize_t
|
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dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
|
|
{
|
|
struct dcssblk_dev_info *dev_info;
|
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struct segment_info *entry;
|
|
|
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if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
|
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return -EINVAL;
|
|
dev_info = container_of(dev, struct dcssblk_dev_info, dev);
|
|
|
|
down_write(&dcssblk_devices_sem);
|
|
if (inbuf[0] == '1') {
|
|
if (atomic_read(&dev_info->use_count) == 0) {
|
|
// device is idle => we save immediately
|
|
pr_info("All DCSSs that map to device %s are "
|
|
"saved\n", dev_info->segment_name);
|
|
list_for_each_entry(entry, &dev_info->seg_list, lh) {
|
|
segment_save(entry->segment_name);
|
|
}
|
|
} else {
|
|
// device is busy => we save it when it becomes
|
|
// idle in dcssblk_release
|
|
pr_info("Device %s is in use, its DCSSs will be "
|
|
"saved when it becomes idle\n",
|
|
dev_info->segment_name);
|
|
dev_info->save_pending = 1;
|
|
}
|
|
} else if (inbuf[0] == '0') {
|
|
if (dev_info->save_pending) {
|
|
// device is busy & the user wants to undo his save
|
|
// request
|
|
dev_info->save_pending = 0;
|
|
pr_info("A pending save request for device %s "
|
|
"has been canceled\n",
|
|
dev_info->segment_name);
|
|
}
|
|
} else {
|
|
up_write(&dcssblk_devices_sem);
|
|
return -EINVAL;
|
|
}
|
|
up_write(&dcssblk_devices_sem);
|
|
return count;
|
|
}
|
|
static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
|
|
dcssblk_save_store);
|
|
|
|
/*
|
|
* device attribute for showing all segments in a device
|
|
*/
|
|
static ssize_t
|
|
dcssblk_seglist_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
int i;
|
|
|
|
struct dcssblk_dev_info *dev_info;
|
|
struct segment_info *entry;
|
|
|
|
down_read(&dcssblk_devices_sem);
|
|
dev_info = container_of(dev, struct dcssblk_dev_info, dev);
|
|
i = 0;
|
|
buf[0] = '\0';
|
|
list_for_each_entry(entry, &dev_info->seg_list, lh) {
|
|
strcpy(&buf[i], entry->segment_name);
|
|
i += strlen(entry->segment_name);
|
|
buf[i] = '\n';
|
|
i++;
|
|
}
|
|
up_read(&dcssblk_devices_sem);
|
|
return i;
|
|
}
|
|
static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL);
|
|
|
|
static struct attribute *dcssblk_dev_attrs[] = {
|
|
&dev_attr_shared.attr,
|
|
&dev_attr_save.attr,
|
|
&dev_attr_seglist.attr,
|
|
NULL,
|
|
};
|
|
static struct attribute_group dcssblk_dev_attr_group = {
|
|
.attrs = dcssblk_dev_attrs,
|
|
};
|
|
static const struct attribute_group *dcssblk_dev_attr_groups[] = {
|
|
&dcssblk_dev_attr_group,
|
|
NULL,
|
|
};
|
|
|
|
/*
|
|
* device attribute for adding devices
|
|
*/
|
|
static ssize_t
|
|
dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
|
|
{
|
|
int rc, i, j, num_of_segments;
|
|
struct dcssblk_dev_info *dev_info;
|
|
struct segment_info *seg_info, *temp;
|
|
char *local_buf;
|
|
unsigned long seg_byte_size;
|
|
|
|
dev_info = NULL;
|
|
seg_info = NULL;
|
|
if (dev != dcssblk_root_dev) {
|
|
rc = -EINVAL;
|
|
goto out_nobuf;
|
|
}
|
|
if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) {
|
|
rc = -ENAMETOOLONG;
|
|
goto out_nobuf;
|
|
}
|
|
|
|
local_buf = kmalloc(count + 1, GFP_KERNEL);
|
|
if (local_buf == NULL) {
|
|
rc = -ENOMEM;
|
|
goto out_nobuf;
|
|
}
|
|
|
|
/*
|
|
* parse input
|
|
*/
|
|
num_of_segments = 0;
|
|
for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) {
|
|
for (j = i; (buf[j] != ':') &&
|
|
(buf[j] != '\0') &&
|
|
(buf[j] != '\n') &&
|
|
j < count; j++) {
|
|
local_buf[j-i] = toupper(buf[j]);
|
|
}
|
|
local_buf[j-i] = '\0';
|
|
if (((j - i) == 0) || ((j - i) > 8)) {
|
|
rc = -ENAMETOOLONG;
|
|
goto seg_list_del;
|
|
}
|
|
|
|
rc = dcssblk_load_segment(local_buf, &seg_info);
|
|
if (rc < 0)
|
|
goto seg_list_del;
|
|
/*
|
|
* get a struct dcssblk_dev_info
|
|
*/
|
|
if (num_of_segments == 0) {
|
|
dev_info = kzalloc(sizeof(struct dcssblk_dev_info),
|
|
GFP_KERNEL);
|
|
if (dev_info == NULL) {
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
strcpy(dev_info->segment_name, local_buf);
|
|
dev_info->segment_type = seg_info->segment_type;
|
|
INIT_LIST_HEAD(&dev_info->seg_list);
|
|
}
|
|
list_add_tail(&seg_info->lh, &dev_info->seg_list);
|
|
num_of_segments++;
|
|
i = j;
|
|
|
|
if ((buf[j] == '\0') || (buf[j] == '\n'))
|
|
break;
|
|
}
|
|
|
|
/* no trailing colon at the end of the input */
|
|
if ((i > 0) && (buf[i-1] == ':')) {
|
|
rc = -ENAMETOOLONG;
|
|
goto seg_list_del;
|
|
}
|
|
strlcpy(local_buf, buf, i + 1);
|
|
dev_info->num_of_segments = num_of_segments;
|
|
rc = dcssblk_is_continuous(dev_info);
|
|
if (rc < 0)
|
|
goto seg_list_del;
|
|
|
|
dev_info->start = dcssblk_find_lowest_addr(dev_info);
|
|
dev_info->end = dcssblk_find_highest_addr(dev_info);
|
|
|
|
dev_set_name(&dev_info->dev, dev_info->segment_name);
|
|
dev_info->dev.release = dcssblk_release_segment;
|
|
dev_info->dev.groups = dcssblk_dev_attr_groups;
|
|
INIT_LIST_HEAD(&dev_info->lh);
|
|
dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
|
|
if (dev_info->gd == NULL) {
|
|
rc = -ENOMEM;
|
|
goto seg_list_del;
|
|
}
|
|
dev_info->gd->major = dcssblk_major;
|
|
dev_info->gd->fops = &dcssblk_devops;
|
|
dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL);
|
|
dev_info->gd->queue = dev_info->dcssblk_queue;
|
|
dev_info->gd->private_data = dev_info;
|
|
dev_info->gd->driverfs_dev = &dev_info->dev;
|
|
blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
|
|
blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096);
|
|
|
|
seg_byte_size = (dev_info->end - dev_info->start + 1);
|
|
set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
|
|
pr_info("Loaded %s with total size %lu bytes and capacity %lu "
|
|
"sectors\n", local_buf, seg_byte_size, seg_byte_size >> 9);
|
|
|
|
dev_info->save_pending = 0;
|
|
dev_info->is_shared = 1;
|
|
dev_info->dev.parent = dcssblk_root_dev;
|
|
|
|
/*
|
|
*get minor, add to list
|
|
*/
|
|
down_write(&dcssblk_devices_sem);
|
|
if (dcssblk_get_segment_by_name(local_buf)) {
|
|
rc = -EEXIST;
|
|
goto release_gd;
|
|
}
|
|
rc = dcssblk_assign_free_minor(dev_info);
|
|
if (rc)
|
|
goto release_gd;
|
|
sprintf(dev_info->gd->disk_name, "dcssblk%d",
|
|
dev_info->gd->first_minor);
|
|
list_add_tail(&dev_info->lh, &dcssblk_devices);
|
|
|
|
if (!try_module_get(THIS_MODULE)) {
|
|
rc = -ENODEV;
|
|
goto dev_list_del;
|
|
}
|
|
/*
|
|
* register the device
|
|
*/
|
|
rc = device_register(&dev_info->dev);
|
|
if (rc)
|
|
goto put_dev;
|
|
|
|
get_device(&dev_info->dev);
|
|
add_disk(dev_info->gd);
|
|
|
|
switch (dev_info->segment_type) {
|
|
case SEG_TYPE_SR:
|
|
case SEG_TYPE_ER:
|
|
case SEG_TYPE_SC:
|
|
set_disk_ro(dev_info->gd,1);
|
|
break;
|
|
default:
|
|
set_disk_ro(dev_info->gd,0);
|
|
break;
|
|
}
|
|
up_write(&dcssblk_devices_sem);
|
|
rc = count;
|
|
goto out;
|
|
|
|
put_dev:
|
|
list_del(&dev_info->lh);
|
|
blk_cleanup_queue(dev_info->dcssblk_queue);
|
|
dev_info->gd->queue = NULL;
|
|
put_disk(dev_info->gd);
|
|
list_for_each_entry(seg_info, &dev_info->seg_list, lh) {
|
|
segment_unload(seg_info->segment_name);
|
|
}
|
|
put_device(&dev_info->dev);
|
|
up_write(&dcssblk_devices_sem);
|
|
goto out;
|
|
dev_list_del:
|
|
list_del(&dev_info->lh);
|
|
release_gd:
|
|
blk_cleanup_queue(dev_info->dcssblk_queue);
|
|
dev_info->gd->queue = NULL;
|
|
put_disk(dev_info->gd);
|
|
up_write(&dcssblk_devices_sem);
|
|
seg_list_del:
|
|
if (dev_info == NULL)
|
|
goto out;
|
|
list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) {
|
|
list_del(&seg_info->lh);
|
|
segment_unload(seg_info->segment_name);
|
|
kfree(seg_info);
|
|
}
|
|
kfree(dev_info);
|
|
out:
|
|
kfree(local_buf);
|
|
out_nobuf:
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* device attribute for removing devices
|
|
*/
|
|
static ssize_t
|
|
dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
|
|
{
|
|
struct dcssblk_dev_info *dev_info;
|
|
struct segment_info *entry;
|
|
int rc, i;
|
|
char *local_buf;
|
|
|
|
if (dev != dcssblk_root_dev) {
|
|
return -EINVAL;
|
|
}
|
|
local_buf = kmalloc(count + 1, GFP_KERNEL);
|
|
if (local_buf == NULL) {
|
|
return -ENOMEM;
|
|
}
|
|
/*
|
|
* parse input
|
|
*/
|
|
for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) {
|
|
local_buf[i] = toupper(buf[i]);
|
|
}
|
|
local_buf[i] = '\0';
|
|
if ((i == 0) || (i > 8)) {
|
|
rc = -ENAMETOOLONG;
|
|
goto out_buf;
|
|
}
|
|
|
|
down_write(&dcssblk_devices_sem);
|
|
dev_info = dcssblk_get_device_by_name(local_buf);
|
|
if (dev_info == NULL) {
|
|
up_write(&dcssblk_devices_sem);
|
|
pr_warning("Device %s cannot be removed because it is not a "
|
|
"known device\n", local_buf);
|
|
rc = -ENODEV;
|
|
goto out_buf;
|
|
}
|
|
if (atomic_read(&dev_info->use_count) != 0) {
|
|
up_write(&dcssblk_devices_sem);
|
|
pr_warning("Device %s cannot be removed while it is in "
|
|
"use\n", local_buf);
|
|
rc = -EBUSY;
|
|
goto out_buf;
|
|
}
|
|
|
|
list_del(&dev_info->lh);
|
|
del_gendisk(dev_info->gd);
|
|
blk_cleanup_queue(dev_info->dcssblk_queue);
|
|
dev_info->gd->queue = NULL;
|
|
put_disk(dev_info->gd);
|
|
device_unregister(&dev_info->dev);
|
|
|
|
/* unload all related segments */
|
|
list_for_each_entry(entry, &dev_info->seg_list, lh)
|
|
segment_unload(entry->segment_name);
|
|
|
|
put_device(&dev_info->dev);
|
|
up_write(&dcssblk_devices_sem);
|
|
|
|
rc = count;
|
|
out_buf:
|
|
kfree(local_buf);
|
|
return rc;
|
|
}
|
|
|
|
static int
|
|
dcssblk_open(struct block_device *bdev, fmode_t mode)
|
|
{
|
|
struct dcssblk_dev_info *dev_info;
|
|
int rc;
|
|
|
|
dev_info = bdev->bd_disk->private_data;
|
|
if (NULL == dev_info) {
|
|
rc = -ENODEV;
|
|
goto out;
|
|
}
|
|
atomic_inc(&dev_info->use_count);
|
|
bdev->bd_block_size = 4096;
|
|
rc = 0;
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static void
|
|
dcssblk_release(struct gendisk *disk, fmode_t mode)
|
|
{
|
|
struct dcssblk_dev_info *dev_info = disk->private_data;
|
|
struct segment_info *entry;
|
|
|
|
if (!dev_info) {
|
|
WARN_ON(1);
|
|
return;
|
|
}
|
|
down_write(&dcssblk_devices_sem);
|
|
if (atomic_dec_and_test(&dev_info->use_count)
|
|
&& (dev_info->save_pending)) {
|
|
pr_info("Device %s has become idle and is being saved "
|
|
"now\n", dev_info->segment_name);
|
|
list_for_each_entry(entry, &dev_info->seg_list, lh) {
|
|
segment_save(entry->segment_name);
|
|
}
|
|
dev_info->save_pending = 0;
|
|
}
|
|
up_write(&dcssblk_devices_sem);
|
|
}
|
|
|
|
static void
|
|
dcssblk_make_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
struct dcssblk_dev_info *dev_info;
|
|
struct bio_vec *bvec;
|
|
unsigned long index;
|
|
unsigned long page_addr;
|
|
unsigned long source_addr;
|
|
unsigned long bytes_done;
|
|
int i;
|
|
|
|
bytes_done = 0;
|
|
dev_info = bio->bi_bdev->bd_disk->private_data;
|
|
if (dev_info == NULL)
|
|
goto fail;
|
|
if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
|
|
/* Request is not page-aligned. */
|
|
goto fail;
|
|
if (bio_end_sector(bio) > get_capacity(bio->bi_bdev->bd_disk)) {
|
|
/* Request beyond end of DCSS segment. */
|
|
goto fail;
|
|
}
|
|
/* verify data transfer direction */
|
|
if (dev_info->is_shared) {
|
|
switch (dev_info->segment_type) {
|
|
case SEG_TYPE_SR:
|
|
case SEG_TYPE_ER:
|
|
case SEG_TYPE_SC:
|
|
/* cannot write to these segments */
|
|
if (bio_data_dir(bio) == WRITE) {
|
|
pr_warning("Writing to %s failed because it "
|
|
"is a read-only device\n",
|
|
dev_name(&dev_info->dev));
|
|
goto fail;
|
|
}
|
|
}
|
|
}
|
|
|
|
index = (bio->bi_sector >> 3);
|
|
bio_for_each_segment(bvec, bio, i) {
|
|
page_addr = (unsigned long)
|
|
page_address(bvec->bv_page) + bvec->bv_offset;
|
|
source_addr = dev_info->start + (index<<12) + bytes_done;
|
|
if (unlikely((page_addr & 4095) != 0) || (bvec->bv_len & 4095) != 0)
|
|
// More paranoia.
|
|
goto fail;
|
|
if (bio_data_dir(bio) == READ) {
|
|
memcpy((void*)page_addr, (void*)source_addr,
|
|
bvec->bv_len);
|
|
} else {
|
|
memcpy((void*)source_addr, (void*)page_addr,
|
|
bvec->bv_len);
|
|
}
|
|
bytes_done += bvec->bv_len;
|
|
}
|
|
bio_endio(bio, 0);
|
|
return;
|
|
fail:
|
|
bio_io_error(bio);
|
|
}
|
|
|
|
static int
|
|
dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
|
|
void **kaddr, unsigned long *pfn)
|
|
{
|
|
struct dcssblk_dev_info *dev_info;
|
|
unsigned long pgoff;
|
|
|
|
dev_info = bdev->bd_disk->private_data;
|
|
if (!dev_info)
|
|
return -ENODEV;
|
|
if (secnum % (PAGE_SIZE/512))
|
|
return -EINVAL;
|
|
pgoff = secnum / (PAGE_SIZE / 512);
|
|
if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start)
|
|
return -ERANGE;
|
|
*kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE);
|
|
*pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
dcssblk_check_params(void)
|
|
{
|
|
int rc, i, j, k;
|
|
char buf[DCSSBLK_PARM_LEN + 1];
|
|
struct dcssblk_dev_info *dev_info;
|
|
|
|
for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
|
|
i++) {
|
|
for (j = i; (dcssblk_segments[j] != ',') &&
|
|
(dcssblk_segments[j] != '\0') &&
|
|
(dcssblk_segments[j] != '(') &&
|
|
(j < DCSSBLK_PARM_LEN); j++)
|
|
{
|
|
buf[j-i] = dcssblk_segments[j];
|
|
}
|
|
buf[j-i] = '\0';
|
|
rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i);
|
|
if ((rc >= 0) && (dcssblk_segments[j] == '(')) {
|
|
for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++)
|
|
buf[k] = toupper(buf[k]);
|
|
buf[k] = '\0';
|
|
if (!strncmp(&dcssblk_segments[j], "(local)", 7)) {
|
|
down_read(&dcssblk_devices_sem);
|
|
dev_info = dcssblk_get_device_by_name(buf);
|
|
up_read(&dcssblk_devices_sem);
|
|
if (dev_info)
|
|
dcssblk_shared_store(&dev_info->dev,
|
|
NULL, "0\n", 2);
|
|
}
|
|
}
|
|
while ((dcssblk_segments[j] != ',') &&
|
|
(dcssblk_segments[j] != '\0'))
|
|
{
|
|
j++;
|
|
}
|
|
if (dcssblk_segments[j] == '\0')
|
|
break;
|
|
i = j;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Suspend / Resume
|
|
*/
|
|
static int dcssblk_freeze(struct device *dev)
|
|
{
|
|
struct dcssblk_dev_info *dev_info;
|
|
int rc = 0;
|
|
|
|
list_for_each_entry(dev_info, &dcssblk_devices, lh) {
|
|
switch (dev_info->segment_type) {
|
|
case SEG_TYPE_SR:
|
|
case SEG_TYPE_ER:
|
|
case SEG_TYPE_SC:
|
|
if (!dev_info->is_shared)
|
|
rc = -EINVAL;
|
|
break;
|
|
default:
|
|
rc = -EINVAL;
|
|
break;
|
|
}
|
|
if (rc)
|
|
break;
|
|
}
|
|
if (rc)
|
|
pr_err("Suspending the system failed because DCSS device %s "
|
|
"is writable\n",
|
|
dev_info->segment_name);
|
|
return rc;
|
|
}
|
|
|
|
static int dcssblk_restore(struct device *dev)
|
|
{
|
|
struct dcssblk_dev_info *dev_info;
|
|
struct segment_info *entry;
|
|
unsigned long start, end;
|
|
int rc = 0;
|
|
|
|
list_for_each_entry(dev_info, &dcssblk_devices, lh) {
|
|
list_for_each_entry(entry, &dev_info->seg_list, lh) {
|
|
segment_unload(entry->segment_name);
|
|
rc = segment_load(entry->segment_name, SEGMENT_SHARED,
|
|
&start, &end);
|
|
if (rc < 0) {
|
|
// TODO in_use check ?
|
|
segment_warning(rc, entry->segment_name);
|
|
goto out_panic;
|
|
}
|
|
if (start != entry->start || end != entry->end) {
|
|
pr_err("The address range of DCSS %s changed "
|
|
"while the system was suspended\n",
|
|
entry->segment_name);
|
|
goto out_panic;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
out_panic:
|
|
panic("fatal dcssblk resume error\n");
|
|
}
|
|
|
|
static int dcssblk_thaw(struct device *dev)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static const struct dev_pm_ops dcssblk_pm_ops = {
|
|
.freeze = dcssblk_freeze,
|
|
.thaw = dcssblk_thaw,
|
|
.restore = dcssblk_restore,
|
|
};
|
|
|
|
static struct platform_driver dcssblk_pdrv = {
|
|
.driver = {
|
|
.name = "dcssblk",
|
|
.owner = THIS_MODULE,
|
|
.pm = &dcssblk_pm_ops,
|
|
},
|
|
};
|
|
|
|
static struct platform_device *dcssblk_pdev;
|
|
|
|
|
|
/*
|
|
* The init/exit functions.
|
|
*/
|
|
static void __exit
|
|
dcssblk_exit(void)
|
|
{
|
|
platform_device_unregister(dcssblk_pdev);
|
|
platform_driver_unregister(&dcssblk_pdrv);
|
|
root_device_unregister(dcssblk_root_dev);
|
|
unregister_blkdev(dcssblk_major, DCSSBLK_NAME);
|
|
}
|
|
|
|
static int __init
|
|
dcssblk_init(void)
|
|
{
|
|
int rc;
|
|
|
|
rc = platform_driver_register(&dcssblk_pdrv);
|
|
if (rc)
|
|
return rc;
|
|
|
|
dcssblk_pdev = platform_device_register_simple("dcssblk", -1, NULL,
|
|
0);
|
|
if (IS_ERR(dcssblk_pdev)) {
|
|
rc = PTR_ERR(dcssblk_pdev);
|
|
goto out_pdrv;
|
|
}
|
|
|
|
dcssblk_root_dev = root_device_register("dcssblk");
|
|
if (IS_ERR(dcssblk_root_dev)) {
|
|
rc = PTR_ERR(dcssblk_root_dev);
|
|
goto out_pdev;
|
|
}
|
|
rc = device_create_file(dcssblk_root_dev, &dev_attr_add);
|
|
if (rc)
|
|
goto out_root;
|
|
rc = device_create_file(dcssblk_root_dev, &dev_attr_remove);
|
|
if (rc)
|
|
goto out_root;
|
|
rc = register_blkdev(0, DCSSBLK_NAME);
|
|
if (rc < 0)
|
|
goto out_root;
|
|
dcssblk_major = rc;
|
|
init_rwsem(&dcssblk_devices_sem);
|
|
|
|
dcssblk_check_params();
|
|
return 0;
|
|
|
|
out_root:
|
|
root_device_unregister(dcssblk_root_dev);
|
|
out_pdev:
|
|
platform_device_unregister(dcssblk_pdev);
|
|
out_pdrv:
|
|
platform_driver_unregister(&dcssblk_pdrv);
|
|
return rc;
|
|
}
|
|
|
|
module_init(dcssblk_init);
|
|
module_exit(dcssblk_exit);
|
|
|
|
module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444);
|
|
MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, "
|
|
"comma-separated list, names in each set separated "
|
|
"by commas are separated by colons, each set contains "
|
|
"names of contiguous segments and each name max. 8 chars.\n"
|
|
"Adding \"(local)\" to the end of each set equals echoing 0 "
|
|
"to /sys/devices/dcssblk/<device name>/shared after loading "
|
|
"the contiguous segments - \n"
|
|
"e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\"");
|
|
|
|
MODULE_LICENSE("GPL");
|