226 lines
5.3 KiB
C
226 lines
5.3 KiB
C
/*
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* Compressed RAM block device
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*
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* Copyright (C) 2008, 2009, 2010 Nitin Gupta
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*
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* This code is released using a dual license strategy: BSD/GPL
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* You can choose the licence that better fits your requirements.
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*
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* Released under the terms of 3-clause BSD License
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* Released under the terms of GNU General Public License Version 2.0
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*
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* Project home: http://compcache.googlecode.com/
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*/
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#include <linux/device.h>
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#include <linux/genhd.h>
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#include <linux/mm.h>
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#include "zram_drv.h"
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static u64 zram_stat64_read(struct zram *zram, u64 *v)
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{
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u64 val;
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spin_lock(&zram->stat64_lock);
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val = *v;
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spin_unlock(&zram->stat64_lock);
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return val;
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}
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static struct zram *dev_to_zram(struct device *dev)
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{
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int i;
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struct zram *zram = NULL;
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for (i = 0; i < zram_get_num_devices(); i++) {
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zram = &zram_devices[i];
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if (disk_to_dev(zram->disk) == dev)
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break;
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}
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return zram;
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}
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static ssize_t disksize_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%llu\n", zram->disksize);
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}
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static ssize_t disksize_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t len)
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{
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int ret;
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u64 disksize;
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struct zram *zram = dev_to_zram(dev);
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ret = kstrtoull(buf, 10, &disksize);
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if (ret)
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return ret;
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down_write(&zram->init_lock);
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if (zram->init_done) {
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up_write(&zram->init_lock);
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pr_info("Cannot change disksize for initialized device\n");
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return -EBUSY;
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}
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zram->disksize = PAGE_ALIGN(disksize);
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set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
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up_write(&zram->init_lock);
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return len;
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}
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static ssize_t initstate_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%u\n", zram->init_done);
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}
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static ssize_t reset_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t len)
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{
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int ret;
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unsigned short do_reset;
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struct zram *zram;
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struct block_device *bdev;
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zram = dev_to_zram(dev);
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bdev = bdget_disk(zram->disk, 0);
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/* Do not reset an active device! */
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if (bdev->bd_holders)
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return -EBUSY;
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ret = kstrtou16(buf, 10, &do_reset);
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if (ret)
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return ret;
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if (!do_reset)
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return -EINVAL;
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/* Make sure all pending I/O is finished */
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if (bdev)
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fsync_bdev(bdev);
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down_write(&zram->init_lock);
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if (zram->init_done)
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__zram_reset_device(zram);
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up_write(&zram->init_lock);
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return len;
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}
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static ssize_t num_reads_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%llu\n",
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zram_stat64_read(zram, &zram->stats.num_reads));
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}
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static ssize_t num_writes_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%llu\n",
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zram_stat64_read(zram, &zram->stats.num_writes));
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}
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static ssize_t invalid_io_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%llu\n",
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zram_stat64_read(zram, &zram->stats.invalid_io));
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}
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static ssize_t notify_free_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%llu\n",
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zram_stat64_read(zram, &zram->stats.notify_free));
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}
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static ssize_t zero_pages_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%u\n", zram->stats.pages_zero);
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}
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static ssize_t orig_data_size_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%llu\n",
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(u64)(zram->stats.pages_stored) << PAGE_SHIFT);
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}
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static ssize_t compr_data_size_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct zram *zram = dev_to_zram(dev);
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return sprintf(buf, "%llu\n",
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zram_stat64_read(zram, &zram->stats.compr_size));
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}
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static ssize_t mem_used_total_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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u64 val = 0;
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struct zram *zram = dev_to_zram(dev);
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if (zram->init_done)
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val = zs_get_total_size_bytes(zram->mem_pool);
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return sprintf(buf, "%llu\n", val);
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}
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static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
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disksize_show, disksize_store);
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static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
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static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
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static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
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static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
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static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
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static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
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static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
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static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
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static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
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static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
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static struct attribute *zram_disk_attrs[] = {
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&dev_attr_disksize.attr,
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&dev_attr_initstate.attr,
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&dev_attr_reset.attr,
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&dev_attr_num_reads.attr,
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&dev_attr_num_writes.attr,
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&dev_attr_invalid_io.attr,
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&dev_attr_notify_free.attr,
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&dev_attr_zero_pages.attr,
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&dev_attr_orig_data_size.attr,
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&dev_attr_compr_data_size.attr,
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&dev_attr_mem_used_total.attr,
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NULL,
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};
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struct attribute_group zram_disk_attr_group = {
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.attrs = zram_disk_attrs,
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};
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