drivers/staging/zram/zram_sysfs.c

   1 /*
   2  * Compressed RAM block device
   3  *
   4  * Copyright (C) 2008, 2009, 2010  Nitin Gupta
   5  *
   6  * This code is released using a dual license strategy: BSD/GPL
   7  * You can choose the licence that better fits your requirements.
   8  *
   9  * Released under the terms of 3-clause BSD License
  10  * Released under the terms of GNU General Public License Version 2.0
  11  *
  12  * Project home: http://compcache.googlecode.com/
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/genhd.h>
  17 #include <linux/mm.h>
  18
  19 #include "zram_drv.h"
  20
  21 static u64 zram_stat64_read(struct zram *zram, u64 *v)
  22 {
  23         u64 val;
  24
  25         spin_lock(&zram->stat64_lock);
  26         val = *v;
  27         spin_unlock(&zram->stat64_lock);
  28
  29         return val;
  30 }
  31
  32 static struct zram *dev_to_zram(struct device *dev)
  33 {
  34         int i;
  35         struct zram *zram = NULL;
  36
  37         for (i = 0; i < zram_num_devices; i++) {
  38                 zram = &zram_devices[i];
  39                 if (disk_to_dev(zram->disk) == dev)
  40                         break;
  41         }
  42
  43         return zram;
  44 }
  45
  46 static ssize_t disksize_show(struct device *dev,
  47                 struct device_attribute *attr, char *buf)
  48 {
  49         struct zram *zram = dev_to_zram(dev);
  50
  51         return sprintf(buf, "%llu\n", zram->disksize);
  52 }
  53
  54 static ssize_t disksize_store(struct device *dev,
  55                 struct device_attribute *attr, const char *buf, size_t len)
  56 {
  57         int ret;
  58         u64 disksize;
  59         struct zram *zram = dev_to_zram(dev);
  60
  61         ret = kstrtoull(buf, 10, &disksize);
  62         if (ret)
  63                 return ret;
  64
  65         down_write(&zram->init_lock);
  66         if (zram->init_done) {
  67                 up_write(&zram->init_lock);
  68                 pr_info("Cannot change disksize for initialized device\n");
  69                 return -EBUSY;
  70         }
  71
  72         zram->disksize = PAGE_ALIGN(disksize);
  73         set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
  74         up_write(&zram->init_lock);
  75
  76         return len;
  77 }
  78
  79 static ssize_t initstate_show(struct device *dev,
  80                 struct device_attribute *attr, char *buf)
  81 {
  82         struct zram *zram = dev_to_zram(dev);
  83
  84         return sprintf(buf, "%u\n", zram->init_done);
  85 }
  86
  87 static ssize_t reset_store(struct device *dev,
  88                 struct device_attribute *attr, const char *buf, size_t len)
  89 {
  90         int ret;
  91         unsigned short do_reset;
  92         struct zram *zram;
  93         struct block_device *bdev;
  94
  95         zram = dev_to_zram(dev);
  96         bdev = bdget_disk(zram->disk, 0);
  97
  98         /* Do not reset an active device! */
  99         if (bdev->bd_holders)
 100                 return -EBUSY;
 101
 102         ret = kstrtou16(buf, 10, &do_reset);
 103         if (ret)
 104                 return ret;
 105
 106         if (!do_reset)
 107                 return -EINVAL;
 108
 109         /* Make sure all pending I/O is finished */
 110         if (bdev)
 111                 fsync_bdev(bdev);
 112
 113         down_write(&zram->init_lock);
 114         if (zram->init_done)
 115                 __zram_reset_device(zram);
 116         up_write(&zram->init_lock);
 117
 118         return len;
 119 }
 120
 121 static ssize_t num_reads_show(struct device *dev,
 122                 struct device_attribute *attr, char *buf)
 123 {
 124         struct zram *zram = dev_to_zram(dev);
 125
 126         return sprintf(buf, "%llu\n",
 127                 zram_stat64_read(zram, &zram->stats.num_reads));
 128 }
 129
 130 static ssize_t num_writes_show(struct device *dev,
 131                 struct device_attribute *attr, char *buf)
 132 {
 133         struct zram *zram = dev_to_zram(dev);
 134
 135         return sprintf(buf, "%llu\n",
 136                 zram_stat64_read(zram, &zram->stats.num_writes));
 137 }
 138
 139 static ssize_t invalid_io_show(struct device *dev,
 140                 struct device_attribute *attr, char *buf)
 141 {
 142         struct zram *zram = dev_to_zram(dev);
 143
 144         return sprintf(buf, "%llu\n",
 145                 zram_stat64_read(zram, &zram->stats.invalid_io));
 146 }
 147
 148 static ssize_t notify_free_show(struct device *dev,
 149                 struct device_attribute *attr, char *buf)
 150 {
 151         struct zram *zram = dev_to_zram(dev);
 152
 153         return sprintf(buf, "%llu\n",
 154                 zram_stat64_read(zram, &zram->stats.notify_free));
 155 }
 156
 157 static ssize_t zero_pages_show(struct device *dev,
 158                 struct device_attribute *attr, char *buf)
 159 {
 160         struct zram *zram = dev_to_zram(dev);
 161
 162         return sprintf(buf, "%u\n", zram->stats.pages_zero);
 163 }
 164
 165 static ssize_t orig_data_size_show(struct device *dev,
 166                 struct device_attribute *attr, char *buf)
 167 {
 168         struct zram *zram = dev_to_zram(dev);
 169
 170         return sprintf(buf, "%llu\n",
 171                 (u64)(zram->stats.pages_stored) << PAGE_SHIFT);
 172 }
 173
 174 static ssize_t compr_data_size_show(struct device *dev,
 175                 struct device_attribute *attr, char *buf)
 176 {
 177         struct zram *zram = dev_to_zram(dev);
 178
 179         return sprintf(buf, "%llu\n",
 180                 zram_stat64_read(zram, &zram->stats.compr_size));
 181 }
 182
 183 static ssize_t mem_used_total_show(struct device *dev,
 184                 struct device_attribute *attr, char *buf)
 185 {
 186         u64 val = 0;
 187         struct zram *zram = dev_to_zram(dev);
 188
 189         if (zram->init_done) {
 190                 val = xv_get_total_size_bytes(zram->mem_pool) +
 191                         ((u64)(zram->stats.pages_expand) << PAGE_SHIFT);
 192         }
 193
 194         return sprintf(buf, "%llu\n", val);
 195 }
 196
 197 static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
 198                 disksize_show, disksize_store);
 199 static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
 200 static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
 201 static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
 202 static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
 203 static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
 204 static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
 205 static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
 206 static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
 207 static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
 208 static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
 209
 210 static struct attribute *zram_disk_attrs[] = {
 211         &dev_attr_disksize.attr,
 212         &dev_attr_initstate.attr,
 213         &dev_attr_reset.attr,
 214         &dev_attr_num_reads.attr,
 215         &dev_attr_num_writes.attr,
 216         &dev_attr_invalid_io.attr,
 217         &dev_attr_notify_free.attr,
 218         &dev_attr_zero_pages.attr,
 219         &dev_attr_orig_data_size.attr,
 220         &dev_attr_compr_data_size.attr,
 221         &dev_attr_mem_used_total.attr,
 222         NULL,
 223 };
 224
 225 struct attribute_group zram_disk_attr_group = {
 226         .attrs = zram_disk_attrs,
 227 };