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 = strict_strtoull(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 long 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         if (!bdev)
  99                 return -ENOMEM;
 100
 101         /* Do not reset an active device! */
 102         if (bdev->bd_holders) {
 103                 ret = -EBUSY;
 104                 goto out;
 105         }
 106
 107         ret = strict_strtoul(buf, 10, &do_reset);
 108         if (ret)
 109                 goto out;
 110
 111         if (!do_reset) {
 112                 ret = -EINVAL;
 113                 goto out;
 114         }
 115
 116         /* Make sure all pending I/O is finished */
 117         fsync_bdev(bdev);
 118         bdput(bdev);
 119
 120         down_write(&zram->init_lock);
 121         if (zram->init_done)
 122                 __zram_reset_device(zram);
 123         up_write(&zram->init_lock);
 124
 125         return len;
 126
 127 out:
 128         bdput(bdev);
 129         return ret;
 130 }
 131
 132 static ssize_t num_reads_show(struct device *dev,
 133                 struct device_attribute *attr, char *buf)
 134 {
 135         struct zram *zram = dev_to_zram(dev);
 136
 137         return sprintf(buf, "%llu\n",
 138                 zram_stat64_read(zram, &zram->stats.num_reads));
 139 }
 140
 141 static ssize_t num_writes_show(struct device *dev,
 142                 struct device_attribute *attr, char *buf)
 143 {
 144         struct zram *zram = dev_to_zram(dev);
 145
 146         return sprintf(buf, "%llu\n",
 147                 zram_stat64_read(zram, &zram->stats.num_writes));
 148 }
 149
 150 static ssize_t invalid_io_show(struct device *dev,
 151                 struct device_attribute *attr, char *buf)
 152 {
 153         struct zram *zram = dev_to_zram(dev);
 154
 155         return sprintf(buf, "%llu\n",
 156                 zram_stat64_read(zram, &zram->stats.invalid_io));
 157 }
 158
 159 static ssize_t notify_free_show(struct device *dev,
 160                 struct device_attribute *attr, char *buf)
 161 {
 162         struct zram *zram = dev_to_zram(dev);
 163
 164         return sprintf(buf, "%llu\n",
 165                 zram_stat64_read(zram, &zram->stats.notify_free));
 166 }
 167
 168 static ssize_t zero_pages_show(struct device *dev,
 169                 struct device_attribute *attr, char *buf)
 170 {
 171         struct zram *zram = dev_to_zram(dev);
 172
 173         return sprintf(buf, "%u\n", zram->stats.pages_zero);
 174 }
 175
 176 static ssize_t orig_data_size_show(struct device *dev,
 177                 struct device_attribute *attr, char *buf)
 178 {
 179         struct zram *zram = dev_to_zram(dev);
 180
 181         return sprintf(buf, "%llu\n",
 182                 (u64)(zram->stats.pages_stored) << PAGE_SHIFT);
 183 }
 184
 185 static ssize_t compr_data_size_show(struct device *dev,
 186                 struct device_attribute *attr, char *buf)
 187 {
 188         struct zram *zram = dev_to_zram(dev);
 189
 190         return sprintf(buf, "%llu\n",
 191                 zram_stat64_read(zram, &zram->stats.compr_size));
 192 }
 193
 194 static ssize_t mem_used_total_show(struct device *dev,
 195                 struct device_attribute *attr, char *buf)
 196 {
 197         u64 val = 0;
 198         struct zram *zram = dev_to_zram(dev);
 199
 200         down_read(&zram->init_lock);
 201         if (zram->init_done) {
 202                 val = xv_get_total_size_bytes(zram->mem_pool) +
 203                         ((u64)(zram->stats.pages_expand) << PAGE_SHIFT);
 204         }
 205         up_read(&zram->init_lock);
 206
 207         return sprintf(buf, "%llu\n", val);
 208 }
 209
 210 static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
 211                 disksize_show, disksize_store);
 212 static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
 213 static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
 214 static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
 215 static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
 216 static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
 217 static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
 218 static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
 219 static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
 220 static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
 221 static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
 222
 223 static struct attribute *zram_disk_attrs[] = {
 224         &dev_attr_disksize.attr,
 225         &dev_attr_initstate.attr,
 226         &dev_attr_reset.attr,
 227         &dev_attr_num_reads.attr,
 228         &dev_attr_num_writes.attr,
 229         &dev_attr_invalid_io.attr,
 230         &dev_attr_notify_free.attr,
 231         &dev_attr_zero_pages.attr,
 232         &dev_attr_orig_data_size.attr,
 233         &dev_attr_compr_data_size.attr,
 234         &dev_attr_mem_used_total.attr,
 235         NULL,
 236 };
 237
 238 struct attribute_group zram_disk_attr_group = {
 239         .attrs = zram_disk_attrs,
 240 };