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 < num_devices; i++) {
  38                 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         struct zram *zram = dev_to_zram(dev);
  59
  60         if (zram->init_done) {
  61                 pr_info("Cannot change disksize for initialized device\n");
  62                 return -EBUSY;
  63         }
  64
  65         ret = strict_strtoull(buf, 10, &zram->disksize);
  66         if (ret)
  67                 return ret;
  68
  69         zram->disksize = PAGE_ALIGN(zram->disksize);
  70         set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
  71
  72         return len;
  73 }
  74
  75 static ssize_t initstate_show(struct device *dev,
  76                 struct device_attribute *attr, char *buf)
  77 {
  78         struct zram *zram = dev_to_zram(dev);
  79
  80         return sprintf(buf, "%u\n", zram->init_done);
  81 }
  82
  83 static ssize_t reset_store(struct device *dev,
  84                 struct device_attribute *attr, const char *buf, size_t len)
  85 {
  86         int ret;
  87         unsigned long do_reset;
  88         struct zram *zram;
  89         struct block_device *bdev;
  90
  91         zram = dev_to_zram(dev);
  92         bdev = bdget_disk(zram->disk, 0);
  93
  94         /* Do not reset an active device! */
  95         if (bdev->bd_holders)
  96                 return -EBUSY;
  97
  98         ret = strict_strtoul(buf, 10, &do_reset);
  99         if (ret)
 100                 return ret;
 101
 102         if (!do_reset)
 103                 return -EINVAL;
 104
 105         /* Make sure all pending I/O is finished */
 106         if (bdev)
 107                 fsync_bdev(bdev);
 108
 109         if (zram->init_done)
 110                 zram_reset_device(zram);
 111
 112         return len;
 113 }
 114
 115 static ssize_t num_reads_show(struct device *dev,
 116                 struct device_attribute *attr, char *buf)
 117 {
 118         struct zram *zram = dev_to_zram(dev);
 119
 120         return sprintf(buf, "%llu\n",
 121                 zram_stat64_read(zram, &zram->stats.num_reads));
 122 }
 123
 124 static ssize_t num_writes_show(struct device *dev,
 125                 struct device_attribute *attr, char *buf)
 126 {
 127         struct zram *zram = dev_to_zram(dev);
 128
 129         return sprintf(buf, "%llu\n",
 130                 zram_stat64_read(zram, &zram->stats.num_writes));
 131 }
 132
 133 static ssize_t invalid_io_show(struct device *dev,
 134                 struct device_attribute *attr, char *buf)
 135 {
 136         struct zram *zram = dev_to_zram(dev);
 137
 138         return sprintf(buf, "%llu\n",
 139                 zram_stat64_read(zram, &zram->stats.invalid_io));
 140 }
 141
 142 static ssize_t notify_free_show(struct device *dev,
 143                 struct device_attribute *attr, char *buf)
 144 {
 145         struct zram *zram = dev_to_zram(dev);
 146
 147         return sprintf(buf, "%llu\n",
 148                 zram_stat64_read(zram, &zram->stats.notify_free));
 149 }
 150
 151 static ssize_t zero_pages_show(struct device *dev,
 152                 struct device_attribute *attr, char *buf)
 153 {
 154         struct zram *zram = dev_to_zram(dev);
 155
 156         return sprintf(buf, "%u\n", zram->stats.pages_zero);
 157 }
 158
 159 static ssize_t orig_data_size_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                 (u64)(zram->stats.pages_stored) << PAGE_SHIFT);
 166 }
 167
 168 static ssize_t compr_data_size_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, "%llu\n",
 174                 zram_stat64_read(zram, &zram->stats.compr_size));
 175 }
 176
 177 static ssize_t mem_used_total_show(struct device *dev,
 178                 struct device_attribute *attr, char *buf)
 179 {
 180         u64 val = 0;
 181         struct zram *zram = dev_to_zram(dev);
 182
 183         if (zram->init_done) {
 184                 val = xv_get_total_size_bytes(zram->mem_pool) +
 185                         ((u64)(zram->stats.pages_expand) << PAGE_SHIFT);
 186         }
 187
 188         return sprintf(buf, "%llu\n", val);
 189 }
 190
 191 static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
 192                 disksize_show, disksize_store);
 193 static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
 194 static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
 195 static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
 196 static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
 197 static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
 198 static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
 199 static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
 200 static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
 201 static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
 202 static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
 203
 204 static struct attribute *zram_disk_attrs[] = {
 205         &dev_attr_disksize.attr,
 206         &dev_attr_initstate.attr,
 207         &dev_attr_reset.attr,
 208         &dev_attr_num_reads.attr,
 209         &dev_attr_num_writes.attr,
 210         &dev_attr_invalid_io.attr,
 211         &dev_attr_notify_free.attr,
 212         &dev_attr_zero_pages.attr,
 213         &dev_attr_orig_data_size.attr,
 214         &dev_attr_compr_data_size.attr,
 215         &dev_attr_mem_used_total.attr,
 216         NULL,
 217 };
 218
 219 struct attribute_group zram_disk_attr_group = {
 220         .attrs = zram_disk_attrs,
 221 };