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
  18 #include "zram_drv.h"
  19
  20 #ifdef CONFIG_SYSFS
  21
  22 static u64 zram_stat64_read(struct zram *zram, u64 *v)
  23 {
  24         u64 val;
  25
  26         spin_lock(&zram->stat64_lock);
  27         val = *v;
  28         spin_unlock(&zram->stat64_lock);
  29
  30         return val;
  31 }
  32
  33 static struct zram *dev_to_zram(struct device *dev)
  34 {
  35         int i;
  36         struct zram *zram = NULL;
  37
  38         for (i = 0; i < num_devices; i++) {
  39                 zram = &devices[i];
  40                 if (disk_to_dev(zram->disk) == dev)
  41                         break;
  42         }
  43
  44         return zram;
  45 }
  46
  47 static ssize_t disksize_show(struct device *dev,
  48                 struct device_attribute *attr, char *buf)
  49 {
  50         struct zram *zram = dev_to_zram(dev);
  51
  52         return sprintf(buf, "%llu\n", zram->disksize);
  53 }
  54
  55 static ssize_t disksize_store(struct device *dev,
  56                 struct device_attribute *attr, const char *buf, size_t len)
  57 {
  58         int ret;
  59         struct zram *zram = dev_to_zram(dev);
  60
  61         if (zram->init_done) {
  62                 pr_info("Cannot change disksize for initialized device\n");
  63                 return -EBUSY;
  64         }
  65
  66         ret = strict_strtoull(buf, 10, &zram->disksize);
  67         if (ret)
  68                 return ret;
  69
  70         zram->disksize &= PAGE_MASK;
  71         set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
  72
  73         return len;
  74 }
  75
  76 static ssize_t initstate_show(struct device *dev,
  77                 struct device_attribute *attr, char *buf)
  78 {
  79         struct zram *zram = dev_to_zram(dev);
  80
  81         return sprintf(buf, "%u\n", zram->init_done);
  82 }
  83
  84 static ssize_t reset_store(struct device *dev,
  85                 struct device_attribute *attr, const char *buf, size_t len)
  86 {
  87         int ret;
  88         unsigned long do_reset;
  89         struct zram *zram;
  90         struct block_device *bdev;
  91
  92         zram = dev_to_zram(dev);
  93         bdev = bdget_disk(zram->disk, 0);
  94
  95         /* Do not reset an active device! */
  96         if (bdev->bd_holders)
  97                 return -EBUSY;
  98
  99         ret = strict_strtoul(buf, 10, &do_reset);
 100         if (ret)
 101                 return ret;
 102
 103         if (!do_reset)
 104                 return -EINVAL;
 105
 106         /* Make sure all pending I/O is finished */
 107         if (bdev)
 108                 fsync_bdev(bdev);
 109
 110         if (zram->init_done)
 111                 zram_reset_device(zram);
 112
 113         return len;
 114 }
 115
 116 static ssize_t num_reads_show(struct device *dev,
 117                 struct device_attribute *attr, char *buf)
 118 {
 119         struct zram *zram = dev_to_zram(dev);
 120
 121         return sprintf(buf, "%llu\n",
 122                 zram_stat64_read(zram, &zram->stats.num_reads));
 123 }
 124
 125 static ssize_t num_writes_show(struct device *dev,
 126                 struct device_attribute *attr, char *buf)
 127 {
 128         struct zram *zram = dev_to_zram(dev);
 129
 130         return sprintf(buf, "%llu\n",
 131                 zram_stat64_read(zram, &zram->stats.num_writes));
 132 }
 133
 134 static ssize_t invalid_io_show(struct device *dev,
 135                 struct device_attribute *attr, char *buf)
 136 {
 137         struct zram *zram = dev_to_zram(dev);
 138
 139         return sprintf(buf, "%llu\n",
 140                 zram_stat64_read(zram, &zram->stats.invalid_io));
 141 }
 142
 143 static ssize_t notify_free_show(struct device *dev,
 144                 struct device_attribute *attr, char *buf)
 145 {
 146         struct zram *zram = dev_to_zram(dev);
 147
 148         return sprintf(buf, "%llu\n",
 149                 zram_stat64_read(zram, &zram->stats.notify_free));
 150 }
 151
 152 static ssize_t zero_pages_show(struct device *dev,
 153                 struct device_attribute *attr, char *buf)
 154 {
 155         struct zram *zram = dev_to_zram(dev);
 156
 157         return sprintf(buf, "%u\n", zram->stats.pages_zero);
 158 }
 159
 160 static ssize_t orig_data_size_show(struct device *dev,
 161                 struct device_attribute *attr, char *buf)
 162 {
 163         struct zram *zram = dev_to_zram(dev);
 164
 165         return sprintf(buf, "%llu\n",
 166                 (u64)(zram->stats.pages_stored) << PAGE_SHIFT);
 167 }
 168
 169 static ssize_t compr_data_size_show(struct device *dev,
 170                 struct device_attribute *attr, char *buf)
 171 {
 172         struct zram *zram = dev_to_zram(dev);
 173
 174         return sprintf(buf, "%llu\n",
 175                 zram_stat64_read(zram, &zram->stats.compr_size));
 176 }
 177
 178 static ssize_t mem_used_total_show(struct device *dev,
 179                 struct device_attribute *attr, char *buf)
 180 {
 181         u64 val = 0;
 182         struct zram *zram = dev_to_zram(dev);
 183
 184         if (zram->init_done) {
 185                 val = xv_get_total_size_bytes(zram->mem_pool) +
 186                         ((u64)(zram->stats.pages_expand) << PAGE_SHIFT);
 187         }
 188
 189         return sprintf(buf, "%llu\n", val);
 190 }
 191
 192 static DEVICE_ATTR(disksize, S_IRUGO | S_IWUGO,
 193                 disksize_show, disksize_store);
 194 static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
 195 static DEVICE_ATTR(reset, S_IWUGO, NULL, reset_store);
 196 static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
 197 static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
 198 static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
 199 static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
 200 static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
 201 static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
 202 static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
 203 static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
 204
 205 static struct attribute *zram_disk_attrs[] = {
 206         &dev_attr_disksize.attr,
 207         &dev_attr_initstate.attr,
 208         &dev_attr_reset.attr,
 209         &dev_attr_num_reads.attr,
 210         &dev_attr_num_writes.attr,
 211         &dev_attr_invalid_io.attr,
 212         &dev_attr_notify_free.attr,
 213         &dev_attr_zero_pages.attr,
 214         &dev_attr_orig_data_size.attr,
 215         &dev_attr_compr_data_size.attr,
 216         &dev_attr_mem_used_total.attr,
 217         NULL,
 218 };
 219
 220 struct attribute_group zram_disk_attr_group = {
 221         .attrs = zram_disk_attrs,
 222 };
 223
 224 #endif  /* CONFIG_SYSFS */