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 #include <linux/kernel.h>
  19
  20 #include "zram_drv.h"
  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 < zram_get_num_devices(); i++) {
  39                 zram = &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         u64 disksize;
  59         struct zram_meta *meta;
  60         struct zram *zram = dev_to_zram(dev);
  61
  62         disksize = memparse(buf, NULL);
  63         if (!disksize)
  64                 return -EINVAL;
  65
  66         disksize = PAGE_ALIGN(disksize);
  67         meta = zram_meta_alloc(disksize);
  68         down_write(&zram->init_lock);
  69         if (zram->init_done) {
  70                 up_write(&zram->init_lock);
  71                 zram_meta_free(meta);
  72                 pr_info("Cannot change disksize for initialized device\n");
  73                 return -EBUSY;
  74         }
  75
  76         zram->disksize = disksize;
  77         set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
  78         zram_init_device(zram, meta);
  79         up_write(&zram->init_lock);
  80
  81         return len;
  82 }
  83
  84 static ssize_t initstate_show(struct device *dev,
  85                 struct device_attribute *attr, char *buf)
  86 {
  87         struct zram *zram = dev_to_zram(dev);
  88
  89         return sprintf(buf, "%u\n", zram->init_done);
  90 }
  91
  92 static ssize_t reset_store(struct device *dev,
  93                 struct device_attribute *attr, const char *buf, size_t len)
  94 {
  95         int ret;
  96         unsigned short do_reset;
  97         struct zram *zram;
  98         struct block_device *bdev;
  99
 100         zram = dev_to_zram(dev);
 101         bdev = bdget_disk(zram->disk, 0);
 102
 103         /* Do not reset an active device! */
 104         if (bdev->bd_holders)
 105                 return -EBUSY;
 106
 107         ret = kstrtou16(buf, 10, &do_reset);
 108         if (ret)
 109                 return ret;
 110
 111         if (!do_reset)
 112                 return -EINVAL;
 113
 114         /* Make sure all pending I/O is finished */
 115         if (bdev)
 116                 fsync_bdev(bdev);
 117
 118         zram_reset_device(zram);
 119         return len;
 120 }
 121
 122 static ssize_t num_reads_show(struct device *dev,
 123                 struct device_attribute *attr, char *buf)
 124 {
 125         struct zram *zram = dev_to_zram(dev);
 126
 127         return sprintf(buf, "%llu\n",
 128                 zram_stat64_read(zram, &zram->stats.num_reads));
 129 }
 130
 131 static ssize_t num_writes_show(struct device *dev,
 132                 struct device_attribute *attr, char *buf)
 133 {
 134         struct zram *zram = dev_to_zram(dev);
 135
 136         return sprintf(buf, "%llu\n",
 137                 zram_stat64_read(zram, &zram->stats.num_writes));
 138 }
 139
 140 static ssize_t invalid_io_show(struct device *dev,
 141                 struct device_attribute *attr, char *buf)
 142 {
 143         struct zram *zram = dev_to_zram(dev);
 144
 145         return sprintf(buf, "%llu\n",
 146                 zram_stat64_read(zram, &zram->stats.invalid_io));
 147 }
 148
 149 static ssize_t notify_free_show(struct device *dev,
 150                 struct device_attribute *attr, char *buf)
 151 {
 152         struct zram *zram = dev_to_zram(dev);
 153
 154         return sprintf(buf, "%llu\n",
 155                 zram_stat64_read(zram, &zram->stats.notify_free));
 156 }
 157
 158 static ssize_t zero_pages_show(struct device *dev,
 159                 struct device_attribute *attr, char *buf)
 160 {
 161         struct zram *zram = dev_to_zram(dev);
 162
 163         return sprintf(buf, "%u\n", zram->stats.pages_zero);
 164 }
 165
 166 static ssize_t orig_data_size_show(struct device *dev,
 167                 struct device_attribute *attr, char *buf)
 168 {
 169         struct zram *zram = dev_to_zram(dev);
 170
 171         return sprintf(buf, "%llu\n",
 172                 (u64)(zram->stats.pages_stored) << PAGE_SHIFT);
 173 }
 174
 175 static ssize_t compr_data_size_show(struct device *dev,
 176                 struct device_attribute *attr, char *buf)
 177 {
 178         struct zram *zram = dev_to_zram(dev);
 179
 180         return sprintf(buf, "%llu\n",
 181                 zram_stat64_read(zram, &zram->stats.compr_size));
 182 }
 183
 184 static ssize_t mem_used_total_show(struct device *dev,
 185                 struct device_attribute *attr, char *buf)
 186 {
 187         u64 val = 0;
 188         struct zram *zram = dev_to_zram(dev);
 189         struct zram_meta *meta = zram->meta;
 190
 191         down_read(&zram->init_lock);
 192         if (zram->init_done)
 193                 val = zs_get_total_size_bytes(meta->mem_pool);
 194         up_read(&zram->init_lock);
 195
 196         return sprintf(buf, "%llu\n", val);
 197 }
 198
 199 static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
 200                 disksize_show, disksize_store);
 201 static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
 202 static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
 203 static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
 204 static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
 205 static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
 206 static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
 207 static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
 208 static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
 209 static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
 210 static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
 211
 212 static struct attribute *zram_disk_attrs[] = {
 213         &dev_attr_disksize.attr,
 214         &dev_attr_initstate.attr,
 215         &dev_attr_reset.attr,
 216         &dev_attr_num_reads.attr,
 217         &dev_attr_num_writes.attr,
 218         &dev_attr_invalid_io.attr,
 219         &dev_attr_notify_free.attr,
 220         &dev_attr_zero_pages.attr,
 221         &dev_attr_orig_data_size.attr,
 222         &dev_attr_compr_data_size.attr,
 223         &dev_attr_mem_used_total.attr,
 224         NULL,
 225 };
 226
 227 struct attribute_group zram_disk_attr_group = {
 228         .attrs = zram_disk_attrs,
 229 };