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 21static 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 32static struct zram *dev_to_zram(struct device *dev) 33{ 34 int i; 35 struct zram *zram = NULL; 36 37 for (i = 0; i < zram_get_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 46static 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 54static 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 79static 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 87static 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 121static 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 130static 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 139static 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 148static 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 157static 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 165static 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 174static 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 183static 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 = zs_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 197static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR, 198 disksize_show, disksize_store); 199static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); 200static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); 201static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); 202static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); 203static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); 204static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); 205static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); 206static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); 207static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); 208static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); 209 210static 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 225struct attribute_group zram_disk_attr_group = { 226 .attrs = zram_disk_attrs, 227}; 228