2 * Compressed RAM block device
4 * Copyright (C) 2008, 2009, 2010 Nitin Gupta
6 * This code is released using a dual license strategy: BSD/GPL
7 * You can choose the licence that better fits your requirements.
9 * Released under the terms of 3-clause BSD License
10 * Released under the terms of GNU General Public License Version 2.0
12 * Project home: http://compcache.googlecode.com/
15 #include <linux/device.h>
16 #include <linux/genhd.h>
21 static u64 zram_stat64_read(struct zram *zram, u64 *v)
25 spin_lock(&zram->stat64_lock);
27 spin_unlock(&zram->stat64_lock);
32 static struct zram *dev_to_zram(struct device *dev)
35 struct zram *zram = NULL;
37 for (i = 0; i < zram_num_devices; i++) {
38 zram = &zram_devices[i];
39 if (disk_to_dev(zram->disk) == dev)
46 static ssize_t disksize_show(struct device *dev,
47 struct device_attribute *attr, char *buf)
49 struct zram *zram = dev_to_zram(dev);
51 return sprintf(buf, "%llu\n", zram->disksize);
54 static ssize_t disksize_store(struct device *dev,
55 struct device_attribute *attr, const char *buf, size_t len)
59 struct zram *zram = dev_to_zram(dev);
61 ret = strict_strtoull(buf, 10, &disksize);
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");
72 zram->disksize = PAGE_ALIGN(disksize);
73 set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
74 up_write(&zram->init_lock);
79 static ssize_t initstate_show(struct device *dev,
80 struct device_attribute *attr, char *buf)
82 struct zram *zram = dev_to_zram(dev);
84 return sprintf(buf, "%u\n", zram->init_done);
87 static ssize_t reset_store(struct device *dev,
88 struct device_attribute *attr, const char *buf, size_t len)
91 unsigned long do_reset;
93 struct block_device *bdev;
95 zram = dev_to_zram(dev);
96 bdev = bdget_disk(zram->disk, 0);
101 /* Do not reset an active device! */
102 if (bdev->bd_holders)
105 ret = strict_strtoul(buf, 10, &do_reset);
112 /* Make sure all pending I/O is finished */
115 down_write(&zram->init_lock);
117 __zram_reset_device(zram);
118 up_write(&zram->init_lock);
123 static ssize_t num_reads_show(struct device *dev,
124 struct device_attribute *attr, char *buf)
126 struct zram *zram = dev_to_zram(dev);
128 return sprintf(buf, "%llu\n",
129 zram_stat64_read(zram, &zram->stats.num_reads));
132 static ssize_t num_writes_show(struct device *dev,
133 struct device_attribute *attr, char *buf)
135 struct zram *zram = dev_to_zram(dev);
137 return sprintf(buf, "%llu\n",
138 zram_stat64_read(zram, &zram->stats.num_writes));
141 static ssize_t invalid_io_show(struct device *dev,
142 struct device_attribute *attr, char *buf)
144 struct zram *zram = dev_to_zram(dev);
146 return sprintf(buf, "%llu\n",
147 zram_stat64_read(zram, &zram->stats.invalid_io));
150 static ssize_t notify_free_show(struct device *dev,
151 struct device_attribute *attr, char *buf)
153 struct zram *zram = dev_to_zram(dev);
155 return sprintf(buf, "%llu\n",
156 zram_stat64_read(zram, &zram->stats.notify_free));
159 static ssize_t zero_pages_show(struct device *dev,
160 struct device_attribute *attr, char *buf)
162 struct zram *zram = dev_to_zram(dev);
164 return sprintf(buf, "%u\n", zram->stats.pages_zero);
167 static ssize_t orig_data_size_show(struct device *dev,
168 struct device_attribute *attr, char *buf)
170 struct zram *zram = dev_to_zram(dev);
172 return sprintf(buf, "%llu\n",
173 (u64)(zram->stats.pages_stored) << PAGE_SHIFT);
176 static ssize_t compr_data_size_show(struct device *dev,
177 struct device_attribute *attr, char *buf)
179 struct zram *zram = dev_to_zram(dev);
181 return sprintf(buf, "%llu\n",
182 zram_stat64_read(zram, &zram->stats.compr_size));
185 static ssize_t mem_used_total_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
189 struct zram *zram = dev_to_zram(dev);
191 down_read(&zram->init_lock);
192 if (zram->init_done) {
193 val = xv_get_total_size_bytes(zram->mem_pool) +
194 ((u64)(zram->stats.pages_expand) << PAGE_SHIFT);
196 up_read(&zram->init_lock);
198 return sprintf(buf, "%llu\n", val);
201 static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
202 disksize_show, disksize_store);
203 static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
204 static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
205 static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
206 static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
207 static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
208 static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
209 static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
210 static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
211 static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
212 static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
214 static struct attribute *zram_disk_attrs[] = {
215 &dev_attr_disksize.attr,
216 &dev_attr_initstate.attr,
217 &dev_attr_reset.attr,
218 &dev_attr_num_reads.attr,
219 &dev_attr_num_writes.attr,
220 &dev_attr_invalid_io.attr,
221 &dev_attr_notify_free.attr,
222 &dev_attr_zero_pages.attr,
223 &dev_attr_orig_data_size.attr,
224 &dev_attr_compr_data_size.attr,
225 &dev_attr_mem_used_total.attr,
229 struct attribute_group zram_disk_attr_group = {
230 .attrs = zram_disk_attrs,