From 33863c21e69e9bd988b63580ada0b729c1d90215 Mon Sep 17 00:00:00 2001 From: Nitin Gupta Date: Mon, 9 Aug 2010 22:56:47 +0530 Subject: Staging: zram: Replace ioctls with sysfs interface Creates per-device sysfs nodes in /sys/block/zram/ Currently following stats are exported: - disksize - num_reads - num_writes - invalid_io - zero_pages - orig_data_size - compr_data_size - mem_used_total By default, disksize is set to 0. So, to start using a zram device, fist write a disksize value and then initialize device by writing any positive value to initstate. For example: # initialize /dev/zram0 with 50MB disksize echo 50*1024*1024 | bc > /sys/block/zram0/disksize echo 1 > /sys/block/zram0/initstate When done using a disk, issue reset to free its memory by writing any positive value to reset node: echo 1 > /sys/block/zram0/reset This change also obviates the need for 'rzscontrol' utility. Signed-off-by: Nitin Gupta Acked-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman --- drivers/staging/zram/zram_sysfs.c | 242 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 242 insertions(+) create mode 100644 drivers/staging/zram/zram_sysfs.c (limited to 'drivers/staging/zram/zram_sysfs.c') diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c new file mode 100644 index 0000000..b8dbaee --- /dev/null +++ b/drivers/staging/zram/zram_sysfs.c @@ -0,0 +1,242 @@ +/* + * Compressed RAM block device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com/ + */ + +#include +#include + +#include "zram_drv.h" + +#ifdef CONFIG_SYSFS + +static u64 zram_stat64_read(struct zram *zram, u64 *v) +{ + u64 val; + + spin_lock(&zram->stat64_lock); + val = *v; + spin_unlock(&zram->stat64_lock); + + return val; +} + +static struct zram *dev_to_zram(struct device *dev) +{ + int i; + struct zram *zram = NULL; + + for (i = 0; i < num_devices; i++) { + zram = &devices[i]; + if (disk_to_dev(zram->disk) == dev) + break; + } + + return zram; +} + +static ssize_t disksize_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", zram->disksize); +} + +static ssize_t disksize_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + struct zram *zram = dev_to_zram(dev); + + if (zram->init_done) + return -EBUSY; + + ret = strict_strtoull(buf, 10, &zram->disksize); + if (ret) + return ret; + + zram->disksize &= PAGE_MASK; + set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); + + return len; +} + +static ssize_t initstate_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->init_done); +} + +static ssize_t initstate_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + unsigned long do_init; + struct zram *zram = dev_to_zram(dev); + + ret = strict_strtoul(buf, 10, &do_init); + if (ret) + return ret; + + if (!do_init) + return -EINVAL; + + zram_init_device(zram); + + return len; +} + +static ssize_t reset_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + unsigned long do_reset; + struct zram *zram; + struct block_device *bdev; + + zram = dev_to_zram(dev); + bdev = bdget_disk(zram->disk, 0); + + /* Do not reset an active device! */ + if (bdev->bd_holders) + return -EBUSY; + + ret = strict_strtoul(buf, 10, &do_reset); + if (ret) + return ret; + + if (!do_reset) + return -EINVAL; + + /* Make sure all pending I/O is finished */ + if (bdev) + fsync_bdev(bdev); + + if (zram->init_done) + zram_reset_device(zram); + + return len; +} + +static ssize_t num_reads_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.num_reads)); +} + +static ssize_t num_writes_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.num_writes)); +} + +static ssize_t invalid_io_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.invalid_io)); +} + +static ssize_t notify_free_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.notify_free)); +} + +static ssize_t zero_pages_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->stats.pages_zero); +} + +static ssize_t orig_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)(zram->stats.pages_stored) << PAGE_SHIFT); +} + +static ssize_t compr_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + zram_stat64_read(zram, &zram->stats.compr_size)); +} + +static ssize_t mem_used_total_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + u64 val = 0; + struct zram *zram = dev_to_zram(dev); + + if (zram->init_done) { + val = xv_get_total_size_bytes(zram->mem_pool) + + ((u64)(zram->stats.pages_expand) << PAGE_SHIFT); + } + + return sprintf(buf, "%llu\n", val); +} + +static DEVICE_ATTR(disksize, S_IRUGO | S_IWUGO, + disksize_show, disksize_store); +static DEVICE_ATTR(initstate, S_IRUGO | S_IWUGO, + initstate_show, initstate_store); +static DEVICE_ATTR(reset, S_IWUGO, NULL, reset_store); +static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); +static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); +static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); +static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); +static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); +static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); +static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); +static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); + +static struct attribute *zram_disk_attrs[] = { + &dev_attr_disksize.attr, + &dev_attr_initstate.attr, + &dev_attr_reset.attr, + &dev_attr_num_reads.attr, + &dev_attr_num_writes.attr, + &dev_attr_invalid_io.attr, + &dev_attr_notify_free.attr, + &dev_attr_zero_pages.attr, + &dev_attr_orig_data_size.attr, + &dev_attr_compr_data_size.attr, + &dev_attr_mem_used_total.attr, + NULL, +}; + +struct attribute_group zram_disk_attr_group = { + .attrs = zram_disk_attrs, +}; + +#endif /* CONFIG_SYSFS */ -- cgit v1.1