Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 1 | /* |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 2 | * Compressed RAM block device |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 3 | * |
Nitin Gupta | 1130ebb | 2010-01-28 21:21:35 +0530 | [diff] [blame] | 4 | * Copyright (C) 2008, 2009, 2010 Nitin Gupta |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 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 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 15 | #define KMSG_COMPONENT "zram" |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 16 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| 17 | |
Robert Jennings | b1f5b81 | 2011-01-28 08:59:26 -0600 | [diff] [blame^] | 18 | #ifdef CONFIG_ZRAM_DEBUG |
| 19 | #define DEBUG |
| 20 | #endif |
| 21 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 22 | #include <linux/module.h> |
| 23 | #include <linux/kernel.h> |
Randy Dunlap | 8946a08 | 2010-06-23 20:27:09 -0700 | [diff] [blame] | 24 | #include <linux/bio.h> |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 25 | #include <linux/bitops.h> |
| 26 | #include <linux/blkdev.h> |
| 27 | #include <linux/buffer_head.h> |
| 28 | #include <linux/device.h> |
| 29 | #include <linux/genhd.h> |
| 30 | #include <linux/highmem.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 31 | #include <linux/slab.h> |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 32 | #include <linux/lzo.h> |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 33 | #include <linux/string.h> |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 34 | #include <linux/vmalloc.h> |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 35 | |
Nitin Gupta | 16a4bfb | 2010-06-01 13:31:24 +0530 | [diff] [blame] | 36 | #include "zram_drv.h" |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 37 | |
| 38 | /* Globals */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 39 | static int zram_major; |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 40 | struct zram *devices; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 41 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 42 | /* Module params (documentation at end) */ |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 43 | unsigned int num_devices; |
| 44 | |
| 45 | static void zram_stat_inc(u32 *v) |
| 46 | { |
| 47 | *v = *v + 1; |
| 48 | } |
| 49 | |
| 50 | static void zram_stat_dec(u32 *v) |
| 51 | { |
| 52 | *v = *v - 1; |
| 53 | } |
| 54 | |
| 55 | static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc) |
| 56 | { |
| 57 | spin_lock(&zram->stat64_lock); |
| 58 | *v = *v + inc; |
| 59 | spin_unlock(&zram->stat64_lock); |
| 60 | } |
| 61 | |
| 62 | static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec) |
| 63 | { |
| 64 | spin_lock(&zram->stat64_lock); |
| 65 | *v = *v - dec; |
| 66 | spin_unlock(&zram->stat64_lock); |
| 67 | } |
| 68 | |
| 69 | static void zram_stat64_inc(struct zram *zram, u64 *v) |
| 70 | { |
| 71 | zram_stat64_add(zram, v, 1); |
| 72 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 73 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 74 | static int zram_test_flag(struct zram *zram, u32 index, |
| 75 | enum zram_pageflags flag) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 76 | { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 77 | return zram->table[index].flags & BIT(flag); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 78 | } |
| 79 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 80 | static void zram_set_flag(struct zram *zram, u32 index, |
| 81 | enum zram_pageflags flag) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 82 | { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 83 | zram->table[index].flags |= BIT(flag); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 84 | } |
| 85 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 86 | static void zram_clear_flag(struct zram *zram, u32 index, |
| 87 | enum zram_pageflags flag) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 88 | { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 89 | zram->table[index].flags &= ~BIT(flag); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 90 | } |
| 91 | |
| 92 | static int page_zero_filled(void *ptr) |
| 93 | { |
| 94 | unsigned int pos; |
| 95 | unsigned long *page; |
| 96 | |
| 97 | page = (unsigned long *)ptr; |
| 98 | |
| 99 | for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { |
| 100 | if (page[pos]) |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | return 1; |
| 105 | } |
| 106 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 107 | static void zram_set_disksize(struct zram *zram, size_t totalram_bytes) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 108 | { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 109 | if (!zram->disksize) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 110 | pr_info( |
| 111 | "disk size not provided. You can use disksize_kb module " |
| 112 | "param to specify size.\nUsing default: (%u%% of RAM).\n", |
| 113 | default_disksize_perc_ram |
| 114 | ); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 115 | zram->disksize = default_disksize_perc_ram * |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 116 | (totalram_bytes / 100); |
| 117 | } |
| 118 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 119 | if (zram->disksize > 2 * (totalram_bytes)) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 120 | pr_info( |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 121 | "There is little point creating a zram of greater than " |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 122 | "twice the size of memory since we expect a 2:1 compression " |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 123 | "ratio. Note that zram uses about 0.1%% of the size of " |
| 124 | "the disk when not in use so a huge zram is " |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 125 | "wasteful.\n" |
| 126 | "\tMemory Size: %zu kB\n" |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 127 | "\tSize you selected: %llu kB\n" |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 128 | "Continuing anyway ...\n", |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 129 | totalram_bytes >> 10, zram->disksize |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 130 | ); |
| 131 | } |
| 132 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 133 | zram->disksize &= PAGE_MASK; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 134 | } |
| 135 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 136 | static void zram_free_page(struct zram *zram, size_t index) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 137 | { |
| 138 | u32 clen; |
| 139 | void *obj; |
| 140 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 141 | struct page *page = zram->table[index].page; |
| 142 | u32 offset = zram->table[index].offset; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 143 | |
| 144 | if (unlikely(!page)) { |
Nitin Gupta | 2e88228 | 2010-01-28 21:13:41 +0530 | [diff] [blame] | 145 | /* |
| 146 | * No memory is allocated for zero filled pages. |
| 147 | * Simply clear zero page flag. |
| 148 | */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 149 | if (zram_test_flag(zram, index, ZRAM_ZERO)) { |
| 150 | zram_clear_flag(zram, index, ZRAM_ZERO); |
| 151 | zram_stat_dec(&zram->stats.pages_zero); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 152 | } |
| 153 | return; |
| 154 | } |
| 155 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 156 | if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 157 | clen = PAGE_SIZE; |
| 158 | __free_page(page); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 159 | zram_clear_flag(zram, index, ZRAM_UNCOMPRESSED); |
| 160 | zram_stat_dec(&zram->stats.pages_expand); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 161 | goto out; |
| 162 | } |
| 163 | |
| 164 | obj = kmap_atomic(page, KM_USER0) + offset; |
| 165 | clen = xv_get_object_size(obj) - sizeof(struct zobj_header); |
| 166 | kunmap_atomic(obj, KM_USER0); |
| 167 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 168 | xv_free(zram->mem_pool, page, offset); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 169 | if (clen <= PAGE_SIZE / 2) |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 170 | zram_stat_dec(&zram->stats.good_compress); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 171 | |
| 172 | out: |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 173 | zram_stat64_sub(zram, &zram->stats.compr_size, clen); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 174 | zram_stat_dec(&zram->stats.pages_stored); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 175 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 176 | zram->table[index].page = NULL; |
| 177 | zram->table[index].offset = 0; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 178 | } |
| 179 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 180 | static void handle_zero_page(struct page *page) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 181 | { |
| 182 | void *user_mem; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 183 | |
| 184 | user_mem = kmap_atomic(page, KM_USER0); |
| 185 | memset(user_mem, 0, PAGE_SIZE); |
| 186 | kunmap_atomic(user_mem, KM_USER0); |
| 187 | |
Nitin Gupta | 30fb8a7 | 2009-12-12 11:44:46 +0530 | [diff] [blame] | 188 | flush_dcache_page(page); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 189 | } |
| 190 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 191 | static void handle_uncompressed_page(struct zram *zram, |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 192 | struct page *page, u32 index) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 193 | { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 194 | unsigned char *user_mem, *cmem; |
| 195 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 196 | user_mem = kmap_atomic(page, KM_USER0); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 197 | cmem = kmap_atomic(zram->table[index].page, KM_USER1) + |
| 198 | zram->table[index].offset; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 199 | |
| 200 | memcpy(user_mem, cmem, PAGE_SIZE); |
| 201 | kunmap_atomic(user_mem, KM_USER0); |
| 202 | kunmap_atomic(cmem, KM_USER1); |
| 203 | |
Nitin Gupta | 30fb8a7 | 2009-12-12 11:44:46 +0530 | [diff] [blame] | 204 | flush_dcache_page(page); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 205 | } |
| 206 | |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 207 | static void zram_read(struct zram *zram, struct bio *bio) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 208 | { |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 209 | |
| 210 | int i; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 211 | u32 index; |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 212 | struct bio_vec *bvec; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 213 | |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 214 | if (unlikely(!zram->init_done)) { |
Jerome Marchand | 1aa3266 | 2010-12-17 17:03:15 +0100 | [diff] [blame] | 215 | bio_endio(bio, -ENXIO); |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 216 | return; |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 217 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 218 | |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 219 | zram_stat64_inc(zram, &zram->stats.num_reads); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 220 | index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 221 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 222 | bio_for_each_segment(bvec, bio, i) { |
| 223 | int ret; |
| 224 | size_t clen; |
| 225 | struct page *page; |
| 226 | struct zobj_header *zheader; |
| 227 | unsigned char *user_mem, *cmem; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 228 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 229 | page = bvec->bv_page; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 230 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 231 | if (zram_test_flag(zram, index, ZRAM_ZERO)) { |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 232 | handle_zero_page(page); |
| 233 | continue; |
| 234 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 235 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 236 | /* Requested page is not present in compressed area */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 237 | if (unlikely(!zram->table[index].page)) { |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 238 | pr_debug("Read before write: sector=%lu, size=%u", |
| 239 | (ulong)(bio->bi_sector), bio->bi_size); |
| 240 | /* Do nothing */ |
| 241 | continue; |
| 242 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 243 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 244 | /* Page is stored uncompressed since it's incompressible */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 245 | if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) { |
| 246 | handle_uncompressed_page(zram, page, index); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 247 | continue; |
| 248 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 249 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 250 | user_mem = kmap_atomic(page, KM_USER0); |
| 251 | clen = PAGE_SIZE; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 252 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 253 | cmem = kmap_atomic(zram->table[index].page, KM_USER1) + |
| 254 | zram->table[index].offset; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 255 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 256 | ret = lzo1x_decompress_safe( |
| 257 | cmem + sizeof(*zheader), |
| 258 | xv_get_object_size(cmem) - sizeof(*zheader), |
| 259 | user_mem, &clen); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 260 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 261 | kunmap_atomic(user_mem, KM_USER0); |
| 262 | kunmap_atomic(cmem, KM_USER1); |
| 263 | |
| 264 | /* Should NEVER happen. Return bio error if it does. */ |
| 265 | if (unlikely(ret != LZO_E_OK)) { |
| 266 | pr_err("Decompression failed! err=%d, page=%u\n", |
| 267 | ret, index); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 268 | zram_stat64_inc(zram, &zram->stats.failed_reads); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 269 | goto out; |
| 270 | } |
| 271 | |
| 272 | flush_dcache_page(page); |
| 273 | index++; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 274 | } |
| 275 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 276 | set_bit(BIO_UPTODATE, &bio->bi_flags); |
| 277 | bio_endio(bio, 0); |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 278 | return; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 279 | |
| 280 | out: |
| 281 | bio_io_error(bio); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 282 | } |
| 283 | |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 284 | static void zram_write(struct zram *zram, struct bio *bio) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 285 | { |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 286 | int i, ret; |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 287 | u32 index; |
| 288 | struct bio_vec *bvec; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 289 | |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 290 | if (unlikely(!zram->init_done)) { |
| 291 | ret = zram_init_device(zram); |
| 292 | if (ret) |
| 293 | goto out; |
| 294 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 295 | |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 296 | zram_stat64_inc(zram, &zram->stats.num_writes); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 297 | index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; |
| 298 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 299 | bio_for_each_segment(bvec, bio, i) { |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 300 | u32 offset; |
| 301 | size_t clen; |
| 302 | struct zobj_header *zheader; |
| 303 | struct page *page, *page_store; |
| 304 | unsigned char *user_mem, *cmem, *src; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 305 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 306 | page = bvec->bv_page; |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 307 | src = zram->compress_buffer; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 308 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 309 | /* |
| 310 | * System overwrites unused sectors. Free memory associated |
| 311 | * with this sector now. |
| 312 | */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 313 | if (zram->table[index].page || |
| 314 | zram_test_flag(zram, index, ZRAM_ZERO)) |
| 315 | zram_free_page(zram, index); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 316 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 317 | mutex_lock(&zram->lock); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 318 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 319 | user_mem = kmap_atomic(page, KM_USER0); |
| 320 | if (page_zero_filled(user_mem)) { |
| 321 | kunmap_atomic(user_mem, KM_USER0); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 322 | mutex_unlock(&zram->lock); |
| 323 | zram_stat_inc(&zram->stats.pages_zero); |
| 324 | zram_set_flag(zram, index, ZRAM_ZERO); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 325 | continue; |
| 326 | } |
| 327 | |
| 328 | ret = lzo1x_1_compress(user_mem, PAGE_SIZE, src, &clen, |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 329 | zram->compress_workmem); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 330 | |
| 331 | kunmap_atomic(user_mem, KM_USER0); |
| 332 | |
| 333 | if (unlikely(ret != LZO_E_OK)) { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 334 | mutex_unlock(&zram->lock); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 335 | pr_err("Compression failed! err=%d\n", ret); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 336 | zram_stat64_inc(zram, &zram->stats.failed_writes); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 337 | goto out; |
| 338 | } |
| 339 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 340 | /* |
| 341 | * Page is incompressible. Store it as-is (uncompressed) |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 342 | * since we do not want to return too many disk write |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 343 | * errors which has side effect of hanging the system. |
| 344 | */ |
| 345 | if (unlikely(clen > max_zpage_size)) { |
| 346 | clen = PAGE_SIZE; |
| 347 | page_store = alloc_page(GFP_NOIO | __GFP_HIGHMEM); |
| 348 | if (unlikely(!page_store)) { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 349 | mutex_unlock(&zram->lock); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 350 | pr_info("Error allocating memory for " |
| 351 | "incompressible page: %u\n", index); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 352 | zram_stat64_inc(zram, |
| 353 | &zram->stats.failed_writes); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 354 | goto out; |
| 355 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 356 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 357 | offset = 0; |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 358 | zram_set_flag(zram, index, ZRAM_UNCOMPRESSED); |
| 359 | zram_stat_inc(&zram->stats.pages_expand); |
| 360 | zram->table[index].page = page_store; |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 361 | src = kmap_atomic(page, KM_USER0); |
| 362 | goto memstore; |
| 363 | } |
| 364 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 365 | if (xv_malloc(zram->mem_pool, clen + sizeof(*zheader), |
| 366 | &zram->table[index].page, &offset, |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 367 | GFP_NOIO | __GFP_HIGHMEM)) { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 368 | mutex_unlock(&zram->lock); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 369 | pr_info("Error allocating memory for compressed " |
| 370 | "page: %u, size=%zu\n", index, clen); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 371 | zram_stat64_inc(zram, &zram->stats.failed_writes); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 372 | goto out; |
| 373 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 374 | |
| 375 | memstore: |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 376 | zram->table[index].offset = offset; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 377 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 378 | cmem = kmap_atomic(zram->table[index].page, KM_USER1) + |
| 379 | zram->table[index].offset; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 380 | |
| 381 | #if 0 |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 382 | /* Back-reference needed for memory defragmentation */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 383 | if (!zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)) { |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 384 | zheader = (struct zobj_header *)cmem; |
| 385 | zheader->table_idx = index; |
| 386 | cmem += sizeof(*zheader); |
| 387 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 388 | #endif |
| 389 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 390 | memcpy(cmem, src, clen); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 391 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 392 | kunmap_atomic(cmem, KM_USER1); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 393 | if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 394 | kunmap_atomic(src, KM_USER0); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 395 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 396 | /* Update stats */ |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 397 | zram_stat64_add(zram, &zram->stats.compr_size, clen); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 398 | zram_stat_inc(&zram->stats.pages_stored); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 399 | if (clen <= PAGE_SIZE / 2) |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 400 | zram_stat_inc(&zram->stats.good_compress); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 401 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 402 | mutex_unlock(&zram->lock); |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 403 | index++; |
| 404 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 405 | |
| 406 | set_bit(BIO_UPTODATE, &bio->bi_flags); |
| 407 | bio_endio(bio, 0); |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 408 | return; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 409 | |
| 410 | out: |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 411 | bio_io_error(bio); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 412 | } |
| 413 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 414 | /* |
| 415 | * Check if request is within bounds and page aligned. |
| 416 | */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 417 | static inline int valid_io_request(struct zram *zram, struct bio *bio) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 418 | { |
| 419 | if (unlikely( |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 420 | (bio->bi_sector >= (zram->disksize >> SECTOR_SHIFT)) || |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 421 | (bio->bi_sector & (SECTORS_PER_PAGE - 1)) || |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 422 | (bio->bi_size & (PAGE_SIZE - 1)))) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 423 | |
| 424 | return 0; |
| 425 | } |
| 426 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 427 | /* I/O request is valid */ |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 428 | return 1; |
| 429 | } |
| 430 | |
| 431 | /* |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 432 | * Handler function for all zram I/O requests. |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 433 | */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 434 | static int zram_make_request(struct request_queue *queue, struct bio *bio) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 435 | { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 436 | struct zram *zram = queue->queuedata; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 437 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 438 | if (!valid_io_request(zram, bio)) { |
| 439 | zram_stat64_inc(zram, &zram->stats.invalid_io); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 440 | bio_io_error(bio); |
| 441 | return 0; |
| 442 | } |
| 443 | |
| 444 | switch (bio_data_dir(bio)) { |
| 445 | case READ: |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 446 | zram_read(zram, bio); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 447 | break; |
| 448 | |
| 449 | case WRITE: |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 450 | zram_write(zram, bio); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 451 | break; |
| 452 | } |
| 453 | |
Nitin Gupta | 7d7854b | 2011-01-22 07:36:15 -0500 | [diff] [blame] | 454 | return 0; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 455 | } |
| 456 | |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 457 | void zram_reset_device(struct zram *zram) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 458 | { |
Nitin Gupta | 97a0638 | 2010-05-13 14:24:21 +0530 | [diff] [blame] | 459 | size_t index; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 460 | |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 461 | mutex_lock(&zram->init_lock); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 462 | zram->init_done = 0; |
Nitin Gupta | 7eef753 | 2010-01-28 21:13:38 +0530 | [diff] [blame] | 463 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 464 | /* Free various per-device buffers */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 465 | kfree(zram->compress_workmem); |
| 466 | free_pages((unsigned long)zram->compress_buffer, 1); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 467 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 468 | zram->compress_workmem = NULL; |
| 469 | zram->compress_buffer = NULL; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 470 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 471 | /* Free all pages that are still in this zram device */ |
| 472 | for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 473 | struct page *page; |
| 474 | u16 offset; |
| 475 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 476 | page = zram->table[index].page; |
| 477 | offset = zram->table[index].offset; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 478 | |
| 479 | if (!page) |
| 480 | continue; |
| 481 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 482 | if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 483 | __free_page(page); |
| 484 | else |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 485 | xv_free(zram->mem_pool, page, offset); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 486 | } |
| 487 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 488 | vfree(zram->table); |
| 489 | zram->table = NULL; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 490 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 491 | xv_destroy_pool(zram->mem_pool); |
| 492 | zram->mem_pool = NULL; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 493 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 494 | /* Reset stats */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 495 | memset(&zram->stats, 0, sizeof(zram->stats)); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 496 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 497 | zram->disksize = 0; |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 498 | mutex_unlock(&zram->init_lock); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 499 | } |
| 500 | |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 501 | int zram_init_device(struct zram *zram) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 502 | { |
| 503 | int ret; |
| 504 | size_t num_pages; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 505 | |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 506 | mutex_lock(&zram->init_lock); |
| 507 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 508 | if (zram->init_done) { |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 509 | mutex_unlock(&zram->init_lock); |
| 510 | return 0; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 511 | } |
| 512 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 513 | zram_set_disksize(zram, totalram_pages << PAGE_SHIFT); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 514 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 515 | zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); |
| 516 | if (!zram->compress_workmem) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 517 | pr_err("Error allocating compressor working memory!\n"); |
| 518 | ret = -ENOMEM; |
| 519 | goto fail; |
| 520 | } |
| 521 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 522 | zram->compress_buffer = (void *)__get_free_pages(__GFP_ZERO, 1); |
| 523 | if (!zram->compress_buffer) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 524 | pr_err("Error allocating compressor buffer space\n"); |
| 525 | ret = -ENOMEM; |
| 526 | goto fail; |
| 527 | } |
| 528 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 529 | num_pages = zram->disksize >> PAGE_SHIFT; |
Joe Perches | 5b84cc7 | 2010-11-04 20:07:59 -0700 | [diff] [blame] | 530 | zram->table = vzalloc(num_pages * sizeof(*zram->table)); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 531 | if (!zram->table) { |
| 532 | pr_err("Error allocating zram address table\n"); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 533 | /* To prevent accessing table entries during cleanup */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 534 | zram->disksize = 0; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 535 | ret = -ENOMEM; |
| 536 | goto fail; |
| 537 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 538 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 539 | set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 540 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 541 | /* zram devices sort of resembles non-rotational disks */ |
| 542 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 543 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 544 | zram->mem_pool = xv_create_pool(); |
| 545 | if (!zram->mem_pool) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 546 | pr_err("Error creating memory pool\n"); |
| 547 | ret = -ENOMEM; |
| 548 | goto fail; |
| 549 | } |
| 550 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 551 | zram->init_done = 1; |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 552 | mutex_unlock(&zram->init_lock); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 553 | |
| 554 | pr_debug("Initialization done!\n"); |
| 555 | return 0; |
| 556 | |
| 557 | fail: |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 558 | mutex_unlock(&zram->init_lock); |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 559 | zram_reset_device(zram); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 560 | |
| 561 | pr_err("Initialization failed: err=%d\n", ret); |
| 562 | return ret; |
| 563 | } |
| 564 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 565 | void zram_slot_free_notify(struct block_device *bdev, unsigned long index) |
Nitin Gupta | 107c161 | 2010-05-17 11:02:44 +0530 | [diff] [blame] | 566 | { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 567 | struct zram *zram; |
Nitin Gupta | 107c161 | 2010-05-17 11:02:44 +0530 | [diff] [blame] | 568 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 569 | zram = bdev->bd_disk->private_data; |
| 570 | zram_free_page(zram, index); |
| 571 | zram_stat64_inc(zram, &zram->stats.notify_free); |
Nitin Gupta | 107c161 | 2010-05-17 11:02:44 +0530 | [diff] [blame] | 572 | } |
| 573 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 574 | static const struct block_device_operations zram_devops = { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 575 | .swap_slot_free_notify = zram_slot_free_notify, |
Nitin Gupta | 107c161 | 2010-05-17 11:02:44 +0530 | [diff] [blame] | 576 | .owner = THIS_MODULE |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 577 | }; |
| 578 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 579 | static int create_device(struct zram *zram, int device_id) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 580 | { |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 581 | int ret = 0; |
| 582 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 583 | mutex_init(&zram->lock); |
Nitin Gupta | 484875a | 2010-08-09 22:56:48 +0530 | [diff] [blame] | 584 | mutex_init(&zram->init_lock); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 585 | spin_lock_init(&zram->stat64_lock); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 586 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 587 | zram->queue = blk_alloc_queue(GFP_KERNEL); |
| 588 | if (!zram->queue) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 589 | pr_err("Error allocating disk queue for device %d\n", |
| 590 | device_id); |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 591 | ret = -ENOMEM; |
| 592 | goto out; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 593 | } |
| 594 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 595 | blk_queue_make_request(zram->queue, zram_make_request); |
| 596 | zram->queue->queuedata = zram; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 597 | |
| 598 | /* gendisk structure */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 599 | zram->disk = alloc_disk(1); |
| 600 | if (!zram->disk) { |
| 601 | blk_cleanup_queue(zram->queue); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 602 | pr_warning("Error allocating disk structure for device %d\n", |
| 603 | device_id); |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 604 | ret = -ENOMEM; |
| 605 | goto out; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 606 | } |
| 607 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 608 | zram->disk->major = zram_major; |
| 609 | zram->disk->first_minor = device_id; |
| 610 | zram->disk->fops = &zram_devops; |
| 611 | zram->disk->queue = zram->queue; |
| 612 | zram->disk->private_data = zram; |
| 613 | snprintf(zram->disk->disk_name, 16, "zram%d", device_id); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 614 | |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 615 | /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 616 | set_capacity(zram->disk, 0); |
Nitin Gupta | 5d83d5a | 2010-01-28 21:13:39 +0530 | [diff] [blame] | 617 | |
Nitin Gupta | a1dd52a | 2010-06-01 13:31:23 +0530 | [diff] [blame] | 618 | /* |
| 619 | * To ensure that we always get PAGE_SIZE aligned |
| 620 | * and n*PAGE_SIZED sized I/O requests. |
| 621 | */ |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 622 | blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); |
Robert Jennings | 7b19b8d | 2011-01-28 08:58:17 -0600 | [diff] [blame] | 623 | blk_queue_logical_block_size(zram->disk->queue, |
| 624 | ZRAM_LOGICAL_BLOCK_SIZE); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 625 | blk_queue_io_min(zram->disk->queue, PAGE_SIZE); |
| 626 | blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); |
Nitin Gupta | 5d83d5a | 2010-01-28 21:13:39 +0530 | [diff] [blame] | 627 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 628 | add_disk(zram->disk); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 629 | |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 630 | ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, |
| 631 | &zram_disk_attr_group); |
| 632 | if (ret < 0) { |
| 633 | pr_warning("Error creating sysfs group"); |
| 634 | goto out; |
| 635 | } |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 636 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 637 | zram->init_done = 0; |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 638 | |
| 639 | out: |
| 640 | return ret; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 641 | } |
| 642 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 643 | static void destroy_device(struct zram *zram) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 644 | { |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 645 | sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, |
| 646 | &zram_disk_attr_group); |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 647 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 648 | if (zram->disk) { |
| 649 | del_gendisk(zram->disk); |
| 650 | put_disk(zram->disk); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 651 | } |
| 652 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 653 | if (zram->queue) |
| 654 | blk_cleanup_queue(zram->queue); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 655 | } |
| 656 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 657 | static int __init zram_init(void) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 658 | { |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 659 | int ret, dev_id; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 660 | |
| 661 | if (num_devices > max_num_devices) { |
| 662 | pr_warning("Invalid value for num_devices: %u\n", |
| 663 | num_devices); |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 664 | ret = -EINVAL; |
| 665 | goto out; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 666 | } |
| 667 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 668 | zram_major = register_blkdev(0, "zram"); |
| 669 | if (zram_major <= 0) { |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 670 | pr_warning("Unable to get major number\n"); |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 671 | ret = -EBUSY; |
| 672 | goto out; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 673 | } |
| 674 | |
| 675 | if (!num_devices) { |
| 676 | pr_info("num_devices not specified. Using default: 1\n"); |
| 677 | num_devices = 1; |
| 678 | } |
| 679 | |
| 680 | /* Allocate the device array and initialize each one */ |
| 681 | pr_info("Creating %u devices ...\n", num_devices); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 682 | devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 683 | if (!devices) { |
| 684 | ret = -ENOMEM; |
| 685 | goto unregister; |
| 686 | } |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 687 | |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 688 | for (dev_id = 0; dev_id < num_devices; dev_id++) { |
| 689 | ret = create_device(&devices[dev_id], dev_id); |
| 690 | if (ret) |
Minchan Kim | 3bf040c | 2010-01-11 16:15:53 +0900 | [diff] [blame] | 691 | goto free_devices; |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 692 | } |
| 693 | |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 694 | return 0; |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 695 | |
Minchan Kim | 3bf040c | 2010-01-11 16:15:53 +0900 | [diff] [blame] | 696 | free_devices: |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 697 | while (dev_id) |
| 698 | destroy_device(&devices[--dev_id]); |
Shahar Havivi | 273ad8d | 2010-08-28 10:09:05 +0300 | [diff] [blame] | 699 | kfree(devices); |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 700 | unregister: |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 701 | unregister_blkdev(zram_major, "zram"); |
Nitin Gupta | de1a21a | 2010-01-28 21:13:40 +0530 | [diff] [blame] | 702 | out: |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 703 | return ret; |
| 704 | } |
| 705 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 706 | static void __exit zram_exit(void) |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 707 | { |
| 708 | int i; |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 709 | struct zram *zram; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 710 | |
| 711 | for (i = 0; i < num_devices; i++) { |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 712 | zram = &devices[i]; |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 713 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 714 | destroy_device(zram); |
| 715 | if (zram->init_done) |
Nitin Gupta | 33863c2 | 2010-08-09 22:56:47 +0530 | [diff] [blame] | 716 | zram_reset_device(zram); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 717 | } |
| 718 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 719 | unregister_blkdev(zram_major, "zram"); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 720 | |
| 721 | kfree(devices); |
| 722 | pr_debug("Cleanup done!\n"); |
| 723 | } |
| 724 | |
| 725 | module_param(num_devices, uint, 0); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 726 | MODULE_PARM_DESC(num_devices, "Number of zram devices"); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 727 | |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 728 | module_init(zram_init); |
| 729 | module_exit(zram_exit); |
Nitin Gupta | 306b0c9 | 2009-09-22 10:26:53 +0530 | [diff] [blame] | 730 | |
| 731 | MODULE_LICENSE("Dual BSD/GPL"); |
| 732 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); |
Nitin Gupta | f1e3cff | 2010-06-01 13:31:25 +0530 | [diff] [blame] | 733 | MODULE_DESCRIPTION("Compressed RAM Block Device"); |