1ffa09b3bSGao Xiang // SPDX-License-Identifier: GPL-2.0-or-later 2ffa09b3bSGao Xiang #include <linux/module.h> 3ffa09b3bSGao Xiang #include <linux/zlib.h> 4ffa09b3bSGao Xiang #include "compress.h" 5ffa09b3bSGao Xiang 6ffa09b3bSGao Xiang struct z_erofs_deflate { 7ffa09b3bSGao Xiang struct z_erofs_deflate *next; 8ffa09b3bSGao Xiang struct z_stream_s z; 9ffa09b3bSGao Xiang u8 bounce[PAGE_SIZE]; 10ffa09b3bSGao Xiang }; 11ffa09b3bSGao Xiang 12ffa09b3bSGao Xiang static DEFINE_SPINLOCK(z_erofs_deflate_lock); 13ffa09b3bSGao Xiang static unsigned int z_erofs_deflate_nstrms, z_erofs_deflate_avail_strms; 14ffa09b3bSGao Xiang static struct z_erofs_deflate *z_erofs_deflate_head; 15ffa09b3bSGao Xiang static DECLARE_WAIT_QUEUE_HEAD(z_erofs_deflate_wq); 16ffa09b3bSGao Xiang 17ffa09b3bSGao Xiang module_param_named(deflate_streams, z_erofs_deflate_nstrms, uint, 0444); 18ffa09b3bSGao Xiang 19ffa09b3bSGao Xiang void z_erofs_deflate_exit(void) 20ffa09b3bSGao Xiang { 21ffa09b3bSGao Xiang /* there should be no running fs instance */ 22ffa09b3bSGao Xiang while (z_erofs_deflate_avail_strms) { 23ffa09b3bSGao Xiang struct z_erofs_deflate *strm; 24ffa09b3bSGao Xiang 25ffa09b3bSGao Xiang spin_lock(&z_erofs_deflate_lock); 26ffa09b3bSGao Xiang strm = z_erofs_deflate_head; 27ffa09b3bSGao Xiang if (!strm) { 28ffa09b3bSGao Xiang spin_unlock(&z_erofs_deflate_lock); 29ffa09b3bSGao Xiang continue; 30ffa09b3bSGao Xiang } 31ffa09b3bSGao Xiang z_erofs_deflate_head = NULL; 32ffa09b3bSGao Xiang spin_unlock(&z_erofs_deflate_lock); 33ffa09b3bSGao Xiang 34ffa09b3bSGao Xiang while (strm) { 35ffa09b3bSGao Xiang struct z_erofs_deflate *n = strm->next; 36ffa09b3bSGao Xiang 37ffa09b3bSGao Xiang vfree(strm->z.workspace); 38ffa09b3bSGao Xiang kfree(strm); 39ffa09b3bSGao Xiang --z_erofs_deflate_avail_strms; 40ffa09b3bSGao Xiang strm = n; 41ffa09b3bSGao Xiang } 42ffa09b3bSGao Xiang } 43ffa09b3bSGao Xiang } 44ffa09b3bSGao Xiang 45ffa09b3bSGao Xiang int __init z_erofs_deflate_init(void) 46ffa09b3bSGao Xiang { 47ffa09b3bSGao Xiang /* by default, use # of possible CPUs instead */ 48ffa09b3bSGao Xiang if (!z_erofs_deflate_nstrms) 49ffa09b3bSGao Xiang z_erofs_deflate_nstrms = num_possible_cpus(); 50ffa09b3bSGao Xiang 51ffa09b3bSGao Xiang for (; z_erofs_deflate_avail_strms < z_erofs_deflate_nstrms; 52ffa09b3bSGao Xiang ++z_erofs_deflate_avail_strms) { 53ffa09b3bSGao Xiang struct z_erofs_deflate *strm; 54ffa09b3bSGao Xiang 55ffa09b3bSGao Xiang strm = kzalloc(sizeof(*strm), GFP_KERNEL); 56ffa09b3bSGao Xiang if (!strm) 57ffa09b3bSGao Xiang goto out_failed; 58ffa09b3bSGao Xiang 59ffa09b3bSGao Xiang /* XXX: in-kernel zlib cannot shrink windowbits currently */ 60ffa09b3bSGao Xiang strm->z.workspace = vmalloc(zlib_inflate_workspacesize()); 61ffa09b3bSGao Xiang if (!strm->z.workspace) { 62ffa09b3bSGao Xiang kfree(strm); 63ffa09b3bSGao Xiang goto out_failed; 64ffa09b3bSGao Xiang } 65ffa09b3bSGao Xiang 66ffa09b3bSGao Xiang spin_lock(&z_erofs_deflate_lock); 67ffa09b3bSGao Xiang strm->next = z_erofs_deflate_head; 68ffa09b3bSGao Xiang z_erofs_deflate_head = strm; 69ffa09b3bSGao Xiang spin_unlock(&z_erofs_deflate_lock); 70ffa09b3bSGao Xiang } 71ffa09b3bSGao Xiang return 0; 72ffa09b3bSGao Xiang 73ffa09b3bSGao Xiang out_failed: 74ffa09b3bSGao Xiang pr_err("failed to allocate zlib workspace\n"); 75ffa09b3bSGao Xiang z_erofs_deflate_exit(); 76ffa09b3bSGao Xiang return -ENOMEM; 77ffa09b3bSGao Xiang } 78ffa09b3bSGao Xiang 79ffa09b3bSGao Xiang int z_erofs_load_deflate_config(struct super_block *sb, 80*586814edSGao Xiang struct erofs_super_block *dsb, void *data, int size) 81ffa09b3bSGao Xiang { 82*586814edSGao Xiang struct z_erofs_deflate_cfgs *dfl = data; 83*586814edSGao Xiang 84ffa09b3bSGao Xiang if (!dfl || size < sizeof(struct z_erofs_deflate_cfgs)) { 85ffa09b3bSGao Xiang erofs_err(sb, "invalid deflate cfgs, size=%u", size); 86ffa09b3bSGao Xiang return -EINVAL; 87ffa09b3bSGao Xiang } 88ffa09b3bSGao Xiang 89ffa09b3bSGao Xiang if (dfl->windowbits > MAX_WBITS) { 90ffa09b3bSGao Xiang erofs_err(sb, "unsupported windowbits %u", dfl->windowbits); 91ffa09b3bSGao Xiang return -EOPNOTSUPP; 92ffa09b3bSGao Xiang } 93ffa09b3bSGao Xiang 94ffa09b3bSGao Xiang erofs_info(sb, "EXPERIMENTAL DEFLATE feature in use. Use at your own risk!"); 95ffa09b3bSGao Xiang return 0; 96ffa09b3bSGao Xiang } 97ffa09b3bSGao Xiang 98ffa09b3bSGao Xiang int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq, 99ffa09b3bSGao Xiang struct page **pagepool) 100ffa09b3bSGao Xiang { 101ffa09b3bSGao Xiang const unsigned int nrpages_out = 102ffa09b3bSGao Xiang PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; 103ffa09b3bSGao Xiang const unsigned int nrpages_in = 104ffa09b3bSGao Xiang PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT; 105ffa09b3bSGao Xiang struct super_block *sb = rq->sb; 106ffa09b3bSGao Xiang unsigned int insz, outsz, pofs; 107ffa09b3bSGao Xiang struct z_erofs_deflate *strm; 108ffa09b3bSGao Xiang u8 *kin, *kout = NULL; 109ffa09b3bSGao Xiang bool bounced = false; 110ffa09b3bSGao Xiang int no = -1, ni = 0, j = 0, zerr, err; 111ffa09b3bSGao Xiang 112ffa09b3bSGao Xiang /* 1. get the exact DEFLATE compressed size */ 113ffa09b3bSGao Xiang kin = kmap_local_page(*rq->in); 114ffa09b3bSGao Xiang err = z_erofs_fixup_insize(rq, kin + rq->pageofs_in, 115ffa09b3bSGao Xiang min_t(unsigned int, rq->inputsize, 116ffa09b3bSGao Xiang sb->s_blocksize - rq->pageofs_in)); 117ffa09b3bSGao Xiang if (err) { 118ffa09b3bSGao Xiang kunmap_local(kin); 119ffa09b3bSGao Xiang return err; 120ffa09b3bSGao Xiang } 121ffa09b3bSGao Xiang 122ffa09b3bSGao Xiang /* 2. get an available DEFLATE context */ 123ffa09b3bSGao Xiang again: 124ffa09b3bSGao Xiang spin_lock(&z_erofs_deflate_lock); 125ffa09b3bSGao Xiang strm = z_erofs_deflate_head; 126ffa09b3bSGao Xiang if (!strm) { 127ffa09b3bSGao Xiang spin_unlock(&z_erofs_deflate_lock); 128ffa09b3bSGao Xiang wait_event(z_erofs_deflate_wq, READ_ONCE(z_erofs_deflate_head)); 129ffa09b3bSGao Xiang goto again; 130ffa09b3bSGao Xiang } 131ffa09b3bSGao Xiang z_erofs_deflate_head = strm->next; 132ffa09b3bSGao Xiang spin_unlock(&z_erofs_deflate_lock); 133ffa09b3bSGao Xiang 134ffa09b3bSGao Xiang /* 3. multi-call decompress */ 135ffa09b3bSGao Xiang insz = rq->inputsize; 136ffa09b3bSGao Xiang outsz = rq->outputsize; 137ffa09b3bSGao Xiang zerr = zlib_inflateInit2(&strm->z, -MAX_WBITS); 138ffa09b3bSGao Xiang if (zerr != Z_OK) { 139ffa09b3bSGao Xiang err = -EIO; 140ffa09b3bSGao Xiang goto failed_zinit; 141ffa09b3bSGao Xiang } 142ffa09b3bSGao Xiang 143ffa09b3bSGao Xiang pofs = rq->pageofs_out; 144ffa09b3bSGao Xiang strm->z.avail_in = min_t(u32, insz, PAGE_SIZE - rq->pageofs_in); 145ffa09b3bSGao Xiang insz -= strm->z.avail_in; 146ffa09b3bSGao Xiang strm->z.next_in = kin + rq->pageofs_in; 147ffa09b3bSGao Xiang strm->z.avail_out = 0; 148ffa09b3bSGao Xiang 149ffa09b3bSGao Xiang while (1) { 150ffa09b3bSGao Xiang if (!strm->z.avail_out) { 151ffa09b3bSGao Xiang if (++no >= nrpages_out || !outsz) { 152ffa09b3bSGao Xiang erofs_err(sb, "insufficient space for decompressed data"); 153ffa09b3bSGao Xiang err = -EFSCORRUPTED; 154ffa09b3bSGao Xiang break; 155ffa09b3bSGao Xiang } 156ffa09b3bSGao Xiang 157ffa09b3bSGao Xiang if (kout) 158ffa09b3bSGao Xiang kunmap_local(kout); 159ffa09b3bSGao Xiang strm->z.avail_out = min_t(u32, outsz, PAGE_SIZE - pofs); 160ffa09b3bSGao Xiang outsz -= strm->z.avail_out; 161ffa09b3bSGao Xiang if (!rq->out[no]) { 162ffa09b3bSGao Xiang rq->out[no] = erofs_allocpage(pagepool, 163ffa09b3bSGao Xiang GFP_KERNEL | __GFP_NOFAIL); 164ffa09b3bSGao Xiang set_page_private(rq->out[no], 165ffa09b3bSGao Xiang Z_EROFS_SHORTLIVED_PAGE); 166ffa09b3bSGao Xiang } 167ffa09b3bSGao Xiang kout = kmap_local_page(rq->out[no]); 168ffa09b3bSGao Xiang strm->z.next_out = kout + pofs; 169ffa09b3bSGao Xiang pofs = 0; 170ffa09b3bSGao Xiang } 171ffa09b3bSGao Xiang 172ffa09b3bSGao Xiang if (!strm->z.avail_in && insz) { 173ffa09b3bSGao Xiang if (++ni >= nrpages_in) { 174ffa09b3bSGao Xiang erofs_err(sb, "invalid compressed data"); 175ffa09b3bSGao Xiang err = -EFSCORRUPTED; 176ffa09b3bSGao Xiang break; 177ffa09b3bSGao Xiang } 178ffa09b3bSGao Xiang 179ffa09b3bSGao Xiang if (kout) { /* unlike kmap(), take care of the orders */ 180ffa09b3bSGao Xiang j = strm->z.next_out - kout; 181ffa09b3bSGao Xiang kunmap_local(kout); 182ffa09b3bSGao Xiang } 183ffa09b3bSGao Xiang kunmap_local(kin); 184ffa09b3bSGao Xiang strm->z.avail_in = min_t(u32, insz, PAGE_SIZE); 185ffa09b3bSGao Xiang insz -= strm->z.avail_in; 186ffa09b3bSGao Xiang kin = kmap_local_page(rq->in[ni]); 187ffa09b3bSGao Xiang strm->z.next_in = kin; 188ffa09b3bSGao Xiang bounced = false; 189ffa09b3bSGao Xiang if (kout) { 190ffa09b3bSGao Xiang kout = kmap_local_page(rq->out[no]); 191ffa09b3bSGao Xiang strm->z.next_out = kout + j; 192ffa09b3bSGao Xiang } 193ffa09b3bSGao Xiang } 194ffa09b3bSGao Xiang 195ffa09b3bSGao Xiang /* 196ffa09b3bSGao Xiang * Handle overlapping: Use bounced buffer if the compressed 197ffa09b3bSGao Xiang * data is under processing; Or use short-lived pages from the 198ffa09b3bSGao Xiang * on-stack pagepool where pages share among the same request 199ffa09b3bSGao Xiang * and not _all_ inplace I/O pages are needed to be doubled. 200ffa09b3bSGao Xiang */ 201ffa09b3bSGao Xiang if (!bounced && rq->out[no] == rq->in[ni]) { 202ffa09b3bSGao Xiang memcpy(strm->bounce, strm->z.next_in, strm->z.avail_in); 203ffa09b3bSGao Xiang strm->z.next_in = strm->bounce; 204ffa09b3bSGao Xiang bounced = true; 205ffa09b3bSGao Xiang } 206ffa09b3bSGao Xiang 207ffa09b3bSGao Xiang for (j = ni + 1; j < nrpages_in; ++j) { 208ffa09b3bSGao Xiang struct page *tmppage; 209ffa09b3bSGao Xiang 210ffa09b3bSGao Xiang if (rq->out[no] != rq->in[j]) 211ffa09b3bSGao Xiang continue; 212ffa09b3bSGao Xiang 213ffa09b3bSGao Xiang DBG_BUGON(erofs_page_is_managed(EROFS_SB(sb), 214ffa09b3bSGao Xiang rq->in[j])); 215ffa09b3bSGao Xiang tmppage = erofs_allocpage(pagepool, 216ffa09b3bSGao Xiang GFP_KERNEL | __GFP_NOFAIL); 217ffa09b3bSGao Xiang set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE); 218ffa09b3bSGao Xiang copy_highpage(tmppage, rq->in[j]); 219ffa09b3bSGao Xiang rq->in[j] = tmppage; 220ffa09b3bSGao Xiang } 221ffa09b3bSGao Xiang 222ffa09b3bSGao Xiang zerr = zlib_inflate(&strm->z, Z_SYNC_FLUSH); 223ffa09b3bSGao Xiang if (zerr != Z_OK || !(outsz + strm->z.avail_out)) { 224ffa09b3bSGao Xiang if (zerr == Z_OK && rq->partial_decoding) 225ffa09b3bSGao Xiang break; 226ffa09b3bSGao Xiang if (zerr == Z_STREAM_END && !outsz) 227ffa09b3bSGao Xiang break; 228ffa09b3bSGao Xiang erofs_err(sb, "failed to decompress %d in[%u] out[%u]", 229ffa09b3bSGao Xiang zerr, rq->inputsize, rq->outputsize); 230ffa09b3bSGao Xiang err = -EFSCORRUPTED; 231ffa09b3bSGao Xiang break; 232ffa09b3bSGao Xiang } 233ffa09b3bSGao Xiang } 234ffa09b3bSGao Xiang 235ffa09b3bSGao Xiang if (zlib_inflateEnd(&strm->z) != Z_OK && !err) 236ffa09b3bSGao Xiang err = -EIO; 237ffa09b3bSGao Xiang if (kout) 238ffa09b3bSGao Xiang kunmap_local(kout); 239ffa09b3bSGao Xiang failed_zinit: 240ffa09b3bSGao Xiang kunmap_local(kin); 241ffa09b3bSGao Xiang /* 4. push back DEFLATE stream context to the global list */ 242ffa09b3bSGao Xiang spin_lock(&z_erofs_deflate_lock); 243ffa09b3bSGao Xiang strm->next = z_erofs_deflate_head; 244ffa09b3bSGao Xiang z_erofs_deflate_head = strm; 245ffa09b3bSGao Xiang spin_unlock(&z_erofs_deflate_lock); 246ffa09b3bSGao Xiang wake_up(&z_erofs_deflate_wq); 247ffa09b3bSGao Xiang return err; 248ffa09b3bSGao Xiang } 249