334 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.4 */5 6#include <linux/blkdev.h>7#include <linux/slab.h>8#include <linux/bitmap.h>9#include <linux/buffer_head.h>10 11#include "exfat_raw.h"12#include "exfat_fs.h"13 14#if BITS_PER_LONG == 3215#define __le_long __le3216#define lel_to_cpu(A) le32_to_cpu(A)17#define cpu_to_lel(A) cpu_to_le32(A)18#elif BITS_PER_LONG == 6419#define __le_long __le6420#define lel_to_cpu(A) le64_to_cpu(A)21#define cpu_to_lel(A) cpu_to_le64(A)22#else23#error "BITS_PER_LONG not 32 or 64"24#endif25 26/*27 * Allocation Bitmap Management Functions28 */29static int exfat_allocate_bitmap(struct super_block *sb,30 struct exfat_dentry *ep)31{32 struct exfat_sb_info *sbi = EXFAT_SB(sb);33 long long map_size;34 unsigned int i, need_map_size;35 sector_t sector;36 37 sbi->map_clu = le32_to_cpu(ep->dentry.bitmap.start_clu);38 map_size = le64_to_cpu(ep->dentry.bitmap.size);39 need_map_size = ((EXFAT_DATA_CLUSTER_COUNT(sbi) - 1) / BITS_PER_BYTE)40 + 1;41 if (need_map_size != map_size) {42 exfat_err(sb, "bogus allocation bitmap size(need : %u, cur : %lld)",43 need_map_size, map_size);44 /*45 * Only allowed when bogus allocation46 * bitmap size is large47 */48 if (need_map_size > map_size)49 return -EIO;50 }51 sbi->map_sectors = ((need_map_size - 1) >>52 (sb->s_blocksize_bits)) + 1;53 sbi->vol_amap = kvmalloc_array(sbi->map_sectors,54 sizeof(struct buffer_head *), GFP_KERNEL);55 if (!sbi->vol_amap)56 return -ENOMEM;57 58 sector = exfat_cluster_to_sector(sbi, sbi->map_clu);59 for (i = 0; i < sbi->map_sectors; i++) {60 sbi->vol_amap[i] = sb_bread(sb, sector + i);61 if (!sbi->vol_amap[i]) {62 /* release all buffers and free vol_amap */63 int j = 0;64 65 while (j < i)66 brelse(sbi->vol_amap[j++]);67 68 kvfree(sbi->vol_amap);69 sbi->vol_amap = NULL;70 return -EIO;71 }72 }73 74 return 0;75}76 77int exfat_load_bitmap(struct super_block *sb)78{79 unsigned int i, type;80 struct exfat_chain clu;81 struct exfat_sb_info *sbi = EXFAT_SB(sb);82 83 exfat_chain_set(&clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN);84 while (clu.dir != EXFAT_EOF_CLUSTER) {85 for (i = 0; i < sbi->dentries_per_clu; i++) {86 struct exfat_dentry *ep;87 struct buffer_head *bh;88 89 ep = exfat_get_dentry(sb, &clu, i, &bh);90 if (!ep)91 return -EIO;92 93 type = exfat_get_entry_type(ep);94 if (type == TYPE_BITMAP &&95 ep->dentry.bitmap.flags == 0x0) {96 int err;97 98 err = exfat_allocate_bitmap(sb, ep);99 brelse(bh);100 return err;101 }102 brelse(bh);103 104 if (type == TYPE_UNUSED)105 return -EINVAL;106 }107 108 if (exfat_get_next_cluster(sb, &clu.dir))109 return -EIO;110 }111 112 return -EINVAL;113}114 115void exfat_free_bitmap(struct exfat_sb_info *sbi)116{117 int i;118 119 for (i = 0; i < sbi->map_sectors; i++)120 __brelse(sbi->vol_amap[i]);121 122 kvfree(sbi->vol_amap);123}124 125int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync)126{127 int i, b;128 unsigned int ent_idx;129 struct super_block *sb = inode->i_sb;130 struct exfat_sb_info *sbi = EXFAT_SB(sb);131 132 if (!is_valid_cluster(sbi, clu))133 return -EINVAL;134 135 ent_idx = CLUSTER_TO_BITMAP_ENT(clu);136 i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);137 b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);138 139 set_bit_le(b, sbi->vol_amap[i]->b_data);140 exfat_update_bh(sbi->vol_amap[i], sync);141 return 0;142}143 144void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)145{146 int i, b;147 unsigned int ent_idx;148 struct super_block *sb = inode->i_sb;149 struct exfat_sb_info *sbi = EXFAT_SB(sb);150 struct exfat_mount_options *opts = &sbi->options;151 152 if (!is_valid_cluster(sbi, clu))153 return;154 155 ent_idx = CLUSTER_TO_BITMAP_ENT(clu);156 i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);157 b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);158 159 clear_bit_le(b, sbi->vol_amap[i]->b_data);160 exfat_update_bh(sbi->vol_amap[i], sync);161 162 if (opts->discard) {163 int ret_discard;164 165 ret_discard = sb_issue_discard(sb,166 exfat_cluster_to_sector(sbi, clu),167 (1 << sbi->sect_per_clus_bits), GFP_NOFS, 0);168 169 if (ret_discard == -EOPNOTSUPP) {170 exfat_err(sb, "discard not supported by device, disabling");171 opts->discard = 0;172 }173 }174}175 176/*177 * If the value of "clu" is 0, it means cluster 2 which is the first cluster of178 * the cluster heap.179 */180unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu)181{182 unsigned int i, map_i, map_b, ent_idx;183 unsigned int clu_base, clu_free;184 unsigned long clu_bits, clu_mask;185 struct exfat_sb_info *sbi = EXFAT_SB(sb);186 __le_long bitval;187 188 WARN_ON(clu < EXFAT_FIRST_CLUSTER);189 ent_idx = ALIGN_DOWN(CLUSTER_TO_BITMAP_ENT(clu), BITS_PER_LONG);190 clu_base = BITMAP_ENT_TO_CLUSTER(ent_idx);191 clu_mask = IGNORED_BITS_REMAINED(clu, clu_base);192 193 map_i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);194 map_b = BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent_idx);195 196 for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters;197 i += BITS_PER_LONG) {198 bitval = *(__le_long *)(sbi->vol_amap[map_i]->b_data + map_b);199 if (clu_mask > 0) {200 bitval |= cpu_to_lel(clu_mask);201 clu_mask = 0;202 }203 if (lel_to_cpu(bitval) != ULONG_MAX) {204 clu_bits = lel_to_cpu(bitval);205 clu_free = clu_base + ffz(clu_bits);206 if (clu_free < sbi->num_clusters)207 return clu_free;208 }209 clu_base += BITS_PER_LONG;210 map_b += sizeof(long);211 212 if (map_b >= sb->s_blocksize ||213 clu_base >= sbi->num_clusters) {214 if (++map_i >= sbi->map_sectors) {215 clu_base = EXFAT_FIRST_CLUSTER;216 map_i = 0;217 }218 map_b = 0;219 }220 }221 222 return EXFAT_EOF_CLUSTER;223}224 225int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count)226{227 struct exfat_sb_info *sbi = EXFAT_SB(sb);228 unsigned int count = 0;229 unsigned int i, map_i = 0, map_b = 0;230 unsigned int total_clus = EXFAT_DATA_CLUSTER_COUNT(sbi);231 unsigned int last_mask = total_clus & (BITS_PER_LONG - 1);232 unsigned long *bitmap, clu_bits;233 234 total_clus &= ~last_mask;235 for (i = 0; i < total_clus; i += BITS_PER_LONG) {236 bitmap = (void *)(sbi->vol_amap[map_i]->b_data + map_b);237 count += hweight_long(*bitmap);238 map_b += sizeof(long);239 if (map_b >= (unsigned int)sb->s_blocksize) {240 map_i++;241 map_b = 0;242 }243 }244 245 if (last_mask) {246 bitmap = (void *)(sbi->vol_amap[map_i]->b_data + map_b);247 clu_bits = lel_to_cpu(*(__le_long *)bitmap);248 count += hweight_long(clu_bits & BITMAP_LAST_WORD_MASK(last_mask));249 }250 251 *ret_count = count;252 return 0;253}254 255int exfat_trim_fs(struct inode *inode, struct fstrim_range *range)256{257 unsigned int trim_begin, trim_end, count, next_free_clu;258 u64 clu_start, clu_end, trim_minlen, trimmed_total = 0;259 struct super_block *sb = inode->i_sb;260 struct exfat_sb_info *sbi = EXFAT_SB(sb);261 int err = 0;262 263 clu_start = max_t(u64, range->start >> sbi->cluster_size_bits,264 EXFAT_FIRST_CLUSTER);265 clu_end = clu_start + (range->len >> sbi->cluster_size_bits) - 1;266 trim_minlen = range->minlen >> sbi->cluster_size_bits;267 268 if (clu_start >= sbi->num_clusters || range->len < sbi->cluster_size)269 return -EINVAL;270 271 if (clu_end >= sbi->num_clusters)272 clu_end = sbi->num_clusters - 1;273 274 mutex_lock(&sbi->bitmap_lock);275 276 trim_begin = trim_end = exfat_find_free_bitmap(sb, clu_start);277 if (trim_begin == EXFAT_EOF_CLUSTER)278 goto unlock;279 280 next_free_clu = exfat_find_free_bitmap(sb, trim_end + 1);281 if (next_free_clu == EXFAT_EOF_CLUSTER)282 goto unlock;283 284 do {285 if (next_free_clu == trim_end + 1) {286 /* extend trim range for continuous free cluster */287 trim_end++;288 } else {289 /* trim current range if it's larger than trim_minlen */290 count = trim_end - trim_begin + 1;291 if (count >= trim_minlen) {292 err = sb_issue_discard(sb,293 exfat_cluster_to_sector(sbi, trim_begin),294 count * sbi->sect_per_clus, GFP_NOFS, 0);295 if (err)296 goto unlock;297 298 trimmed_total += count;299 }300 301 /* set next start point of the free hole */302 trim_begin = trim_end = next_free_clu;303 }304 305 if (next_free_clu >= clu_end)306 break;307 308 if (fatal_signal_pending(current)) {309 err = -ERESTARTSYS;310 goto unlock;311 }312 313 next_free_clu = exfat_find_free_bitmap(sb, next_free_clu + 1);314 } while (next_free_clu != EXFAT_EOF_CLUSTER &&315 next_free_clu > trim_end);316 317 /* try to trim remainder */318 count = trim_end - trim_begin + 1;319 if (count >= trim_minlen) {320 err = sb_issue_discard(sb, exfat_cluster_to_sector(sbi, trim_begin),321 count * sbi->sect_per_clus, GFP_NOFS, 0);322 if (err)323 goto unlock;324 325 trimmed_total += count;326 }327 328unlock:329 mutex_unlock(&sbi->bitmap_lock);330 range->len = trimmed_total << sbi->cluster_size_bits;331 332 return err;333}334