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266 lines
7.6 KiB
266 lines
7.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. |
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*/ |
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#include <linux/blkdev.h> |
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#include <linux/slab.h> |
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#include <linux/buffer_head.h> |
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#include "exfat_raw.h" |
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#include "exfat_fs.h" |
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static const unsigned char free_bit[] = { |
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/* 0 ~ 19*/ |
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0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3,/* 20 ~ 39*/ |
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0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/* 40 ~ 59*/ |
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0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/* 60 ~ 79*/ |
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2,/* 80 ~ 99*/ |
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0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3,/*100 ~ 119*/ |
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0, 1, 0, 2, 0, 1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*120 ~ 139*/ |
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0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5,/*140 ~ 159*/ |
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/*160 ~ 179*/ |
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0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3,/*180 ~ 199*/ |
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0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*200 ~ 219*/ |
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0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/*220 ~ 239*/ |
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 /*240 ~ 254*/ |
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}; |
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static const unsigned char used_bit[] = { |
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0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3,/* 0 ~ 19*/ |
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2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4,/* 20 ~ 39*/ |
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2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5,/* 40 ~ 59*/ |
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4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,/* 60 ~ 79*/ |
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2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4,/* 80 ~ 99*/ |
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3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6,/*100 ~ 119*/ |
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4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4,/*120 ~ 139*/ |
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3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,/*140 ~ 159*/ |
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2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5,/*160 ~ 179*/ |
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4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5,/*180 ~ 199*/ |
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3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6,/*200 ~ 219*/ |
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5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,/*220 ~ 239*/ |
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4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 /*240 ~ 255*/ |
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}; |
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/* |
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* Allocation Bitmap Management Functions |
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*/ |
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static int exfat_allocate_bitmap(struct super_block *sb, |
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struct exfat_dentry *ep) |
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{ |
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struct exfat_sb_info *sbi = EXFAT_SB(sb); |
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long long map_size; |
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unsigned int i, need_map_size; |
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sector_t sector; |
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sbi->map_clu = le32_to_cpu(ep->dentry.bitmap.start_clu); |
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map_size = le64_to_cpu(ep->dentry.bitmap.size); |
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need_map_size = ((EXFAT_DATA_CLUSTER_COUNT(sbi) - 1) / BITS_PER_BYTE) |
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+ 1; |
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if (need_map_size != map_size) { |
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exfat_err(sb, "bogus allocation bitmap size(need : %u, cur : %lld)", |
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need_map_size, map_size); |
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/* |
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* Only allowed when bogus allocation |
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* bitmap size is large |
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*/ |
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if (need_map_size > map_size) |
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return -EIO; |
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} |
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sbi->map_sectors = ((need_map_size - 1) >> |
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(sb->s_blocksize_bits)) + 1; |
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sbi->vol_amap = kmalloc_array(sbi->map_sectors, |
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sizeof(struct buffer_head *), GFP_KERNEL); |
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if (!sbi->vol_amap) |
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return -ENOMEM; |
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sector = exfat_cluster_to_sector(sbi, sbi->map_clu); |
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for (i = 0; i < sbi->map_sectors; i++) { |
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sbi->vol_amap[i] = sb_bread(sb, sector + i); |
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if (!sbi->vol_amap[i]) { |
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/* release all buffers and free vol_amap */ |
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int j = 0; |
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while (j < i) |
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brelse(sbi->vol_amap[j++]); |
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kfree(sbi->vol_amap); |
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sbi->vol_amap = NULL; |
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return -EIO; |
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} |
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} |
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return 0; |
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} |
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int exfat_load_bitmap(struct super_block *sb) |
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{ |
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unsigned int i, type; |
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struct exfat_chain clu; |
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struct exfat_sb_info *sbi = EXFAT_SB(sb); |
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exfat_chain_set(&clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN); |
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while (clu.dir != EXFAT_EOF_CLUSTER) { |
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for (i = 0; i < sbi->dentries_per_clu; i++) { |
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struct exfat_dentry *ep; |
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struct buffer_head *bh; |
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ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); |
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if (!ep) |
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return -EIO; |
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type = exfat_get_entry_type(ep); |
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if (type == TYPE_UNUSED) |
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break; |
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if (type != TYPE_BITMAP) |
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continue; |
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if (ep->dentry.bitmap.flags == 0x0) { |
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int err; |
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err = exfat_allocate_bitmap(sb, ep); |
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brelse(bh); |
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return err; |
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} |
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brelse(bh); |
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} |
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if (exfat_get_next_cluster(sb, &clu.dir)) |
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return -EIO; |
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} |
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return -EINVAL; |
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} |
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void exfat_free_bitmap(struct exfat_sb_info *sbi) |
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{ |
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int i; |
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for (i = 0; i < sbi->map_sectors; i++) |
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__brelse(sbi->vol_amap[i]); |
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kfree(sbi->vol_amap); |
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} |
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int exfat_set_bitmap(struct inode *inode, unsigned int clu) |
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{ |
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int i, b; |
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unsigned int ent_idx; |
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struct super_block *sb = inode->i_sb; |
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struct exfat_sb_info *sbi = EXFAT_SB(sb); |
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WARN_ON(clu < EXFAT_FIRST_CLUSTER); |
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ent_idx = CLUSTER_TO_BITMAP_ENT(clu); |
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i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx); |
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b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx); |
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set_bit_le(b, sbi->vol_amap[i]->b_data); |
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exfat_update_bh(sbi->vol_amap[i], IS_DIRSYNC(inode)); |
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return 0; |
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} |
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void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync) |
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{ |
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int i, b; |
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unsigned int ent_idx; |
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struct super_block *sb = inode->i_sb; |
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struct exfat_sb_info *sbi = EXFAT_SB(sb); |
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struct exfat_mount_options *opts = &sbi->options; |
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WARN_ON(clu < EXFAT_FIRST_CLUSTER); |
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ent_idx = CLUSTER_TO_BITMAP_ENT(clu); |
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i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx); |
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b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx); |
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clear_bit_le(b, sbi->vol_amap[i]->b_data); |
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exfat_update_bh(sbi->vol_amap[i], sync); |
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if (opts->discard) { |
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int ret_discard; |
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ret_discard = sb_issue_discard(sb, |
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exfat_cluster_to_sector(sbi, clu), |
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(1 << sbi->sect_per_clus_bits), GFP_NOFS, 0); |
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if (ret_discard == -EOPNOTSUPP) { |
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exfat_err(sb, "discard not supported by device, disabling"); |
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opts->discard = 0; |
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} |
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} |
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} |
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/* |
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* If the value of "clu" is 0, it means cluster 2 which is the first cluster of |
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* the cluster heap. |
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*/ |
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unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu) |
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{ |
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unsigned int i, map_i, map_b, ent_idx; |
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unsigned int clu_base, clu_free; |
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unsigned char k, clu_mask; |
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struct exfat_sb_info *sbi = EXFAT_SB(sb); |
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WARN_ON(clu < EXFAT_FIRST_CLUSTER); |
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ent_idx = CLUSTER_TO_BITMAP_ENT(clu); |
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clu_base = BITMAP_ENT_TO_CLUSTER(ent_idx & ~(BITS_PER_BYTE_MASK)); |
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clu_mask = IGNORED_BITS_REMAINED(clu, clu_base); |
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map_i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx); |
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map_b = BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent_idx); |
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for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters; |
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i += BITS_PER_BYTE) { |
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k = *(sbi->vol_amap[map_i]->b_data + map_b); |
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if (clu_mask > 0) { |
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k |= clu_mask; |
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clu_mask = 0; |
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} |
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if (k < 0xFF) { |
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clu_free = clu_base + free_bit[k]; |
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if (clu_free < sbi->num_clusters) |
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return clu_free; |
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} |
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clu_base += BITS_PER_BYTE; |
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if (++map_b >= sb->s_blocksize || |
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clu_base >= sbi->num_clusters) { |
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if (++map_i >= sbi->map_sectors) { |
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clu_base = EXFAT_FIRST_CLUSTER; |
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map_i = 0; |
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} |
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map_b = 0; |
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} |
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} |
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return EXFAT_EOF_CLUSTER; |
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} |
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int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count) |
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{ |
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struct exfat_sb_info *sbi = EXFAT_SB(sb); |
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unsigned int count = 0; |
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unsigned int i, map_i = 0, map_b = 0; |
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unsigned int total_clus = EXFAT_DATA_CLUSTER_COUNT(sbi); |
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unsigned int last_mask = total_clus & BITS_PER_BYTE_MASK; |
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unsigned char clu_bits; |
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const unsigned char last_bit_mask[] = {0, 0b00000001, 0b00000011, |
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0b00000111, 0b00001111, 0b00011111, 0b00111111, 0b01111111}; |
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total_clus &= ~last_mask; |
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for (i = 0; i < total_clus; i += BITS_PER_BYTE) { |
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clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b); |
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count += used_bit[clu_bits]; |
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if (++map_b >= (unsigned int)sb->s_blocksize) { |
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map_i++; |
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map_b = 0; |
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} |
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} |
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if (last_mask) { |
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clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b); |
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clu_bits &= last_bit_mask[last_mask]; |
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count += used_bit[clu_bits]; |
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} |
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*ret_count = count; |
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return 0; |
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}
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