| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. |
| */ |
| |
| #include <linux/slab.h> |
| #include <asm/unaligned.h> |
| #include <linux/buffer_head.h> |
| |
| #include "exfat_raw.h" |
| #include "exfat_fs.h" |
| |
| static int exfat_mirror_bh(struct super_block *sb, sector_t sec, |
| struct buffer_head *bh) |
| { |
| struct buffer_head *c_bh; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| sector_t sec2; |
| int err = 0; |
| |
| if (sbi->FAT2_start_sector != sbi->FAT1_start_sector) { |
| sec2 = sec - sbi->FAT1_start_sector + sbi->FAT2_start_sector; |
| c_bh = sb_getblk(sb, sec2); |
| if (!c_bh) |
| return -ENOMEM; |
| memcpy(c_bh->b_data, bh->b_data, sb->s_blocksize); |
| set_buffer_uptodate(c_bh); |
| mark_buffer_dirty(c_bh); |
| if (sb->s_flags & SB_SYNCHRONOUS) |
| err = sync_dirty_buffer(c_bh); |
| brelse(c_bh); |
| } |
| |
| return err; |
| } |
| |
| static int __exfat_ent_get(struct super_block *sb, unsigned int loc, |
| unsigned int *content) |
| { |
| unsigned int off; |
| sector_t sec; |
| struct buffer_head *bh; |
| |
| sec = FAT_ENT_OFFSET_SECTOR(sb, loc); |
| off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc); |
| |
| bh = sb_bread(sb, sec); |
| if (!bh) |
| return -EIO; |
| |
| *content = le32_to_cpu(*(__le32 *)(&bh->b_data[off])); |
| |
| /* remap reserved clusters to simplify code */ |
| if (*content > EXFAT_BAD_CLUSTER) |
| *content = EXFAT_EOF_CLUSTER; |
| |
| brelse(bh); |
| return 0; |
| } |
| |
| int exfat_ent_set(struct super_block *sb, unsigned int loc, |
| unsigned int content) |
| { |
| unsigned int off; |
| sector_t sec; |
| __le32 *fat_entry; |
| struct buffer_head *bh; |
| |
| sec = FAT_ENT_OFFSET_SECTOR(sb, loc); |
| off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc); |
| |
| bh = sb_bread(sb, sec); |
| if (!bh) |
| return -EIO; |
| |
| fat_entry = (__le32 *)&(bh->b_data[off]); |
| *fat_entry = cpu_to_le32(content); |
| exfat_update_bh(sb, bh, sb->s_flags & SB_SYNCHRONOUS); |
| exfat_mirror_bh(sb, sec, bh); |
| brelse(bh); |
| return 0; |
| } |
| |
| static inline bool is_valid_cluster(struct exfat_sb_info *sbi, |
| unsigned int clus) |
| { |
| if (clus < EXFAT_FIRST_CLUSTER || sbi->num_clusters <= clus) |
| return false; |
| return true; |
| } |
| |
| int exfat_ent_get(struct super_block *sb, unsigned int loc, |
| unsigned int *content) |
| { |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| int err; |
| |
| if (!is_valid_cluster(sbi, loc)) { |
| exfat_fs_error(sb, "invalid access to FAT (entry 0x%08x)", |
| loc); |
| return -EIO; |
| } |
| |
| err = __exfat_ent_get(sb, loc, content); |
| if (err) { |
| exfat_fs_error(sb, |
| "failed to access to FAT (entry 0x%08x, err:%d)", |
| loc, err); |
| return err; |
| } |
| |
| if (*content == EXFAT_FREE_CLUSTER) { |
| exfat_fs_error(sb, |
| "invalid access to FAT free cluster (entry 0x%08x)", |
| loc); |
| return -EIO; |
| } |
| |
| if (*content == EXFAT_BAD_CLUSTER) { |
| exfat_fs_error(sb, |
| "invalid access to FAT bad cluster (entry 0x%08x)", |
| loc); |
| return -EIO; |
| } |
| |
| if (*content != EXFAT_EOF_CLUSTER && !is_valid_cluster(sbi, *content)) { |
| exfat_fs_error(sb, |
| "invalid access to FAT (entry 0x%08x) bogus content (0x%08x)", |
| loc, *content); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain, |
| unsigned int len) |
| { |
| if (!len) |
| return 0; |
| |
| while (len > 1) { |
| if (exfat_ent_set(sb, chain, chain + 1)) |
| return -EIO; |
| chain++; |
| len--; |
| } |
| |
| if (exfat_ent_set(sb, chain, EXFAT_EOF_CLUSTER)) |
| return -EIO; |
| return 0; |
| } |
| |
| int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain) |
| { |
| unsigned int num_clusters = 0; |
| unsigned int clu; |
| struct super_block *sb = inode->i_sb; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| |
| /* invalid cluster number */ |
| if (p_chain->dir == EXFAT_FREE_CLUSTER || |
| p_chain->dir == EXFAT_EOF_CLUSTER || |
| p_chain->dir < EXFAT_FIRST_CLUSTER) |
| return 0; |
| |
| /* no cluster to truncate */ |
| if (p_chain->size == 0) |
| return 0; |
| |
| /* check cluster validation */ |
| if (p_chain->dir < 2 && p_chain->dir >= sbi->num_clusters) { |
| exfat_err(sb, "invalid start cluster (%u)", p_chain->dir); |
| return -EIO; |
| } |
| |
| set_bit(EXFAT_SB_DIRTY, &sbi->s_state); |
| clu = p_chain->dir; |
| |
| if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { |
| do { |
| exfat_clear_bitmap(inode, clu); |
| clu++; |
| |
| num_clusters++; |
| } while (num_clusters < p_chain->size); |
| } else { |
| do { |
| exfat_clear_bitmap(inode, clu); |
| |
| if (exfat_get_next_cluster(sb, &clu)) |
| goto dec_used_clus; |
| |
| num_clusters++; |
| } while (clu != EXFAT_EOF_CLUSTER); |
| } |
| |
| dec_used_clus: |
| sbi->used_clusters -= num_clusters; |
| return 0; |
| } |
| |
| int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain, |
| unsigned int *ret_clu) |
| { |
| unsigned int clu, next; |
| unsigned int count = 0; |
| |
| next = p_chain->dir; |
| if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { |
| *ret_clu = next + p_chain->size - 1; |
| return 0; |
| } |
| |
| do { |
| count++; |
| clu = next; |
| if (exfat_ent_get(sb, clu, &next)) |
| return -EIO; |
| } while (next != EXFAT_EOF_CLUSTER); |
| |
| if (p_chain->size != count) { |
| exfat_fs_error(sb, |
| "bogus directory size (clus : ondisk(%d) != counted(%d))", |
| p_chain->size, count); |
| return -EIO; |
| } |
| |
| *ret_clu = clu; |
| return 0; |
| } |
| |
| static inline int exfat_sync_bhs(struct buffer_head **bhs, int nr_bhs) |
| { |
| int i, err = 0; |
| |
| for (i = 0; i < nr_bhs; i++) |
| write_dirty_buffer(bhs[i], 0); |
| |
| for (i = 0; i < nr_bhs; i++) { |
| wait_on_buffer(bhs[i]); |
| if (!err && !buffer_uptodate(bhs[i])) |
| err = -EIO; |
| } |
| return err; |
| } |
| |
| int exfat_zeroed_cluster(struct inode *dir, unsigned int clu) |
| { |
| struct super_block *sb = dir->i_sb; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| struct buffer_head *bhs[MAX_BUF_PER_PAGE]; |
| int nr_bhs = MAX_BUF_PER_PAGE; |
| sector_t blknr, last_blknr; |
| int err, i, n; |
| |
| blknr = exfat_cluster_to_sector(sbi, clu); |
| last_blknr = blknr + sbi->sect_per_clus; |
| |
| if (last_blknr > sbi->num_sectors && sbi->num_sectors > 0) { |
| exfat_fs_error_ratelimit(sb, |
| "%s: out of range(sect:%llu len:%u)", |
| __func__, (unsigned long long)blknr, |
| sbi->sect_per_clus); |
| return -EIO; |
| } |
| |
| /* Zeroing the unused blocks on this cluster */ |
| n = 0; |
| while (blknr < last_blknr) { |
| bhs[n] = sb_getblk(sb, blknr); |
| if (!bhs[n]) { |
| err = -ENOMEM; |
| goto release_bhs; |
| } |
| memset(bhs[n]->b_data, 0, sb->s_blocksize); |
| exfat_update_bh(sb, bhs[n], 0); |
| |
| n++; |
| blknr++; |
| |
| if (n == nr_bhs) { |
| if (IS_DIRSYNC(dir)) { |
| err = exfat_sync_bhs(bhs, n); |
| if (err) |
| goto release_bhs; |
| } |
| |
| for (i = 0; i < n; i++) |
| brelse(bhs[i]); |
| n = 0; |
| } |
| } |
| |
| if (IS_DIRSYNC(dir)) { |
| err = exfat_sync_bhs(bhs, n); |
| if (err) |
| goto release_bhs; |
| } |
| |
| for (i = 0; i < n; i++) |
| brelse(bhs[i]); |
| |
| return 0; |
| |
| release_bhs: |
| exfat_err(sb, "failed zeroed sect %llu\n", (unsigned long long)blknr); |
| for (i = 0; i < n; i++) |
| bforget(bhs[i]); |
| return err; |
| } |
| |
| int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, |
| struct exfat_chain *p_chain) |
| { |
| int ret = -ENOSPC; |
| unsigned int num_clusters = 0, total_cnt; |
| unsigned int hint_clu, new_clu, last_clu = EXFAT_EOF_CLUSTER; |
| struct super_block *sb = inode->i_sb; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| |
| total_cnt = EXFAT_DATA_CLUSTER_COUNT(sbi); |
| |
| if (unlikely(total_cnt < sbi->used_clusters)) { |
| exfat_fs_error_ratelimit(sb, |
| "%s: invalid used clusters(t:%u,u:%u)\n", |
| __func__, total_cnt, sbi->used_clusters); |
| return -EIO; |
| } |
| |
| if (num_alloc > total_cnt - sbi->used_clusters) |
| return -ENOSPC; |
| |
| hint_clu = p_chain->dir; |
| /* find new cluster */ |
| if (hint_clu == EXFAT_EOF_CLUSTER) { |
| if (sbi->clu_srch_ptr < EXFAT_FIRST_CLUSTER) { |
| exfat_err(sb, "sbi->clu_srch_ptr is invalid (%u)\n", |
| sbi->clu_srch_ptr); |
| sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER; |
| } |
| |
| hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr); |
| if (hint_clu == EXFAT_EOF_CLUSTER) |
| return -ENOSPC; |
| } |
| |
| /* check cluster validation */ |
| if (hint_clu < EXFAT_FIRST_CLUSTER && hint_clu >= sbi->num_clusters) { |
| exfat_err(sb, "hint_cluster is invalid (%u)", |
| hint_clu); |
| hint_clu = EXFAT_FIRST_CLUSTER; |
| if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { |
| if (exfat_chain_cont_cluster(sb, p_chain->dir, |
| num_clusters)) |
| return -EIO; |
| p_chain->flags = ALLOC_FAT_CHAIN; |
| } |
| } |
| |
| set_bit(EXFAT_SB_DIRTY, &sbi->s_state); |
| |
| p_chain->dir = EXFAT_EOF_CLUSTER; |
| |
| while ((new_clu = exfat_find_free_bitmap(sb, hint_clu)) != |
| EXFAT_EOF_CLUSTER) { |
| if (new_clu != hint_clu && |
| p_chain->flags == ALLOC_NO_FAT_CHAIN) { |
| if (exfat_chain_cont_cluster(sb, p_chain->dir, |
| num_clusters)) { |
| ret = -EIO; |
| goto free_cluster; |
| } |
| p_chain->flags = ALLOC_FAT_CHAIN; |
| } |
| |
| /* update allocation bitmap */ |
| if (exfat_set_bitmap(inode, new_clu)) { |
| ret = -EIO; |
| goto free_cluster; |
| } |
| |
| num_clusters++; |
| |
| /* update FAT table */ |
| if (p_chain->flags == ALLOC_FAT_CHAIN) { |
| if (exfat_ent_set(sb, new_clu, EXFAT_EOF_CLUSTER)) { |
| ret = -EIO; |
| goto free_cluster; |
| } |
| } |
| |
| if (p_chain->dir == EXFAT_EOF_CLUSTER) { |
| p_chain->dir = new_clu; |
| } else if (p_chain->flags == ALLOC_FAT_CHAIN) { |
| if (exfat_ent_set(sb, last_clu, new_clu)) { |
| ret = -EIO; |
| goto free_cluster; |
| } |
| } |
| last_clu = new_clu; |
| |
| if (--num_alloc == 0) { |
| sbi->clu_srch_ptr = hint_clu; |
| sbi->used_clusters += num_clusters; |
| |
| p_chain->size += num_clusters; |
| return 0; |
| } |
| |
| hint_clu = new_clu + 1; |
| if (hint_clu >= sbi->num_clusters) { |
| hint_clu = EXFAT_FIRST_CLUSTER; |
| |
| if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { |
| if (exfat_chain_cont_cluster(sb, p_chain->dir, |
| num_clusters)) { |
| ret = -EIO; |
| goto free_cluster; |
| } |
| p_chain->flags = ALLOC_FAT_CHAIN; |
| } |
| } |
| } |
| free_cluster: |
| if (num_clusters) |
| exfat_free_cluster(inode, p_chain); |
| return ret; |
| } |
| |
| int exfat_count_num_clusters(struct super_block *sb, |
| struct exfat_chain *p_chain, unsigned int *ret_count) |
| { |
| unsigned int i, count; |
| unsigned int clu; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| |
| if (!p_chain->dir || p_chain->dir == EXFAT_EOF_CLUSTER) { |
| *ret_count = 0; |
| return 0; |
| } |
| |
| if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { |
| *ret_count = p_chain->size; |
| return 0; |
| } |
| |
| clu = p_chain->dir; |
| count = 0; |
| for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters; i++) { |
| count++; |
| if (exfat_ent_get(sb, clu, &clu)) |
| return -EIO; |
| if (clu == EXFAT_EOF_CLUSTER) |
| break; |
| } |
| |
| *ret_count = count; |
| return 0; |
| } |