diff options
Diffstat (limited to 'fs/exfat/dir.c')
| -rw-r--r-- | fs/exfat/dir.c | 1411 |
1 files changed, 1411 insertions, 0 deletions
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c new file mode 100644 index 000000000000..3045a58e124a --- /dev/null +++ b/fs/exfat/dir.c @@ -0,0 +1,1411 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. + */ + +#include <linux/slab.h> +#include <linux/compat.h> +#include <linux/bio.h> +#include <linux/buffer_head.h> + +#include "exfat_raw.h" +#include "exfat_fs.h" + +static int exfat_extract_uni_name(struct exfat_dentry *ep, + unsigned short *uniname) +{ + int i, len = 0; + + for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { + *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]); + if (*uniname == 0x0) + return len; + uniname++; + len++; + } + + *uniname = 0x0; + return len; + +} + +static int exfat_get_uniname_from_ext_entry(struct super_block *sb, + struct exfat_chain *p_dir, int entry, unsigned short *uniname) +{ + int i, err; + struct exfat_entry_set_cache es; + unsigned int uni_len = 0, len; + + err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES); + if (err) + return err; + + /* + * First entry : file entry + * Second entry : stream-extension entry + * Third entry : first file-name entry + * So, the index of first file-name dentry should start from 2. + */ + for (i = ES_IDX_FIRST_FILENAME; i < es.num_entries; i++) { + struct exfat_dentry *ep = exfat_get_dentry_cached(&es, i); + + /* end of name entry */ + if (exfat_get_entry_type(ep) != TYPE_EXTEND) + break; + + len = exfat_extract_uni_name(ep, uniname); + uni_len += len; + if (len != EXFAT_FILE_NAME_LEN || uni_len >= MAX_NAME_LENGTH) + break; + uniname += EXFAT_FILE_NAME_LEN; + } + + exfat_put_dentry_set(&es, false); + return 0; +} + +/* read a directory entry from the opened directory */ +static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) +{ + int i, dentries_per_clu, num_ext, err; + unsigned int type, clu_offset, max_dentries; + struct exfat_chain dir, clu; + struct exfat_uni_name uni_name; + struct exfat_dentry *ep; + struct super_block *sb = inode->i_sb; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_inode_info *ei = EXFAT_I(inode); + unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; + struct buffer_head *bh; + + /* check if the given file ID is opened */ + if (ei->type != TYPE_DIR) + return -EPERM; + + exfat_chain_set(&dir, ei->start_clu, + EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); + + dentries_per_clu = sbi->dentries_per_clu; + max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES, + (u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi)); + + clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi); + exfat_chain_dup(&clu, &dir); + + if (clu.flags == ALLOC_NO_FAT_CHAIN) { + clu.dir += clu_offset; + clu.size -= clu_offset; + } else { + /* hint_information */ + if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && + ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { + clu_offset -= ei->hint_bmap.off; + clu.dir = ei->hint_bmap.clu; + } + + while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) { + if (exfat_get_next_cluster(sb, &(clu.dir))) + return -EIO; + + clu_offset--; + } + } + + while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) { + i = dentry & (dentries_per_clu - 1); + + for ( ; i < dentries_per_clu; i++, dentry++) { + ep = exfat_get_dentry(sb, &clu, i, &bh); + if (!ep) + return -EIO; + + type = exfat_get_entry_type(ep); + if (type == TYPE_UNUSED) { + brelse(bh); + goto out; + } + + if (type != TYPE_FILE && type != TYPE_DIR) { + brelse(bh); + continue; + } + + num_ext = ep->dentry.file.num_ext; + dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); + + *uni_name.name = 0x0; + err = exfat_get_uniname_from_ext_entry(sb, &clu, i, + uni_name.name); + if (err) { + brelse(bh); + continue; + } + exfat_utf16_to_nls(sb, &uni_name, + dir_entry->namebuf.lfn, + dir_entry->namebuf.lfnbuf_len); + brelse(bh); + + ep = exfat_get_dentry(sb, &clu, i + 1, &bh); + if (!ep) + return -EIO; + dir_entry->entry = i; + dir_entry->dir = clu; + brelse(bh); + + ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi); + ei->hint_bmap.clu = clu.dir; + + *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); + return 0; + } + + if (clu.flags == ALLOC_NO_FAT_CHAIN) { + if (--clu.size > 0) + clu.dir++; + else + clu.dir = EXFAT_EOF_CLUSTER; + } else { + if (exfat_get_next_cluster(sb, &(clu.dir))) + return -EIO; + } + } + +out: + dir_entry->namebuf.lfn[0] = '\0'; + *cpos = EXFAT_DEN_TO_B(dentry); + return 0; +} + +static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) +{ + nb->lfn = NULL; + nb->lfnbuf_len = 0; +} + +static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) +{ + nb->lfn = __getname(); + if (!nb->lfn) + return -ENOMEM; + nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; + return 0; +} + +static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) +{ + if (!nb->lfn) + return; + + __putname(nb->lfn); + exfat_init_namebuf(nb); +} + +/* + * Before calling dir_emit*(), sbi->s_lock should be released + * because page fault can occur in dir_emit*(). + */ +#define ITER_POS_FILLED_DOTS (2) +static int exfat_iterate(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + struct super_block *sb = inode->i_sb; + struct inode *tmp; + struct exfat_dir_entry de; + struct exfat_dentry_namebuf *nb = &(de.namebuf); + struct exfat_inode_info *ei = EXFAT_I(inode); + unsigned long inum; + loff_t cpos, i_pos; + int err = 0, fake_offset = 0; + + exfat_init_namebuf(nb); + + cpos = ctx->pos; + if (!dir_emit_dots(file, ctx)) + goto out; + + if (ctx->pos == ITER_POS_FILLED_DOTS) { + cpos = 0; + fake_offset = 1; + } + + cpos = round_up(cpos, DENTRY_SIZE); + + /* name buffer should be allocated before use */ + err = exfat_alloc_namebuf(nb); + if (err) + goto out; +get_new: + mutex_lock(&EXFAT_SB(sb)->s_lock); + + if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode)) + goto end_of_dir; + + err = exfat_readdir(inode, &cpos, &de); + if (err) { + /* + * At least we tried to read a sector. + * Move cpos to next sector position (should be aligned). + */ + if (err == -EIO) { + cpos += 1 << (sb->s_blocksize_bits); + cpos &= ~(sb->s_blocksize - 1); + } + + err = -EIO; + goto end_of_dir; + } + + if (!nb->lfn[0]) + goto end_of_dir; + + i_pos = ((loff_t)de.dir.dir << 32) | (de.entry & 0xffffffff); + tmp = exfat_iget(sb, i_pos); + if (tmp) { + inum = tmp->i_ino; + iput(tmp); + } else { + inum = iunique(sb, EXFAT_ROOT_INO); + } + + mutex_unlock(&EXFAT_SB(sb)->s_lock); + if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, + (de.attr & EXFAT_ATTR_SUBDIR) ? DT_DIR : DT_REG)) + goto out; + ctx->pos = cpos; + goto get_new; + +end_of_dir: + if (!cpos && fake_offset) + cpos = ITER_POS_FILLED_DOTS; + ctx->pos = cpos; + mutex_unlock(&EXFAT_SB(sb)->s_lock); +out: + /* + * To improve performance, free namebuf after unlock sb_lock. + * If namebuf is not allocated, this function do nothing + */ + exfat_free_namebuf(nb); + return err; +} + +WRAP_DIR_ITER(exfat_iterate) // FIXME! +const struct file_operations exfat_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = shared_exfat_iterate, + .unlocked_ioctl = exfat_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = exfat_compat_ioctl, +#endif + .fsync = exfat_file_fsync, +}; + +int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) +{ + int ret; + + exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); + + ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode)); + if (ret) + return ret; + + return exfat_zeroed_cluster(inode, clu->dir); +} + +int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) +{ + int len; + + len = p_uniname->name_len; + if (len == 0) + return -EINVAL; + + /* 1 file entry + 1 stream entry + name entries */ + return ES_ENTRY_NUM(len); +} + +unsigned int exfat_get_entry_type(struct exfat_dentry *ep) +{ + if (ep->type == EXFAT_UNUSED) + return TYPE_UNUSED; + if (IS_EXFAT_DELETED(ep->type)) + return TYPE_DELETED; + if (ep->type == EXFAT_INVAL) + return TYPE_INVALID; + if (IS_EXFAT_CRITICAL_PRI(ep->type)) { + if (ep->type == EXFAT_BITMAP) + return TYPE_BITMAP; + if (ep->type == EXFAT_UPCASE) + return TYPE_UPCASE; + if (ep->type == EXFAT_VOLUME) + return TYPE_VOLUME; + if (ep->type == EXFAT_FILE) { + if (le16_to_cpu(ep->dentry.file.attr) & EXFAT_ATTR_SUBDIR) + return TYPE_DIR; + return TYPE_FILE; + } + return TYPE_CRITICAL_PRI; + } + if (IS_EXFAT_BENIGN_PRI(ep->type)) { + if (ep->type == EXFAT_GUID) + return TYPE_GUID; + if (ep->type == EXFAT_PADDING) + return TYPE_PADDING; + if (ep->type == EXFAT_ACLTAB) + return TYPE_ACLTAB; + return TYPE_BENIGN_PRI; + } + if (IS_EXFAT_CRITICAL_SEC(ep->type)) { + if (ep->type == EXFAT_STREAM) + return TYPE_STREAM; + if (ep->type == EXFAT_NAME) + return TYPE_EXTEND; + if (ep->type == EXFAT_ACL) + return TYPE_ACL; + return TYPE_CRITICAL_SEC; + } + + if (ep->type == EXFAT_VENDOR_EXT) + return TYPE_VENDOR_EXT; + if (ep->type == EXFAT_VENDOR_ALLOC) + return TYPE_VENDOR_ALLOC; + + return TYPE_BENIGN_SEC; +} + +static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) +{ + if (type == TYPE_UNUSED) { + ep->type = EXFAT_UNUSED; + } else if (type == TYPE_DELETED) { + ep->type &= EXFAT_DELETE; + } else if (type == TYPE_STREAM) { + ep->type = EXFAT_STREAM; + } else if (type == TYPE_EXTEND) { + ep->type = EXFAT_NAME; + } else if (type == TYPE_BITMAP) { + ep->type = EXFAT_BITMAP; + } else if (type == TYPE_UPCASE) { + ep->type = EXFAT_UPCASE; + } else if (type == TYPE_VOLUME) { + ep->type = EXFAT_VOLUME; + } else if (type == TYPE_DIR) { + ep->type = EXFAT_FILE; + ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_SUBDIR); + } else if (type == TYPE_FILE) { + ep->type = EXFAT_FILE; + ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_ARCHIVE); + } +} + +static void exfat_init_stream_entry(struct exfat_dentry *ep, + unsigned int start_clu, unsigned long long size) +{ + memset(ep, 0, sizeof(*ep)); + exfat_set_entry_type(ep, TYPE_STREAM); + if (size == 0) + ep->dentry.stream.flags = ALLOC_FAT_CHAIN; + else + ep->dentry.stream.flags = ALLOC_NO_FAT_CHAIN; + ep->dentry.stream.start_clu = cpu_to_le32(start_clu); + ep->dentry.stream.valid_size = cpu_to_le64(size); + ep->dentry.stream.size = cpu_to_le64(size); +} + +static void exfat_init_name_entry(struct exfat_dentry *ep, + unsigned short *uniname) +{ + int i; + + exfat_set_entry_type(ep, TYPE_EXTEND); + ep->dentry.name.flags = 0x0; + + for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { + if (*uniname != 0x0) { + ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); + uniname++; + } else { + ep->dentry.name.unicode_0_14[i] = 0x0; + } + } +} + +void exfat_init_dir_entry(struct exfat_entry_set_cache *es, + unsigned int type, unsigned int start_clu, + unsigned long long size, struct timespec64 *ts) +{ + struct super_block *sb = es->sb; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_dentry *ep; + + ep = exfat_get_dentry_cached(es, ES_IDX_FILE); + memset(ep, 0, sizeof(*ep)); + exfat_set_entry_type(ep, type); + exfat_set_entry_time(sbi, ts, + &ep->dentry.file.create_tz, + &ep->dentry.file.create_time, + &ep->dentry.file.create_date, + &ep->dentry.file.create_time_cs); + exfat_set_entry_time(sbi, ts, + &ep->dentry.file.modify_tz, + &ep->dentry.file.modify_time, + &ep->dentry.file.modify_date, + &ep->dentry.file.modify_time_cs); + exfat_set_entry_time(sbi, ts, + &ep->dentry.file.access_tz, + &ep->dentry.file.access_time, + &ep->dentry.file.access_date, + NULL); + + ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); + exfat_init_stream_entry(ep, start_clu, size); +} + +static void exfat_free_benign_secondary_clusters(struct inode *inode, + struct exfat_dentry *ep) +{ + struct super_block *sb = inode->i_sb; + struct exfat_chain dir; + unsigned int start_clu = + le32_to_cpu(ep->dentry.generic_secondary.start_clu); + u64 size = le64_to_cpu(ep->dentry.generic_secondary.size); + unsigned char flags = ep->dentry.generic_secondary.flags; + + if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size) + return; + + exfat_chain_set(&dir, start_clu, + EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)), + flags); + exfat_free_cluster(inode, &dir); +} + +void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries, + struct exfat_uni_name *p_uniname) +{ + int i; + unsigned short *uniname = p_uniname->name; + struct exfat_dentry *ep; + + ep = exfat_get_dentry_cached(es, ES_IDX_FILE); + ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); + + ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); + ep->dentry.stream.name_len = p_uniname->name_len; + ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); + + for (i = ES_IDX_FIRST_FILENAME; i < num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + exfat_init_name_entry(ep, uniname); + uniname += EXFAT_FILE_NAME_LEN; + } + + exfat_update_dir_chksum(es); +} + +void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es, + int order) +{ + int i; + struct exfat_dentry *ep; + + for (i = order; i < es->num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + + if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC) + exfat_free_benign_secondary_clusters(inode, ep); + + exfat_set_entry_type(ep, TYPE_DELETED); + } + + if (order < es->num_entries) + es->modified = true; +} + +void exfat_update_dir_chksum(struct exfat_entry_set_cache *es) +{ + int chksum_type = CS_DIR_ENTRY, i; + unsigned short chksum = 0; + struct exfat_dentry *ep; + + for (i = ES_IDX_FILE; i < es->num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, + chksum_type); + chksum_type = CS_DEFAULT; + } + ep = exfat_get_dentry_cached(es, ES_IDX_FILE); + ep->dentry.file.checksum = cpu_to_le16(chksum); + es->modified = true; +} + +int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync) +{ + int i, err = 0; + + if (es->modified) + err = exfat_update_bhs(es->bh, es->num_bh, sync); + + for (i = 0; i < es->num_bh; i++) + if (err) + bforget(es->bh[i]); + else + brelse(es->bh[i]); + + if (IS_DYNAMIC_ES(es)) + kfree(es->bh); + + return err; +} + +static int exfat_walk_fat_chain(struct super_block *sb, + struct exfat_chain *p_dir, unsigned int byte_offset, + unsigned int *clu) +{ + struct exfat_sb_info *sbi = EXFAT_SB(sb); + unsigned int clu_offset; + unsigned int cur_clu; + + clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); + cur_clu = p_dir->dir; + + if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { + cur_clu += clu_offset; + } else { + while (clu_offset > 0) { + if (exfat_get_next_cluster(sb, &cur_clu)) + return -EIO; + if (cur_clu == EXFAT_EOF_CLUSTER) { + exfat_fs_error(sb, + "invalid dentry access beyond EOF (clu : %u, eidx : %d)", + p_dir->dir, + EXFAT_B_TO_DEN(byte_offset)); + return -EIO; + } + clu_offset--; + } + } + + *clu = cur_clu; + return 0; +} + +static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, + int entry, sector_t *sector, int *offset) +{ + int ret; + unsigned int off, clu = 0; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + + off = EXFAT_DEN_TO_B(entry); + + ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); + if (ret) + return ret; + + if (!exfat_test_bitmap(sb, clu)) { + exfat_err(sb, "failed to test cluster bit(%u)", clu); + return -EIO; + } + + /* byte offset in cluster */ + off = EXFAT_CLU_OFFSET(off, sbi); + + /* byte offset in sector */ + *offset = EXFAT_BLK_OFFSET(off, sb); + + /* sector offset in cluster */ + *sector = EXFAT_B_TO_BLK(off, sb); + *sector += exfat_cluster_to_sector(sbi, clu); + return 0; +} + +#define EXFAT_MAX_RA_SIZE (128*1024) +static int exfat_dir_readahead(struct super_block *sb, sector_t sec) +{ + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct buffer_head *bh; + unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; + unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; + unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); + unsigned int ra_count = min(adj_ra_count, max_ra_count); + + /* Read-ahead is not required */ + if (sbi->sect_per_clus == 1) + return 0; + + if (sec < sbi->data_start_sector) { + exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", + (unsigned long long)sec, sbi->data_start_sector); + return -EIO; + } + + /* Not sector aligned with ra_count, resize ra_count to page size */ + if ((sec - sbi->data_start_sector) & (ra_count - 1)) + ra_count = page_ra_count; + + bh = sb_find_get_block(sb, sec); + if (!bh || !buffer_uptodate(bh)) { + unsigned int i; + + for (i = 0; i < ra_count; i++) + sb_breadahead(sb, (sector_t)(sec + i)); + } + brelse(bh); + return 0; +} + +struct exfat_dentry *exfat_get_dentry(struct super_block *sb, + struct exfat_chain *p_dir, int entry, struct buffer_head **bh) +{ + unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); + int off; + sector_t sec; + + if (p_dir->dir == DIR_DELETED) { + exfat_err(sb, "abnormal access to deleted dentry"); + return NULL; + } + + if (exfat_find_location(sb, p_dir, entry, &sec, &off)) + return NULL; + + if (p_dir->dir != EXFAT_FREE_CLUSTER && + !(entry & (dentries_per_page - 1))) + exfat_dir_readahead(sb, sec); + + *bh = sb_bread(sb, sec); + if (!*bh) + return NULL; + + return (struct exfat_dentry *)((*bh)->b_data + off); +} + +enum exfat_validate_dentry_mode { + ES_MODE_GET_FILE_ENTRY, + ES_MODE_GET_STRM_ENTRY, + ES_MODE_GET_NAME_ENTRY, + ES_MODE_GET_CRITICAL_SEC_ENTRY, + ES_MODE_GET_BENIGN_SEC_ENTRY, +}; + +static bool exfat_validate_entry(unsigned int type, + enum exfat_validate_dentry_mode *mode) +{ + if (type == TYPE_UNUSED || type == TYPE_DELETED) + return false; + + switch (*mode) { + case ES_MODE_GET_FILE_ENTRY: + if (type != TYPE_STREAM) + return false; + *mode = ES_MODE_GET_STRM_ENTRY; + break; + case ES_MODE_GET_STRM_ENTRY: + if (type != TYPE_EXTEND) + return false; + *mode = ES_MODE_GET_NAME_ENTRY; + break; + case ES_MODE_GET_NAME_ENTRY: + if (type & TYPE_BENIGN_SEC) + *mode = ES_MODE_GET_BENIGN_SEC_ENTRY; + else if (type != TYPE_EXTEND) + return false; + break; + case ES_MODE_GET_BENIGN_SEC_ENTRY: + /* Assume unreconized benign secondary entry */ + if (!(type & TYPE_BENIGN_SEC)) + return false; + break; + default: + return false; + } + + return true; +} + +struct exfat_dentry *exfat_get_dentry_cached( + struct exfat_entry_set_cache *es, int num) +{ + int off = es->start_off + num * DENTRY_SIZE; + struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; + char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); + + return (struct exfat_dentry *)p; +} + +/* + * Returns a set of dentries. + * + * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). + * User should call exfat_get_dentry_set() after setting 'modified' to apply + * changes made in this entry set to the real device. + * + * in: + * sb+p_dir+entry: indicates a file/dir + * num_entries: specifies how many dentries should be included. + * It will be set to es->num_entries if it is not 0. + * If num_entries is 0, es->num_entries will be obtained + * from the first dentry. + * out: + * es: pointer of entry set on success. + * return: + * 0 on success + * -error code on failure + */ +static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es, + struct super_block *sb, struct exfat_chain *p_dir, int entry, + unsigned int num_entries) +{ + int ret, i, num_bh; + unsigned int off; + sector_t sec; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct buffer_head *bh; + + if (p_dir->dir == DIR_DELETED) { + exfat_err(sb, "access to deleted dentry"); + return -EIO; + } + + ret = exfat_find_location(sb, p_dir, entry, &sec, &off); + if (ret) + return ret; + + memset(es, 0, sizeof(*es)); + es->sb = sb; + es->modified = false; + es->start_off = off; + es->bh = es->__bh; + + bh = sb_bread(sb, sec); + if (!bh) + return -EIO; + es->bh[es->num_bh++] = bh; + + if (num_entries == ES_ALL_ENTRIES) { + struct exfat_dentry *ep; + + ep = exfat_get_dentry_cached(es, ES_IDX_FILE); + if (ep->type != EXFAT_FILE) { + brelse(bh); + return -EIO; + } + + num_entries = ep->dentry.file.num_ext + 1; + } + + es->num_entries = num_entries; + + num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); + if (num_bh > ARRAY_SIZE(es->__bh)) { + es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_NOFS); + if (!es->bh) { + brelse(bh); + return -ENOMEM; + } + es->bh[0] = bh; + } + + for (i = 1; i < num_bh; i++) { + /* get the next sector */ + if (exfat_is_last_sector_in_cluster(sbi, sec)) { + unsigned int clu = exfat_sector_to_cluster(sbi, sec); + + if (p_dir->flags == ALLOC_NO_FAT_CHAIN) + clu++; + else if (exfat_get_next_cluster(sb, &clu)) + goto put_es; + sec = exfat_cluster_to_sector(sbi, clu); + } else { + sec++; + } + + bh = sb_bread(sb, sec); + if (!bh) + goto put_es; + es->bh[es->num_bh++] = bh; + } + + return 0; + +put_es: + exfat_put_dentry_set(es, false); + return -EIO; +} + +int exfat_get_dentry_set(struct exfat_entry_set_cache *es, + struct super_block *sb, struct exfat_chain *p_dir, + int entry, unsigned int num_entries) +{ + int ret, i; + struct exfat_dentry *ep; + enum exfat_validate_dentry_mode mode = ES_MODE_GET_FILE_ENTRY; + + ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); + if (ret < 0) + return ret; + + /* validate cached dentries */ + for (i = ES_IDX_STREAM; i < es->num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) + goto put_es; + } + return 0; + +put_es: + exfat_put_dentry_set(es, false); + return -EIO; +} + +static int exfat_validate_empty_dentry_set(struct exfat_entry_set_cache *es) +{ + struct exfat_dentry *ep; + struct buffer_head *bh; + int i, off; + bool unused_hit = false; + + /* + * ONLY UNUSED OR DELETED DENTRIES ARE ALLOWED: + * Although it violates the specification for a deleted entry to + * follow an unused entry, some exFAT implementations could work + * like this. Therefore, to improve compatibility, let's allow it. + */ + for (i = 0; i < es->num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + if (ep->type == EXFAT_UNUSED) { + unused_hit = true; + } else if (!IS_EXFAT_DELETED(ep->type)) { + if (unused_hit) + goto err_used_follow_unused; + i++; + goto count_skip_entries; + } + } + + return 0; + +err_used_follow_unused: + off = es->start_off + (i << DENTRY_SIZE_BITS); + bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; + + exfat_fs_error(es->sb, + "in sector %lld, dentry %d should be unused, but 0x%x", + bh->b_blocknr, off >> DENTRY_SIZE_BITS, ep->type); + + return -EIO; + +count_skip_entries: + es->num_entries = EXFAT_B_TO_DEN(EXFAT_BLK_TO_B(es->num_bh, es->sb) - es->start_off); + for (; i < es->num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + if (IS_EXFAT_DELETED(ep->type)) + break; + } + + return i; +} + +/* + * Get an empty dentry set. + * + * in: + * sb+p_dir+entry: indicates the empty dentry location + * num_entries: specifies how many empty dentries should be included. + * out: + * es: pointer of empty dentry set on success. + * return: + * 0 : on success + * >0 : the dentries are not empty, the return value is the number of + * dentries to be skipped for the next lookup. + * <0 : on failure + */ +int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es, + struct super_block *sb, struct exfat_chain *p_dir, + int entry, unsigned int num_entries) +{ + int ret; + + ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); + if (ret < 0) + return ret; + + ret = exfat_validate_empty_dentry_set(es); + if (ret) + exfat_put_dentry_set(es, false); + + return ret; +} + +static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp) +{ + hint_femp->eidx = EXFAT_HINT_NONE; + hint_femp->count = 0; +} + +static inline void exfat_set_empty_hint(struct exfat_inode_info *ei, + struct exfat_hint_femp *candi_empty, struct exfat_chain *clu, + int dentry, int num_entries, int entry_type) +{ + if (ei->hint_femp.eidx == EXFAT_HINT_NONE || + ei->hint_femp.eidx > dentry) { + int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode)); + + if (candi_empty->count == 0) { + candi_empty->cur = *clu; + candi_empty->eidx = dentry; + } + + if (entry_type == TYPE_UNUSED) + candi_empty->count += total_entries - dentry; + else + candi_empty->count++; + + if (candi_empty->count == num_entries || + candi_empty->count + candi_empty->eidx == total_entries) + ei->hint_femp = *candi_empty; + } +} + +enum { + DIRENT_STEP_FILE, + DIRENT_STEP_STRM, + DIRENT_STEP_NAME, + DIRENT_STEP_SECD, +}; + +/* + * @ei: inode info of parent directory + * @p_dir: directory structure of parent directory + * @num_entries:entry size of p_uniname + * @hint_opt: If p_uniname is found, filled with optimized dir/entry + * for traversing cluster chain. + * @return: + * >= 0: file directory entry position where the name exists + * -ENOENT: entry with the name does not exist + * -EIO: I/O error + */ +int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, + struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, + struct exfat_hint *hint_opt) +{ + int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; + int order, step, name_len = 0; + int dentries_per_clu; + unsigned int entry_type; + unsigned short *uniname = NULL; + struct exfat_chain clu; + struct exfat_hint *hint_stat = &ei->hint_stat; + struct exfat_hint_femp candi_empty; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + int num_entries = exfat_calc_num_entries(p_uniname); + unsigned int clu_count = 0; + + if (num_entries < 0) + return num_entries; + + dentries_per_clu = sbi->dentries_per_clu; + + exfat_chain_dup(&clu, p_dir); + + if (hint_stat->eidx) { + clu.dir = hint_stat->clu; + dentry = hint_stat->eidx; + end_eidx = dentry; + } + + exfat_reset_empty_hint(&ei->hint_femp); + +rewind: + order = 0; + step = DIRENT_STEP_FILE; + exfat_reset_empty_hint(&candi_empty); + + while (clu.dir != EXFAT_EOF_CLUSTER) { + i = dentry & (dentries_per_clu - 1); + for (; i < dentries_per_clu; i++, dentry++) { + struct exfat_dentry *ep; + struct buffer_head *bh; + + if (rewind && dentry == end_eidx) + goto not_found; + + ep = exfat_get_dentry(sb, &clu, i, &bh); + if (!ep) + return -EIO; + + entry_type = exfat_get_entry_type(ep); + + if (entry_type == TYPE_UNUSED || + entry_type == TYPE_DELETED) { + step = DIRENT_STEP_FILE; + + exfat_set_empty_hint(ei, &candi_empty, &clu, + dentry, num_entries, + entry_type); + + brelse(bh); + if (entry_type == TYPE_UNUSED) + goto not_found; + continue; + } + + exfat_reset_empty_hint(&candi_empty); + + if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { + step = DIRENT_STEP_FILE; + hint_opt->clu = clu.dir; + hint_opt->eidx = i; + num_ext = ep->dentry.file.num_ext; + step = DIRENT_STEP_STRM; + brelse(bh); + continue; + } + + if (entry_type == TYPE_STREAM) { + u16 name_hash; + + if (step != DIRENT_STEP_STRM) { + step = DIRENT_STEP_FILE; + brelse(bh); + continue; + } + step = DIRENT_STEP_FILE; + name_hash = le16_to_cpu( + ep->dentry.stream.name_hash); + if (p_uniname->name_hash == name_hash && + p_uniname->name_len == + ep->dentry.stream.name_len) { + step = DIRENT_STEP_NAME; + order = 1; + name_len = 0; + } + brelse(bh); + continue; + } + + brelse(bh); + if (entry_type == TYPE_EXTEND) { + unsigned short entry_uniname[16], unichar; + + if (step != DIRENT_STEP_NAME || + name_len >= MAX_NAME_LENGTH) { + step = DIRENT_STEP_FILE; + continue; + } + + if (++order == 2) + uniname = p_uniname->name; + else + uniname += EXFAT_FILE_NAME_LEN; + + len = exfat_extract_uni_name(ep, entry_uniname); + name_len += len; + + unichar = *(uniname+len); + *(uniname+len) = 0x0; + + if (exfat_uniname_ncmp(sb, uniname, + entry_uniname, len)) { + step = DIRENT_STEP_FILE; + } else if (p_uniname->name_len == name_len) { + if (order == num_ext) + goto found; + step = DIRENT_STEP_SECD; + } + + *(uniname+len) = unichar; + continue; + } + + if (entry_type & + (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { + if (step == DIRENT_STEP_SECD) { + if (++order == num_ext) + goto found; + continue; + } + } + step = DIRENT_STEP_FILE; + } + + if (clu.flags == ALLOC_NO_FAT_CHAIN) { + if (--clu.size > 0) + clu.dir++; + else + clu.dir = EXFAT_EOF_CLUSTER; + } else { + if (exfat_get_next_cluster(sb, &clu.dir)) + return -EIO; + + /* break if the cluster chain includes a loop */ + if (unlikely(++clu_count > EXFAT_DATA_CLUSTER_COUNT(sbi))) + goto not_found; + } + } + +not_found: + /* + * We started at not 0 index,so we should try to find target + * from 0 index to the index we started at. + */ + if (!rewind && end_eidx) { + rewind = 1; + dentry = 0; + clu.dir = p_dir->dir; + goto rewind; + } + + /* + * set the EXFAT_EOF_CLUSTER flag to avoid search + * from the beginning again when allocated a new cluster + */ + if (ei->hint_femp.eidx == EXFAT_HINT_NONE) { + ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER; + ei->hint_femp.eidx = p_dir->size * dentries_per_clu; + ei->hint_femp.count = 0; + } + + /* initialized hint_stat */ + hint_stat->clu = p_dir->dir; + hint_stat->eidx = 0; + return -ENOENT; + +found: + /* next dentry we'll find is out of this cluster */ + if (!((dentry + 1) & (dentries_per_clu - 1))) { + int ret = 0; + + if (clu.flags == ALLOC_NO_FAT_CHAIN) { + if (--clu.size > 0) + clu.dir++; + else + clu.dir = EXFAT_EOF_CLUSTER; + } else { + ret = exfat_get_next_cluster(sb, &clu.dir); + } + + if (ret || clu.dir == EXFAT_EOF_CLUSTER) { + /* just initialized hint_stat */ + hint_stat->clu = p_dir->dir; + hint_stat->eidx = 0; + return (dentry - num_ext); + } + } + + hint_stat->clu = clu.dir; + hint_stat->eidx = dentry + 1; + return dentry - num_ext; +} + +int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) +{ + int i, count = 0; + int dentries_per_clu; + unsigned int entry_type; + unsigned int clu_count = 0; + struct exfat_chain clu; + struct exfat_dentry *ep; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct buffer_head *bh; + + dentries_per_clu = sbi->dentries_per_clu; + + exfat_chain_dup(&clu, p_dir); + + while (clu.dir != EXFAT_EOF_CLUSTER) { + for (i = 0; i < dentries_per_clu; i++) { + ep = exfat_get_dentry(sb, &clu, i, &bh); + if (!ep) + return -EIO; + entry_type = exfat_get_entry_type(ep); + brelse(bh); + + if (entry_type == TYPE_UNUSED) + return count; + if (entry_type != TYPE_DIR) + continue; + count++; + } + + if (clu.flags == ALLOC_NO_FAT_CHAIN) { + if (--clu.size > 0) + clu.dir++; + else + clu.dir = EXFAT_EOF_CLUSTER; + } else { + if (exfat_get_next_cluster(sb, &(clu.dir))) + return -EIO; + + if (unlikely(++clu_count > sbi->used_clusters)) { + exfat_fs_error(sb, "FAT or bitmap is corrupted"); + return -EIO; + } + + } + } + + return count; +} + +static int exfat_get_volume_label_dentry(struct super_block *sb, + struct exfat_entry_set_cache *es) +{ + int i; + int dentry = 0; + unsigned int type; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_hint_femp hint_femp; + struct exfat_inode_info *ei = EXFAT_I(sb->s_root->d_inode); + struct exfat_chain clu; + struct exfat_dentry *ep; + struct buffer_head *bh; + + hint_femp.eidx = EXFAT_HINT_NONE; + exfat_chain_set(&clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN); + + while (clu.dir != EXFAT_EOF_CLUSTER) { + for (i = 0; i < sbi->dentries_per_clu; i++, dentry++) { + ep = exfat_get_dentry(sb, &clu, i, &bh); + if (!ep) + return -EIO; + + type = exfat_get_entry_type(ep); + if (hint_femp.eidx == EXFAT_HINT_NONE) { + if (type == TYPE_DELETED || type == TYPE_UNUSED) { + hint_femp.cur = clu; + hint_femp.eidx = dentry; + hint_femp.count = 1; + } + } + + if (type == TYPE_UNUSED) { + brelse(bh); + goto not_found; + } + + if (type != TYPE_VOLUME) { + brelse(bh); + continue; + } + + memset(es, 0, sizeof(*es)); + es->sb = sb; + es->bh = es->__bh; + es->bh[0] = bh; + es->num_bh = 1; + es->start_off = EXFAT_DEN_TO_B(i) % sb->s_blocksize; + + return 0; + } + + if (exfat_get_next_cluster(sb, &(clu.dir))) + return -EIO; + } + +not_found: + if (hint_femp.eidx == EXFAT_HINT_NONE) { + hint_femp.cur.dir = EXFAT_EOF_CLUSTER; + hint_femp.eidx = dentry; + hint_femp.count = 0; + } + + ei->hint_femp = hint_femp; + + return -ENOENT; +} + +int exfat_read_volume_label(struct super_block *sb, struct exfat_uni_name *label_out) +{ + int ret, i; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_entry_set_cache es; + struct exfat_dentry *ep; + + mutex_lock(&sbi->s_lock); + + memset(label_out, 0, sizeof(*label_out)); + ret = exfat_get_volume_label_dentry(sb, &es); + if (ret < 0) { + /* + * ENOENT signifies that a volume label dentry doesn't exist + * We will treat this as an empty volume label and not fail. + */ + if (ret == -ENOENT) + ret = 0; + + goto unlock; + } + + ep = exfat_get_dentry_cached(&es, 0); + label_out->name_len = ep->dentry.volume_label.char_count; + if (label_out->name_len > EXFAT_VOLUME_LABEL_LEN) { + ret = -EIO; + exfat_put_dentry_set(&es, false); + goto unlock; + } + + for (i = 0; i < label_out->name_len; i++) + label_out->name[i] = le16_to_cpu(ep->dentry.volume_label.volume_label[i]); + + exfat_put_dentry_set(&es, false); +unlock: + mutex_unlock(&sbi->s_lock); + return ret; +} + +int exfat_write_volume_label(struct super_block *sb, + struct exfat_uni_name *label) +{ + int ret, i; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct inode *root_inode = sb->s_root->d_inode; + struct exfat_entry_set_cache es; + struct exfat_chain clu; + struct exfat_dentry *ep; + + if (label->name_len > EXFAT_VOLUME_LABEL_LEN) + return -EINVAL; + + mutex_lock(&sbi->s_lock); + + ret = exfat_get_volume_label_dentry(sb, &es); + if (ret == -ENOENT) { + if (label->name_len == 0) { + /* No volume label dentry, no need to clear */ + ret = 0; + goto unlock; + } + + ret = exfat_find_empty_entry(root_inode, &clu, 1, &es); + } + + if (ret < 0) + goto unlock; + + ep = exfat_get_dentry_cached(&es, 0); + + if (label->name_len == 0 && ep->dentry.volume_label.char_count == 0) { + /* volume label had been cleared */ + exfat_put_dentry_set(&es, 0); + goto unlock; + } + + memset(ep, 0, sizeof(*ep)); + ep->type = EXFAT_VOLUME; + + for (i = 0; i < label->name_len; i++) + ep->dentry.volume_label.volume_label[i] = + cpu_to_le16(label->name[i]); + + ep->dentry.volume_label.char_count = label->name_len; + es.modified = true; + + ret = exfat_put_dentry_set(&es, IS_DIRSYNC(root_inode)); + +unlock: + mutex_unlock(&sbi->s_lock); + return ret; +} |