diff options
Diffstat (limited to 'fs/exfat/dir.c')
| -rw-r--r-- | fs/exfat/dir.c | 630 |
1 files changed, 411 insertions, 219 deletions
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index 1dfa67f307f1..3045a58e124a 100644 --- a/fs/exfat/dir.c +++ b/fs/exfat/dir.c @@ -29,14 +29,16 @@ static int exfat_extract_uni_name(struct exfat_dentry *ep, } -static void exfat_get_uniname_from_ext_entry(struct super_block *sb, +static int exfat_get_uniname_from_ext_entry(struct super_block *sb, struct exfat_chain *p_dir, int entry, unsigned short *uniname) { - int i; + int i, err; struct exfat_entry_set_cache es; + unsigned int uni_len = 0, len; - if (exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES)) - return; + err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES); + if (err) + return err; /* * First entry : file entry @@ -51,17 +53,21 @@ static void exfat_get_uniname_from_ext_entry(struct super_block *sb, if (exfat_get_entry_type(ep) != TYPE_EXTEND) break; - exfat_extract_uni_name(ep, uniname); + 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; + 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; @@ -76,11 +82,8 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent if (ei->type != TYPE_DIR) return -EPERM; - if (ei->entry == -1) - exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); - else - exfat_chain_set(&dir, ei->start_clu, - EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); + 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, @@ -100,7 +103,7 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent clu.dir = ei->hint_bmap.clu; } - while (clu_offset > 0) { + while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) { if (exfat_get_next_cluster(sb, &(clu.dir))) return -EIO; @@ -119,7 +122,7 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent type = exfat_get_entry_type(ep); if (type == TYPE_UNUSED) { brelse(bh); - break; + goto out; } if (type != TYPE_FILE && type != TYPE_DIR) { @@ -129,25 +132,14 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent num_ext = ep->dentry.file.num_ext; dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); - exfat_get_entry_time(sbi, &dir_entry->crtime, - ep->dentry.file.create_tz, - ep->dentry.file.create_time, - ep->dentry.file.create_date, - ep->dentry.file.create_time_cs); - exfat_get_entry_time(sbi, &dir_entry->mtime, - ep->dentry.file.modify_tz, - ep->dentry.file.modify_time, - ep->dentry.file.modify_date, - ep->dentry.file.modify_time_cs); - exfat_get_entry_time(sbi, &dir_entry->atime, - ep->dentry.file.access_tz, - ep->dentry.file.access_time, - ep->dentry.file.access_date, - 0); *uni_name.name = 0x0; - exfat_get_uniname_from_ext_entry(sb, &clu, i, + 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); @@ -156,9 +148,8 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent ep = exfat_get_dentry(sb, &clu, i + 1, &bh); if (!ep) return -EIO; - dir_entry->size = - le64_to_cpu(ep->dentry.stream.valid_size); - dir_entry->entry = dentry; + dir_entry->entry = i; + dir_entry->dir = clu; brelse(bh); ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi); @@ -179,6 +170,7 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent } } +out: dir_entry->namebuf.lfn[0] = '\0'; *cpos = EXFAT_DEN_TO_B(dentry); return 0; @@ -208,7 +200,10 @@ static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) exfat_init_namebuf(nb); } -/* skip iterating emit_dots when dir is empty */ +/* + * 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) { @@ -223,35 +218,33 @@ static int exfat_iterate(struct file *file, struct dir_context *ctx) int err = 0, fake_offset = 0; exfat_init_namebuf(nb); - mutex_lock(&EXFAT_SB(sb)->s_lock); cpos = ctx->pos; if (!dir_emit_dots(file, ctx)) - goto unlock; + goto out; if (ctx->pos == ITER_POS_FILLED_DOTS) { cpos = 0; fake_offset = 1; } - if (cpos & (DENTRY_SIZE - 1)) { - err = -ENOENT; - goto unlock; - } + cpos = round_up(cpos, DENTRY_SIZE); /* name buffer should be allocated before use */ err = exfat_alloc_namebuf(nb); if (err) - goto unlock; + 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). + * 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); @@ -265,7 +258,7 @@ get_new: if (!nb->lfn[0]) goto end_of_dir; - i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff); + i_pos = ((loff_t)de.dir.dir << 32) | (de.entry & 0xffffffff); tmp = exfat_iget(sb, i_pos); if (tmp) { inum = tmp->i_ino; @@ -274,16 +267,10 @@ get_new: inum = iunique(sb, EXFAT_ROOT_INO); } - /* - * Before calling dir_emit(), sb_lock should be released. - * Because page fault can occur in dir_emit() when the size - * of buffer given from user is larger than one page size. - */ mutex_unlock(&EXFAT_SB(sb)->s_lock); if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, - (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG)) - goto out_unlocked; - mutex_lock(&EXFAT_SB(sb)->s_lock); + (de.attr & EXFAT_ATTR_SUBDIR) ? DT_DIR : DT_REG)) + goto out; ctx->pos = cpos; goto get_new; @@ -291,9 +278,8 @@ end_of_dir: if (!cpos && fake_offset) cpos = ITER_POS_FILLED_DOTS; ctx->pos = cpos; -unlock: mutex_unlock(&EXFAT_SB(sb)->s_lock); -out_unlocked: +out: /* * To improve performance, free namebuf after unlock sb_lock. * If namebuf is not allocated, this function do nothing @@ -302,10 +288,11 @@ out_unlocked: return err; } +WRAP_DIR_ITER(exfat_iterate) // FIXME! const struct file_operations exfat_dir_operations = { .llseek = generic_file_llseek, .read = generic_read_dir, - .iterate = exfat_iterate, + .iterate_shared = shared_exfat_iterate, .unlocked_ioctl = exfat_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = exfat_compat_ioctl, @@ -354,7 +341,7 @@ unsigned int exfat_get_entry_type(struct exfat_dentry *ep) if (ep->type == EXFAT_VOLUME) return TYPE_VOLUME; if (ep->type == EXFAT_FILE) { - if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR) + if (le16_to_cpu(ep->dentry.file.attr) & EXFAT_ATTR_SUBDIR) return TYPE_DIR; return TYPE_FILE; } @@ -378,6 +365,12 @@ unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 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; } @@ -399,19 +392,22 @@ static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) ep->type = EXFAT_VOLUME; } else if (type == TYPE_DIR) { ep->type = EXFAT_FILE; - ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR); + 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(ATTR_ARCHIVE); + ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_ARCHIVE); } } static void exfat_init_stream_entry(struct exfat_dentry *ep, - unsigned char flags, unsigned int start_clu, - unsigned long long size) + unsigned int start_clu, unsigned long long size) { + memset(ep, 0, sizeof(*ep)); exfat_set_entry_type(ep, TYPE_STREAM); - ep->dentry.stream.flags = flags; + 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); @@ -435,156 +431,99 @@ static void exfat_init_name_entry(struct exfat_dentry *ep, } } -int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, - int entry, unsigned int type, unsigned int start_clu, - unsigned long long size) +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 = inode->i_sb; + struct super_block *sb = es->sb; struct exfat_sb_info *sbi = EXFAT_SB(sb); - struct timespec64 ts = current_time(inode); struct exfat_dentry *ep; - struct buffer_head *bh; - - /* - * We cannot use exfat_get_dentry_set here because file ep is not - * initialized yet. - */ - ep = exfat_get_dentry(sb, p_dir, entry, &bh); - if (!ep) - return -EIO; + 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, + 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, + 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, + exfat_set_entry_time(sbi, ts, &ep->dentry.file.access_tz, &ep->dentry.file.access_time, &ep->dentry.file.access_date, NULL); - exfat_update_bh(bh, IS_DIRSYNC(inode)); - brelse(bh); - - ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); - if (!ep) - return -EIO; - - exfat_init_stream_entry(ep, - (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN, - start_clu, size); - exfat_update_bh(bh, IS_DIRSYNC(inode)); - brelse(bh); - - return 0; + ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); + exfat_init_stream_entry(ep, start_clu, size); } -int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, - int entry) +static void exfat_free_benign_secondary_clusters(struct inode *inode, + struct exfat_dentry *ep) { struct super_block *sb = inode->i_sb; - int ret = 0; - int i, num_entries; - u16 chksum; - struct exfat_dentry *ep, *fep; - struct buffer_head *fbh, *bh; - - fep = exfat_get_dentry(sb, p_dir, entry, &fbh); - if (!fep) - return -EIO; + 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; - num_entries = fep->dentry.file.num_ext + 1; - chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); - - for (i = 1; i < num_entries; i++) { - ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); - if (!ep) { - ret = -EIO; - goto release_fbh; - } - chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, - CS_DEFAULT); - brelse(bh); - } + if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size) + return; - fep->dentry.file.checksum = cpu_to_le16(chksum); - exfat_update_bh(fbh, IS_DIRSYNC(inode)); -release_fbh: - brelse(fbh); - return ret; + exfat_chain_set(&dir, start_clu, + EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)), + flags); + exfat_free_cluster(inode, &dir); } -int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, - int entry, int num_entries, struct exfat_uni_name *p_uniname) +void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries, + struct exfat_uni_name *p_uniname) { - struct super_block *sb = inode->i_sb; int i; unsigned short *uniname = p_uniname->name; struct exfat_dentry *ep; - struct buffer_head *bh; - int sync = IS_DIRSYNC(inode); - - ep = exfat_get_dentry(sb, p_dir, entry, &bh); - if (!ep) - return -EIO; + ep = exfat_get_dentry_cached(es, ES_IDX_FILE); ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); - exfat_update_bh(bh, sync); - brelse(bh); - - ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); - if (!ep) - return -EIO; + 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); - exfat_update_bh(bh, sync); - brelse(bh); - - for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { - ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); - if (!ep) - return -EIO; + for (i = ES_IDX_FIRST_FILENAME; i < num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); exfat_init_name_entry(ep, uniname); - exfat_update_bh(bh, sync); - brelse(bh); uniname += EXFAT_FILE_NAME_LEN; } - exfat_update_dir_chksum(inode, p_dir, entry); - return 0; + exfat_update_dir_chksum(es); } -int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, - int entry, int order, int num_entries) +void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es, + int order) { - struct super_block *sb = inode->i_sb; int i; struct exfat_dentry *ep; - struct buffer_head *bh; - for (i = order; i < num_entries; i++) { - ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); - if (!ep) - return -EIO; + 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); - exfat_update_bh(bh, IS_DIRSYNC(inode)); - brelse(bh); } - return 0; + if (order < es->num_entries) + es->modified = true; } -void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) +void exfat_update_dir_chksum(struct exfat_entry_set_cache *es) { int chksum_type = CS_DIR_ENTRY, i; unsigned short chksum = 0; @@ -665,6 +604,11 @@ static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir 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); @@ -739,11 +683,11 @@ struct exfat_dentry *exfat_get_dentry(struct super_block *sb, } enum exfat_validate_dentry_mode { - ES_MODE_STARTED, 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, @@ -753,40 +697,32 @@ static bool exfat_validate_entry(unsigned int type, return false; switch (*mode) { - case ES_MODE_STARTED: - if (type != TYPE_FILE && type != TYPE_DIR) - return false; - *mode = ES_MODE_GET_FILE_ENTRY; - return true; case ES_MODE_GET_FILE_ENTRY: if (type != TYPE_STREAM) return false; *mode = ES_MODE_GET_STRM_ENTRY; - return true; + break; case ES_MODE_GET_STRM_ENTRY: if (type != TYPE_EXTEND) return false; *mode = ES_MODE_GET_NAME_ENTRY; - return true; + break; case ES_MODE_GET_NAME_ENTRY: - if (type == TYPE_STREAM) - return false; - if (type != TYPE_EXTEND) { - if (!(type & TYPE_CRITICAL_SEC)) - return false; - *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; - } - return true; - case ES_MODE_GET_CRITICAL_SEC_ENTRY: - if (type == TYPE_EXTEND || type == TYPE_STREAM) + if (type & TYPE_BENIGN_SEC) + *mode = ES_MODE_GET_BENIGN_SEC_ENTRY; + else if (type != TYPE_EXTEND) return false; - if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) + break; + case ES_MODE_GET_BENIGN_SEC_ENTRY: + /* Assume unreconized benign secondary entry */ + if (!(type & TYPE_BENIGN_SEC)) return false; - return true; + break; default: - WARN_ON_ONCE(1); return false; } + + return true; } struct exfat_dentry *exfat_get_dentry_cached( @@ -800,7 +736,7 @@ struct exfat_dentry *exfat_get_dentry_cached( } /* - * Returns a set of dentries for a file or dir. + * 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 @@ -808,22 +744,24 @@ struct exfat_dentry *exfat_get_dentry_cached( * * in: * sb+p_dir+entry: indicates a file/dir - * type: specifies how many dentries should be included. + * 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: - * pointer of entry set on success, - * NULL on failure. + * 0 on success + * -error code on failure */ -int exfat_get_dentry_set(struct exfat_entry_set_cache *es, +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 type) + unsigned int num_entries) { int ret, i, num_bh; unsigned int off; sector_t sec; struct exfat_sb_info *sbi = EXFAT_SB(sb); - struct exfat_dentry *ep; - int num_entries; - enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; struct buffer_head *bh; if (p_dir->dir == DIR_DELETED) { @@ -846,17 +784,23 @@ int exfat_get_dentry_set(struct exfat_entry_set_cache *es, return -EIO; es->bh[es->num_bh++] = bh; - ep = exfat_get_dentry_cached(es, ES_IDX_FILE); - if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) - goto put_es; + 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; + } - num_entries = type == ES_ALL_ENTRIES ? - ep->dentry.file.num_ext + 1 : type; 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_KERNEL); + es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_NOFS); if (!es->bh) { brelse(bh); return -ENOMEM; @@ -884,8 +828,27 @@ int exfat_get_dentry_set(struct exfat_entry_set_cache *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 < num_entries; i++) { + 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; @@ -897,6 +860,85 @@ put_es: 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; @@ -959,6 +1001,7 @@ int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 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; @@ -1047,7 +1090,8 @@ rewind: if (entry_type == TYPE_EXTEND) { unsigned short entry_uniname[16], unichar; - if (step != DIRENT_STEP_NAME) { + if (step != DIRENT_STEP_NAME || + name_len >= MAX_NAME_LENGTH) { step = DIRENT_STEP_FILE; continue; } @@ -1095,6 +1139,10 @@ rewind: } 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; } } @@ -1152,34 +1200,12 @@ found: return dentry - num_ext; } -int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, - int entry, struct exfat_dentry *ep) -{ - int i, count = 0; - unsigned int type; - struct exfat_dentry *ext_ep; - struct buffer_head *bh; - - for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { - ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh); - if (!ext_ep) - return -EIO; - - type = exfat_get_entry_type(ext_ep); - brelse(bh); - if (type == TYPE_EXTEND || type == TYPE_STREAM) - count++; - else - break; - } - return count; -} - 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); @@ -1212,8 +1238,174 @@ int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) } 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; +} |