diff options
Diffstat (limited to 'fs/exfat/dir.c')
| -rw-r--r-- | fs/exfat/dir.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index ee060e26f51d..7229146fe2bf 100644 --- a/fs/exfat/dir.c +++ b/fs/exfat/dir.c @@ -1244,3 +1244,163 @@ int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 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; +} |