From: Yuezhang Mo Yuezhang.Mo@sony.com
[ Upstream commit dab48b8f2fe7264d51ec9eed0adea0fe3c78830a ]
After repairing a corrupted file system with exfatprogs' fsck.exfat, zero-size directories may result. It is also possible to create zero-size directories in other exFAT implementation, such as Paragon ufsd dirver.
As described in the specification, the lower directory size limits is 0 bytes.
Without this commit, sub-directories and files cannot be created under a zero-size directory, and it cannot be removed.
Signed-off-by: Yuezhang Mo Yuezhang.Mo@sony.com Reviewed-by: Andy Wu Andy.Wu@sony.com Reviewed-by: Aoyama Wataru wataru.aoyama@sony.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/exfat/namei.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c index 90b0477911449..30e97c51f0e14 100644 --- a/fs/exfat/namei.c +++ b/fs/exfat/namei.c @@ -338,14 +338,20 @@ static int exfat_find_empty_entry(struct inode *inode, if (exfat_check_max_dentries(inode)) return -ENOSPC;
- /* we trust p_dir->size regardless of FAT type */ - if (exfat_find_last_cluster(sb, p_dir, &last_clu)) - return -EIO; - /* * Allocate new cluster to this directory */ - exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags); + if (ei->start_clu != EXFAT_EOF_CLUSTER) { + /* we trust p_dir->size regardless of FAT type */ + if (exfat_find_last_cluster(sb, p_dir, &last_clu)) + return -EIO; + + exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags); + } else { + /* This directory is empty */ + exfat_chain_set(&clu, EXFAT_EOF_CLUSTER, 0, + ALLOC_NO_FAT_CHAIN); + }
/* allocate a cluster */ ret = exfat_alloc_cluster(inode, 1, &clu, IS_DIRSYNC(inode)); @@ -355,6 +361,11 @@ static int exfat_find_empty_entry(struct inode *inode, if (exfat_zeroed_cluster(inode, clu.dir)) return -EIO;
+ if (ei->start_clu == EXFAT_EOF_CLUSTER) { + ei->start_clu = clu.dir; + p_dir->dir = clu.dir; + } + /* append to the FAT chain */ if (clu.flags != p_dir->flags) { /* no-fat-chain bit is disabled, @@ -644,7 +655,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname, info->type = exfat_get_entry_type(ep); info->attr = le16_to_cpu(ep->dentry.file.attr); info->size = le64_to_cpu(ep2->dentry.stream.valid_size); - if ((info->type == TYPE_FILE) && (info->size == 0)) { + if (info->size == 0) { info->flags = ALLOC_NO_FAT_CHAIN; info->start_clu = EXFAT_EOF_CLUSTER; } else { @@ -888,6 +899,9 @@ static int exfat_check_dir_empty(struct super_block *sb,
dentries_per_clu = sbi->dentries_per_clu;
+ if (p_dir->dir == EXFAT_EOF_CLUSTER) + return 0; + exfat_chain_dup(&clu, p_dir);
while (clu.dir != EXFAT_EOF_CLUSTER) { @@ -1262,7 +1276,8 @@ static int __exfat_rename(struct inode *old_parent_inode, }
/* Free the clusters if new_inode is a dir(as if exfat_rmdir) */ - if (new_entry_type == TYPE_DIR) { + if (new_entry_type == TYPE_DIR && + new_ei->start_clu != EXFAT_EOF_CLUSTER) { /* new_ei, new_clu_to_free */ struct exfat_chain new_clu_to_free;