diff --git a/fs/fat/fat.h b/fs/fat/fat.h index e0c4ba39a377..64e295e8ff38 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -370,6 +370,7 @@ extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync); /* fat/inode.c */ +extern int fat_block_truncate_page(struct inode *inode, loff_t from); extern void fat_attach(struct inode *inode, loff_t i_pos); extern void fat_detach(struct inode *inode); extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); diff --git a/fs/fat/file.c b/fs/fat/file.c index 85f79a89e747..8429c68e3057 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -443,6 +443,9 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr) } if (attr->ia_valid & ATTR_SIZE) { + error = fat_block_truncate_page(inode, attr->ia_size); + if (error) + goto out; down_write(&MSDOS_I(inode)->truncate_lock); truncate_setsize(inode, attr->ia_size); fat_truncate_blocks(inode, attr->ia_size); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 756aead10d96..7b41a2dcdd76 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -294,6 +294,18 @@ static sector_t _fat_bmap(struct address_space *mapping, sector_t block) return blocknr; } +/* + * fat_block_truncate_page() zeroes out a mapping from file offset `from' + * up to the end of the block which corresponds to `from'. + * This is required during truncate to physically zeroout the tail end + * of that block so it doesn't yield old data if the file is later grown. + * Also, avoid causing failure from fsx for cases of "data past EOF" + */ +int fat_block_truncate_page(struct inode *inode, loff_t from) +{ + return block_truncate_page(inode->i_mapping, from, fat_get_block); +} + static const struct address_space_operations fat_aops = { .readpage = fat_readpage, .readpages = fat_readpages,