Namjae Jeon <namjae.jeon@xxxxxxxxxxx> writes: > When running FSX with direct I/O mode, fsx resulted in DATA past EOF issues. > > fsx ./file2 -Z -r 4096 -w 4096 > ... > .. > truncating to largest ever: 0x907c > fallocating to largest ever: 0x11137 > truncating to largest ever: 0x2c6fe > truncating to largest ever: 0x2cfdf > fallocating to largest ever: 0x40000 > Mapped Read: non-zero data past EOF (0x18628) page offset 0x629 is 0x2a4e > ... > .. > > The reason being, it is doing a truncate down, but the zeroing does > not happen on the last block boundary when offset is not aligned. > Even though it calls truncate_setsize()->truncate_inode_pages()-> > truncate_inode_pages_range() and considers the partial zeroout but it > retrieves the page using find_lock_page() - which only looks the page in > the cache. So, zeroing out does not happen in case of direct IO. > > Make a truncate page based around block_truncate_page for FAT filesystem and > invoke that helper to zerout in case the offset is not aligned with > the blocksize. Good catch. However implementation looks like strange a bit. > @@ -374,6 +374,7 @@ 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); We can't use "static" for fat_block_truncate_page()? > --- a/fs/fat/file.c > +++ b/fs/fat/file.c > @@ -526,6 +526,8 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr) > down_write(&MSDOS_I(inode)->truncate_lock); > truncate_setsize(inode, attr->ia_size); > fat_truncate_blocks(inode, attr->ia_size); > + if (inode->i_size & (inode->i_sb->s_blocksize - 1)) > + fat_block_truncate_page(inode, inode->i_size); > up_write(&MSDOS_I(inode)->truncate_lock); > } Let's remove block alignment, because it was done in block_truncate_page(). Then, move fat_block_truncate_page() before truncate_setsize(). Looks like other fs calls it before truncate_setsize(). Thanks. -- OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
