Re: [RFC v2 06/83] Add inode get/read methods.

Andiry Xu
2018-04-23T15:55:35Z

On Sun, Apr 22, 2018 at 11:12 PM, Darrick J. Wong
<darrick.wong@oracle.com> wrote:
> [haaa, I finally found time to read more of these]
>
> On Sat, Mar 10, 2018 at 10:17:47AM -0800, Andiry Xu wrote:
>> From: Andiry Xu <jix024@cs.ucsd.edu>
>>
>> These routines are incomplete and currently only support reserved inodes,
>> whose addresses are fixed. This is necessary for fill_super to work.
>> File/dir operations are left NULL.
>>
>> Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
>> ---
>> fs/nova/inode.c | 176 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/nova/inode.h | 3 +
>> 2 files changed, 179 insertions(+)
>> create mode 100644 fs/nova/inode.c
>>
>> diff --git a/fs/nova/inode.c b/fs/nova/inode.c
>> new file mode 100644
>> index 0000000..bfdc5dc
>> --- /dev/null
>> +++ b/fs/nova/inode.c
>> @@ -0,0 +1,176 @@
>> +/*
>> + * BRIEF DESCRIPTION
>> + *
>> + * Inode methods (allocate/free/read/write).
>> + *
>> + * Copyright 2015-2016 Regents of the University of California,
>> + * UCSD Non-Volatile Systems Lab, Andiry Xu <jix024@cs.ucsd.edu>
>> + * Copyright 2012-2013 Intel Corporation
>> + * Copyright 2009-2011 Marco Stornelli <marco.stornelli@gmail.com>
>> + * Copyright 2003 Sony Corporation
>> + * Copyright 2003 Matsushita Electric Industrial Co., Ltd.
>> + * 2003-2004 (c) MontaVista Software, Inc. , Steve Longerbeam
>> + * This file is licensed under the terms of the GNU General Public
>> + * License version 2. This program is licensed "as is" without any
>> + * warranty of any kind, whether express or implied.
>> + */
>> +
>> +#include <linux/fs.h>
>> +#include <linux/aio.h>
>> +#include <linux/highuid.h>
>> +#include <linux/module.h>
>> +#include <linux/mpage.h>
>> +#include <linux/backing-dev.h>
>> +#include <linux/types.h>
>> +#include <linux/ratelimit.h>
>> +#include "nova.h"
>> +#include "inode.h"
>> +
>> +unsigned int blk_type_to_shift[NOVA_BLOCK_TYPE_MAX] = {12, 21, 30};
>> +uint32_t blk_type_to_size[NOVA_BLOCK_TYPE_MAX] = {0x1000, 0x200000, 0x40000000};
>> +
>> +void nova_set_inode_flags(struct inode *inode, struct nova_inode *pi,
>> + unsigned int flags)
>> +{
>> + inode->i_flags &=
>> + ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC);
>> + if (flags & FS_SYNC_FL)
>> + inode->i_flags |= S_SYNC;
>> + if (flags & FS_APPEND_FL)
>> + inode->i_flags |= S_APPEND;
>> + if (flags & FS_IMMUTABLE_FL)
>> + inode->i_flags |= S_IMMUTABLE;
>> + if (flags & FS_NOATIME_FL)
>> + inode->i_flags |= S_NOATIME;
>> + if (flags & FS_DIRSYNC_FL)
>> + inode->i_flags |= S_DIRSYNC;
>> + if (!pi->i_xattr)
>> + inode_has_no_xattr(inode);
>> + inode->i_flags |= S_DAX;
>> +}
>> +
>> +/* copy persistent state to struct inode */
>> +static int nova_read_inode(struct super_block *sb, struct inode *inode,
>> + u64 pi_addr)
>> +{
>> + struct nova_inode_info *si = NOVA_I(inode);
>> + struct nova_inode *pi, fake_pi;
>> + struct nova_inode_info_header *sih = &si->header;
>> + int ret = -EIO;
>> + unsigned long ino;
>> +
>> + ret = nova_get_reference(sb, pi_addr, &fake_pi,
>> + (void **)&pi, sizeof(struct nova_inode));
>> + if (ret) {
>> + nova_dbg("%s: read pi @ 0x%llx failed\n",
>> + __func__, pi_addr);
>> + goto bad_inode;
>> + }
>> +
>> + inode->i_mode = sih->i_mode;
>
> Hm, do you validate the on-pmem metadata as it's read in? What if
> i_mode is garbage?
>

I have checksum for inode and all metadata structures in the
NOVA-fortis code. I removed them in this patchset to make the code
shorter and simpler.

>> + i_uid_write(inode, le32_to_cpu(pi->i_uid));
>> + i_gid_write(inode, le32_to_cpu(pi->i_gid));
>> +// set_nlink(inode, le16_to_cpu(pi->i_links_count));
>
> C++ comment?
>

Will fix.

>> + inode->i_generation = le32_to_cpu(pi->i_generation);
>> + nova_set_inode_flags(inode, pi, le32_to_cpu(pi->i_flags));
>> + ino = inode->i_ino;
>> +
>> + /* check if the inode is active. */
>> + if (inode->i_mode == 0 || pi->deleted == 1) {
>> + /* this inode is deleted */
>> + ret = -ESTALE;
>> + goto bad_inode;
>> + }
>> +
>> + inode->i_blocks = sih->i_blocks;
>
> Not le64_to_cpu(sih->i_blocks)? Or is that somewhere else I'm
> missing...
>

sih is the in-DRAM inode structure, so le64_to_cpu is not needed. When
we read inode from pmem (nova_inode *pi) to sih, we need
le64_to_cpu(). The endian checking is not performed thoroughly as it
only supports x86-64 now.

>> +
>> + switch (inode->i_mode & S_IFMT) {
>> + case S_IFREG:
>> + break;
>> + case S_IFDIR:
>> + break;
>> + case S_IFLNK:
>> + break;
>> + default:
>> + init_special_inode(inode, inode->i_mode,
>> + le32_to_cpu(pi->dev.rdev));
>> + break;
>> + }
>> +
>> + /* Update size and time after rebuild the tree */
>> + inode->i_size = le64_to_cpu(sih->i_size);
>
> FWIW the type of i_size is loff_t, which is an unsigned type. Despite
> this, the VFS does not support files with negative sizes... which means
> that this probably ought to check for that.
>

I will think about that. Thanks.

Thanks,
Andiry

> --D
>
>> + inode->i_atime.tv_sec = (__s32)le32_to_cpu(pi->i_atime);
>> + inode->i_ctime.tv_sec = (__s32)le32_to_cpu(pi->i_ctime);
>> + inode->i_mtime.tv_sec = (__s32)le32_to_cpu(pi->i_mtime);
>> + inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec =
>> + inode->i_ctime.tv_nsec = 0;
>> + set_nlink(inode, le16_to_cpu(pi->i_links_count));
>> + return 0;
>> +
>> +bad_inode:
>> + make_bad_inode(inode);
>> + return ret;
>> +}
>> +
>> +/* Get the address in PMEM of an inode by inode number. Allocate additional
>> + * block to store additional inodes if necessary.
>> + */
>> +int nova_get_inode_address(struct super_block *sb, u64 ino,
>> + u64 *pi_addr, int extendable)
>> +{
>> + if (ino < NOVA_NORMAL_INODE_START) {
>> + *pi_addr = nova_get_reserved_inode_addr(sb, ino);
>> + return 0;
>> + }
>> +
>> + *pi_addr = 0;
>> + return 0;
>> +}
>> +
>> +struct inode *nova_iget(struct super_block *sb, unsigned long ino)
>> +{
>> + struct nova_inode_info *si;
>> + struct inode *inode;
>> + u64 pi_addr;
>> + int err;
>> +
>> + inode = iget_locked(sb, ino);
>> + if (unlikely(!inode))
>> + return ERR_PTR(-ENOMEM);
>> + if (!(inode->i_state & I_NEW))
>> + return inode;
>> +
>> + si = NOVA_I(inode);
>> +
>> + nova_dbgv("%s: inode %lu\n", __func__, ino);
>> +
>> + err = nova_get_inode_address(sb, ino, &pi_addr, 0);
>> + if (err) {
>> + nova_dbg("%s: get inode %lu address failed %d\n",
>> + __func__, ino, err);
>> + goto fail;
>> + }
>> +
>> + if (pi_addr == 0) {
>> + nova_dbg("%s: failed to get pi_addr for inode %lu\n",
>> + __func__, ino);
>> + err = -EACCES;
>> + goto fail;
>> + }
>> +
>> + err = nova_read_inode(sb, inode, pi_addr);
>> + if (unlikely(err)) {
>> + nova_dbg("%s: failed to read inode %lu\n", __func__, ino);
>> + goto fail;
>> +
>> + }
>> +
>> + inode->i_ino = ino;
>> +
>> + unlock_new_inode(inode);
>> + return inode;
>> +fail:
>> + iget_failed(inode);
>> + return ERR_PTR(err);
>> +}
>> +
>> diff --git a/fs/nova/inode.h b/fs/nova/inode.h
>> index f9187e3..dbd5256 100644
>> --- a/fs/nova/inode.h
>> +++ b/fs/nova/inode.h
>> @@ -184,4 +184,7 @@ static inline int nova_persist_inode(struct nova_inode *pi)
>> return 0;
>> }
>>
>> +int nova_get_inode_address(struct super_block *sb, u64 ino,
>> + u64 *pi_addr, int extendable);
>> +struct inode *nova_iget(struct super_block *sb, unsigned long ino);
>> #endif
>> --
>> 2.7.4
>>