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

Commit Message

Andiry Xu March 10, 2018, 6:17 p.m. UTC

From: Andiry Xu <[e-mail]>

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 <[e-mail]>
---
 fs/nova/inode.c | 176 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/nova/inode.h |   3 +
 2 files changed, 179 insertions(+)
 create mode 100644 fs/nova/inode.c

Comments

Darrick J. Wong April 23, 2018, 6:12 a.m. UTC | #1

[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 <[e-mail]>
> 
> 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 <[e-mail]>
> ---
>  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 <[e-mail]>
> + * Copyright 2012-2013 Intel Corporation
> + * Copyright 2009-2011 Marco Stornelli <[e-mail]>
> + * 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_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?

> +	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...

> +
> +	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.

--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
>

Andiry Xu April 23, 2018, 3:55 p.m. UTC | #2

On Sun, Apr 22, 2018 at 11:12 PM, Darrick J. Wong
<[e-mail]> 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 <[e-mail]>
>>
>> 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 <[e-mail]>
>> ---
>>  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 <[e-mail]>
>> + * Copyright 2012-2013 Intel Corporation
>> + * Copyright 2009-2011 Marco Stornelli <[e-mail]>
>> + * 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
>>

Patch

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 <[e-mail]>
+ * Copyright 2012-2013 Intel Corporation
+ * Copyright 2009-2011 Marco Stornelli <[e-mail]>
+ * 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;
+	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));
+	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;
+
+	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);
+	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