Re: [PATCH v1 10/17] xfs: parent pointer attribute creation

[Alli <allison.henderson@oracle.com>]

On Wed, 2022-06-29 at 11:41 -0700, Darrick J. Wong wrote:
> On Sat, Jun 11, 2022 at 02:41:53AM -0700, Allison Henderson wrote:
> > Add parent pointer attribute during xfs_create, and subroutines to
> > initialize attributes
> > 
> > [bfoster: rebase, use VFS inode generation]
> > [achender: rebased, changed __unint32_t to xfs_dir2_dataptr_t,
> >            fixed some null pointer bugs,
> >            merged error handling patch,
> >            added subroutines to handle attribute initialization,
> >            remove unnecessary ENOSPC handling in
> > xfs_attr_set_first_parent]
> > 
> > Signed-off-by: Dave Chinner <dchinner@redhat.com>
> > Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
> > ---
> >  fs/xfs/Makefile            |  1 +
> >  fs/xfs/libxfs/xfs_attr.c   |  2 +-
> >  fs/xfs/libxfs/xfs_attr.h   |  1 +
> >  fs/xfs/libxfs/xfs_parent.c | 77 +++++++++++++++++++++++++++++++++
> >  fs/xfs/libxfs/xfs_parent.h | 31 ++++++++++++++
> >  fs/xfs/xfs_inode.c         | 88 +++++++++++++++++++++++++++-------
> > ----
> >  fs/xfs/xfs_xattr.c         |  2 +-
> >  fs/xfs/xfs_xattr.h         |  1 +
> >  8 files changed, 177 insertions(+), 26 deletions(-)
> > 
> > diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
> > index b056cfc6398e..fc717dc3470c 100644
> > --- a/fs/xfs/Makefile
> > +++ b/fs/xfs/Makefile
> > @@ -40,6 +40,7 @@ xfs-y				+= $(addprefix
> > libxfs/, \
> >  				   xfs_inode_fork.o \
> >  				   xfs_inode_buf.o \
> >  				   xfs_log_rlimit.o \
> > +				   xfs_parent.o \
> >  				   xfs_ag_resv.o \
> >  				   xfs_rmap.o \
> >  				   xfs_rmap_btree.o \
> > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> > index 30c8d9e9c2f1..f814a9177237 100644
> > --- a/fs/xfs/libxfs/xfs_attr.c
> > +++ b/fs/xfs/libxfs/xfs_attr.c
> > @@ -926,7 +926,7 @@ xfs_attr_intent_init(
> >  }
> >  
> >  /* Sets an attribute for an inode as a deferred operation */
> > -static int
> > +int
> >  xfs_attr_defer_add(
> >  	struct xfs_da_args	*args)
> >  {
> > diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> > index a87bc503976b..576062e37d11 100644
> > --- a/fs/xfs/libxfs/xfs_attr.h
> > +++ b/fs/xfs/libxfs/xfs_attr.h
> > @@ -559,6 +559,7 @@ int xfs_inode_hasattr(struct xfs_inode *ip);
> >  bool xfs_attr_is_leaf(struct xfs_inode *ip);
> >  int xfs_attr_get_ilocked(struct xfs_da_args *args);
> >  int xfs_attr_get(struct xfs_da_args *args);
> > +int xfs_attr_defer_add(struct xfs_da_args *args);
> >  int xfs_attr_set(struct xfs_da_args *args);
> >  int xfs_attr_set_iter(struct xfs_attr_intent *attr);
> >  int xfs_attr_remove_iter(struct xfs_attr_intent *attr);
> > diff --git a/fs/xfs/libxfs/xfs_parent.c
> > b/fs/xfs/libxfs/xfs_parent.c
> > new file mode 100644
> > index 000000000000..cb546652bde9
> > --- /dev/null
> > +++ b/fs/xfs/libxfs/xfs_parent.c
> > @@ -0,0 +1,77 @@
> > +/*
> 
> New files need an SPDX header.
ok, will fix
> 
> > + * Copyright (c) 2015 Red Hat, Inc.
> > + * All rights reserved.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License as
> > + * published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it would be
> > useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public
> > License
> > + * along with this program; if not, write the Free Software
> > Foundation
> 
> No need for all this boilerplate once you've switched to SPDX tags.
> 
yep, will remove
> > + */
> > +#include "xfs.h"
> > +#include "xfs_fs.h"
> > +#include "xfs_format.h"
> > +#include "xfs_da_format.h"
> > +#include "xfs_log_format.h"
> > +#include "xfs_shared.h"
> > +#include "xfs_trans_resv.h"
> > +#include "xfs_mount.h"
> > +#include "xfs_bmap_btree.h"
> > +#include "xfs_inode.h"
> > +#include "xfs_error.h"
> > +#include "xfs_trace.h"
> > +#include "xfs_trans.h"
> > +#include "xfs_da_btree.h"
> > +#include "xfs_attr.h"
> > +#include "xfs_da_btree.h"
> > +#include "xfs_attr_sf.h"
> > +#include "xfs_bmap.h"
> > +
> > +/*
> > + * Parent pointer attribute handling.
> > + *
> > + * Because the attribute value is a filename component, it will
> > never be longer
> > + * than 255 bytes. This means the attribute will always be a local
> > format
> > + * attribute as it is xfs_attr_leaf_entsize_local_max() for v5
> > filesystems will
> > + * always be larger than this (max is 75% of block size).
> > + *
> > + * Creating a new parent attribute will always create a new
> > attribute - there
> > + * should never, ever be an existing attribute in the tree for a
> > new inode.
> > + * ENOSPC behavior is problematic - creating the inode without the
> > parent
> > + * pointer is effectively a corruption, so we allow parent
> > attribute creation
> > + * to dip into the reserve block pool to avoid unexpected ENOSPC
> > errors from
> > + * occurring.
> > + */
> > +
> > +
> > +/* Initializes a xfs_parent_name_rec to be stored as an attribute
> > name */
> > +void
> > +xfs_init_parent_name_rec(
> > +	struct xfs_parent_name_rec	*rec,
> > +	struct xfs_inode		*ip,
> > +	uint32_t			p_diroffset)
> > +{
> > +	xfs_ino_t			p_ino = ip->i_ino;
> > +	uint32_t			p_gen = VFS_I(ip)->i_generation;
> > +
> > +	rec->p_ino = cpu_to_be64(p_ino);
> > +	rec->p_gen = cpu_to_be32(p_gen);
> > +	rec->p_diroffset = cpu_to_be32(p_diroffset);
> > +}
> > +
> > +/* Initializes a xfs_parent_name_irec from an xfs_parent_name_rec
> > */
> > +void
> > +xfs_init_parent_name_irec(
> > +	struct xfs_parent_name_irec	*irec,
> > +	struct xfs_parent_name_rec	*rec)
> 
> Should this second arg be const struct xfs_parent_name_rec* ?
> 
I guess it could be, but now that I look harder at it, it's not
actually used.  I suspect it was likely just a suggestion from an older
review to add it as a sort of utility function, but with out an actuall
call, maybe we should just take it out

> > +{
> > +	irec->p_ino = be64_to_cpu(rec->p_ino);
> > +	irec->p_gen = be32_to_cpu(rec->p_gen);
> > +	irec->p_diroffset = be32_to_cpu(rec->p_diroffset);
> > +}
> > diff --git a/fs/xfs/libxfs/xfs_parent.h
> > b/fs/xfs/libxfs/xfs_parent.h
> > new file mode 100644
> > index 000000000000..10dc576ce693
> > --- /dev/null
> > +++ b/fs/xfs/libxfs/xfs_parent.h
> > @@ -0,0 +1,31 @@
> > +/*
> > + * Copyright (c) 2018 Oracle, Inc.
> 
> New file needs an SPDX header, and you should probably update the
> copyright to be 2018-2022.
will fix

> 
> > + * All Rights Reserved.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License as
> > + * published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it would be
> > useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public
> > License
> > + * along with this program; if not, write the Free Software
> > Foundation Inc.
> 
> No need for all this boilerplate once you've switched to SPDX tags.
> 
> > + */
> > +#ifndef	__XFS_PARENT_H__
> > +#define	__XFS_PARENT_H__
> > +
> > +#include "xfs_da_format.h"
> > +#include "xfs_format.h"
> 
> Don't include headers in headers.  If it's really a mess to add these
> two to every single .c file, then just add:
> 
> struct xfs_inode;
> struct xfs_parent_name_rec;
> struct xfs_parent_name_irec;
> 
> and that'll do for pointers.
> 
Alrighty, will do

> > +
> > +/*
> > + * Parent pointer attribute prototypes
> > + */
> > +void xfs_init_parent_name_rec(struct xfs_parent_name_rec *rec,
> > +			      struct xfs_inode *ip,
> > +			      uint32_t p_diroffset);
> > +void xfs_init_parent_name_irec(struct xfs_parent_name_irec *irec,
> > +			       struct xfs_parent_name_rec *rec);
> > +#endif	/* __XFS_PARENT_H__ */
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > index b2dfd84e1f62..6b1e4cb11b5c 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -36,6 +36,8 @@
> >  #include "xfs_reflink.h"
> >  #include "xfs_ag.h"
> >  #include "xfs_log_priv.h"
> > +#include "xfs_parent.h"
> > +#include "xfs_xattr.h"
> >  
> >  struct kmem_cache *xfs_inode_cache;
> >  
> > @@ -962,27 +964,40 @@ xfs_bumplink(
> >  
> >  int
> >  xfs_create(
> > -	struct user_namespace	*mnt_userns,
> > -	xfs_inode_t		*dp,
> > -	struct xfs_name		*name,
> > -	umode_t			mode,
> > -	dev_t			rdev,
> > -	bool			init_xattrs,
> > -	xfs_inode_t		**ipp)
> > -{
> > -	int			is_dir = S_ISDIR(mode);
> > -	struct xfs_mount	*mp = dp->i_mount;
> > -	struct xfs_inode	*ip = NULL;
> > -	struct xfs_trans	*tp = NULL;
> > -	int			error;
> > -	bool                    unlock_dp_on_error = false;
> > -	prid_t			prid;
> > -	struct xfs_dquot	*udqp = NULL;
> > -	struct xfs_dquot	*gdqp = NULL;
> > -	struct xfs_dquot	*pdqp = NULL;
> > -	struct xfs_trans_res	*tres;
> > -	uint			resblks;
> > -	xfs_ino_t		ino;
> > +	struct user_namespace		*mnt_userns,
> > +	xfs_inode_t			*dp,
> 
> Convert the struct typedefs...
> 
Ok, thx for the reviews!
Allison

> --D
> 
> > +	struct xfs_name			*name,
> > +	umode_t				mode,
> > +	dev_t				rdev,
> > +	bool				init_xattrs,
> > +	xfs_inode_t			**ipp)
> > +{
> > +	int				is_dir = S_ISDIR(mode);
> > +	struct xfs_mount		*mp = dp->i_mount;
> > +	struct xfs_inode		*ip = NULL;
> > +	struct xfs_trans		*tp = NULL;
> > +	int				error;
> > +	bool				unlock_dp_on_error = false;
> > +	prid_t				prid;
> > +	struct xfs_dquot		*udqp = NULL;
> > +	struct xfs_dquot		*gdqp = NULL;
> > +	struct xfs_dquot		*pdqp = NULL;
> > +	struct xfs_trans_res		*tres;
> > +	uint				resblks;
> > +	xfs_ino_t			ino;
> > +	xfs_dir2_dataptr_t		diroffset;
> > +	struct xfs_parent_name_rec	rec;
> > +	struct xfs_da_args		args = {
> > +		.dp		= dp,
> > +		.geo		= mp->m_attr_geo,
> > +		.whichfork	= XFS_ATTR_FORK,
> > +		.attr_filter	= XFS_ATTR_PARENT,
> > +		.op_flags	= XFS_DA_OP_OKNOENT,
> > +		.name		= (const uint8_t *)&rec,
> > +		.namelen	= sizeof(rec),
> > +		.value		= (void *)name->name,
> > +		.valuelen	= name->len,
> > +	};
> >  
> >  	trace_xfs_create(dp, name);
> >  
> > @@ -1009,6 +1024,12 @@ xfs_create(
> >  		tres = &M_RES(mp)->tr_create;
> >  	}
> >  
> > +	if (xfs_has_larp(mp)) {
> > +		error = xfs_attr_grab_log_assist(mp);
> > +		if (error)
> > +			goto out_release_dquots;
> > +	}
> > +
> >  	/*
> >  	 * Initially assume that the file does not exist and
> >  	 * reserve the resources for that case.  If that is not
> > @@ -1024,7 +1045,7 @@ xfs_create(
> >  				resblks, &tp);
> >  	}
> >  	if (error)
> > -		goto out_release_dquots;
> > +		goto drop_incompat;
> >  
> >  	xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
> >  	unlock_dp_on_error = true;
> > @@ -1048,11 +1069,12 @@ xfs_create(
> >  	 * the transaction cancel unlocking dp so don't do it
> > explicitly in the
> >  	 * error path.
> >  	 */
> > -	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
> > +	xfs_trans_ijoin(tp, dp, 0);
> >  	unlock_dp_on_error = false;
> >  
> >  	error = xfs_dir_createname(tp, dp, name, ip->i_ino,
> > -				   resblks - XFS_IALLOC_SPACE_RES(mp),
> > NULL);
> > +				   resblks - XFS_IALLOC_SPACE_RES(mp),
> > +				   &diroffset);
> >  	if (error) {
> >  		ASSERT(error != -ENOSPC);
> >  		goto out_trans_cancel;
> > @@ -1068,6 +1090,20 @@ xfs_create(
> >  		xfs_bumplink(tp, dp);
> >  	}
> >  
> > +	/*
> > +	 * If we have parent pointers, we need to add the attribute
> > containing
> > +	 * the parent information now.
> > +	 */
> > +	if (xfs_sb_version_hasparent(&mp->m_sb)) {
> > +		xfs_init_parent_name_rec(&rec, dp, diroffset);
> > +		args.dp	= ip;
> > +		args.trans = tp;
> > +		args.hashval = xfs_da_hashname(args.name,
> > args.namelen);
> > +		error =  xfs_attr_defer_add(&args);
> > +		if (error)
> > +			goto out_trans_cancel;
> > +	}
> > +
> >  	/*
> >  	 * If this is a synchronous mount, make sure that the
> >  	 * create transaction goes to disk before returning to
> > @@ -1093,6 +1129,7 @@ xfs_create(
> >  
> >  	*ipp = ip;
> >  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
> > +	xfs_iunlock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
> >  	return 0;
> >  
> >   out_trans_cancel:
> > @@ -1107,6 +1144,9 @@ xfs_create(
> >  		xfs_finish_inode_setup(ip);
> >  		xfs_irele(ip);
> >  	}
> > + drop_incompat:
> > +	if (xfs_has_larp(mp))
> > +		xlog_drop_incompat_feat(mp->m_log);
> >   out_release_dquots:
> >  	xfs_qm_dqrele(udqp);
> >  	xfs_qm_dqrele(gdqp);
> > diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
> > index 35e13e125ec6..6012a6ba512c 100644
> > --- a/fs/xfs/xfs_xattr.c
> > +++ b/fs/xfs/xfs_xattr.c
> > @@ -27,7 +27,7 @@
> >   * they must release the permission by calling
> > xlog_drop_incompat_feat
> >   * when they're done.
> >   */
> > -static inline int
> > +inline int
> >  xfs_attr_grab_log_assist(
> >  	struct xfs_mount	*mp)
> >  {
> > diff --git a/fs/xfs/xfs_xattr.h b/fs/xfs/xfs_xattr.h
> > index 2b09133b1b9b..3fd6520a4d69 100644
> > --- a/fs/xfs/xfs_xattr.h
> > +++ b/fs/xfs/xfs_xattr.h
> > @@ -7,6 +7,7 @@
> >  #define __XFS_XATTR_H__
> >  
> >  int xfs_attr_change(struct xfs_da_args *args);
> > +int xfs_attr_grab_log_assist(struct xfs_mount *mp);
> >  
> >  extern const struct xattr_handler *xfs_xattr_handlers[];
> >  
> > -- 
> > 2.25.1
> >