Re: [PATCH 02/17] Set up infastructure for deferred attribute operations

From: Allison Henderson <allison.henderson@oracle.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 02/17] Set up infastructure for deferred attribute operations
Date: Fri, 20 Oct 2017 18:08:15 -0700	[thread overview]
Message-ID: <04a77160-0c55-34d1-5f31-a114f75ad509@oracle.com> (raw)
In-Reply-To: <20171019190232.GC4755@magnolia>

On 10/19/2017 12:02 PM, Darrick J. Wong wrote:

> On Wed, Oct 18, 2017 at 03:55:18PM -0700, Allison Henderson wrote:
>> This patch adds two new log item types for setting or
>> removing attributes as deferred operations.  The
>> xfs_attri_log_item logs an intent to set or remove an
>> attribute.  The corresponding xfs_attrd_log_item holds
>> a reference to the xfs_attri_log_item and is freed once
>> the transaction is done.  Both log items use a generic
>> xfs_attr_log_format structure that contains the attribute
>> name, value, flags, inode, and an op_flag that indicates
>> if the operations is a set or remove.
>>
>> At the moment, this feature will only be used by the parent
>> pointer patch set which uses attributes to store information
>> about an inodes parent.
>>
>> Signed-off-by: Allison Henderson<allison.henderson@oracle.com>
>> ---
>>   fs/xfs/Makefile                |   2 +
>>   fs/xfs/libxfs/xfs_attr.c       |   2 +-
>>   fs/xfs/libxfs/xfs_defer.h      |   1 +
>>   fs/xfs/libxfs/xfs_log_format.h |  36 ++-
>>   fs/xfs/libxfs/xfs_types.h      |   1 +
>>   fs/xfs/xfs_attr.h              |  20 +-
>>   fs/xfs/xfs_attr_item.c         | 512 +++++++++++++++++++++++++++++++++++++++++
>>   fs/xfs/xfs_attr_item.h         | 111 +++++++++
>>   fs/xfs/xfs_log_recover.c       | 140 +++++++++++
>>   fs/xfs/xfs_super.c             |   1 +
>>   fs/xfs/xfs_trans.h             |  13 ++
>>   fs/xfs/xfs_trans_attr.c        | 286 +++++++++++++++++++++++
>>   12 files changed, 1121 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
>> index a6e955b..ec6486b 100644
>> --- a/fs/xfs/Makefile
>> +++ b/fs/xfs/Makefile
>> @@ -106,6 +106,7 @@ xfs-y				+= xfs_log.o \
>>   				   xfs_bmap_item.o \
>>   				   xfs_buf_item.o \
>>   				   xfs_extfree_item.o \
>> +				   xfs_attr_item.o \
>>   				   xfs_icreate_item.o \
>>   				   xfs_inode_item.o \
>>   				   xfs_refcount_item.o \
>> @@ -115,6 +116,7 @@ xfs-y				+= xfs_log.o \
>>   				   xfs_trans_bmap.o \
>>   				   xfs_trans_buf.o \
>>   				   xfs_trans_extfree.o \
>> +				   xfs_trans_attr.o \
>>   				   xfs_trans_inode.o \
>>   				   xfs_trans_refcount.o \
>>   				   xfs_trans_rmap.o \
>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
>> index b00ec1f..5325ec2 100644
>> --- a/fs/xfs/libxfs/xfs_attr.c
>> +++ b/fs/xfs/libxfs/xfs_attr.c
>> @@ -74,7 +74,7 @@ STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
>>   STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
>>   
>>   
>> -STATIC int
>> +int
>>   xfs_attr_args_init(
>>   	struct xfs_da_args	*args,
>>   	struct xfs_inode	*dp,
>> diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
>> index d4f046d..ef0f8bf 100644
>> --- a/fs/xfs/libxfs/xfs_defer.h
>> +++ b/fs/xfs/libxfs/xfs_defer.h
>> @@ -55,6 +55,7 @@ enum xfs_defer_ops_type {
>>   	XFS_DEFER_OPS_TYPE_REFCOUNT,
>>   	XFS_DEFER_OPS_TYPE_RMAP,
>>   	XFS_DEFER_OPS_TYPE_FREE,
>> +	XFS_DEFER_OPS_TYPE_ATTR,
>>   	XFS_DEFER_OPS_TYPE_MAX,
>>   };
>>   
>> diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
>> index 8372e9b..b0ce87e 100644
>> --- a/fs/xfs/libxfs/xfs_log_format.h
>> +++ b/fs/xfs/libxfs/xfs_log_format.h
>> @@ -18,6 +18,8 @@
>>   #ifndef	__XFS_LOG_FORMAT_H__
>>   #define __XFS_LOG_FORMAT_H__
>>   
>> +#include "xfs_attr.h"
>> +
>>   struct xfs_mount;
>>   struct xfs_trans_res;
>>   
>> @@ -116,7 +118,12 @@ static inline uint xlog_get_cycle(char *ptr)
>>   #define XLOG_REG_TYPE_CUD_FORMAT	24
>>   #define XLOG_REG_TYPE_BUI_FORMAT	25
>>   #define XLOG_REG_TYPE_BUD_FORMAT	26
>> -#define XLOG_REG_TYPE_MAX		26
>> +#define XLOG_REG_TYPE_ATTRI_FORMAT	27
>> +#define XLOG_REG_TYPE_ATTRD_FORMAT	28
>> +#define XLOG_REG_TYPE_ATTR_NAME		29
>> +#define XLOG_REG_TYPE_ATTR_VALUE	30
>> +#define XLOG_REG_TYPE_MAX		31
>> +
>>   
>>   /*
>>    * Flags to log operation header
>> @@ -239,6 +246,8 @@ typedef struct xfs_trans_header {
>>   #define	XFS_LI_CUD		0x1243
>>   #define	XFS_LI_BUI		0x1244	/* bmbt update intent */
>>   #define	XFS_LI_BUD		0x1245
>> +#define	XFS_LI_ATTRI		0x1246  /* attr set/remove intent*/
>> +#define	XFS_LI_ATTRD		0x1247  /* attr set/remove done */
>>   
>>   #define XFS_LI_TYPE_DESC \
>>   	{ XFS_LI_EFI,		"XFS_LI_EFI" }, \
>> @@ -254,7 +263,9 @@ typedef struct xfs_trans_header {
>>   	{ XFS_LI_CUI,		"XFS_LI_CUI" }, \
>>   	{ XFS_LI_CUD,		"XFS_LI_CUD" }, \
>>   	{ XFS_LI_BUI,		"XFS_LI_BUI" }, \
>> -	{ XFS_LI_BUD,		"XFS_LI_BUD" }
>> +	{ XFS_LI_BUD,		"XFS_LI_BUD" }, \
>> +	{ XFS_LI_ATTRI,		"XFS_LI_ATTRI" }, \
>> +	{ XFS_LI_ATTRD,		"XFS_LI_ATTRD" }
>>   
>>   /*
>>    * Inode Log Item Format definitions.
>> @@ -863,4 +874,25 @@ struct xfs_icreate_log {
>>   	__be32		icl_gen;	/* inode generation number to use */
>>   };
>>   
>> +/* Flags for deferred attribute operations */
>> +#define ATTR_OP_FLAGS_SET	0x01	/* Set the attribute */
> The names need to have "XFS_" prefixed here because this is a public
> header file, e.g. XFS_ATTR_OP_FLAGS_SET.
OK, will fix

>> +#define ATTR_OP_FLAGS_REMOVE	0x02	/* Remove the attribute */
>> +#define ATTR_OP_FLAGS_MAX	0x02	/* Max flags */
> I would be a little more explicit about which bits of op_flags are
> actual bit flags and which parts are mutually exclusive type codes.
> IOWs, from just these definitions here it's not clear that _SET and
> _REMOVE can't both be set at the same time.
>
> /* upper bits are flags, lower byte is type code */
> #define XFS_ATTR_OP_FLAGS_SET		1
> #define XFS_ATTR_OP_FLAGS_REMOVE	2
> #define XFS_ATTR_OP_FLAGS_TYPE_MASK	0xFF
>
> (TBH this opcode part could be an enum defined elsewhere like what RUI
> pe_flags does...)
>
> #define XFS_ATTR_OP_FLAGS_AFLAG		(1U << 31)
> #define XFS_ATTR_OP_FLAGS_SOMEOTHERFLAG	(1U << 30)
>
Sure that makes sense.  Will update.
>> +
>> +/*
>> + * This is the structure used to lay out an attr log item in the
>> + * log.
>> + */
>> +struct xfs_attr_log_format {
>> +	uint64_t	id;		/* attri identifier */
>> +	xfs_ino_t       ino;		/* the inode for this attr operation */
>> +	uint32_t        op_flags;	/* marks the op as a set or remove */
>> +	uint32_t        name_len;	/* attr name length */
>> +	uint32_t        value_len;	/* attr value length */
>> +	uint32_t        attr_flags;	/* attr flags */
>> +	uint16_t	type;		/* attri log item type */
>> +	uint16_t	size;		/* size of this item */
>> +	uint32_t	pad;		/* pad to 64 bit aligned */
> The names ought to have structure prefixes because this is a public header.
>
> uint64_t	alf_id;
> uint64_t	alf_ino;
> ...
> uint32_t	alf_pad;
>
Alrighty, will do
>> +};
>> +
>>   #endif /* __XFS_LOG_FORMAT_H__ */
>> diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
>> index 0220159..5372063 100644
>> --- a/fs/xfs/libxfs/xfs_types.h
>> +++ b/fs/xfs/libxfs/xfs_types.h
>> @@ -23,6 +23,7 @@ typedef uint32_t	prid_t;		/* project ID */
>>   typedef uint32_t	xfs_agblock_t;	/* blockno in alloc. group */
>>   typedef uint32_t	xfs_agino_t;	/* inode # within allocation grp */
>>   typedef uint32_t	xfs_extlen_t;	/* extent length in blocks */
>> +typedef uint32_t	xfs_attrlen_t;	/* attr length */
>>   typedef uint32_t	xfs_agnumber_t;	/* allocation group number */
>>   typedef int32_t		xfs_extnum_t;	/* # of extents in a file */
>>   typedef int16_t		xfs_aextnum_t;	/* # extents in an attribute fork */
>> diff --git a/fs/xfs/xfs_attr.h b/fs/xfs/xfs_attr.h
>> index 8542606..34bb4cb 100644
>> --- a/fs/xfs/xfs_attr.h
>> +++ b/fs/xfs/xfs_attr.h
>> @@ -18,6 +18,8 @@
>>   #ifndef __XFS_ATTR_H__
>>   #define	__XFS_ATTR_H__
>>   
>> +#include "libxfs/xfs_defer.h"
> What does this header file need from xfs_defer.h?
>
>>   struct xfs_inode;
>>   struct xfs_da_args;
>>   struct xfs_attr_list_context;
>> @@ -87,6 +89,20 @@ typedef struct attrlist_ent {	/* data from attr_list() */
>>   } attrlist_ent_t;
>>   
>>   /*
>> + * List of attrs to commit later.
>> + */
>> +struct xfs_attr_item {
>> +	xfs_ino_t	  xattri_ino;
>> +	uint32_t	  xattri_op_flags;
>> +	uint32_t	  xattri_value_len;   /* length of name and val */
>> +	uint32_t	  xattri_name_len;    /* length of name */
>> +	uint32_t	  xattri_flags;       /* attr flags */
>> +	char		  xattri_name[XATTR_NAME_MAX];
>> +	char              xattri_value[XATTR_SIZE_MAX];
> MAXNAMELEN and XFS_XATTR_SIZE_MAX ?
>
> (Ugh, really, we should just clean that up to XFS_MAXNAMELEN...)
>
Yeah, I think you suggest using a "xattri_namevalue[0];" here in the
next patch review.  I'll just pull all the array stuff out....
>> +	struct list_head  xattri_list;
>> +};
>> +
>> +/*
>>    * Given a pointer to the (char*) buffer containing the attr_list() result,
>>    * and an index, return a pointer to the indicated attribute in the buffer.
>>    */
>> @@ -154,6 +170,8 @@ int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name, int flags);
>>   int xfs_attr_remove_args(struct xfs_da_args *args, int flags);
>>   int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
>>   		  int flags, struct attrlist_cursor_kern *cursor);
>> -
>> +int xfs_attr_args_init(struct xfs_da_args *args, struct xfs_inode *dp,
>> +		       const unsigned char *name, int flags);
>> +int xfs_attr_calc_size(struct xfs_da_args *args, int *local);
>>   
>>   #endif	/* __XFS_ATTR_H__ */
>> diff --git a/fs/xfs/xfs_attr_item.c b/fs/xfs/xfs_attr_item.c
>> new file mode 100644
>> index 0000000..8cbe9b0
>> --- /dev/null
>> +++ b/fs/xfs/xfs_attr_item.c
>> @@ -0,0 +1,512 @@
>> +/*
>> + * Copyright (c) 2017 Oracle, 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 Inc.
>> + */
>> +#include "xfs.h"
>> +#include "xfs_fs.h"
>> +#include "xfs_format.h"
>> +#include "xfs_log_format.h"
>> +#include "xfs_trans_resv.h"
>> +#include "xfs_bit.h"
>> +#include "xfs_mount.h"
>> +#include "xfs_trans.h"
>> +#include "xfs_trans_priv.h"
>> +#include "xfs_buf_item.h"
>> +#include "xfs_attr_item.h"
>> +#include "xfs_log.h"
>> +#include "xfs_btree.h"
>> +#include "xfs_rmap.h"
>> +
>> +
>> +static inline struct xfs_attri_log_item *ATTRI_ITEM(struct xfs_log_item *lip)
>> +{
>> +	return container_of(lip, struct xfs_attri_log_item, item);
>> +}
>> +
>> +void
>> +xfs_attri_item_free(
>> +	struct xfs_attri_log_item	*attrip)
>> +{
>> +	kmem_free(attrip->item.li_lv_shadow);
>> +	kmem_free(attrip);
>> +}
>> +
>> +/*
>> + * This returns the number of iovecs needed to log the given attri item.
>> + * We only need 1 iovec for an attri item.  It just logs the attr_log_format
>> + * structure.
>> + */
>> +static inline int
>> +xfs_attri_item_sizeof(
>> +	struct xfs_attri_log_item *attrip)
>> +{
>> +	return sizeof(struct xfs_attr_log_format);
>> +}
>> +
>> +STATIC void
>> +xfs_attri_item_size(
>> +	struct xfs_log_item	*lip,
>> +	int			*nvecs,
>> +	int			*nbytes)
>> +{
>> +	struct xfs_attri_log_item       *attrip = ATTRI_ITEM(lip);
>> +
>> +	*nvecs += 1;
>> +	*nbytes += xfs_attri_item_sizeof(attrip);
>> +
>> +	if (attrip->name_len > 0) {
>> +		*nvecs += 1;
>> +		nbytes += attrip->name_len;
>> +	}
>> +
>> +	if (attrip->value_len > 0) {
>> +		*nvecs += 1;
>> +		nbytes += attrip->value_len;
>> +	}
>> +}
>> +
>> +/*
>> + * This is called to fill in the vector of log iovecs for the
>> + * given attri log item. We use only 1 iovec, and we point that
>> + * at the attri_log_format structure embedded in the attri item.
>> + * It is at this point that we assert that all of the attr
>> + * slots in the attri item have been filled.
>> + */
>> +STATIC void
>> +xfs_attri_item_format(
>> +	struct xfs_log_item	*lip,
>> +	struct xfs_log_vec	*lv)
>> +{
>> +	struct xfs_attri_log_item	*attrip = ATTRI_ITEM(lip);
>> +	struct xfs_log_iovec	*vecp = NULL;
>> +
>> +	attrip->format.type = XFS_LI_ATTRI;
>> +	attrip->format.size = 1;
>> +
>> +	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTRI_FORMAT,
>> +			&attrip->format,
>> +			xfs_attri_item_sizeof(attrip));
>> +	if (attrip->name_len > 0)
>> +		xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTR_NAME,
>> +				attrip->name, attrip->name_len);
>> +
>> +	if (attrip->value_len > 0)
>> +		xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTR_VALUE,
>> +				attrip->value, attrip->value_len);
>> +}
>> +
>> +
>> +/*
>> + * Pinning has no meaning for an attri item, so just return.
>> + */
>> +STATIC void
>> +xfs_attri_item_pin(
>> +	struct xfs_log_item	*lip)
>> +{
>> +}
>> +
>> +/*
>> + * The unpin operation is the last place an ATTRI is manipulated in the log. It
>> + * is either inserted in the AIL or aborted in the event of a log I/O error. In
>> + * either case, the EFI transaction has been successfully committed to make it
> EFI?
Typo left over from extent free intent code that I used as a template....
Will fix :-)
>> + * this far. Therefore, we expect whoever committed the ATTRI to either
>> + * construct and commit the ATTRD or drop the ATTRD's reference in the event of
>> + * error. Simply drop the log's ATTRI reference now that the log is done with
>> + * it.
>> + */
>> +STATIC void
>> +xfs_attri_item_unpin(
>> +	struct xfs_log_item	*lip,
>> +	int			remove)
>> +{
>> +	struct xfs_attri_log_item	*attrip = ATTRI_ITEM(lip);
>> +
>> +	xfs_attri_release(attrip);
>> +}
>> +
>> +/*
>> + * attri items have no locking or pushing.  However, since ATTRIs are pulled
>> + * from the AIL when their corresponding ATTRDs are committed to disk, their
>> + * situation is very similar to being pinned.  Return XFS_ITEM_PINNED so that
>> + * the caller will eventually flush the log.  This should help in getting the
>> + * ATTRI out of the AIL.
>> + */
>> +STATIC uint
>> +xfs_attri_item_push(
>> +	struct xfs_log_item	*lip,
>> +	struct list_head	*buffer_list)
>> +{
>> +	return XFS_ITEM_PINNED;
>> +}
>> +
>> +/*
>> + * The ATTRI has been either committed or aborted if the transaction has been
>> + * cancelled. If the transaction was cancelled, an ATTRD isn't going to be
>> + * constructed and thus we free the ATTRI here directly.
>> + */
>> +STATIC void
>> +xfs_attri_item_unlock(
>> +	struct xfs_log_item	*lip)
>> +{
>> +	if (lip->li_flags & XFS_LI_ABORTED)
>> +		xfs_attri_item_free(ATTRI_ITEM(lip));
>> +}
>> +
>> +/*
>> + * The ATTRI is logged only once and cannot be moved in the log, so simply
>> + * return the lsn at which it's been logged.
>> + */
>> +STATIC xfs_lsn_t
>> +xfs_attri_item_committed(
>> +	struct xfs_log_item	*lip,
>> +	xfs_lsn_t		lsn)
>> +{
>> +	return lsn;
>> +}
>> +
>> +STATIC void
>> +xfs_attri_item_committing(
>> +	struct xfs_log_item	*lip,
>> +	xfs_lsn_t		lsn)
>> +{
>> +}
>> +
>> +/*
>> + * This is the ops vector shared by all attri log items.
>> + */
>> +static const struct xfs_item_ops xfs_attri_item_ops = {
>> +	.iop_size	= xfs_attri_item_size,
>> +	.iop_format	= xfs_attri_item_format,
>> +	.iop_pin	= xfs_attri_item_pin,
>> +	.iop_unpin	= xfs_attri_item_unpin,
>> +	.iop_unlock	= xfs_attri_item_unlock,
>> +	.iop_committed	= xfs_attri_item_committed,
>> +	.iop_push	= xfs_attri_item_push,
>> +	.iop_committing = xfs_attri_item_committing
>> +};
>> +
>> +
>> +/*
>> + * Allocate and initialize an attri item
>> + */
>> +struct xfs_attri_log_item *
>> +xfs_attri_init(
>> +	struct xfs_mount	*mp)
>> +
>> +{
>> +	struct xfs_attri_log_item	*attrip;
>> +	uint			size;
>> +
>> +	size = (uint)(sizeof(struct xfs_attri_log_item));
>> +	attrip = kmem_zalloc(size, KM_SLEEP);
>> +
>> +	xfs_log_item_init(mp, &(attrip->item), XFS_LI_ATTRI,
>> +			  &xfs_attri_item_ops);
>> +	attrip->format.id = (uintptr_t)(void *)attrip;
>> +	atomic_set(&attrip->refcount, 2);
>> +
>> +	return attrip;
>> +}
>> +
>> +/*
>> + * Copy an attr format buffer from the given buf, and into the destination
>> + * attr format structure.
>> + */
>> +int
>> +xfs_attr_copy_format(struct xfs_log_iovec *buf,
>> +		      struct xfs_attr_log_format *dst_attr_fmt)
>> +{
>> +	struct xfs_attr_log_format *src_attr_fmt = buf->i_addr;
>> +	uint len = sizeof(struct xfs_attr_log_format);
>> +
>> +	if (buf->i_len == len) {
>> +		memcpy((char *)dst_attr_fmt, (char *)src_attr_fmt, len);
>> +		return 0;
>> +	}
>> +	return -EFSCORRUPTED;
>> +}
>> +
>> +/*
>> + * Freeing the attri requires that we remove it from the AIL if it has already
>> + * been placed there. However, the ATTRI may not yet have been placed in the
>> + * AIL when called by xfs_attri_release() from ATTRD processing due to the
>> + * ordering of committed vs unpin operations in bulk insert operations. Hence
>> + * the reference count to ensure only the last caller frees the ATTRI.
>> + */
>> +void
>> +xfs_attri_release(
>> +	struct xfs_attri_log_item	*attrip)
>> +{
>> +	ASSERT(atomic_read(&attrip->refcount) > 0);
>> +	if (atomic_dec_and_test(&attrip->refcount)) {
>> +		xfs_trans_ail_remove(&attrip->item,
>> +				     SHUTDOWN_LOG_IO_ERROR);
>> +		xfs_attri_item_free(attrip);
>> +	}
>> +}
>> +
>> +static inline struct xfs_attrd_log_item *ATTRD_ITEM(struct xfs_log_item *lip)
>> +{
>> +	return container_of(lip, struct xfs_attrd_log_item, item);
>> +}
>> +
>> +STATIC void
>> +xfs_attrd_item_free(struct xfs_attrd_log_item *attrdp)
>> +{
>> +	kmem_free(attrdp->item.li_lv_shadow);
>> +	kmem_free(attrdp);
>> +}
>> +
>> +/*
>> + * This returns the number of iovecs needed to log the given attrd item.
>> + * We only need 1 iovec for an attrd item.  It just logs the attr_log_format
>> + * structure.
>> + */
>> +static inline int
>> +xfs_attrd_item_sizeof(
>> +	struct xfs_attrd_log_item *attrdp)
>> +{
>> +	return sizeof(struct xfs_attr_log_format);
>> +}
>> +
>> +STATIC void
>> +xfs_attrd_item_size(
>> +	struct xfs_log_item	*lip,
>> +	int			*nvecs,
>> +	int			*nbytes)
>> +{
>> +	struct xfs_attrd_log_item	*attrdp = ATTRD_ITEM(lip);
>> +	*nvecs += 1;
>> +	*nbytes += xfs_attrd_item_sizeof(attrdp);
>> +
>> +	if (attrdp->name_len > 0) {
>> +		*nvecs += 1;
>> +		nbytes += attrdp->name_len;
>> +	}
>> +
>> +	if (attrdp->value_len > 0) {
>> +		*nvecs += 1;
>> +		nbytes += attrdp->value_len;
>> +	}
>> +}
>> +
>> +/*
>> + * This is called to fill in the vector of log iovecs for the
>> + * given attrd log item. We use only 1 iovec, and we point that
>> + * at the attr_log_format structure embedded in the attrd item.
>> + * It is at this point that we assert that all of the attr
>> + * slots in the attrd item have been filled.
>> + */
>> +STATIC void
>> +xfs_attrd_item_format(
>> +	struct xfs_log_item	*lip,
>> +	struct xfs_log_vec	*lv)
>> +{
>> +	struct xfs_attrd_log_item	*attrdp = ATTRD_ITEM(lip);
>> +	struct xfs_log_iovec	*vecp = NULL;
>> +
>> +	attrdp->format.type = XFS_LI_ATTRD;
>> +	attrdp->format.size = 1;
>> +
>> +	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTRD_FORMAT,
>> +			&attrdp->format,
>> +			xfs_attrd_item_sizeof(attrdp));
>> +
>> +	if (attrdp->name_len > 0)
>> +		xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTR_NAME,
>> +				attrdp->name, attrdp->name_len);
>> +
>> +	if (attrdp->value_len > 0)
>> +		xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTR_VALUE,
>> +				attrdp->value, attrdp->value_len);
> No need to log name/value for ATTRD items, since we only care about
> matching alf_id between ATTRI and ATTRD items.
Alrighty
>> +}
>> +
>> +/*
>> + * Pinning has no meaning for an attrd item, so just return.
>> + */
>> +STATIC void
>> +xfs_attrd_item_pin(
>> +	struct xfs_log_item	*lip)
>> +{
>> +}
>> +
>> +/*
>> + * Since pinning has no meaning for an attrd item, unpinning does
>> + * not either.
>> + */
>> +STATIC void
>> +xfs_attrd_item_unpin(
>> +	struct xfs_log_item	*lip,
>> +	int			remove)
>> +{
>> +}
>> +
>> +/*
>> + * There isn't much you can do to push on an attrd item.  It is simply stuck
>> + * waiting for the log to be flushed to disk.
>> + */
>> +STATIC uint
>> +xfs_attrd_item_push(
>> +	struct xfs_log_item	*lip,
>> +	struct list_head	*buffer_list)
>> +{
>> +	return XFS_ITEM_PINNED;
>> +}
>> +
>> +/*
>> + * The ATTRD is either committed or aborted if the transaction is cancelled. If
>> + * the transaction is cancelled, drop our reference to the ATTRI and free the
>> + * ATTRD.
>> + */
>> +STATIC void
>> +xfs_attrd_item_unlock(
>> +	struct xfs_log_item	*lip)
>> +{
>> +	struct xfs_attrd_log_item	*attrdp = ATTRD_ITEM(lip);
>> +
>> +	if (lip->li_flags & XFS_LI_ABORTED) {
>> +		xfs_attri_release(attrdp->attrip);
>> +		xfs_attrd_item_free(attrdp);
>> +	}
>> +}
>> +
>> +/*
>> + * When the attrd item is committed to disk, all we need to do is delete our
>> + * reference to our partner attri item and then free ourselves. Since we're
>> + * freeing ourselves we must return -1 to keep the transaction code from
>> + * further referencing this item.
>> + */
>> +STATIC xfs_lsn_t
>> +xfs_attrd_item_committed(
>> +	struct xfs_log_item	*lip,
>> +	xfs_lsn_t		lsn)
>> +{
>> +	struct xfs_attrd_log_item	*attrdp = ATTRD_ITEM(lip);
>> +
>> +	/*
>> +	 * Drop the ATTRI reference regardless of whether the ATTRD has been
>> +	 * aborted. Once the ATTRD transaction is constructed, it is the sole
>> +	 * responsibility of the ATTRD to release the ATTRI (even if the ATTRI
>> +	 * is aborted due to log I/O error).
>> +	 */
>> +	xfs_attri_release(attrdp->attrip);
>> +	xfs_attrd_item_free(attrdp);
>> +
>> +	return (xfs_lsn_t)-1;
>> +}
>> +
>> +STATIC void
>> +xfs_attrd_item_committing(
>> +	struct xfs_log_item	*lip,
>> +	xfs_lsn_t		lsn)
>> +{
>> +}
>> +
>> +/*
>> + * This is the ops vector shared by all attrd log items.
>> + */
>> +static const struct xfs_item_ops xfs_attrd_item_ops = {
>> +	.iop_size	= xfs_attrd_item_size,
>> +	.iop_format	= xfs_attrd_item_format,
>> +	.iop_pin	= xfs_attrd_item_pin,
>> +	.iop_unpin	= xfs_attrd_item_unpin,
>> +	.iop_unlock	= xfs_attrd_item_unlock,
>> +	.iop_committed	= xfs_attrd_item_committed,
>> +	.iop_push	= xfs_attrd_item_push,
>> +	.iop_committing = xfs_attrd_item_committing
>> +};
>> +
>> +/*
>> + * Allocate and initialize an attrd item
>> + */
>> +struct xfs_attrd_log_item *
>> +xfs_attrd_init(
>> +	struct xfs_mount	*mp,
>> +	struct xfs_attri_log_item	*attrip)
>> +
>> +{
>> +	struct xfs_attrd_log_item	*attrdp;
>> +	uint			size;
>> +
>> +	size = (uint)(sizeof(struct xfs_attrd_log_item));
>> +	attrdp = kmem_zalloc(size, KM_SLEEP);
>> +
>> +	xfs_log_item_init(mp, &attrdp->item, XFS_LI_ATTRD,
>> +			  &xfs_attrd_item_ops);
>> +	attrdp->attrip = attrip;
>> +	attrdp->format.id = attrip->format.id;
>> +
>> +	return attrdp;
>> +}
>> +
>> +/*
>> + * Process an attr intent item that was recovered from
>> + * the log.  We need to delete the attr that it describes.
>> + */
>> +int
>> +xfs_attri_recover(
>> +	struct xfs_mount	*mp,
>> +	struct xfs_attri_log_item	*attrip)
>> +{
>> +	struct xfs_attrd_log_item	*attrdp;
>> +	struct xfs_trans	*tp;
>> +	int			error = 0;
>> +	struct xfs_attr_log_format	*attrp;
>> +
>> +	ASSERT(!test_bit(XFS_ATTRI_RECOVERED, &attrip->flags));
>> +
>> +	/*
>> +	 * First check the validity of the attr described by the
>> +	 * ATTRI.  If any are bad, then assume that all are bad and
>> +	 * just toss the ATTRI.
>> +	 */
>> +	attrp = &attrip->format;
>> +	if (attrp->value_len == 0 ||
>> +	    attrp->name_len == 0 ||
>> +	    attrp->op_flags > ATTR_OP_FLAGS_MAX) {
>> +		/*
>> +		 * This will pull the ATTRI from the AIL and
>> +		 * free the memory associated with it.
>> +		 */
>> +		set_bit(XFS_ATTRI_RECOVERED, &attrip->flags);
>> +		xfs_attri_release(attrip);
>> +		return -EIO;
>> +	}
>> +
>> +	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
>> +	if (error)
>> +		return error;
>> +	attrdp = xfs_trans_get_attrd(tp, attrip);
>> +	attrp = &attrip->format;
>> +
>> +	error = xfs_trans_attr(tp, attrdp, attrp->ino,
>> +				attrp->op_flags,
>> +				attrp->attr_flags,
>> +				attrp->name_len,
>> +				attrp->value_len,
>> +				attrip->name,
>> +				attrip->value);
>> +	if (error)
>> +		goto abort_error;
>> +
>> +
>> +	set_bit(XFS_ATTRI_RECOVERED, &attrip->flags);
>> +	error = xfs_trans_commit(tp);
>> +	return error;
>> +
>> +abort_error:
>> +	xfs_trans_cancel(tp);
>> +	return error;
>> +}
>> diff --git a/fs/xfs/xfs_attr_item.h b/fs/xfs/xfs_attr_item.h
>> new file mode 100644
>> index 0000000..023675d
>> --- /dev/null
>> +++ b/fs/xfs/xfs_attr_item.h
>> @@ -0,0 +1,111 @@
>> +/*
>> + * Copyright (c) 2017 Oracle, 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 Inc.
>> + */
>> +#ifndef	__XFS_ATTR_ITEM_H__
>> +#define	__XFS_ATTR_ITEM_H__
>> +
>> +/* kernel only ATTRI/ATTRD definitions */
>> +
>> +struct xfs_mount;
>> +struct kmem_zone;
>> +
>> +/*
>> + * Max number of attrs in fast allocation path.
>> + */
>> +#define XFS_ATTRI_MAX_FAST_ATTRS        16
> Daaaang, we can cram *sixteen* different attribute name/value updates in
> a single defer_ops item? :)
>
> Each defer_ops item gets its own transaction to make changes and log the
> done item.  Sixteen attr updates is a /lot/ to be pushing through one
> transaction since (AFAICT) the static log reservations provide worst
> case space for one update.  I think this ought to be 1, especially since
> the actual attr log item structure only appears to have space to store
> one name and one value.
Ok, that sounds reasonable.  :-)  I likely forgot to come back and update it
from what extent free had it set to.  Thx for the catch!

>> +
>> +
>> +/*
>> + * Define ATTR flag bits. Manipulated by set/clear/test_bit operators.
>> + */
>> +#define	XFS_ATTRI_RECOVERED	1
>> +
>> +/*
>> + * This is the "attr intention" log item.  It is used to log the fact
>> + * that some attrs need to be processed.  It is used in conjunction with the
>> + * "attr done" log item described below.
>> + *
>> + * The ATTRI is reference counted so that it is not freed prior to both the
>> + * ATTRI and ATTRD being committed and unpinned. This ensures the ATTRI is
>> + * inserted into the AIL even in the event of out of order ATTRI/ATTRD
>> + * processing. In other words, an ATTRI is born with two references:
>> + *
>> + *      1.) an ATTRI held reference to track ATTRI AIL insertion
>> + *      2.) an ATTRD held reference to track ATTRD commit
>> + *
>> + * On allocation, both references are the responsibility of the caller. Once
>> + * the ATTRI is added to and dirtied in a transaction, ownership of reference
>> + * one transfers to the transaction. The reference is dropped once the ATTRI is
>> + * inserted to the AIL or in the event of failure along the way (e.g., commit
>> + * failure, log I/O error, etc.). Note that the caller remains responsible for
>> + * the ATTRD reference under all circumstances to this point. The caller has no
>> + * means to detect failure once the transaction is committed, however.
>> + * Therefore, an ATTRD is required after this point, even in the event of
>> + * unrelated failure.
>> + *
>> + * Once an ATTRD is allocated and dirtied in a transaction, reference two
>> + * transfers to the transaction. The ATTRD reference is dropped once it reaches
>> + * the unpin handler. Similar to the ATTRI, the reference also drops in the
>> + * event of commit failure or log I/O errors. Note that the ATTRD is not
>> + * inserted in the AIL, so at this point both the ATTI and ATTRD are freed.
>> + */
>> +struct xfs_attri_log_item {
>> +	xfs_log_item_t			item;
>> +	atomic_t			refcount;
>> +	unsigned long			flags;	/* misc flags */
>> +	int				name_len;
>> +	void				*name;
>> +	int				value_len;
>> +	void				*value;
>> +	struct xfs_attr_log_format	format;
>> +};
>> +
>> +/*
>> + * This is the "attr done" log item.  It is used to log
>> + * the fact that some attrs earlier mentioned in an attri item
>> + * have been freed.
>> + */
>> +struct xfs_attrd_log_item {
>> +	struct xfs_log_item		item;
>> +	struct xfs_attri_log_item	*attrip;
>> +	uint				next_attr;
>> +	int				name_len;
>> +	void				*name;
>> +	int				value_len;
>> +	void				*value;
>> +	struct xfs_attr_log_format	format;
>> +};
>> +
>> +/*
>> + * Max number of attrs in fast allocation path.
>> + */
>> +#define	XFS_ATTRD_MAX_FAST_ATTRS	16
>> +
>> +extern struct kmem_zone	*xfs_attri_zone;
>> +extern struct kmem_zone	*xfs_attrd_zone;
>> +
>> +struct xfs_attri_log_item	*xfs_attri_init(struct xfs_mount *mp);
>> +struct xfs_attrd_log_item	*xfs_attrd_init(struct xfs_mount *mp,
>> +					struct xfs_attri_log_item *attrip);
>> +int xfs_attr_copy_format(struct xfs_log_iovec *buf,
>> +			 struct xfs_attr_log_format *dst_attri_fmt);
>> +void			xfs_attri_item_free(struct xfs_attri_log_item *attrip);
>> +void			xfs_attri_release(struct xfs_attri_log_item *attrip);
>> +
>> +int			xfs_attri_recover(struct xfs_mount *mp,
>> +					struct xfs_attri_log_item *attrip);
>> +
>> +#endif	/* __XFS_ATTR_ITEM_H__ */
>> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
>> index ee34899..8326f56 100644
>> --- a/fs/xfs/xfs_log_recover.c
>> +++ b/fs/xfs/xfs_log_recover.c
>> @@ -33,6 +33,7 @@
>>   #include "xfs_log_recover.h"
>>   #include "xfs_inode_item.h"
>>   #include "xfs_extfree_item.h"
>> +#include "xfs_attr_item.h"
>>   #include "xfs_trans_priv.h"
>>   #include "xfs_alloc.h"
>>   #include "xfs_ialloc.h"
>> @@ -1956,6 +1957,8 @@ xlog_recover_reorder_trans(
>>   		case XFS_LI_CUD:
>>   		case XFS_LI_BUI:
>>   		case XFS_LI_BUD:
>> +		case XFS_LI_ATTRI:
>> +		case XFS_LI_ATTRD:
>>   			trace_xfs_log_recover_item_reorder_tail(log,
>>   							trans, item, pass);
>>   			list_move_tail(&item->ri_list, &inode_list);
>> @@ -3489,6 +3492,92 @@ xlog_recover_efd_pass2(
>>   	return 0;
>>   }
>>   
>> +STATIC int
>> +xlog_recover_attri_pass2(
>> +	struct xlog                     *log,
>> +	struct xlog_recover_item        *item,
>> +	xfs_lsn_t                       lsn)
>> +{
>> +	int                             error;
>> +	struct xfs_mount                *mp = log->l_mp;
>> +	struct xfs_attri_log_item       *attrip;
>> +	struct xfs_attr_log_format     *attri_formatp;
>> +
>> +	attri_formatp = item->ri_buf[0].i_addr;
>> +
>> +	attrip = xfs_attri_init(mp);
>> +	error = xfs_attr_copy_format(&item->ri_buf[0], &attrip->format);
>> +	if (error) {
>> +		xfs_attri_item_free(attrip);
>> +		return error;
>> +	}
>> +
>> +	spin_lock(&log->l_ailp->xa_lock);
>> +	/*
>> +	 * The ATTRI has two references. One for the ATTRD and one for ATTRI to
>> +	 * ensure it makes it into the AIL. Insert the ATTRI into the AIL
>> +	 * directly and drop the ATTRI reference. Note that
>> +	 * xfs_trans_ail_update() drops the AIL lock.
>> +	 */
>> +	xfs_trans_ail_update(log->l_ailp, &attrip->item, lsn);
>> +	xfs_attri_release(attrip);
>> +	return 0;
>> +}
>> +
>> +
>> +/*
>> + * This routine is called when an ATTRD format structure is found in a committed
>> + * transaction in the log. Its purpose is to cancel the corresponding ATTRI if
>> + * it was still in the log. To do this it searches the AIL for the ATTRI with
>> + * an id equal to that in the ATTRD format structure. If we find it we drop
>> + * the ATTRD reference, which removes the ATTRI from the AIL and frees it.
>> + */
>> +STATIC int
>> +xlog_recover_attrd_pass2(
>> +	struct xlog                     *log,
>> +	struct xlog_recover_item        *item)
>> +{
>> +	struct xfs_attr_log_format    *attrd_formatp;
>> +	struct xfs_attri_log_item      *attrip = NULL;
>> +	struct xfs_log_item          *lip;
>> +	uint64_t                attri_id;
>> +	struct xfs_ail_cursor   cur;
>> +	struct xfs_ail          *ailp = log->l_ailp;
>> +
>> +	attrd_formatp = item->ri_buf[0].i_addr;
>> +	ASSERT((item->ri_buf[0].i_len ==
>> +				(sizeof(struct xfs_attr_log_format))));
>> +	attri_id = attrd_formatp->id;
>> +
>> +	/*
>> +	 * Search for the ATTRI with the id in the ATTRD format structure in the
>> +	 * AIL.
>> +	 */
>> +	spin_lock(&ailp->xa_lock);
>> +	lip = xfs_trans_ail_cursor_first(ailp, &cur, 0);
>> +	while (lip != NULL) {
>> +		if (lip->li_type == XFS_LI_ATTRI) {
>> +			attrip = (struct xfs_attri_log_item *)lip;
>> +			if (attrip->format.id == attri_id) {
>> +				/*
>> +				 * Drop the ATTRD reference to the ATTRI. This
>> +				 * removes the ATTRI from the AIL and frees it.
>> +				 */
>> +				spin_unlock(&ailp->xa_lock);
>> +				xfs_attri_release(attrip);
>> +				spin_lock(&ailp->xa_lock);
>> +				break;
>> +			}
>> +		}
>> +		lip = xfs_trans_ail_cursor_next(ailp, &cur);
>> +	}
>> +
>> +	xfs_trans_ail_cursor_done(&cur);
>> +	spin_unlock(&ailp->xa_lock);
>> +
>> +	return 0;
>> +}
>> +
>>   /*
>>    * This routine is called to create an in-core extent rmap update
>>    * item from the rui format structure which was logged on disk.
>> @@ -4108,6 +4197,10 @@ xlog_recover_commit_pass2(
>>   		return xlog_recover_efi_pass2(log, item, trans->r_lsn);
>>   	case XFS_LI_EFD:
>>   		return xlog_recover_efd_pass2(log, item);
>> +	case XFS_LI_ATTRI:
>> +		return xlog_recover_attri_pass2(log, item, trans->r_lsn);
>> +	case XFS_LI_ATTRD:
>> +		return xlog_recover_attrd_pass2(log, item);
>>   	case XFS_LI_RUI:
>>   		return xlog_recover_rui_pass2(log, item, trans->r_lsn);
>>   	case XFS_LI_RUD:
>> @@ -4669,6 +4762,49 @@ xlog_recover_cancel_efi(
>>   	spin_lock(&ailp->xa_lock);
>>   }
>>   
>> +/* Recover the ATTRI if necessary. */
>> +STATIC int
>> +xlog_recover_process_attri(
>> +	struct xfs_mount                *mp,
>> +	struct xfs_ail                  *ailp,
>> +	struct xfs_log_item             *lip)
>> +{
>> +	struct xfs_attri_log_item       *attrip;
>> +	int                             error;
>> +
>> +	/*
>> +	 * Skip ATTRIs that we've already processed.
>> +	 */
>> +	attrip = container_of(lip, struct xfs_attri_log_item, item);
>> +	if (test_bit(XFS_ATTRI_RECOVERED, &attrip->flags))
>> +		return 0;
>> +
>> +	spin_unlock(&ailp->xa_lock);
>> +	error = xfs_attri_recover(mp, attrip);
>> +	spin_lock(&ailp->xa_lock);
>> +
>> +	return error;
>> +}
>> +
>> +/* Release the ATTRI since we're cancelling everything. */
>> +STATIC void
>> +xlog_recover_cancel_attri(
>> +	struct xfs_mount                *mp,
>> +	struct xfs_ail                  *ailp,
>> +	struct xfs_log_item             *lip)
>> +{
>> +	struct xfs_attri_log_item         *attrip;
>> +
>> +	attrip = container_of(lip, struct xfs_attri_log_item, item);
>> +
>> +	spin_unlock(&ailp->xa_lock);
>> +	xfs_attri_release(attrip);
>> +	spin_lock(&ailp->xa_lock);
>> +}
>> +
>> +
>> +
>> +
>>   /* Recover the RUI if necessary. */
>>   STATIC int
>>   xlog_recover_process_rui(
>> @@ -4861,6 +4997,10 @@ xlog_recover_process_intents(
>>   		case XFS_LI_EFI:
>>   			error = xlog_recover_process_efi(log->l_mp, ailp, lip);
>>   			break;
>> +		case XFS_LI_ATTRI:
>> +			error = xlog_recover_process_attri(log->l_mp,
>> +							   ailp, lip);
> FWIW you're allowed (in xfs land only) to use the double-indent
> convention:
>
> error = xlog_recover_process_attri(log->l_mp,
> 		ailp, lip);
>
> Instead of spending time lining things up with the '('.
>
Ok, from here out I'll use the double indent then
>> +			break;
>>   		case XFS_LI_RUI:
>>   			error = xlog_recover_process_rui(log->l_mp, ailp, lip);
>>   			break;
>> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
>> index 584cf2d..046ced4 100644
>> --- a/fs/xfs/xfs_super.c
>> +++ b/fs/xfs/xfs_super.c
>> @@ -2024,6 +2024,7 @@ init_xfs_fs(void)
>>   	xfs_rmap_update_init_defer_op();
>>   	xfs_refcount_update_init_defer_op();
>>   	xfs_bmap_update_init_defer_op();
>> +	xfs_attr_init_defer_op();
>>   
>>   	xfs_dir_startup();
>>   
>> diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
>> index 815b53d2..d003637 100644
>> --- a/fs/xfs/xfs_trans.h
>> +++ b/fs/xfs/xfs_trans.h
>> @@ -40,6 +40,9 @@ struct xfs_cud_log_item;
>>   struct xfs_defer_ops;
>>   struct xfs_bui_log_item;
>>   struct xfs_bud_log_item;
>> +struct xfs_attrd_log_item;
>> +struct xfs_attri_log_item;
>> +
>>   
>>   typedef struct xfs_log_item {
>>   	struct list_head		li_ail;		/* AIL pointers */
>> @@ -223,12 +226,22 @@ void		xfs_trans_dirty_buf(struct xfs_trans *, struct xfs_buf *);
>>   void		xfs_trans_log_inode(xfs_trans_t *, struct xfs_inode *, uint);
>>   
>>   void		xfs_extent_free_init_defer_op(void);
>> +void            xfs_attr_init_defer_op(void);
>> +
>>   struct xfs_efd_log_item	*xfs_trans_get_efd(struct xfs_trans *,
>>   				  struct xfs_efi_log_item *,
>>   				  uint);
>>   int		xfs_trans_free_extent(struct xfs_trans *,
>>   				      struct xfs_efd_log_item *, xfs_fsblock_t,
>>   				      xfs_extlen_t, struct xfs_owner_info *);
>> +struct xfs_attrd_log_item *
>> +xfs_trans_get_attrd(struct xfs_trans *tp,
>> +		    struct xfs_attri_log_item *attrip);
>> +int xfs_trans_attr(struct xfs_trans *tp, struct xfs_attrd_log_item *attrdp,
>> +			xfs_ino_t ino, uint32_t attr_op_flags, uint32_t flags,
>> +			uint32_t name_len, uint32_t value_len,
>> +			char *name, char *value);
>> +
>>   int		xfs_trans_commit(struct xfs_trans *);
>>   int		xfs_trans_roll(struct xfs_trans **);
>>   int		xfs_trans_roll_inode(struct xfs_trans **, struct xfs_inode *);
>> diff --git a/fs/xfs/xfs_trans_attr.c b/fs/xfs/xfs_trans_attr.c
>> new file mode 100644
>> index 0000000..39eb18d
>> --- /dev/null
>> +++ b/fs/xfs/xfs_trans_attr.c
>> @@ -0,0 +1,286 @@
>> +/*
>> + * Copyright (c) 2017, Oracle 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 Inc.
>> + */
>> +#include "xfs.h"
>> +#include "xfs_fs.h"
>> +#include "xfs_shared.h"
>> +#include "xfs_format.h"
>> +#include "xfs_log_format.h"
>> +#include "xfs_trans_resv.h"
>> +#include "xfs_bit.h"
>> +#include "xfs_mount.h"
>> +#include "xfs_defer.h"
>> +#include "xfs_trans.h"
>> +#include "xfs_trans_priv.h"
>> +#include "xfs_attr_item.h"
>> +#include "xfs_alloc.h"
>> +#include "xfs_bmap.h"
>> +#include "xfs_trace.h"
>> +#include "libxfs/xfs_da_format.h"
>> +#include "xfs_da_btree.h"
>> +#include "xfs_attr.h"
>> +#include "xfs_inode.h"
>> +#include "xfs_icache.h"
>> +
>> +/*
>> + * This routine is called to allocate an "extent free done"
>> + * log item that will hold nextents worth of extents.  The
>> + * caller must use all nextents extents, because we are not
>> + * flexible about this at all.
>> + */
>> +struct xfs_attrd_log_item *
>> +xfs_trans_get_attrd(struct xfs_trans		*tp,
>> +		  struct xfs_attri_log_item	*attrip)
>> +{
>> +	struct xfs_attrd_log_item			*attrdp;
>> +
>> +	ASSERT(tp != NULL);
>> +
>> +	attrdp = xfs_attrd_init(tp->t_mountp, attrip);
>> +	ASSERT(attrdp != NULL);
>> +
>> +	/*
>> +	 * Get a log_item_desc to point at the new item.
>> +	 */
>> +	xfs_trans_add_item(tp, &attrdp->item);
>> +	return attrdp;
>> +}
>> +
>> +/*
>> + * Delete an attr and log it to the ATTRD. Note that the transaction is marked
>> + * dirty regardless of whether the attr delete succeeds or fails to support the
>> + * ATTRI/ATTRD lifecycle rules.
>> + */
>> +int
>> +xfs_trans_attr(
>> +	struct xfs_trans	*tp,
>> +	struct xfs_attrd_log_item	*attrdp,
>> +	xfs_ino_t		ino,
>> +	uint32_t		op_flags,
>> +	uint32_t                flags,
>> +	uint32_t		name_len,
>> +	uint32_t		value_len,
>> +	char			*name,
>> +	char			*value)
>> +{
>> +	uint			next_attr;
>> +	struct xfs_attr_log_format *attrp;
>> +	int			error;
>> +	int                     local;
>> +	struct xfs_da_args      args;
>> +	struct xfs_inode	*dp;
>> +	struct xfs_defer_ops    dfops;
>> +	xfs_fsblock_t		firstblock = NULLFSBLOCK;
>> +	struct xfs_mount	*mp = tp->t_mountp;
>> +
>> +	error = xfs_iget(mp, tp, ino, flags, 0, &dp);
>> +	if (error)
>> +		return error;
>> +
>> +	ASSERT(XFS_IFORK_Q((dp)));
>> +	tp->t_flags |= XFS_TRANS_RESERVE;
>> +
>> +	error = xfs_attr_args_init(&args, dp, name, flags);
>> +	if (error)
>> +		return error;
>> +
>> +	args.name = name;
>> +	args.namelen = name_len;
>> +	args.hashval = xfs_da_hashname(args.name, args.namelen);
>> +	args.value = value;
>> +	args.valuelen = value_len;
>> +	args.dfops = &dfops;
> dfops needs an xfs_defer_init().
>
> Oh, the initialization of dfops is after where we start using it.
> Please move it up (or the args.dfops assignment down).
Good catch, will fix :-)
>> +	args.firstblock = &firstblock;
>> +	args.op_flags = XFS_DA_OP_OKNOENT;
>> +	args.total = xfs_attr_calc_size(&args, &local);
>> +	args.trans = tp;
>> +	ASSERT(local);
>> +
>> +	xfs_ilock(dp, XFS_ILOCK_EXCL);
>> +	xfs_defer_init(args.dfops, args.firstblock);
>> +
>> +	if (op_flags & ATTR_OP_FLAGS_SET) {
> switch (op_flags & XFS_ATTR_OP_FLAGS_TYPE_MASK) {
> case XFS_ATTR_OP_FLAGS_SET:
> 	...
> case XFS_ATTR_OP_FLAGS_REMOVE:
> 	...
> default:
> 	...
> }
Alrighty, will update
>> +		args.op_flags |= XFS_DA_OP_ADDNAME;
>> +		error = xfs_attr_set_args(&args, flags, false);
>> +	} else if (op_flags & ATTR_OP_FLAGS_REMOVE) {
>> +		error = xfs_attr_remove_args(&args, flags);
>> +	} else {
>> +		ASSERT(0);
> We're reading and processing log items off the disk, so cleaning up and
> returning -EFSCORRUPTED is more appropriate here.
>
Ok then, will fix
>> +	}
>> +
>> +	if (error)
>> +		xfs_defer_cancel(&dfops);
>> +
>> +	xfs_iunlock(dp, XFS_ILOCK_EXCL);
>> +
>> +	/*
>> +	 * Mark the transaction dirty, even on error. This ensures the
>> +	 * transaction is aborted, which:
>> +	 *
>> +	 * 1.) releases the ATTRI and frees the ATTRD
>> +	 * 2.) shuts down the filesystem
>> +	 */
>> +	tp->t_flags |= XFS_TRANS_DIRTY;
>> +	attrdp->item.li_desc->lid_flags |= XFS_LID_DIRTY;
>> +
>> +	next_attr = attrdp->next_attr;
>> +	attrp = &(attrdp->format);
>> +	attrp->ino = ino;
>> +	attrp->op_flags = op_flags;
>> +	attrp->value_len = value_len;
>> +	attrp->name_len = name_len;
>> +	attrp->attr_flags = flags;
>> +
>> +	attrdp->name = name;
>> +	attrdp->value = value;
>> +	attrdp->name_len = name_len;
>> +	attrdp->value_len = value_len;
>> +	attrdp->next_attr++;
>> +
>> +	return error;
>> +}
>> +
>> +static int
>> +xfs_attr_diff_items(
>> +	void				*priv,
>> +	struct list_head		*a,
>> +	struct list_head		*b)
>> +{
>> +	return 0;
>> +}
>> +
>> +/* Get an ATTRI. */
>> +STATIC void *
>> +xfs_attr_create_intent(
>> +	struct xfs_trans		*tp,
>> +	unsigned int			count)
>> +{
>> +	struct xfs_attri_log_item		*attrip;
>> +
>> +	ASSERT(tp != NULL);
>> +	ASSERT(count > 0);
>> +
>> +	attrip = xfs_attri_init(tp->t_mountp);
>> +	ASSERT(attrip != NULL);
>> +
>> +	/*
>> +	 * Get a log_item_desc to point at the new item.
>> +	 */
>> +	xfs_trans_add_item(tp, &attrip->item);
>> +	return attrip;
>> +}
>> +
>> +/* Log an attr to the intent item. */
>> +STATIC void
>> +xfs_attr_log_item(
>> +	struct xfs_trans		*tp,
>> +	void				*intent,
>> +	struct list_head		*item)
>> +{
>> +	struct xfs_attri_log_item	*attrip = intent;
>> +	struct xfs_attr_item		*free;
>> +	struct xfs_attr_log_format	*attrp;
>> +
>> +	free = container_of(item, struct xfs_attr_item, xattri_list);
>> +
>> +	tp->t_flags |= XFS_TRANS_DIRTY;
>> +	attrip->item.li_desc->lid_flags |= XFS_LID_DIRTY;
>> +
>> +	attrp = &attrip->format;
>> +	attrp->ino = free->xattri_ino;
>> +	attrp->op_flags = free->xattri_op_flags;
>> +	attrp->value_len = free->xattri_value_len;
>> +	attrp->name_len = free->xattri_name_len;
>> +	attrp->attr_flags = free->xattri_flags;
>> +
>> +	attrip->name = &(free->xattri_name[0]);
>> +	attrip->value = &(free->xattri_value[0]);
>> +	attrip->name_len = free->xattri_name_len;
>> +	attrip->value_len = free->xattri_value_len;
>> +}
>> +
>> +/* Get an ATTRD so we can process all the attrs. */
>> +STATIC void *
>> +xfs_attr_create_done(
>> +	struct xfs_trans		*tp,
>> +	void				*intent,
>> +	unsigned int			count)
>> +{
>> +	return xfs_trans_get_attrd(tp, intent);
>> +}
>> +
>> +/* Process an attr. */
>> +STATIC int
>> +xfs_attr_finish_item(
>> +	struct xfs_trans		*tp,
>> +	struct xfs_defer_ops		*dop,
>> +	struct list_head		*item,
>> +	void				*done_item,
>> +	void				**state)
>> +{
>> +	struct xfs_attr_item	*free;
>> +	int				error;
>> +
>> +	free = container_of(item, struct xfs_attr_item, xattri_list);
>> +	error = xfs_trans_attr(tp, done_item,
>> +			free->xattri_ino,
>> +			free->xattri_op_flags,
>> +			free->xattri_flags,
>> +			free->xattri_name_len,
>> +			free->xattri_value_len,
>> +			free->xattri_name,
>> +			free->xattri_value);
>> +	kmem_free(free);
>> +	return error;
>> +}
>> +
>> +/* Abort all pending EFIs. */
> EFIs?
>
> --D
I'll do a search for the EFI's and weed them out.  Thank you!! :-)
>> +STATIC void
>> +xfs_attr_abort_intent(
>> +	void				*intent)
>> +{
>> +	xfs_attri_release(intent);
>> +}
>> +
>> +/* Cancel an attr */
>> +STATIC void
>> +xfs_attr_cancel_item(
>> +	struct list_head		*item)
>> +{
>> +	struct xfs_attr_item	*free;
>> +
>> +	free = container_of(item, struct xfs_attr_item, xattri_list);
>> +	kmem_free(free);
>> +}
>> +
>> +static const struct xfs_defer_op_type xfs_attr_defer_type = {
>> +	.type		= XFS_DEFER_OPS_TYPE_ATTR,
>> +	.max_items	= XFS_ATTRI_MAX_FAST_ATTRS,
>> +	.diff_items	= xfs_attr_diff_items,
>> +	.create_intent	= xfs_attr_create_intent,
>> +	.abort_intent	= xfs_attr_abort_intent,
>> +	.log_item	= xfs_attr_log_item,
>> +	.create_done	= xfs_attr_create_done,
>> +	.finish_item	= xfs_attr_finish_item,
>> +	.cancel_item	= xfs_attr_cancel_item,
>> +};
>> +
>> +/* Register the deferred op type. */
>> +void
>> +xfs_attr_init_defer_op(void)
>> +{
>> +	xfs_defer_init_op_type(&xfs_attr_defer_type);
>> +}
>> -- 
>> 2.7.4
>>
>> --
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