[XFS] Add EA list callbacks for xfs kernel use. Cleanup some namespace

[linux-2.6] / fs / xfs / xfs_attr.c

/*
 * Copyright (c) 2000-2005 Silicon Graphics, 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.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/capability.h>

#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_btree.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_trans_space.h"
#include "xfs_acl.h"
#include "xfs_rw.h"

/*
 * xfs_attr.c
 *
 * Provide the external interfaces to manage attribute lists.
 */

#define ATTR_SYSCOUNT   2
STATIC struct attrnames posix_acl_access;
STATIC struct attrnames posix_acl_default;
STATIC struct attrnames *attr_system_names[ATTR_SYSCOUNT];

/*========================================================================
 * Function prototypes for the kernel.
 *========================================================================*/

/*
 * Internal routines when attribute list fits inside the inode.
 */
STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);

/*
 * Internal routines when attribute list is one block.
 */
STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_list(xfs_attr_list_context_t *context);

/*
 * Internal routines when attribute list is more than one block.
 */
STATIC int xfs_attr_node_get(xfs_da_args_t *args);
STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
STATIC int xfs_attr_node_list(xfs_attr_list_context_t *context);
STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
STATIC int xfs_attr_refillstate(xfs_da_state_t *state);

/*
 * Routines to manipulate out-of-line attribute values.
 */
STATIC int xfs_attr_rmtval_set(xfs_da_args_t *args);
STATIC int xfs_attr_rmtval_remove(xfs_da_args_t *args);

#define ATTR_RMTVALUE_MAPSIZE   1       /* # of map entries at once */

#if defined(XFS_ATTR_TRACE)
ktrace_t *xfs_attr_trace_buf;
#endif


/*========================================================================
 * Overall external interface routines.
 *========================================================================*/

int
xfs_attr_fetch(xfs_inode_t *ip, const char *name, int namelen,
               char *value, int *valuelenp, int flags, struct cred *cred)
{
        xfs_da_args_t   args;
        int             error;

        if ((XFS_IFORK_Q(ip) == 0) ||
            (ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
             ip->i_d.di_anextents == 0))
                return(ENOATTR);

        /*
         * Fill in the arg structure for this request.
         */
        memset((char *)&args, 0, sizeof(args));
        args.name = name;
        args.namelen = namelen;
        args.value = value;
        args.valuelen = *valuelenp;
        args.flags = flags;
        args.hashval = xfs_da_hashname(args.name, args.namelen);
        args.dp = ip;
        args.whichfork = XFS_ATTR_FORK;

        /*
         * Decide on what work routines to call based on the inode size.
         */
        if (XFS_IFORK_Q(ip) == 0 ||
            (ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
             ip->i_d.di_anextents == 0)) {
                error = XFS_ERROR(ENOATTR);
        } else if (ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
                error = xfs_attr_shortform_getvalue(&args);
        } else if (xfs_bmap_one_block(ip, XFS_ATTR_FORK)) {
                error = xfs_attr_leaf_get(&args);
        } else {
                error = xfs_attr_node_get(&args);
        }

        /*
         * Return the number of bytes in the value to the caller.
         */
        *valuelenp = args.valuelen;

        if (error == EEXIST)
                error = 0;
        return(error);
}

int
xfs_attr_get(bhv_desc_t *bdp, const char *name, char *value, int *valuelenp,
             int flags, struct cred *cred)
{
        xfs_inode_t     *ip = XFS_BHVTOI(bdp);
        int             error, namelen;

        XFS_STATS_INC(xs_attr_get);

        if (!name)
                return(EINVAL);
        namelen = strlen(name);
        if (namelen >= MAXNAMELEN)
                return(EFAULT);         /* match IRIX behaviour */

        if (XFS_FORCED_SHUTDOWN(ip->i_mount))
                return(EIO);

        xfs_ilock(ip, XFS_ILOCK_SHARED);
        error = xfs_attr_fetch(ip, name, namelen, value, valuelenp, flags, cred);
        xfs_iunlock(ip, XFS_ILOCK_SHARED);
        return(error);
}

int
xfs_attr_set_int(xfs_inode_t *dp, const char *name, int namelen,
                 char *value, int valuelen, int flags)
{
        xfs_da_args_t   args;
        xfs_fsblock_t   firstblock;
        xfs_bmap_free_t flist;
        int             error, err2, committed;
        int             local, size;
        uint            nblks;
        xfs_mount_t     *mp = dp->i_mount;
        int             rsvd = (flags & ATTR_ROOT) != 0;

        /*
         * Attach the dquots to the inode.
         */
        if ((error = XFS_QM_DQATTACH(mp, dp, 0)))
                return (error);

        /*
         * Determine space new attribute will use, and if it would be
         * "local" or "remote" (note: local != inline).
         */
        size = xfs_attr_leaf_newentsize(namelen, valuelen,
                                        mp->m_sb.sb_blocksize, &local);

        /*
         * If the inode doesn't have an attribute fork, add one.
         * (inode must not be locked when we call this routine)
         */
        if (XFS_IFORK_Q(dp) == 0) {
                if ((error = xfs_bmap_add_attrfork(dp, size, rsvd)))
                        return(error);
        }

        /*
         * Fill in the arg structure for this request.
         */
        memset((char *)&args, 0, sizeof(args));
        args.name = name;
        args.namelen = namelen;
        args.value = value;
        args.valuelen = valuelen;
        args.flags = flags;
        args.hashval = xfs_da_hashname(args.name, args.namelen);
        args.dp = dp;
        args.firstblock = &firstblock;
        args.flist = &flist;
        args.whichfork = XFS_ATTR_FORK;
        args.addname = 1;
        args.oknoent = 1;

        nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
        if (local) {
                if (size > (mp->m_sb.sb_blocksize >> 1)) {
                        /* Double split possible */
                        nblks <<= 1;
                }
        } else {
                uint    dblocks = XFS_B_TO_FSB(mp, valuelen);
                /* Out of line attribute, cannot double split, but make
                 * room for the attribute value itself.
                 */
                nblks += dblocks;
                nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
        }

        /* Size is now blocks for attribute data */
        args.total = nblks;

        /*
         * Start our first transaction of the day.
         *
         * All future transactions during this code must be "chained" off
         * this one via the trans_dup() call.  All transactions will contain
         * the inode, and the inode will always be marked with trans_ihold().
         * Since the inode will be locked in all transactions, we must log
         * the inode in every transaction to let it float upward through
         * the log.
         */
        args.trans = xfs_trans_alloc(mp, XFS_TRANS_ATTR_SET);

        /*
         * Root fork attributes can use reserved data blocks for this
         * operation if necessary
         */

        if (rsvd)
                args.trans->t_flags |= XFS_TRANS_RESERVE;

        if ((error = xfs_trans_reserve(args.trans, (uint) nblks,
                                      XFS_ATTRSET_LOG_RES(mp, nblks),
                                      0, XFS_TRANS_PERM_LOG_RES,
                                      XFS_ATTRSET_LOG_COUNT))) {
                xfs_trans_cancel(args.trans, 0);
                return(error);
        }
        xfs_ilock(dp, XFS_ILOCK_EXCL);

        error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, args.trans, dp, nblks, 0,
                         rsvd ? XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
                                XFS_QMOPT_RES_REGBLKS);
        if (error) {
                xfs_iunlock(dp, XFS_ILOCK_EXCL);
                xfs_trans_cancel(args.trans, XFS_TRANS_RELEASE_LOG_RES);
                return (error);
        }

        xfs_trans_ijoin(args.trans, dp, XFS_ILOCK_EXCL);
        xfs_trans_ihold(args.trans, dp);

        /*
         * If the attribute list is non-existent or a shortform list,
         * upgrade it to a single-leaf-block attribute list.
         */
        if ((dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) ||
            ((dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS) &&
             (dp->i_d.di_anextents == 0))) {

                /*
                 * Build initial attribute list (if required).
                 */
                if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
                        xfs_attr_shortform_create(&args);

                /*
                 * Try to add the attr to the attribute list in
                 * the inode.
                 */
                error = xfs_attr_shortform_addname(&args);
                if (error != ENOSPC) {
                        /*
                         * Commit the shortform mods, and we're done.
                         * NOTE: this is also the error path (EEXIST, etc).
                         */
                        ASSERT(args.trans != NULL);

                        /*
                         * If this is a synchronous mount, make sure that
                         * the transaction goes to disk before returning
                         * to the user.
                         */
                        if (mp->m_flags & XFS_MOUNT_WSYNC) {
                                xfs_trans_set_sync(args.trans);
                        }
                        err2 = xfs_trans_commit(args.trans,
                                                 XFS_TRANS_RELEASE_LOG_RES,
                                                 NULL);
                        xfs_iunlock(dp, XFS_ILOCK_EXCL);

                        /*
                         * Hit the inode change time.
                         */
                        if (!error && (flags & ATTR_KERNOTIME) == 0) {
                                xfs_ichgtime(dp, XFS_ICHGTIME_CHG);
                        }
                        return(error == 0 ? err2 : error);
                }

                /*
                 * It won't fit in the shortform, transform to a leaf block.
                 * GROT: another possible req'mt for a double-split btree op.
                 */
                XFS_BMAP_INIT(args.flist, args.firstblock);
                error = xfs_attr_shortform_to_leaf(&args);
                if (!error) {
                        error = xfs_bmap_finish(&args.trans, args.flist,
                                                *args.firstblock, &committed);
                }
                if (error) {
                        ASSERT(committed);
                        args.trans = NULL;
                        xfs_bmap_cancel(&flist);
                        goto out;
                }

                /*
                 * bmap_finish() may have committed the last trans and started
                 * a new one.  We need the inode to be in all transactions.
                 */
                if (committed) {
                        xfs_trans_ijoin(args.trans, dp, XFS_ILOCK_EXCL);
                        xfs_trans_ihold(args.trans, dp);
                }

                /*
                 * Commit the leaf transformation.  We'll need another (linked)
                 * transaction to add the new attribute to the leaf.
                 */
                if ((error = xfs_attr_rolltrans(&args.trans, dp)))
                        goto out;

        }

        if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
                error = xfs_attr_leaf_addname(&args);
        } else {
                error = xfs_attr_node_addname(&args);
        }
        if (error) {
                goto out;
        }

        /*
         * If this is a synchronous mount, make sure that the
         * transaction goes to disk before returning to the user.
         */
        if (mp->m_flags & XFS_MOUNT_WSYNC) {
                xfs_trans_set_sync(args.trans);
        }

        /*
         * Commit the last in the sequence of transactions.
         */
        xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
        error = xfs_trans_commit(args.trans, XFS_TRANS_RELEASE_LOG_RES,
                                 NULL);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);

        /*
         * Hit the inode change time.
         */
        if (!error && (flags & ATTR_KERNOTIME) == 0) {
                xfs_ichgtime(dp, XFS_ICHGTIME_CHG);
        }

        return(error);

out:
        if (args.trans)
                xfs_trans_cancel(args.trans,
                        XFS_TRANS_RELEASE_LOG_RES|XFS_TRANS_ABORT);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);
        return(error);
}

int
xfs_attr_set(bhv_desc_t *bdp, const char *name, char *value, int valuelen, int flags,
             struct cred *cred)
{
        xfs_inode_t     *dp;
        int             namelen;

        namelen = strlen(name);
        if (namelen >= MAXNAMELEN)
                return EFAULT;          /* match IRIX behaviour */

        XFS_STATS_INC(xs_attr_set);

        dp = XFS_BHVTOI(bdp);
        if (XFS_FORCED_SHUTDOWN(dp->i_mount))
                return (EIO);

        return xfs_attr_set_int(dp, name, namelen, value, valuelen, flags);
}

/*
 * Generic handler routine to remove a name from an attribute list.
 * Transitions attribute list from Btree to shortform as necessary.
 */
int
xfs_attr_remove_int(xfs_inode_t *dp, const char *name, int namelen, int flags)
{
        xfs_da_args_t   args;
        xfs_fsblock_t   firstblock;
        xfs_bmap_free_t flist;
        int             error;
        xfs_mount_t     *mp = dp->i_mount;

        /*
         * Fill in the arg structure for this request.
         */
        memset((char *)&args, 0, sizeof(args));
        args.name = name;
        args.namelen = namelen;
        args.flags = flags;
        args.hashval = xfs_da_hashname(args.name, args.namelen);
        args.dp = dp;
        args.firstblock = &firstblock;
        args.flist = &flist;
        args.total = 0;
        args.whichfork = XFS_ATTR_FORK;

        /*
         * Attach the dquots to the inode.
         */
        if ((error = XFS_QM_DQATTACH(mp, dp, 0)))
                return (error);

        /*
         * Start our first transaction of the day.
         *
         * All future transactions during this code must be "chained" off
         * this one via the trans_dup() call.  All transactions will contain
         * the inode, and the inode will always be marked with trans_ihold().
         * Since the inode will be locked in all transactions, we must log
         * the inode in every transaction to let it float upward through
         * the log.
         */
        args.trans = xfs_trans_alloc(mp, XFS_TRANS_ATTR_RM);

        /*
         * Root fork attributes can use reserved data blocks for this
         * operation if necessary
         */

        if (flags & ATTR_ROOT)
                args.trans->t_flags |= XFS_TRANS_RESERVE;

        if ((error = xfs_trans_reserve(args.trans,
                                      XFS_ATTRRM_SPACE_RES(mp),
                                      XFS_ATTRRM_LOG_RES(mp),
                                      0, XFS_TRANS_PERM_LOG_RES,
                                      XFS_ATTRRM_LOG_COUNT))) {
                xfs_trans_cancel(args.trans, 0);
                return(error);
        }

        xfs_ilock(dp, XFS_ILOCK_EXCL);
        /*
         * No need to make quota reservations here. We expect to release some
         * blocks not allocate in the common case.
         */
        xfs_trans_ijoin(args.trans, dp, XFS_ILOCK_EXCL);
        xfs_trans_ihold(args.trans, dp);

        /*
         * Decide on what work routines to call based on the inode size.
         */
        if (XFS_IFORK_Q(dp) == 0 ||
            (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
             dp->i_d.di_anextents == 0)) {
                error = XFS_ERROR(ENOATTR);
                goto out;
        }
        if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
                ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
                error = xfs_attr_shortform_remove(&args);
                if (error) {
                        goto out;
                }
        } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
                error = xfs_attr_leaf_removename(&args);
        } else {
                error = xfs_attr_node_removename(&args);
        }
        if (error) {
                goto out;
        }

        /*
         * If this is a synchronous mount, make sure that the
         * transaction goes to disk before returning to the user.
         */
        if (mp->m_flags & XFS_MOUNT_WSYNC) {
                xfs_trans_set_sync(args.trans);
        }

        /*
         * Commit the last in the sequence of transactions.
         */
        xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
        error = xfs_trans_commit(args.trans, XFS_TRANS_RELEASE_LOG_RES,
                                 NULL);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);

        /*
         * Hit the inode change time.
         */
        if (!error && (flags & ATTR_KERNOTIME) == 0) {
                xfs_ichgtime(dp, XFS_ICHGTIME_CHG);
        }

        return(error);

out:
        if (args.trans)
                xfs_trans_cancel(args.trans,
                        XFS_TRANS_RELEASE_LOG_RES|XFS_TRANS_ABORT);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);
        return(error);
}

int
xfs_attr_remove(bhv_desc_t *bdp, const char *name, int flags, struct cred *cred)
{
        xfs_inode_t         *dp;
        int                 namelen;

        namelen = strlen(name);
        if (namelen >= MAXNAMELEN)
                return EFAULT;          /* match IRIX behaviour */

        XFS_STATS_INC(xs_attr_remove);

        dp = XFS_BHVTOI(bdp);
        if (XFS_FORCED_SHUTDOWN(dp->i_mount))
                return (EIO);

        xfs_ilock(dp, XFS_ILOCK_SHARED);
        if (XFS_IFORK_Q(dp) == 0 ||
                   (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
                    dp->i_d.di_anextents == 0)) {
                xfs_iunlock(dp, XFS_ILOCK_SHARED);
                return(XFS_ERROR(ENOATTR));
        }
        xfs_iunlock(dp, XFS_ILOCK_SHARED);

        return xfs_attr_remove_int(dp, name, namelen, flags);
}

int                                                             /* error */
xfs_attr_list_int(xfs_attr_list_context_t *context)
{
        int error;
        xfs_inode_t *dp = context->dp;

        /*
         * Decide on what work routines to call based on the inode size.
         */
        if (XFS_IFORK_Q(dp) == 0 ||
            (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
             dp->i_d.di_anextents == 0)) {
                error = 0;
        } else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
                error = xfs_attr_shortform_list(context);
        } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
                error = xfs_attr_leaf_list(context);
        } else {
                error = xfs_attr_node_list(context);
        }
        return error;
}

#define ATTR_ENTBASESIZE                /* minimum bytes used by an attr */ \
        (((struct attrlist_ent *) 0)->a_name - (char *) 0)
#define ATTR_ENTSIZE(namelen)           /* actual bytes used by an attr */ \
        ((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(u_int32_t)-1) \
         & ~(sizeof(u_int32_t)-1))

/*
 * Format an attribute and copy it out to the user's buffer.
 * Take care to check values and protect against them changing later,
 * we may be reading them directly out of a user buffer.
 */
/*ARGSUSED*/
STATIC int
xfs_attr_put_listent(xfs_attr_list_context_t *context, attrnames_t *namesp,
                     char *name, int namelen,
                     int valuelen, char *value)
{
        attrlist_ent_t *aep;
        int arraytop;

        ASSERT(!(context->flags & ATTR_KERNOVAL));
        ASSERT(context->count >= 0);
        ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
        ASSERT(context->firstu >= sizeof(*context->alist));
        ASSERT(context->firstu <= context->bufsize);

        arraytop = sizeof(*context->alist) +
                        context->count * sizeof(context->alist->al_offset[0]);
        context->firstu -= ATTR_ENTSIZE(namelen);
        if (context->firstu < arraytop) {
                xfs_attr_trace_l_c("buffer full", context);
                context->alist->al_more = 1;
                context->seen_enough = 1;
                return 1;
        }

        aep = (attrlist_ent_t *)&(((char *)context->alist)[ context->firstu ]);
        aep->a_valuelen = valuelen;
        memcpy(aep->a_name, name, namelen);
        aep->a_name[ namelen ] = 0;
        context->alist->al_offset[ context->count++ ] = context->firstu;
        context->alist->al_count = context->count;
        xfs_attr_trace_l_c("add", context);
        return 0;
}

STATIC int
xfs_attr_kern_list(xfs_attr_list_context_t *context, attrnames_t *namesp,
                     char *name, int namelen,
                     int valuelen, char *value)
{
        char *offset;
        int arraytop;

        ASSERT(context->count >= 0);

        arraytop = context->count + namesp->attr_namelen + namelen + 1;
        if (arraytop > context->firstu) {
                context->count = -1;    /* insufficient space */
                return 1;
        }
        offset = (char *)context->alist + context->count;
        strncpy(offset, namesp->attr_name, namesp->attr_namelen);
        offset += namesp->attr_namelen;
        strncpy(offset, name, namelen);                 /* real name */
        offset += namelen;
        *offset = '\0';
        context->count += namesp->attr_namelen + namelen + 1;
        return 0;
}

/*ARGSUSED*/
STATIC int
xfs_attr_kern_list_sizes(xfs_attr_list_context_t *context, attrnames_t *namesp,
                     char *name, int namelen,
                     int valuelen, char *value)
{
        context->count += namesp->attr_namelen + namelen + 1;
        return 0;
}

/*
 * Generate a list of extended attribute names and optionally
 * also value lengths.  Positive return value follows the XFS
 * convention of being an error, zero or negative return code
 * is the length of the buffer returned (negated), indicating
 * success.
 */
int
xfs_attr_list(bhv_desc_t *bdp, char *buffer, int bufsize, int flags,
                      attrlist_cursor_kern_t *cursor, struct cred *cred)
{
        xfs_attr_list_context_t context;
        xfs_inode_t *dp;
        int error;

        XFS_STATS_INC(xs_attr_list);

        /*
         * Validate the cursor.
         */
        if (cursor->pad1 || cursor->pad2)
                return(XFS_ERROR(EINVAL));
        if ((cursor->initted == 0) &&
            (cursor->hashval || cursor->blkno || cursor->offset))
                return XFS_ERROR(EINVAL);

        /*
         * Check for a properly aligned buffer.
         */
        if (((long)buffer) & (sizeof(int)-1))
                return XFS_ERROR(EFAULT);
        if (flags & ATTR_KERNOVAL)
                bufsize = 0;

        /*
         * Initialize the output buffer.
         */
        context.dp = dp = XFS_BHVTOI(bdp);
        context.cursor = cursor;
        context.count = 0;
        context.dupcnt = 0;
        context.resynch = 1;
        context.flags = flags;
        context.seen_enough = 0;
        context.alist = (attrlist_t *)buffer;
        context.put_value = 0;

        if (flags & ATTR_KERNAMELS) {
                context.bufsize = bufsize;
                context.firstu = context.bufsize;
                if (flags & ATTR_KERNOVAL)
                        context.put_listent = xfs_attr_kern_list_sizes;
                else
                        context.put_listent = xfs_attr_kern_list;
        } else {
                context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
                context.firstu = context.bufsize;
                context.alist->al_count = 0;
                context.alist->al_more = 0;
                context.alist->al_offset[0] = context.bufsize;
                context.put_listent = xfs_attr_put_listent;
        }

        if (XFS_FORCED_SHUTDOWN(dp->i_mount))
                return EIO;

        xfs_ilock(dp, XFS_ILOCK_SHARED);
        xfs_attr_trace_l_c("syscall start", &context);

        error = xfs_attr_list_int(&context);

        xfs_iunlock(dp, XFS_ILOCK_SHARED);
        xfs_attr_trace_l_c("syscall end", &context);

        if (context.flags & (ATTR_KERNOVAL|ATTR_KERNAMELS)) {
                /* must return negated buffer size or the error */
                if (context.count < 0)
                        error = XFS_ERROR(ERANGE);
                else
                        error = -context.count;
        } else
                ASSERT(error >= 0);

        return error;
}

int                                                             /* error */
xfs_attr_inactive(xfs_inode_t *dp)
{
        xfs_trans_t *trans;
        xfs_mount_t *mp;
        int error;

        mp = dp->i_mount;
        ASSERT(! XFS_NOT_DQATTACHED(mp, dp));

        xfs_ilock(dp, XFS_ILOCK_SHARED);
        if ((XFS_IFORK_Q(dp) == 0) ||
            (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) ||
            (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
             dp->i_d.di_anextents == 0)) {
                xfs_iunlock(dp, XFS_ILOCK_SHARED);
                return(0);
        }
        xfs_iunlock(dp, XFS_ILOCK_SHARED);

        /*
         * Start our first transaction of the day.
         *
         * All future transactions during this code must be "chained" off
         * this one via the trans_dup() call.  All transactions will contain
         * the inode, and the inode will always be marked with trans_ihold().
         * Since the inode will be locked in all transactions, we must log
         * the inode in every transaction to let it float upward through
         * the log.
         */
        trans = xfs_trans_alloc(mp, XFS_TRANS_ATTRINVAL);
        if ((error = xfs_trans_reserve(trans, 0, XFS_ATTRINVAL_LOG_RES(mp), 0,
                                      XFS_TRANS_PERM_LOG_RES,
                                      XFS_ATTRINVAL_LOG_COUNT))) {
                xfs_trans_cancel(trans, 0);
                return(error);
        }
        xfs_ilock(dp, XFS_ILOCK_EXCL);

        /*
         * No need to make quota reservations here. We expect to release some
         * blocks, not allocate, in the common case.
         */
        xfs_trans_ijoin(trans, dp, XFS_ILOCK_EXCL);
        xfs_trans_ihold(trans, dp);

        /*
         * Decide on what work routines to call based on the inode size.
         */
        if ((XFS_IFORK_Q(dp) == 0) ||
            (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) ||
            (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
             dp->i_d.di_anextents == 0)) {
                error = 0;
                goto out;
        }
        error = xfs_attr_root_inactive(&trans, dp);
        if (error)
                goto out;
        /*
         * signal synchronous inactive transactions unless this
         * is a synchronous mount filesystem in which case we
         * know that we're here because we've been called out of
         * xfs_inactive which means that the last reference is gone
         * and the unlink transaction has already hit the disk so
         * async inactive transactions are safe.
         */
        if ((error = xfs_itruncate_finish(&trans, dp, 0LL, XFS_ATTR_FORK,
                                (!(mp->m_flags & XFS_MOUNT_WSYNC)
                                 ? 1 : 0))))
                goto out;

        /*
         * Commit the last in the sequence of transactions.
         */
        xfs_trans_log_inode(trans, dp, XFS_ILOG_CORE);
        error = xfs_trans_commit(trans, XFS_TRANS_RELEASE_LOG_RES,
                                 NULL);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);

        return(error);

out:
        xfs_trans_cancel(trans, XFS_TRANS_RELEASE_LOG_RES|XFS_TRANS_ABORT);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);
        return(error);
}



/*========================================================================
 * External routines when attribute list is inside the inode
 *========================================================================*/

/*
 * Add a name to the shortform attribute list structure
 * This is the external routine.
 */
STATIC int
xfs_attr_shortform_addname(xfs_da_args_t *args)
{
        int newsize, forkoff, retval;

        retval = xfs_attr_shortform_lookup(args);
        if ((args->flags & ATTR_REPLACE) && (retval == ENOATTR)) {
                return(retval);
        } else if (retval == EEXIST) {
                if (args->flags & ATTR_CREATE)
                        return(retval);
                retval = xfs_attr_shortform_remove(args);
                ASSERT(retval == 0);
        }

        if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
            args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
                return(XFS_ERROR(ENOSPC));

        newsize = XFS_ATTR_SF_TOTSIZE(args->dp);
        newsize += XFS_ATTR_SF_ENTSIZE_BYNAME(args->namelen, args->valuelen);

        forkoff = xfs_attr_shortform_bytesfit(args->dp, newsize);
        if (!forkoff)
                return(XFS_ERROR(ENOSPC));

        xfs_attr_shortform_add(args, forkoff);
        return(0);
}


/*========================================================================
 * External routines when attribute list is one block
 *========================================================================*/

/*
 * Add a name to the leaf attribute list structure
 *
 * This leaf block cannot have a "remote" value, we only call this routine
 * if bmap_one_block() says there is only one block (ie: no remote blks).
 */
int
xfs_attr_leaf_addname(xfs_da_args_t *args)
{
        xfs_inode_t *dp;
        xfs_dabuf_t *bp;
        int retval, error, committed, forkoff;

        /*
         * Read the (only) block in the attribute list in.
         */
        dp = args->dp;
        args->blkno = 0;
        error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
                                             XFS_ATTR_FORK);
        if (error)
                return(error);
        ASSERT(bp != NULL);

        /*
         * Look up the given attribute in the leaf block.  Figure out if
         * the given flags produce an error or call for an atomic rename.
         */
        retval = xfs_attr_leaf_lookup_int(bp, args);
        if ((args->flags & ATTR_REPLACE) && (retval == ENOATTR)) {
                xfs_da_brelse(args->trans, bp);
                return(retval);
        } else if (retval == EEXIST) {
                if (args->flags & ATTR_CREATE) {        /* pure create op */
                        xfs_da_brelse(args->trans, bp);
                        return(retval);
                }
                args->rename = 1;                       /* an atomic rename */
                args->blkno2 = args->blkno;             /* set 2nd entry info*/
                args->index2 = args->index;
                args->rmtblkno2 = args->rmtblkno;
                args->rmtblkcnt2 = args->rmtblkcnt;
        }

        /*
         * Add the attribute to the leaf block, transitioning to a Btree
         * if required.
         */
        retval = xfs_attr_leaf_add(bp, args);
        xfs_da_buf_done(bp);
        if (retval == ENOSPC) {
                /*
                 * Promote the attribute list to the Btree format, then
                 * Commit that transaction so that the node_addname() call
                 * can manage its own transactions.
                 */
                XFS_BMAP_INIT(args->flist, args->firstblock);
                error = xfs_attr_leaf_to_node(args);
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                *args->firstblock, &committed);
                }
                if (error) {
                        ASSERT(committed);
                        args->trans = NULL;
                        xfs_bmap_cancel(args->flist);
                        return(error);
                }

                /*
                 * bmap_finish() may have committed the last trans and started
                 * a new one.  We need the inode to be in all transactions.
                 */
                if (committed) {
                        xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                        xfs_trans_ihold(args->trans, dp);
                }

                /*
                 * Commit the current trans (including the inode) and start
                 * a new one.
                 */
                if ((error = xfs_attr_rolltrans(&args->trans, dp)))
                        return (error);

                /*
                 * Fob the whole rest of the problem off on the Btree code.
                 */
                error = xfs_attr_node_addname(args);
                return(error);
        }

        /*
         * Commit the transaction that added the attr name so that
         * later routines can manage their own transactions.
         */
        if ((error = xfs_attr_rolltrans(&args->trans, dp)))
                return (error);

        /*
         * If there was an out-of-line value, allocate the blocks we
         * identified for its storage and copy the value.  This is done
         * after we create the attribute so that we don't overflow the
         * maximum size of a transaction and/or hit a deadlock.
         */
        if (args->rmtblkno > 0) {
                error = xfs_attr_rmtval_set(args);
                if (error)
                        return(error);
        }

        /*
         * If this is an atomic rename operation, we must "flip" the
         * incomplete flags on the "new" and "old" attribute/value pairs
         * so that one disappears and one appears atomically.  Then we
         * must remove the "old" attribute/value pair.
         */
        if (args->rename) {
                /*
                 * In a separate transaction, set the incomplete flag on the
                 * "old" attr and clear the incomplete flag on the "new" attr.
                 */
                error = xfs_attr_leaf_flipflags(args);
                if (error)
                        return(error);

                /*
                 * Dismantle the "old" attribute/value pair by removing
                 * a "remote" value (if it exists).
                 */
                args->index = args->index2;
                args->blkno = args->blkno2;
                args->rmtblkno = args->rmtblkno2;
                args->rmtblkcnt = args->rmtblkcnt2;
                if (args->rmtblkno) {
                        error = xfs_attr_rmtval_remove(args);
                        if (error)
                                return(error);
                }

                /*
                 * Read in the block containing the "old" attr, then
                 * remove the "old" attr from that block (neat, huh!)
                 */
                error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1,
                                                     &bp, XFS_ATTR_FORK);
                if (error)
                        return(error);
                ASSERT(bp != NULL);
                (void)xfs_attr_leaf_remove(bp, args);

                /*
                 * If the result is small enough, shrink it all into the inode.
                 */
                if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
                        XFS_BMAP_INIT(args->flist, args->firstblock);
                        error = xfs_attr_leaf_to_shortform(bp, args, forkoff);
                        /* bp is gone due to xfs_da_shrink_inode */
                        if (!error) {
                                error = xfs_bmap_finish(&args->trans,
                                                        args->flist,
                                                        *args->firstblock,
                                                        &committed);
                        }
                        if (error) {
                                ASSERT(committed);
                                args->trans = NULL;
                                xfs_bmap_cancel(args->flist);
                                return(error);
                        }

                        /*
                         * bmap_finish() may have committed the last trans
                         * and started a new one.  We need the inode to be
                         * in all transactions.
                         */
                        if (committed) {
                                xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                                xfs_trans_ihold(args->trans, dp);
                        }
                } else
                        xfs_da_buf_done(bp);

                /*
                 * Commit the remove and start the next trans in series.
                 */
                error = xfs_attr_rolltrans(&args->trans, dp);

        } else if (args->rmtblkno > 0) {
                /*
                 * Added a "remote" value, just clear the incomplete flag.
                 */
                error = xfs_attr_leaf_clearflag(args);
        }
        return(error);
}

/*
 * Remove a name from the leaf attribute list structure
 *
 * This leaf block cannot have a "remote" value, we only call this routine
 * if bmap_one_block() says there is only one block (ie: no remote blks).
 */
STATIC int
xfs_attr_leaf_removename(xfs_da_args_t *args)
{
        xfs_inode_t *dp;
        xfs_dabuf_t *bp;
        int error, committed, forkoff;

        /*
         * Remove the attribute.
         */
        dp = args->dp;
        args->blkno = 0;
        error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
                                             XFS_ATTR_FORK);
        if (error) {
                return(error);
        }

        ASSERT(bp != NULL);
        error = xfs_attr_leaf_lookup_int(bp, args);
        if (error == ENOATTR) {
                xfs_da_brelse(args->trans, bp);
                return(error);
        }

        (void)xfs_attr_leaf_remove(bp, args);

        /*
         * If the result is small enough, shrink it all into the inode.
         */
        if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
                XFS_BMAP_INIT(args->flist, args->firstblock);
                error = xfs_attr_leaf_to_shortform(bp, args, forkoff);
                /* bp is gone due to xfs_da_shrink_inode */
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                *args->firstblock, &committed);
                }
                if (error) {
                        ASSERT(committed);
                        args->trans = NULL;
                        xfs_bmap_cancel(args->flist);
                        return(error);
                }

                /*
                 * bmap_finish() may have committed the last trans and started
                 * a new one.  We need the inode to be in all transactions.
                 */
                if (committed) {
                        xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                        xfs_trans_ihold(args->trans, dp);
                }
        } else
                xfs_da_buf_done(bp);
        return(0);
}

/*
 * Look up a name in a leaf attribute list structure.
 *
 * This leaf block cannot have a "remote" value, we only call this routine
 * if bmap_one_block() says there is only one block (ie: no remote blks).
 */
STATIC int
xfs_attr_leaf_get(xfs_da_args_t *args)
{
        xfs_dabuf_t *bp;
        int error;

        args->blkno = 0;
        error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
                                             XFS_ATTR_FORK);
        if (error)
                return(error);
        ASSERT(bp != NULL);

        error = xfs_attr_leaf_lookup_int(bp, args);
        if (error != EEXIST)  {
                xfs_da_brelse(args->trans, bp);
                return(error);
        }
        error = xfs_attr_leaf_getvalue(bp, args);
        xfs_da_brelse(args->trans, bp);
        if (!error && (args->rmtblkno > 0) && !(args->flags & ATTR_KERNOVAL)) {
                error = xfs_attr_rmtval_get(args);
        }
        return(error);
}

/*
 * Copy out attribute entries for attr_list(), for leaf attribute lists.
 */
STATIC int
xfs_attr_leaf_list(xfs_attr_list_context_t *context)
{
        xfs_attr_leafblock_t *leaf;
        int error;
        xfs_dabuf_t *bp;

        context->cursor->blkno = 0;
        error = xfs_da_read_buf(NULL, context->dp, 0, -1, &bp, XFS_ATTR_FORK);
        if (error)
                return XFS_ERROR(error);
        ASSERT(bp != NULL);
        leaf = bp->data;
        if (unlikely(be16_to_cpu(leaf->hdr.info.magic) != XFS_ATTR_LEAF_MAGIC)) {
                XFS_CORRUPTION_ERROR("xfs_attr_leaf_list", XFS_ERRLEVEL_LOW,
                                     context->dp->i_mount, leaf);
                xfs_da_brelse(NULL, bp);
                return XFS_ERROR(EFSCORRUPTED);
        }

        error = xfs_attr_leaf_list_int(bp, context);
        xfs_da_brelse(NULL, bp);
        return XFS_ERROR(error);
}


/*========================================================================
 * External routines when attribute list size > XFS_LBSIZE(mp).
 *========================================================================*/

/*
 * Add a name to a Btree-format attribute list.
 *
 * This will involve walking down the Btree, and may involve splitting
 * leaf nodes and even splitting intermediate nodes up to and including
 * the root node (a special case of an intermediate node).
 *
 * "Remote" attribute values confuse the issue and atomic rename operations
 * add a whole extra layer of confusion on top of that.
 */
STATIC int
xfs_attr_node_addname(xfs_da_args_t *args)
{
        xfs_da_state_t *state;
        xfs_da_state_blk_t *blk;
        xfs_inode_t *dp;
        xfs_mount_t *mp;
        int committed, retval, error;

        /*
         * Fill in bucket of arguments/results/context to carry around.
         */
        dp = args->dp;
        mp = dp->i_mount;
restart:
        state = xfs_da_state_alloc();
        state->args = args;
        state->mp = mp;
        state->blocksize = state->mp->m_sb.sb_blocksize;
        state->node_ents = state->mp->m_attr_node_ents;

        /*
         * Search to see if name already exists, and get back a pointer
         * to where it should go.
         */
        error = xfs_da_node_lookup_int(state, &retval);
        if (error)
                goto out;
        blk = &state->path.blk[ state->path.active-1 ];
        ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
        if ((args->flags & ATTR_REPLACE) && (retval == ENOATTR)) {
                goto out;
        } else if (retval == EEXIST) {
                if (args->flags & ATTR_CREATE)
                        goto out;
                args->rename = 1;                       /* atomic rename op */
                args->blkno2 = args->blkno;             /* set 2nd entry info*/
                args->index2 = args->index;
                args->rmtblkno2 = args->rmtblkno;
                args->rmtblkcnt2 = args->rmtblkcnt;
                args->rmtblkno = 0;
                args->rmtblkcnt = 0;
        }

        retval = xfs_attr_leaf_add(blk->bp, state->args);
        if (retval == ENOSPC) {
                if (state->path.active == 1) {
                        /*
                         * Its really a single leaf node, but it had
                         * out-of-line values so it looked like it *might*
                         * have been a b-tree.
                         */
                        xfs_da_state_free(state);
                        XFS_BMAP_INIT(args->flist, args->firstblock);
                        error = xfs_attr_leaf_to_node(args);
                        if (!error) {
                                error = xfs_bmap_finish(&args->trans,
                                                        args->flist,
                                                        *args->firstblock,
                                                        &committed);
                        }
                        if (error) {
                                ASSERT(committed);
                                args->trans = NULL;
                                xfs_bmap_cancel(args->flist);
                                goto out;
                        }

                        /*
                         * bmap_finish() may have committed the last trans
                         * and started a new one.  We need the inode to be
                         * in all transactions.
                         */
                        if (committed) {
                                xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                                xfs_trans_ihold(args->trans, dp);
                        }

                        /*
                         * Commit the node conversion and start the next
                         * trans in the chain.
                         */
                        if ((error = xfs_attr_rolltrans(&args->trans, dp)))
                                goto out;

                        goto restart;
                }

                /*
                 * Split as many Btree elements as required.
                 * This code tracks the new and old attr's location
                 * in the index/blkno/rmtblkno/rmtblkcnt fields and
                 * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
                 */
                XFS_BMAP_INIT(args->flist, args->firstblock);
                error = xfs_da_split(state);
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                *args->firstblock, &committed);
                }
                if (error) {
                        ASSERT(committed);
                        args->trans = NULL;
                        xfs_bmap_cancel(args->flist);
                        goto out;
                }

                /*
                 * bmap_finish() may have committed the last trans and started
                 * a new one.  We need the inode to be in all transactions.
                 */
                if (committed) {
                        xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                        xfs_trans_ihold(args->trans, dp);
                }
        } else {
                /*
                 * Addition succeeded, update Btree hashvals.
                 */
                xfs_da_fixhashpath(state, &state->path);
        }

        /*
         * Kill the state structure, we're done with it and need to
         * allow the buffers to come back later.
         */
        xfs_da_state_free(state);
        state = NULL;

        /*
         * Commit the leaf addition or btree split and start the next
         * trans in the chain.
         */
        if ((error = xfs_attr_rolltrans(&args->trans, dp)))
                goto out;

        /*
         * If there was an out-of-line value, allocate the blocks we
         * identified for its storage and copy the value.  This is done
         * after we create the attribute so that we don't overflow the
         * maximum size of a transaction and/or hit a deadlock.
         */
        if (args->rmtblkno > 0) {
                error = xfs_attr_rmtval_set(args);
                if (error)
                        return(error);
        }

        /*
         * If this is an atomic rename operation, we must "flip" the
         * incomplete flags on the "new" and "old" attribute/value pairs
         * so that one disappears and one appears atomically.  Then we
         * must remove the "old" attribute/value pair.
         */
        if (args->rename) {
                /*
                 * In a separate transaction, set the incomplete flag on the
                 * "old" attr and clear the incomplete flag on the "new" attr.
                 */
                error = xfs_attr_leaf_flipflags(args);
                if (error)
                        goto out;

                /*
                 * Dismantle the "old" attribute/value pair by removing
                 * a "remote" value (if it exists).
                 */
                args->index = args->index2;
                args->blkno = args->blkno2;
                args->rmtblkno = args->rmtblkno2;
                args->rmtblkcnt = args->rmtblkcnt2;
                if (args->rmtblkno) {
                        error = xfs_attr_rmtval_remove(args);
                        if (error)
                                return(error);
                }

                /*
                 * Re-find the "old" attribute entry after any split ops.
                 * The INCOMPLETE flag means that we will find the "old"
                 * attr, not the "new" one.
                 */
                args->flags |= XFS_ATTR_INCOMPLETE;
                state = xfs_da_state_alloc();
                state->args = args;
                state->mp = mp;
                state->blocksize = state->mp->m_sb.sb_blocksize;
                state->node_ents = state->mp->m_attr_node_ents;
                state->inleaf = 0;
                error = xfs_da_node_lookup_int(state, &retval);
                if (error)
                        goto out;

                /*
                 * Remove the name and update the hashvals in the tree.
                 */
                blk = &state->path.blk[ state->path.active-1 ];
                ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
                error = xfs_attr_leaf_remove(blk->bp, args);
                xfs_da_fixhashpath(state, &state->path);

                /*
                 * Check to see if the tree needs to be collapsed.
                 */
                if (retval && (state->path.active > 1)) {
                        XFS_BMAP_INIT(args->flist, args->firstblock);
                        error = xfs_da_join(state);
                        if (!error) {
                                error = xfs_bmap_finish(&args->trans,
                                                        args->flist,
                                                        *args->firstblock,
                                                        &committed);
                        }
                        if (error) {
                                ASSERT(committed);
                                args->trans = NULL;
                                xfs_bmap_cancel(args->flist);
                                goto out;
                        }

                        /*
                         * bmap_finish() may have committed the last trans
                         * and started a new one.  We need the inode to be
                         * in all transactions.
                         */
                        if (committed) {
                                xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                                xfs_trans_ihold(args->trans, dp);
                        }
                }

                /*
                 * Commit and start the next trans in the chain.
                 */
                if ((error = xfs_attr_rolltrans(&args->trans, dp)))
                        goto out;

        } else if (args->rmtblkno > 0) {
                /*
                 * Added a "remote" value, just clear the incomplete flag.
                 */
                error = xfs_attr_leaf_clearflag(args);
                if (error)
                        goto out;
        }
        retval = error = 0;

out:
        if (state)
                xfs_da_state_free(state);
        if (error)
                return(error);
        return(retval);
}

/*
 * Remove a name from a B-tree attribute list.
 *
 * This will involve walking down the Btree, and may involve joining
 * leaf nodes and even joining intermediate nodes up to and including
 * the root node (a special case of an intermediate node).
 */
STATIC int
xfs_attr_node_removename(xfs_da_args_t *args)
{
        xfs_da_state_t *state;
        xfs_da_state_blk_t *blk;
        xfs_inode_t *dp;
        xfs_dabuf_t *bp;
        int retval, error, committed, forkoff;

        /*
         * Tie a string around our finger to remind us where we are.
         */
        dp = args->dp;
        state = xfs_da_state_alloc();
        state->args = args;
        state->mp = dp->i_mount;
        state->blocksize = state->mp->m_sb.sb_blocksize;
        state->node_ents = state->mp->m_attr_node_ents;

        /*
         * Search to see if name exists, and get back a pointer to it.
         */
        error = xfs_da_node_lookup_int(state, &retval);
        if (error || (retval != EEXIST)) {
                if (error == 0)
                        error = retval;
                goto out;
        }

        /*
         * If there is an out-of-line value, de-allocate the blocks.
         * This is done before we remove the attribute so that we don't
         * overflow the maximum size of a transaction and/or hit a deadlock.
         */
        blk = &state->path.blk[ state->path.active-1 ];
        ASSERT(blk->bp != NULL);
        ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
        if (args->rmtblkno > 0) {
                /*
                 * Fill in disk block numbers in the state structure
                 * so that we can get the buffers back after we commit
                 * several transactions in the following calls.
                 */
                error = xfs_attr_fillstate(state);
                if (error)
                        goto out;

                /*
                 * Mark the attribute as INCOMPLETE, then bunmapi() the
                 * remote value.
                 */
                error = xfs_attr_leaf_setflag(args);
                if (error)
                        goto out;
                error = xfs_attr_rmtval_remove(args);
                if (error)
                        goto out;

                /*
                 * Refill the state structure with buffers, the prior calls
                 * released our buffers.
                 */
                error = xfs_attr_refillstate(state);
                if (error)
                        goto out;
        }

        /*
         * Remove the name and update the hashvals in the tree.
         */
        blk = &state->path.blk[ state->path.active-1 ];
        ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
        retval = xfs_attr_leaf_remove(blk->bp, args);
        xfs_da_fixhashpath(state, &state->path);

        /*
         * Check to see if the tree needs to be collapsed.
         */
        if (retval && (state->path.active > 1)) {
                XFS_BMAP_INIT(args->flist, args->firstblock);
                error = xfs_da_join(state);
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                *args->firstblock, &committed);
                }
                if (error) {
                        ASSERT(committed);
                        args->trans = NULL;
                        xfs_bmap_cancel(args->flist);
                        goto out;
                }

                /*
                 * bmap_finish() may have committed the last trans and started
                 * a new one.  We need the inode to be in all transactions.
                 */
                if (committed) {
                        xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                        xfs_trans_ihold(args->trans, dp);
                }

                /*
                 * Commit the Btree join operation and start a new trans.
                 */
                if ((error = xfs_attr_rolltrans(&args->trans, dp)))
                        goto out;
        }

        /*
         * If the result is small enough, push it all into the inode.
         */
        if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
                /*
                 * Have to get rid of the copy of this dabuf in the state.
                 */
                ASSERT(state->path.active == 1);
                ASSERT(state->path.blk[0].bp);
                xfs_da_buf_done(state->path.blk[0].bp);
                state->path.blk[0].bp = NULL;

                error = xfs_da_read_buf(args->trans, args->dp, 0, -1, &bp,
                                                     XFS_ATTR_FORK);
                if (error)
                        goto out;
                ASSERT(be16_to_cpu(((xfs_attr_leafblock_t *)
                                      bp->data)->hdr.info.magic)
                                                       == XFS_ATTR_LEAF_MAGIC);

                if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
                        XFS_BMAP_INIT(args->flist, args->firstblock);
                        error = xfs_attr_leaf_to_shortform(bp, args, forkoff);
                        /* bp is gone due to xfs_da_shrink_inode */
                        if (!error) {
                                error = xfs_bmap_finish(&args->trans,
                                                        args->flist,
                                                        *args->firstblock,
                                                        &committed);
                        }
                        if (error) {
                                ASSERT(committed);
                                args->trans = NULL;
                                xfs_bmap_cancel(args->flist);
                                goto out;
                        }

                        /*
                         * bmap_finish() may have committed the last trans
                         * and started a new one.  We need the inode to be
                         * in all transactions.
                         */
                        if (committed) {
                                xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                                xfs_trans_ihold(args->trans, dp);
                        }
                } else
                        xfs_da_brelse(args->trans, bp);
        }
        error = 0;

out:
        xfs_da_state_free(state);
        return(error);
}

/*
 * Fill in the disk block numbers in the state structure for the buffers
 * that are attached to the state structure.
 * This is done so that we can quickly reattach ourselves to those buffers
 * after some set of transaction commits have released these buffers.
 */
STATIC int
xfs_attr_fillstate(xfs_da_state_t *state)
{
        xfs_da_state_path_t *path;
        xfs_da_state_blk_t *blk;
        int level;

        /*
         * Roll down the "path" in the state structure, storing the on-disk
         * block number for those buffers in the "path".
         */
        path = &state->path;
        ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
        for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
                if (blk->bp) {
                        blk->disk_blkno = xfs_da_blkno(blk->bp);
                        xfs_da_buf_done(blk->bp);
                        blk->bp = NULL;
                } else {
                        blk->disk_blkno = 0;
                }
        }

        /*
         * Roll down the "altpath" in the state structure, storing the on-disk
         * block number for those buffers in the "altpath".
         */
        path = &state->altpath;
        ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
        for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
                if (blk->bp) {
                        blk->disk_blkno = xfs_da_blkno(blk->bp);
                        xfs_da_buf_done(blk->bp);
                        blk->bp = NULL;
                } else {
                        blk->disk_blkno = 0;
                }
        }

        return(0);
}

/*
 * Reattach the buffers to the state structure based on the disk block
 * numbers stored in the state structure.
 * This is done after some set of transaction commits have released those
 * buffers from our grip.
 */
STATIC int
xfs_attr_refillstate(xfs_da_state_t *state)
{
        xfs_da_state_path_t *path;
        xfs_da_state_blk_t *blk;
        int level, error;

        /*
         * Roll down the "path" in the state structure, storing the on-disk
         * block number for those buffers in the "path".
         */
        path = &state->path;
        ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
        for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
                if (blk->disk_blkno) {
                        error = xfs_da_read_buf(state->args->trans,
                                                state->args->dp,
                                                blk->blkno, blk->disk_blkno,
                                                &blk->bp, XFS_ATTR_FORK);
                        if (error)
                                return(error);
                } else {
                        blk->bp = NULL;
                }
        }

        /*
         * Roll down the "altpath" in the state structure, storing the on-disk
         * block number for those buffers in the "altpath".
         */
        path = &state->altpath;
        ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
        for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
                if (blk->disk_blkno) {
                        error = xfs_da_read_buf(state->args->trans,
                                                state->args->dp,
                                                blk->blkno, blk->disk_blkno,
                                                &blk->bp, XFS_ATTR_FORK);
                        if (error)
                                return(error);
                } else {
                        blk->bp = NULL;
                }
        }

        return(0);
}

/*
 * Look up a filename in a node attribute list.
 *
 * This routine gets called for any attribute fork that has more than one
 * block, ie: both true Btree attr lists and for single-leaf-blocks with
 * "remote" values taking up more blocks.
 */
STATIC int
xfs_attr_node_get(xfs_da_args_t *args)
{
        xfs_da_state_t *state;
        xfs_da_state_blk_t *blk;
        int error, retval;
        int i;

        state = xfs_da_state_alloc();
        state->args = args;
        state->mp = args->dp->i_mount;
        state->blocksize = state->mp->m_sb.sb_blocksize;
        state->node_ents = state->mp->m_attr_node_ents;

        /*
         * Search to see if name exists, and get back a pointer to it.
         */
        error = xfs_da_node_lookup_int(state, &retval);
        if (error) {
                retval = error;
        } else if (retval == EEXIST) {
                blk = &state->path.blk[ state->path.active-1 ];
                ASSERT(blk->bp != NULL);
                ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);

                /*
                 * Get the value, local or "remote"
                 */
                retval = xfs_attr_leaf_getvalue(blk->bp, args);
                if (!retval && (args->rmtblkno > 0)
                    && !(args->flags & ATTR_KERNOVAL)) {
                        retval = xfs_attr_rmtval_get(args);
                }
        }

        /*
         * If not in a transaction, we have to release all the buffers.
         */
        for (i = 0; i < state->path.active; i++) {
                xfs_da_brelse(args->trans, state->path.blk[i].bp);
                state->path.blk[i].bp = NULL;
        }

        xfs_da_state_free(state);
        return(retval);
}

STATIC int                                                      /* error */
xfs_attr_node_list(xfs_attr_list_context_t *context)
{
        attrlist_cursor_kern_t *cursor;
        xfs_attr_leafblock_t *leaf;
        xfs_da_intnode_t *node;
        xfs_da_node_entry_t *btree;
        int error, i;
        xfs_dabuf_t *bp;

        cursor = context->cursor;
        cursor->initted = 1;

        /*
         * Do all sorts of validation on the passed-in cursor structure.
         * If anything is amiss, ignore the cursor and look up the hashval
         * starting from the btree root.
         */
        bp = NULL;
        if (cursor->blkno > 0) {
                error = xfs_da_read_buf(NULL, context->dp, cursor->blkno, -1,
                                              &bp, XFS_ATTR_FORK);
                if ((error != 0) && (error != EFSCORRUPTED))
                        return(error);
                if (bp) {
                        node = bp->data;
                        switch (be16_to_cpu(node->hdr.info.magic)) {
                        case XFS_DA_NODE_MAGIC:
                                xfs_attr_trace_l_cn("wrong blk", context, node);
                                xfs_da_brelse(NULL, bp);
                                bp = NULL;
                                break;
                        case XFS_ATTR_LEAF_MAGIC:
                                leaf = bp->data;
                                if (cursor->hashval > be32_to_cpu(leaf->entries[
                                    be16_to_cpu(leaf->hdr.count)-1].hashval)) {
                                        xfs_attr_trace_l_cl("wrong blk",
                                                           context, leaf);
                                        xfs_da_brelse(NULL, bp);
                                        bp = NULL;
                                } else if (cursor->hashval <=
                                             be32_to_cpu(leaf->entries[0].hashval)) {
                                        xfs_attr_trace_l_cl("maybe wrong blk",
                                                           context, leaf);
                                        xfs_da_brelse(NULL, bp);
                                        bp = NULL;
                                }
                                break;
                        default:
                                xfs_attr_trace_l_c("wrong blk - ??", context);
                                xfs_da_brelse(NULL, bp);
                                bp = NULL;
                        }
                }
        }

        /*
         * We did not find what we expected given the cursor's contents,
         * so we start from the top and work down based on the hash value.
         * Note that start of node block is same as start of leaf block.
         */
        if (bp == NULL) {
                cursor->blkno = 0;
                for (;;) {
                        error = xfs_da_read_buf(NULL, context->dp,
                                                      cursor->blkno, -1, &bp,
                                                      XFS_ATTR_FORK);
                        if (error)
                                return(error);
                        if (unlikely(bp == NULL)) {
                                XFS_ERROR_REPORT("xfs_attr_node_list(2)",
                                                 XFS_ERRLEVEL_LOW,
                                                 context->dp->i_mount);
                                return(XFS_ERROR(EFSCORRUPTED));
                        }
                        node = bp->data;
                        if (be16_to_cpu(node->hdr.info.magic)
                                                        == XFS_ATTR_LEAF_MAGIC)
                                break;
                        if (unlikely(be16_to_cpu(node->hdr.info.magic)
                                                        != XFS_DA_NODE_MAGIC)) {
                                XFS_CORRUPTION_ERROR("xfs_attr_node_list(3)",
                                                     XFS_ERRLEVEL_LOW,
                                                     context->dp->i_mount,
                                                     node);
                                xfs_da_brelse(NULL, bp);
                                return(XFS_ERROR(EFSCORRUPTED));
                        }
                        btree = node->btree;
                        for (i = 0; i < be16_to_cpu(node->hdr.count);
                                                                btree++, i++) {
                                if (cursor->hashval
                                                <= be32_to_cpu(btree->hashval)) {
                                        cursor->blkno = be32_to_cpu(btree->before);
                                        xfs_attr_trace_l_cb("descending",
                                                            context, btree);
                                        break;
                                }
                        }
                        if (i == be16_to_cpu(node->hdr.count)) {
                                xfs_da_brelse(NULL, bp);
                                return(0);
                        }
                        xfs_da_brelse(NULL, bp);
                }
        }
        ASSERT(bp != NULL);

        /*
         * Roll upward through the blocks, processing each leaf block in
         * order.  As long as there is space in the result buffer, keep
         * adding the information.
         */
        for (;;) {
                leaf = bp->data;
                if (unlikely(be16_to_cpu(leaf->hdr.info.magic)
                                                != XFS_ATTR_LEAF_MAGIC)) {
                        XFS_CORRUPTION_ERROR("xfs_attr_node_list(4)",
                                             XFS_ERRLEVEL_LOW,
                                             context->dp->i_mount, leaf);
                        xfs_da_brelse(NULL, bp);
                        return(XFS_ERROR(EFSCORRUPTED));
                }
                error = xfs_attr_leaf_list_int(bp, context);
                if (error) {
                        xfs_da_brelse(NULL, bp);
                        return error;
                }
                if (context->seen_enough || leaf->hdr.info.forw == 0)
                        break;
                cursor->blkno = be32_to_cpu(leaf->hdr.info.forw);
                xfs_da_brelse(NULL, bp);
                error = xfs_da_read_buf(NULL, context->dp, cursor->blkno, -1,
                                              &bp, XFS_ATTR_FORK);
                if (error)
                        return(error);
                if (unlikely((bp == NULL))) {
                        XFS_ERROR_REPORT("xfs_attr_node_list(5)",
                                         XFS_ERRLEVEL_LOW,
                                         context->dp->i_mount);
                        return(XFS_ERROR(EFSCORRUPTED));
                }
        }
        xfs_da_brelse(NULL, bp);
        return(0);
}


/*========================================================================
 * External routines for manipulating out-of-line attribute values.
 *========================================================================*/

/*
 * Read the value associated with an attribute from the out-of-line buffer
 * that we stored it in.
 */
int
xfs_attr_rmtval_get(xfs_da_args_t *args)
{
        xfs_bmbt_irec_t map[ATTR_RMTVALUE_MAPSIZE];
        xfs_mount_t *mp;
        xfs_daddr_t dblkno;
        xfs_caddr_t dst;
        xfs_buf_t *bp;
        int nmap, error, tmp, valuelen, blkcnt, i;
        xfs_dablk_t lblkno;

        ASSERT(!(args->flags & ATTR_KERNOVAL));

        mp = args->dp->i_mount;
        dst = args->value;
        valuelen = args->valuelen;
        lblkno = args->rmtblkno;
        while (valuelen > 0) {
                nmap = ATTR_RMTVALUE_MAPSIZE;
                error = xfs_bmapi(args->trans, args->dp, (xfs_fileoff_t)lblkno,
                                  args->rmtblkcnt,
                                  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
                                  NULL, 0, map, &nmap, NULL, NULL);
                if (error)
                        return(error);
                ASSERT(nmap >= 1);

                for (i = 0; (i < nmap) && (valuelen > 0); i++) {
                        ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
                               (map[i].br_startblock != HOLESTARTBLOCK));
                        dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
                        blkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
                        error = xfs_read_buf(mp, mp->m_ddev_targp, dblkno,
                                             blkcnt, XFS_BUF_LOCK, &bp);
                        if (error)
                                return(error);

                        tmp = (valuelen < XFS_BUF_SIZE(bp))
                                ? valuelen : XFS_BUF_SIZE(bp);
                        xfs_biomove(bp, 0, tmp, dst, XFS_B_READ);
                        xfs_buf_relse(bp);
                        dst += tmp;
                        valuelen -= tmp;

                        lblkno += map[i].br_blockcount;
                }
        }
        ASSERT(valuelen == 0);
        return(0);
}

/*
 * Write the value associated with an attribute into the out-of-line buffer
 * that we have defined for it.
 */
STATIC int
xfs_attr_rmtval_set(xfs_da_args_t *args)
{
        xfs_mount_t *mp;
        xfs_fileoff_t lfileoff;
        xfs_inode_t *dp;
        xfs_bmbt_irec_t map;
        xfs_daddr_t dblkno;
        xfs_caddr_t src;
        xfs_buf_t *bp;
        xfs_dablk_t lblkno;
        int blkcnt, valuelen, nmap, error, tmp, committed;

        dp = args->dp;
        mp = dp->i_mount;
        src = args->value;

        /*
         * Find a "hole" in the attribute address space large enough for
         * us to drop the new attribute's value into.
         */
        blkcnt = XFS_B_TO_FSB(mp, args->valuelen);
        lfileoff = 0;
        error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
                                                   XFS_ATTR_FORK);
        if (error) {
                return(error);
        }
        args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
        args->rmtblkcnt = blkcnt;

        /*
         * Roll through the "value", allocating blocks on disk as required.
         */
        while (blkcnt > 0) {
                /*
                 * Allocate a single extent, up to the size of the value.
                 */
                XFS_BMAP_INIT(args->flist, args->firstblock);
                nmap = 1;
                error = xfs_bmapi(args->trans, dp, (xfs_fileoff_t)lblkno,
                                  blkcnt,
                                  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA |
                                                        XFS_BMAPI_WRITE,
                                  args->firstblock, args->total, &map, &nmap,
                                  args->flist, NULL);
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                *args->firstblock, &committed);
                }
                if (error) {
                        ASSERT(committed);
                        args->trans = NULL;
                        xfs_bmap_cancel(args->flist);
                        return(error);
                }

                /*
                 * bmap_finish() may have committed the last trans and started
                 * a new one.  We need the inode to be in all transactions.
                 */
                if (committed) {
                        xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
                        xfs_trans_ihold(args->trans, dp);
                }

                ASSERT(nmap == 1);
                ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
                       (map.br_startblock != HOLESTARTBLOCK));
                lblkno += map.br_blockcount;
                blkcnt -= map.br_blockcount;

                /*
                 * Start the next trans in the chain.
                 */
                if ((error = xfs_attr_rolltrans(&args->trans, dp)))
                        return (error);
        }

        /*
         * Roll through the "value", copying the attribute value to the
         * already-allocated blocks.  Blocks are written synchronously
         * so that we can know they are all on disk before we turn off
         * the INCOMPLETE flag.
         */
        lblkno = args->rmtblkno;
        valuelen = args->valuelen;
        while (valuelen > 0) {
                /*
                 * Try to remember where we decided to put the value.
                 */
                XFS_BMAP_INIT(args->flist, args->firstblock);
                nmap = 1;
                error = xfs_bmapi(NULL, dp, (xfs_fileoff_t)lblkno,
                                  args->rmtblkcnt,
                                  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
                                  args->firstblock, 0, &map, &nmap,
                                  NULL, NULL);
                if (error) {
                        return(error);
                }
                ASSERT(nmap == 1);
                ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
                       (map.br_startblock != HOLESTARTBLOCK));

                dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
                blkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);

                bp = xfs_buf_get_flags(mp->m_ddev_targp, dblkno,
                                                        blkcnt, XFS_BUF_LOCK);
                ASSERT(bp);
                ASSERT(!XFS_BUF_GETERROR(bp));

                tmp = (valuelen < XFS_BUF_SIZE(bp)) ? valuelen :
                                                        XFS_BUF_SIZE(bp);
                xfs_biomove(bp, 0, tmp, src, XFS_B_WRITE);
                if (tmp < XFS_BUF_SIZE(bp))
                        xfs_biozero(bp, tmp, XFS_BUF_SIZE(bp) - tmp);
                if ((error = xfs_bwrite(mp, bp))) {/* GROT: NOTE: synchronous write */
                        return (error);
                }
                src += tmp;
                valuelen -= tmp;

                lblkno += map.br_blockcount;
        }
        ASSERT(valuelen == 0);
        return(0);
}

/*
 * Remove the value associated with an attribute by deleting the
 * out-of-line buffer that it is stored on.
 */
STATIC int
xfs_attr_rmtval_remove(xfs_da_args_t *args)
{
        xfs_mount_t *mp;
        xfs_bmbt_irec_t map;
        xfs_buf_t *bp;
        xfs_daddr_t dblkno;
        xfs_dablk_t lblkno;
        int valuelen, blkcnt, nmap, error, done, committed;

        mp = args->dp->i_mount;

        /*
         * Roll through the "value", invalidating the attribute value's
         * blocks.
         */
        lblkno = args->rmtblkno;
        valuelen = args->rmtblkcnt;
        while (valuelen > 0) {
                /*
                 * Try to remember where we decided to put the value.
                 */
                XFS_BMAP_INIT(args->flist, args->firstblock);
                nmap = 1;
                error = xfs_bmapi(NULL, args->dp, (xfs_fileoff_t)lblkno,
                                        args->rmtblkcnt,
                                        XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
                                        args->firstblock, 0, &map, &nmap,
                                        args->flist, NULL);
                if (error) {
                        return(error);
                }
                ASSERT(nmap == 1);
                ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
                       (map.br_startblock != HOLESTARTBLOCK));

                dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
                blkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);

                /*
                 * If the "remote" value is in the cache, remove it.
                 */
                bp = xfs_incore(mp->m_ddev_targp, dblkno, blkcnt,
                                XFS_INCORE_TRYLOCK);
                if (bp) {
                        XFS_BUF_STALE(bp);
                        XFS_BUF_UNDELAYWRITE(bp);
                        xfs_buf_relse(bp);
                        bp = NULL;
                }

                valuelen -= map.br_blockcount;

                lblkno += map.br_blockcount;
        }

        /*
         * Keep de-allocating extents until the remote-value region is gone.
         */
        lblkno = args->rmtblkno;
        blkcnt = args->rmtblkcnt;
        done = 0;
        while (!done) {
                XFS_BMAP_INIT(args->flist, args->firstblock);
                error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
                                    XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
                                    1, args->firstblock, args->flist,
                                    NULL, &done);
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                *args->firstblock, &committed);
                }
                if (error) {
                        ASSERT(committed);
                        args->trans = NULL;
                        xfs_bmap_cancel(args->flist);
                        return(error);
                }

                /*
                 * bmap_finish() may have committed the last trans and started
                 * a new one.  We need the inode to be in all transactions.
                 */
                if (committed) {
                        xfs_trans_ijoin(args->trans, args->dp, XFS_ILOCK_EXCL);
                        xfs_trans_ihold(args->trans, args->dp);
                }

                /*
                 * Close out trans and start the next one in the chain.
                 */
                if ((error = xfs_attr_rolltrans(&args->trans, args->dp)))
                        return (error);
        }
        return(0);
}

#if defined(XFS_ATTR_TRACE)
/*
 * Add a trace buffer entry for an attr_list context structure.
 */
void
xfs_attr_trace_l_c(char *where, struct xfs_attr_list_context *context)
{
        xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_C, where,
                (__psunsigned_t)context->dp,
                (__psunsigned_t)context->cursor->hashval,
                (__psunsigned_t)context->cursor->blkno,
                (__psunsigned_t)context->cursor->offset,
                (__psunsigned_t)context->alist,
                (__psunsigned_t)context->bufsize,
                (__psunsigned_t)context->count,
                (__psunsigned_t)context->firstu,
                (__psunsigned_t)
                        ((context->count > 0) &&
                        !(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
                                ? (ATTR_ENTRY(context->alist,
                                              context->count-1)->a_valuelen)
                                : 0,
                (__psunsigned_t)context->dupcnt,
                (__psunsigned_t)context->flags,
                (__psunsigned_t)NULL,
                (__psunsigned_t)NULL,
                (__psunsigned_t)NULL);
}

/*
 * Add a trace buffer entry for a context structure and a Btree node.
 */
void
xfs_attr_trace_l_cn(char *where, struct xfs_attr_list_context *context,
                         struct xfs_da_intnode *node)
{
        xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_CN, where,
                (__psunsigned_t)context->dp,
                (__psunsigned_t)context->cursor->hashval,
                (__psunsigned_t)context->cursor->blkno,
                (__psunsigned_t)context->cursor->offset,
                (__psunsigned_t)context->alist,
                (__psunsigned_t)context->bufsize,
                (__psunsigned_t)context->count,
                (__psunsigned_t)context->firstu,
                (__psunsigned_t)
                        ((context->count > 0) &&
                        !(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
                                ? (ATTR_ENTRY(context->alist,
                                              context->count-1)->a_valuelen)
                                : 0,
                (__psunsigned_t)context->dupcnt,
                (__psunsigned_t)context->flags,
                (__psunsigned_t)be16_to_cpu(node->hdr.count),
                (__psunsigned_t)be32_to_cpu(node->btree[0].hashval),
                (__psunsigned_t)be32_to_cpu(node->btree[
                                    be16_to_cpu(node->hdr.count)-1].hashval));
}

/*
 * Add a trace buffer entry for a context structure and a Btree element.
 */
void
xfs_attr_trace_l_cb(char *where, struct xfs_attr_list_context *context,
                          struct xfs_da_node_entry *btree)
{
        xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_CB, where,
                (__psunsigned_t)context->dp,
                (__psunsigned_t)context->cursor->hashval,
                (__psunsigned_t)context->cursor->blkno,
                (__psunsigned_t)context->cursor->offset,
                (__psunsigned_t)context->alist,
                (__psunsigned_t)context->bufsize,
                (__psunsigned_t)context->count,
                (__psunsigned_t)context->firstu,
                (__psunsigned_t)
                        ((context->count > 0) &&
                        !(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
                                ? (ATTR_ENTRY(context->alist,
                                              context->count-1)->a_valuelen)
                                : 0,
                (__psunsigned_t)context->dupcnt,
                (__psunsigned_t)context->flags,
                (__psunsigned_t)be32_to_cpu(btree->hashval),
                (__psunsigned_t)be32_to_cpu(btree->before),
                (__psunsigned_t)NULL);
}

/*
 * Add a trace buffer entry for a context structure and a leaf block.
 */
void
xfs_attr_trace_l_cl(char *where, struct xfs_attr_list_context *context,
                              struct xfs_attr_leafblock *leaf)
{
        xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_CL, where,
                (__psunsigned_t)context->dp,
                (__psunsigned_t)context->cursor->hashval,
                (__psunsigned_t)context->cursor->blkno,
                (__psunsigned_t)context->cursor->offset,
                (__psunsigned_t)context->alist,
                (__psunsigned_t)context->bufsize,
                (__psunsigned_t)context->count,
                (__psunsigned_t)context->firstu,
                (__psunsigned_t)
                        ((context->count > 0) &&
                        !(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
                                ? (ATTR_ENTRY(context->alist,
                                              context->count-1)->a_valuelen)
                                : 0,
                (__psunsigned_t)context->dupcnt,
                (__psunsigned_t)context->flags,
                (__psunsigned_t)be16_to_cpu(leaf->hdr.count),
                (__psunsigned_t)be32_to_cpu(leaf->entries[0].hashval),
                (__psunsigned_t)be32_to_cpu(leaf->entries[
                                be16_to_cpu(leaf->hdr.count)-1].hashval));
}

/*
 * Add a trace buffer entry for the arguments given to the routine,
 * generic form.
 */
void
xfs_attr_trace_enter(int type, char *where,
                         __psunsigned_t a2, __psunsigned_t a3,
                         __psunsigned_t a4, __psunsigned_t a5,
                         __psunsigned_t a6, __psunsigned_t a7,
                         __psunsigned_t a8, __psunsigned_t a9,
                         __psunsigned_t a10, __psunsigned_t a11,
                         __psunsigned_t a12, __psunsigned_t a13,
                         __psunsigned_t a14, __psunsigned_t a15)
{
        ASSERT(xfs_attr_trace_buf);
        ktrace_enter(xfs_attr_trace_buf, (void *)((__psunsigned_t)type),
                                         (void *)where,
                                         (void *)a2,  (void *)a3,  (void *)a4,
                                         (void *)a5,  (void *)a6,  (void *)a7,
                                         (void *)a8,  (void *)a9,  (void *)a10,
                                         (void *)a11, (void *)a12, (void *)a13,
                                         (void *)a14, (void *)a15);
}
#endif  /* XFS_ATTR_TRACE */


/*========================================================================
 * System (pseudo) namespace attribute interface routines.
 *========================================================================*/

STATIC int
posix_acl_access_set(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        return xfs_acl_vset(vp, data, size, _ACL_TYPE_ACCESS);
}

STATIC int
posix_acl_access_remove(
        bhv_vnode_t *vp, char *name, int xflags)
{
        return xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
}

STATIC int
posix_acl_access_get(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        return xfs_acl_vget(vp, data, size, _ACL_TYPE_ACCESS);
}

STATIC int
posix_acl_access_exists(
        bhv_vnode_t *vp)
{
        return xfs_acl_vhasacl_access(vp);
}

STATIC int
posix_acl_default_set(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        return xfs_acl_vset(vp, data, size, _ACL_TYPE_DEFAULT);
}

STATIC int
posix_acl_default_get(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        return xfs_acl_vget(vp, data, size, _ACL_TYPE_DEFAULT);
}

STATIC int
posix_acl_default_remove(
        bhv_vnode_t *vp, char *name, int xflags)
{
        return xfs_acl_vremove(vp, _ACL_TYPE_DEFAULT);
}

STATIC int
posix_acl_default_exists(
        bhv_vnode_t *vp)
{
        return xfs_acl_vhasacl_default(vp);
}

STATIC struct attrnames posix_acl_access = {
        .attr_name      = "posix_acl_access",
        .attr_namelen   = sizeof("posix_acl_access") - 1,
        .attr_get       = posix_acl_access_get,
        .attr_set       = posix_acl_access_set,
        .attr_remove    = posix_acl_access_remove,
        .attr_exists    = posix_acl_access_exists,
};

STATIC struct attrnames posix_acl_default = {
        .attr_name      = "posix_acl_default",
        .attr_namelen   = sizeof("posix_acl_default") - 1,
        .attr_get       = posix_acl_default_get,
        .attr_set       = posix_acl_default_set,
        .attr_remove    = posix_acl_default_remove,
        .attr_exists    = posix_acl_default_exists,
};

STATIC struct attrnames *attr_system_names[] =
        { &posix_acl_access, &posix_acl_default };


/*========================================================================
 * Namespace-prefix-style attribute name interface routines.
 *========================================================================*/

STATIC int
attr_generic_set(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        return -bhv_vop_attr_set(vp, name, data, size, xflags, NULL);
}

STATIC int
attr_generic_get(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        int     error, asize = size;

        error = bhv_vop_attr_get(vp, name, data, &asize, xflags, NULL);
        if (!error)
                return asize;
        return -error;
}

STATIC int
attr_generic_remove(
        bhv_vnode_t *vp, char *name, int xflags)
{
        return -bhv_vop_attr_remove(vp, name, xflags, NULL);
}

STATIC int
attr_generic_listadd(
        attrnames_t             *prefix,
        attrnames_t             *namesp,
        void                    *data,
        size_t                  size,
        ssize_t                 *result)
{
        char                    *p = data + *result;

        *result += prefix->attr_namelen;
        *result += namesp->attr_namelen + 1;
        if (!size)
                return 0;
        if (*result > size)
                return -ERANGE;
        strcpy(p, prefix->attr_name);
        p += prefix->attr_namelen;
        strcpy(p, namesp->attr_name);
        p += namesp->attr_namelen + 1;
        return 0;
}

STATIC int
attr_system_list(
        bhv_vnode_t             *vp,
        void                    *data,
        size_t                  size,
        ssize_t                 *result)
{
        attrnames_t             *namesp;
        int                     i, error = 0;

        for (i = 0; i < ATTR_SYSCOUNT; i++) {
                namesp = attr_system_names[i];
                if (!namesp->attr_exists || !namesp->attr_exists(vp))
                        continue;
                error = attr_generic_listadd(&attr_system, namesp,
                                                data, size, result);
                if (error)
                        break;
        }
        return error;
}

int
attr_generic_list(
        bhv_vnode_t *vp, void *data, size_t size, int xflags, ssize_t *result)
{
        attrlist_cursor_kern_t  cursor = { 0 };
        int                     error;

        error = bhv_vop_attr_list(vp, data, size, xflags, &cursor, NULL);
        if (error > 0)
                return -error;
        *result = -error;
        return attr_system_list(vp, data, size, result);
}

attrnames_t *
attr_lookup_namespace(
        char                    *name,
        struct attrnames        **names,
        int                     nnames)
{
        int                     i;

        for (i = 0; i < nnames; i++)
                if (!strncmp(name, names[i]->attr_name, names[i]->attr_namelen))
                        return names[i];
        return NULL;
}

/*
 * Some checks to prevent people abusing EAs to get over quota:
 * - Don't allow modifying user EAs on devices/symlinks;
 * - Don't allow modifying user EAs if sticky bit set;
 */
STATIC int
attr_user_capable(
        bhv_vnode_t     *vp,
        cred_t          *cred)
{
        struct inode    *inode = vn_to_inode(vp);

        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                return -EPERM;
        if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode) &&
            !capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
            (current_fsuid(cred) != inode->i_uid) && !capable(CAP_FOWNER))
                return -EPERM;
        return 0;
}

STATIC int
attr_trusted_capable(
        bhv_vnode_t     *vp,
        cred_t          *cred)
{
        struct inode    *inode = vn_to_inode(vp);

        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                return -EPERM;
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
        return 0;
}

STATIC int
attr_secure_capable(
        bhv_vnode_t     *vp,
        cred_t          *cred)
{
        return -ENOSECURITY;
}

STATIC int
attr_system_set(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        attrnames_t     *namesp;
        int             error;

        if (xflags & ATTR_CREATE)
                return -EINVAL;

        namesp = attr_lookup_namespace(name, attr_system_names, ATTR_SYSCOUNT);
        if (!namesp)
                return -EOPNOTSUPP;
        error = namesp->attr_set(vp, name, data, size, xflags);
        if (!error)
                error = vn_revalidate(vp);
        return error;
}

STATIC int
attr_system_get(
        bhv_vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
        attrnames_t     *namesp;

        namesp = attr_lookup_namespace(name, attr_system_names, ATTR_SYSCOUNT);
        if (!namesp)
                return -EOPNOTSUPP;
        return namesp->attr_get(vp, name, data, size, xflags);
}

STATIC int
attr_system_remove(
        bhv_vnode_t *vp, char *name, int xflags)
{
        attrnames_t     *namesp;

        namesp = attr_lookup_namespace(name, attr_system_names, ATTR_SYSCOUNT);
        if (!namesp)
                return -EOPNOTSUPP;
        return namesp->attr_remove(vp, name, xflags);
}

struct attrnames attr_system = {
        .attr_name      = "system.",
        .attr_namelen   = sizeof("system.") - 1,
        .attr_flag      = ATTR_SYSTEM,
        .attr_get       = attr_system_get,
        .attr_set       = attr_system_set,
        .attr_remove    = attr_system_remove,
        .attr_capable   = (attrcapable_t)fs_noerr,
};

struct attrnames attr_trusted = {
        .attr_name      = "trusted.",
        .attr_namelen   = sizeof("trusted.") - 1,
        .attr_flag      = ATTR_ROOT,
        .attr_get       = attr_generic_get,
        .attr_set       = attr_generic_set,
        .attr_remove    = attr_generic_remove,
        .attr_capable   = attr_trusted_capable,
};

struct attrnames attr_secure = {
        .attr_name      = "security.",
        .attr_namelen   = sizeof("security.") - 1,
        .attr_flag      = ATTR_SECURE,
        .attr_get       = attr_generic_get,
        .attr_set       = attr_generic_set,
        .attr_remove    = attr_generic_remove,
        .attr_capable   = attr_secure_capable,
};

struct attrnames attr_user = {
        .attr_name      = "user.",
        .attr_namelen   = sizeof("user.") - 1,
        .attr_get       = attr_generic_get,
        .attr_set       = attr_generic_set,
        .attr_remove    = attr_generic_remove,
        .attr_capable   = attr_user_capable,
};

struct attrnames *attr_namespaces[] =
        { &attr_system, &attr_trusted, &attr_secure, &attr_user };