Avoid beyond bounds copy while caching ACL

[zen-stable.git] / 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 "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_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_alloc.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_rw.h"
#include "xfs_vnodeops.h"
#include "xfs_trace.h"

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

/*========================================================================
 * 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 */

STATIC int
xfs_attr_name_to_xname(
        struct xfs_name *xname,
        const unsigned char *aname)
{
        if (!aname)
                return EINVAL;
        xname->name = aname;
        xname->len = strlen((char *)aname);
        if (xname->len >= MAXNAMELEN)
                return EFAULT;          /* match IRIX behaviour */

        return 0;
}

STATIC int
xfs_inode_hasattr(
        struct xfs_inode        *ip)
{
        if (!XFS_IFORK_Q(ip) ||
            (ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
             ip->i_d.di_anextents == 0))
                return 0;
        return 1;
}

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

STATIC int
xfs_attr_get_int(
        struct xfs_inode        *ip,
        struct xfs_name         *name,
        unsigned char           *value,
        int                     *valuelenp,
        int                     flags)
{
        xfs_da_args_t   args;
        int             error;

        if (!xfs_inode_hasattr(ip))
                return ENOATTR;

        /*
         * Fill in the arg structure for this request.
         */
        memset((char *)&args, 0, sizeof(args));
        args.name = name->name;
        args.namelen = name->len;
        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 (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(
        xfs_inode_t     *ip,
        const unsigned char *name,
        unsigned char   *value,
        int             *valuelenp,
        int             flags)
{
        int             error;
        struct xfs_name xname;

        XFS_STATS_INC(xs_attr_get);

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

        error = xfs_attr_name_to_xname(&xname, name);
        if (error)
                return error;

        xfs_ilock(ip, XFS_ILOCK_SHARED);
        error = xfs_attr_get_int(ip, &xname, value, valuelenp, flags);
        xfs_iunlock(ip, XFS_ILOCK_SHARED);
        return(error);
}

/*
 * Calculate how many blocks we need for the new attribute,
 */
STATIC int
xfs_attr_calc_size(
        struct xfs_inode        *ip,
        int                     namelen,
        int                     valuelen,
        int                     *local)
{
        struct xfs_mount        *mp = ip->i_mount;
        int                     size;
        int                     nblks;

        /*
         * 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);

        nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
        if (*local) {
                if (size > (mp->m_sb.sb_blocksize >> 1)) {
                        /* Double split possible */
                        nblks *= 2;
                }
        } else {
                /*
                 * Out of line attribute, cannot double split, but
                 * make room for the attribute value itself.
                 */
                uint    dblocks = XFS_B_TO_FSB(mp, valuelen);
                nblks += dblocks;
                nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
        }

        return nblks;
}

STATIC int
xfs_attr_set_int(
        struct xfs_inode *dp,
        struct xfs_name *name,
        unsigned char   *value,
        int             valuelen,
        int             flags)
{
        xfs_da_args_t   args;
        xfs_fsblock_t   firstblock;
        xfs_bmap_free_t flist;
        int             error, err2, committed;
        xfs_mount_t     *mp = dp->i_mount;
        int             rsvd = (flags & ATTR_ROOT) != 0;
        int             local;

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

        /*
         * 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) {
                int sf_size = sizeof(xfs_attr_sf_hdr_t) +
                              XFS_ATTR_SF_ENTSIZE_BYNAME(name->len, valuelen);

                if ((error = xfs_bmap_add_attrfork(dp, sf_size, rsvd)))
                        return(error);
        }

        /*
         * Fill in the arg structure for this request.
         */
        memset((char *)&args, 0, sizeof(args));
        args.name = name->name;
        args.namelen = name->len;
        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.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;

        /* Size is now blocks for attribute data */
        args.total = xfs_attr_calc_size(dp, name->len, valuelen, &local);

        /*
         * 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, args.total,
                        XFS_ATTRSET_LOG_RES(mp, args.total), 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(args.trans, dp, args.total, 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, 0);

        /*
         * 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);
                        }

                        if (!error && (flags & ATTR_KERNOTIME) == 0) {
                                xfs_trans_ichgtime(args.trans, dp,
                                                        XFS_ICHGTIME_CHG);
                        }
                        err2 = xfs_trans_commit(args.trans,
                                                 XFS_TRANS_RELEASE_LOG_RES);
                        xfs_iunlock(dp, XFS_ILOCK_EXCL);

                        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,
                                                &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, 0);

                /*
                 * Commit the leaf transformation.  We'll need another (linked)
                 * transaction to add the new attribute to the leaf.
                 */

                error = xfs_trans_roll(&args.trans, dp);
                if (error)
                        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);
        }

        if ((flags & ATTR_KERNOTIME) == 0)
                xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);

        /*
         * 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);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);

        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(
        xfs_inode_t     *dp,
        const unsigned char *name,
        unsigned char   *value,
        int             valuelen,
        int             flags)
{
        int             error;
        struct xfs_name xname;

        XFS_STATS_INC(xs_attr_set);

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

        error = xfs_attr_name_to_xname(&xname, name);
        if (error)
                return error;

        return xfs_attr_set_int(dp, &xname, value, valuelen, flags);
}

/*
 * Generic handler routine to remove a name from an attribute list.
 * Transitions attribute list from Btree to shortform as necessary.
 */
STATIC int
xfs_attr_remove_int(xfs_inode_t *dp, struct xfs_name *name, 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->name;
        args.namelen = name->len;
        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;

        /*
         * we have no control over the attribute names that userspace passes us
         * to remove, so we have to allow the name lookup prior to attribute
         * removal to fail.
         */
        args.op_flags = XFS_DA_OP_OKNOENT;

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

        /*
         * Decide on what work routines to call based on the inode size.
         */
        if (!xfs_inode_hasattr(dp)) {
                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);
        }

        if ((flags & ATTR_KERNOTIME) == 0)
                xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);

        /*
         * 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);
        xfs_iunlock(dp, XFS_ILOCK_EXCL);

        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(
        xfs_inode_t     *dp,
        const unsigned char *name,
        int             flags)
{
        int             error;
        struct xfs_name xname;

        XFS_STATS_INC(xs_attr_remove);

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

        error = xfs_attr_name_to_xname(&xname, name);
        if (error)
                return error;

        xfs_ilock(dp, XFS_ILOCK_SHARED);
        if (!xfs_inode_hasattr(dp)) {
                xfs_iunlock(dp, XFS_ILOCK_SHARED);
                return XFS_ERROR(ENOATTR);
        }
        xfs_iunlock(dp, XFS_ILOCK_SHARED);

        return xfs_attr_remove_int(dp, &xname, flags);
}

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

        XFS_STATS_INC(xs_attr_list);

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

        xfs_ilock(dp, XFS_ILOCK_SHARED);

        /*
         * Decide on what work routines to call based on the inode size.
         */
        if (!xfs_inode_hasattr(dp)) {
                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);
        }

        xfs_iunlock(dp, XFS_ILOCK_SHARED);

        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,
        int             flags,
        unsigned char   *name,
        int             namelen,
        int             valuelen,
        unsigned char   *value)
{
        struct attrlist *alist = (struct attrlist *)context->alist;
        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(*alist));
        ASSERT(context->firstu <= context->bufsize);

        /*
         * Only list entries in the right namespace.
         */
        if (((context->flags & ATTR_SECURE) == 0) !=
            ((flags & XFS_ATTR_SECURE) == 0))
                return 0;
        if (((context->flags & ATTR_ROOT) == 0) !=
            ((flags & XFS_ATTR_ROOT) == 0))
                return 0;

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

        aep = (attrlist_ent_t *)&context->alist[context->firstu];
        aep->a_valuelen = valuelen;
        memcpy(aep->a_name, name, namelen);
        aep->a_name[namelen] = 0;
        alist->al_offset[context->count++] = context->firstu;
        alist->al_count = context->count;
        trace_xfs_attr_list_add(context);
        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(
        xfs_inode_t     *dp,
        char            *buffer,
        int             bufsize,
        int             flags,
        attrlist_cursor_kern_t *cursor)
{
        xfs_attr_list_context_t context;
        struct attrlist *alist;
        int error;

        /*
         * 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.
         */
        memset(&context, 0, sizeof(context));
        context.dp = dp;
        context.cursor = cursor;
        context.resynch = 1;
        context.flags = flags;
        context.alist = buffer;
        context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
        context.firstu = context.bufsize;
        context.put_listent = xfs_attr_put_listent;

        alist = (struct attrlist *)context.alist;
        alist->al_count = 0;
        alist->al_more = 0;
        alist->al_offset[0] = context.bufsize;

        error = xfs_attr_list_int(&context);
        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_inode_hasattr(dp) ||
            dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
                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, 0);

        /*
         * Decide on what work routines to call based on the inode size.
         */
        if (!xfs_inode_hasattr(dp) ||
            dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
                error = 0;
                goto out;
        }
        error = xfs_attr_root_inactive(&trans, dp);
        if (error)
                goto out;

        error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK, 0);
        if (error)
                goto out;

        error = xfs_trans_commit(trans, XFS_TRANS_RELEASE_LOG_RES);
        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).
 */
STATIC 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->op_flags |= XFS_DA_OP_RENAME;     /* 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,
                                                &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, 0);

                /*
                 * Commit the current trans (including the inode) and start
                 * a new one.
                 */
                error = xfs_trans_roll(&args->trans, dp);
                if (error)
                        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.
         */
        error = xfs_trans_roll(&args->trans, dp);
        if (error)
                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->op_flags & XFS_DA_OP_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,
                                                        &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, 0);
                } else
                        xfs_da_buf_done(bp);

                /*
                 * Commit the remove and start the next trans in series.
                 */
                error = xfs_trans_roll(&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,
                                                &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, 0);
        } 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(leaf->hdr.info.magic != cpu_to_be16(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->op_flags |= XFS_DA_OP_RENAME;     /* 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,
                                                        &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, 0);

                        /*
                         * Commit the node conversion and start the next
                         * trans in the chain.
                         */
                        error = xfs_trans_roll(&args->trans, dp);
                        if (error)
                                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,
                                                &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, 0);
        } 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.
         */
        error = xfs_trans_roll(&args->trans, dp);
        if (error)
                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->op_flags & XFS_DA_OP_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,
                                                        &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, 0);
                }

                /*
                 * Commit and start the next trans in the chain.
                 */
                error = xfs_trans_roll(&args->trans, dp);
                if (error)
                        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,
                                                &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, 0);

                /*
                 * Commit the Btree join operation and start a new trans.
                 */
                error = xfs_trans_roll(&args->trans, dp);
                if (error)
                        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((((xfs_attr_leafblock_t *)bp->data)->hdr.info.magic) ==
                       cpu_to_be16(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,
                                                        &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, 0);
                } 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:
                                trace_xfs_attr_list_wrong_blk(context);
                                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)) {
                                        trace_xfs_attr_list_wrong_blk(context);
                                        xfs_da_brelse(NULL, bp);
                                        bp = NULL;
                                } else if (cursor->hashval <=
                                             be32_to_cpu(leaf->entries[0].hashval)) {
                                        trace_xfs_attr_list_wrong_blk(context);
                                        xfs_da_brelse(NULL, bp);
                                        bp = NULL;
                                }
                                break;
                        default:
                                trace_xfs_attr_list_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 (node->hdr.info.magic ==
                            cpu_to_be16(XFS_ATTR_LEAF_MAGIC))
                                break;
                        if (unlikely(node->hdr.info.magic !=
                                     cpu_to_be16(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);
                                        trace_xfs_attr_list_node_descend(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(leaf->hdr.info.magic !=
                             cpu_to_be16(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;
        void *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_read(args->dp, (xfs_fileoff_t)lblkno,
                                       args->rmtblkcnt, map, &nmap,
                                       XFS_BMAPI_ATTRFORK);
                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, XBF_LOCK | XBF_DONT_BLOCK,
                                             &bp);
                        if (error)
                                return(error);

                        tmp = (valuelen < XFS_BUF_SIZE(bp))
                                ? valuelen : XFS_BUF_SIZE(bp);
                        xfs_buf_iomove(bp, 0, tmp, dst, XBRW_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;
        void *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_write(args->trans, dp, (xfs_fileoff_t)lblkno,
                                  blkcnt,
                                  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
                                  args->firstblock, args->total, &map, &nmap,
                                  args->flist);
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                &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, 0);

                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.
                 */
                error = xfs_trans_roll(&args->trans, dp);
                if (error)
                        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_read(dp, (xfs_fileoff_t)lblkno,
                                       args->rmtblkcnt, &map, &nmap,
                                       XFS_BMAPI_ATTRFORK);
                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(mp->m_ddev_targp, dblkno, blkcnt,
                                 XBF_LOCK | XBF_DONT_BLOCK);
                if (!bp)
                        return ENOMEM;
                tmp = (valuelen < XFS_BUF_SIZE(bp)) ? valuelen :
                                                        XFS_BUF_SIZE(bp);
                xfs_buf_iomove(bp, 0, tmp, src, XBRW_WRITE);
                if (tmp < XFS_BUF_SIZE(bp))
                        xfs_buf_zero(bp, tmp, XFS_BUF_SIZE(bp) - tmp);
                error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
                xfs_buf_relse(bp);
                if (error)
                        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.
                 */
                nmap = 1;
                error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
                                       args->rmtblkcnt, &map, &nmap,
                                       XFS_BMAPI_ATTRFORK);
                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, XBF_TRYLOCK);
                if (bp) {
                        xfs_buf_stale(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,
                                    &done);
                if (!error) {
                        error = xfs_bmap_finish(&args->trans, args->flist,
                                                &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, 0);

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