path: root/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_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_attr_sf.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_bmap_btree.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_attr_remote.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_trans_space.h"
#include "xfs_trace.h"
#include "xfs_dinode.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);

/*
 * 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_fillstate(xfs_da_state_t *state);
STATIC int xfs_attr_refillstate(xfs_da_state_t *state);


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;
}

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;
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_trans_res	tres;
	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 attribut