path: root/fs/xfs/libxfs/xfs_attr.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#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_mount.h"
#include "xfs_defer.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_attr_sf.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_bmap_btree.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_attr_remote.h"
#include "xfs_quota.h"
#include "xfs_trans_space.h"
#include "xfs_trace.h"
#include "xfs_attr_item.h"
#include "xfs_xattr.h"

struct kmem_cache		*xfs_attr_intent_cache;

/*
 * 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_removename(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
STATIC int xfs_attr_leaf_try_add(struct xfs_da_args *args);

/*
 * Internal routines when attribute list is more than one block.
 */
STATIC int xfs_attr_node_get(xfs_da_args_t *args);
STATIC void xfs_attr_restore_rmt_blk(struct xfs_da_args *args);
static int xfs_attr_node_try_addname(struct xfs_attr_intent *attr);
STATIC int xfs_attr_node_addname_find_attr(struct xfs_attr_intent *attr);
STATIC int xfs_attr_node_remove_attr(struct xfs_attr_intent *attr);
STATIC int xfs_attr_node_lookup(struct xfs_da_args *args,
		struct xfs_da_state *state);

int
xfs_inode_hasattr(
	struct xfs_inode	*ip)
{
	if (!xfs_inode_has_attr_fork(ip))
		return 0;
	if (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS &&
	    ip->i_af.if_nextents == 0)
		return 0;
	return 1;
}

/*
 * Returns true if the there is exactly only block in the attr fork, in which
 * case the attribute fork consists of a single leaf block entry.
 */
bool
xfs_attr_is_leaf(
	struct xfs_inode	*ip)
{
	struct xfs_ifork	*ifp = &ip->i_af;
	struct xfs_iext_cursor	icur;
	struct xfs_bmbt_irec	imap;

	if (ifp->if_nextents != 1 || ifp->if_format != XFS_DINODE_FMT_EXTENTS)
		return false;

	xfs_iext_first(ifp, &icur);
	xfs_iext_get_extent(ifp, &icur, &imap);
	return imap.br_startoff == 0 && imap.br_blockcount == 1;
}

/*
 * XXX (dchinner): name path state saving and refilling is an optimisation to
 * avoid needing to look up name entries after rolling transactions removing
 * remote xattr blocks between the name entry lookup and name entry removal.
 * This optimisation got sidelined when combining the set and remove state
 * machines, but the code has been left in place because it is worthwhile to
 * restore the optimisation once the combined state machine paths have settled.
 *
 * This comment is a public service announcement to remind Future Dave that he
 * still needs to restore this code to working order.
 */
#if 0
/*
 * 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;

	trace_xfs_attr_fillstate(state->args);

	/*
	 * 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_buf_daddr(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_buf_daddr(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;

	trace_xfs_attr_refillstate(state->args);

	/*
	 * 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->a