xfs_attr.c 41.6 KB
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// SPDX-License-Identifier: GPL-2.0
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/*
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 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
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 */
#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_shared.h"
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#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
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#include "xfs_mount.h"
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#include "xfs_defer.h"
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#include "xfs_da_format.h"
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#include "xfs_da_btree.h"
#include "xfs_attr_sf.h"
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#include "xfs_inode.h"
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#include "xfs_trans.h"
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#include "xfs_bmap.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
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#include "xfs_attr_remote.h"
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#include "xfs_quota.h"
#include "xfs_trans_space.h"
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#include "xfs_trace.h"
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#include "xfs_attr_item.h"
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#include "xfs_log.h"
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struct kmem_cache		*xfs_attri_cache;
struct kmem_cache		*xfs_attrd_cache;
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/*
 * 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.
 */
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STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
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STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
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STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
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STATIC int xfs_attr_leaf_try_add(struct xfs_da_args *args, struct xfs_buf *bp);
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/*
 * Internal routines when attribute list is more than one block.
 */
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STATIC int xfs_attr_node_get(xfs_da_args_t *args);
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STATIC void xfs_attr_restore_rmt_blk(struct xfs_da_args *args);
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static int xfs_attr_node_try_addname(struct xfs_attr_item *attr);
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STATIC int xfs_attr_node_addname_find_attr(struct xfs_attr_item *attr);
STATIC int xfs_attr_node_addname_clear_incomplete(struct xfs_attr_item *attr);
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STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
				 struct xfs_da_state **state);
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STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
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STATIC int xfs_attr_node_removename(struct xfs_da_args *args,
				    struct xfs_da_state *state);
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int
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xfs_inode_hasattr(
	struct xfs_inode	*ip)
{
	if (!XFS_IFORK_Q(ip) ||
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	    (ip->i_afp->if_format == XFS_DINODE_FMT_EXTENTS &&
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	     ip->i_afp->if_nextents == 0))
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		return 0;
	return 1;
}

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/*
 * 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_afp;
	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;
}

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

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/*
 * Retrieve an extended attribute and its value.  Must have ilock.
 * Returns 0 on successful retrieval, otherwise an error.
 */
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int
xfs_attr_get_ilocked(
	struct xfs_da_args	*args)
{
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	ASSERT(xfs_isilocked(args->dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
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	if (!xfs_inode_hasattr(args->dp))
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		return -ENOATTR;
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	if (args->dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
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		return xfs_attr_shortform_getvalue(args);
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	if (xfs_attr_is_leaf(args->dp))
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		return xfs_attr_leaf_get(args);
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	return xfs_attr_node_get(args);
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}

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/*
 * Retrieve an extended attribute by name, and its value if requested.
 *
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 * If args->valuelen is zero, then the caller does not want the value, just an
 * indication whether the attribute exists and the size of the value if it
 * exists. The size is returned in args.valuelen.
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 *
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 * If args->value is NULL but args->valuelen is non-zero, allocate the buffer
 * for the value after existence of the attribute has been determined. The
 * caller always has to free args->value if it is set, no matter if this
 * function was successful or not.
 *
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 * If the attribute is found, but exceeds the size limit set by the caller in
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 * args->valuelen, return -ERANGE with the size of the attribute that was found
 * in args->valuelen.
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 */
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int
xfs_attr_get(
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	struct xfs_da_args	*args)
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{
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	uint			lock_mode;
	int			error;

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	XFS_STATS_INC(args->dp->i_mount, xs_attr_get);
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	if (xfs_is_shutdown(args->dp->i_mount))
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		return -EIO;
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	args->geo = args->dp->i_mount->m_attr_geo;
	args->whichfork = XFS_ATTR_FORK;
	args->hashval = xfs_da_hashname(args->name, args->namelen);
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	/* Entirely possible to look up a name which doesn't exist */
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	args->op_flags = XFS_DA_OP_OKNOENT;
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	lock_mode = xfs_ilock_attr_map_shared(args->dp);
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	error = xfs_attr_get_ilocked(args);
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	xfs_iunlock(args->dp, lock_mode);
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	return error;
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}

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/*
 * Calculate how many blocks we need for the new attribute,
 */
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int
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xfs_attr_calc_size(
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	struct xfs_da_args	*args,
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	int			*local)
{
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	struct xfs_mount	*mp = args->dp->i_mount;
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	int			size;
	int			nblks;

	/*
	 * Determine space new attribute will use, and if it would be
	 * "local" or "remote" (note: local != inline).
	 */
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	size = xfs_attr_leaf_newentsize(args, local);
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	nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
	if (*local) {
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		if (size > (args->geo->blksize / 2)) {
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			/* Double split possible */
			nblks *= 2;
		}
	} else {
		/*
		 * Out of line attribute, cannot double split, but
		 * make room for the attribute value itself.
		 */
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		uint	dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
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		nblks += dblocks;
		nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
	}

	return nblks;
}

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/* Initialize transaction reservation for attr operations */
void
xfs_init_attr_trans(
	struct xfs_da_args	*args,
	struct xfs_trans_res	*tres,
	unsigned int		*total)
{
	struct xfs_mount	*mp = args->dp->i_mount;

	if (args->value) {
		tres->tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
				 M_RES(mp)->tr_attrsetrt.tr_logres *
				 args->total;
		tres->tr_logcount = XFS_ATTRSET_LOG_COUNT;
		tres->tr_logflags = XFS_TRANS_PERM_LOG_RES;
		*total = args->total;
	} else {
		*tres = M_RES(mp)->tr_attrrm;
		*total = XFS_ATTRRM_SPACE_RES(mp);
	}
}

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/*
 * Add an attr to a shortform fork. If there is no space,
 * xfs_attr_shortform_addname() will convert to leaf format and return -ENOSPC.
 * to use.
 */
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STATIC int
xfs_attr_try_sf_addname(
	struct xfs_inode	*dp,
	struct xfs_da_args	*args)
{

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	int			error;

	/*
	 * Build initial attribute list (if required).
	 */
	if (dp->i_afp->if_format == XFS_DINODE_FMT_EXTENTS)
		xfs_attr_shortform_create(args);
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	error = xfs_attr_shortform_addname(args);
	if (error == -ENOSPC)
		return error;

	/*
	 * Commit the shortform mods, and we're done.
	 * NOTE: this is also the error path (EEXIST, etc).
	 */
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	if (!error && !(args->op_flags & XFS_DA_OP_NOTIME))
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		xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);

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	if (xfs_has_wsync(dp->i_mount))
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		xfs_trans_set_sync(args->trans);

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	return error;
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}

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static int
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xfs_attr_sf_addname(
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	struct xfs_attr_item		*attr)
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{
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	struct xfs_da_args		*args = attr->xattri_da_args;
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	struct xfs_inode		*dp = args->dp;
	int				error = 0;
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	error = xfs_attr_try_sf_addname(dp, args);
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	if (error != -ENOSPC) {
		ASSERT(!error || error == -EEXIST);
		attr->xattri_dela_state = XFS_DAS_DONE;
		goto out;
	}
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	/*
	 * It won't fit in the shortform, transform to a leaf block.  GROT:
	 * another possible req'mt for a double-split btree op.
	 */
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	error = xfs_attr_shortform_to_leaf(args, &attr->xattri_leaf_bp);
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	if (error)
		return error;

	/*
	 * Prevent the leaf buffer from being unlocked so that a concurrent AIL
	 * push cannot grab the half-baked leaf buffer and run into problems
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	 * with the write verifier.
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	 */
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	xfs_trans_bhold(args->trans, attr->xattri_leaf_bp);
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	attr->xattri_dela_state = XFS_DAS_LEAF_ADD;
	error = -EAGAIN;
out:
	trace_xfs_attr_sf_addname_return(attr->xattri_dela_state, args->dp);
	return error;
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}

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static int
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xfs_attr_leaf_addname(
	struct xfs_attr_item	*attr)
{
	struct xfs_da_args	*args = attr->xattri_da_args;
	int			error;

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	ASSERT(xfs_attr_is_leaf(args->dp));
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	/*
	 * Use the leaf buffer we may already hold locked as a result of
	 * a sf-to-leaf conversion. The held buffer is no longer valid
	 * after this call, regardless of the result.
	 */
	error = xfs_attr_leaf_try_add(args, attr->xattri_leaf_bp);
	attr->xattri_leaf_bp = NULL;
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	if (error == -ENOSPC) {
		error = xfs_attr3_leaf_to_node(args);
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		if (error)
			return error;

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		/*
		 * We're not in leaf format anymore, so roll the transaction and
		 * retry the add to the newly allocated node block.
		 */
		attr->xattri_dela_state = XFS_DAS_NODE_ADD;
		error = -EAGAIN;
		goto out;
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	}
	if (error)
		return error;
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	/*
	 * We need to commit and roll if we need to allocate remote xattr blocks
	 * or perform more xattr manipulations. Otherwise there is nothing more
	 * to do and we can return success.
	 */
	if (args->rmtblkno ||
	    (args->op_flags & XFS_DA_OP_RENAME)) {
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		attr->xattri_dela_state = XFS_DAS_FOUND_LBLK;
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		error = -EAGAIN;
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	} else {
		attr->xattri_dela_state = XFS_DAS_DONE;
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	}
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out:
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	trace_xfs_attr_leaf_addname_return(attr->xattri_dela_state, args->dp);
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	return error;
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}

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static int
xfs_attr_node_addname(
	struct xfs_attr_item	*attr)
{
	struct xfs_da_args	*args = attr->xattri_da_args;
	int			error;

	ASSERT(!attr->xattri_leaf_bp);

	error = xfs_attr_node_addname_find_attr(attr);
	if (error)
		return error;

	error = xfs_attr_node_try_addname(attr);
	if (error)
		return error;

	if (args->rmtblkno ||
	    (args->op_flags & XFS_DA_OP_RENAME)) {
		attr->xattri_dela_state = XFS_DAS_FOUND_NBLK;
		error = -EAGAIN;
	} else {
		attr->xattri_dela_state = XFS_DAS_DONE;
	}

	trace_xfs_attr_node_addname_return(attr->xattri_dela_state, args->dp);
	return error;
}


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/*
 * Set the attribute specified in @args.
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 * This routine is meant to function as a delayed operation, and may return
 * -EAGAIN when the transaction needs to be rolled.  Calling functions will need
 * to handle this, and recall the function until a successful error code is
 * returned.
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 */
int
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xfs_attr_set_iter(
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	struct xfs_attr_item		*attr)
388
{
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	struct xfs_da_args              *args = attr->xattri_da_args;
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	struct xfs_inode		*dp = args->dp;
	struct xfs_buf			*bp = NULL;
	int				forkoff, error = 0;
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	struct xfs_mount		*mp = args->dp->i_mount;
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	/* State machine switch */
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next_state:
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	switch (attr->xattri_dela_state) {
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	case XFS_DAS_UNINIT:
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		ASSERT(0);
		return -EFSCORRUPTED;
	case XFS_DAS_SF_ADD:
		return xfs_attr_sf_addname(attr);
	case XFS_DAS_LEAF_ADD:
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		return xfs_attr_leaf_addname(attr);
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	case XFS_DAS_NODE_ADD:
		return xfs_attr_node_addname(attr);
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	case XFS_DAS_FOUND_LBLK:
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	case XFS_DAS_FOUND_NBLK:
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		/*
		 * Find space for remote blocks and fall into the allocation
		 * state.
		 */
		if (args->rmtblkno > 0) {
			error = xfs_attr_rmtval_find_space(attr);
			if (error)
				return error;
		}
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		attr->xattri_dela_state++;
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		fallthrough;
	case XFS_DAS_LEAF_ALLOC_RMT:
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	case XFS_DAS_NODE_ALLOC_RMT:
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		/*
		 * 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.
		 */
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		if (args->rmtblkno > 0) {
			if (attr->xattri_blkcnt > 0) {
				error = xfs_attr_rmtval_set_blk(attr);
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				if (error)
					return error;
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				trace_xfs_attr_set_iter_return(
						attr->xattri_dela_state,
						args->dp);
				return -EAGAIN;
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			}

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			error = xfs_attr_rmtval_set_value(args);
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			if (error)
				return error;
		}

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		/*
		 * If this is not a rename, clear the incomplete flag and we're
		 * done.
		 */
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		if (!(args->op_flags & XFS_DA_OP_RENAME)) {
			if (args->rmtblkno > 0)
				error = xfs_attr3_leaf_clearflag(args);
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			return error;
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		}
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		/*
		 * 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.
		 *
		 * In a separate transaction, set the incomplete flag on the
		 * "old" attr and clear the incomplete flag on the "new" attr.
		 */
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		if (!xfs_has_larp(mp)) {
			error = xfs_attr3_leaf_flipflags(args);
			if (error)
				return error;
			/*
			 * Commit the flag value change and start the next trans
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			 * in series at FLIP_FLAG.
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			 */
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			attr->xattri_dela_state++;
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			trace_xfs_attr_set_iter_return(attr->xattri_dela_state,
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						       args->dp);
			return -EAGAIN;
		}

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		attr->xattri_dela_state++;
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		fallthrough;
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	case XFS_DAS_FLIP_LFLAG:
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	case XFS_DAS_FLIP_NFLAG:
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		/*
		 * Dismantle the "old" attribute/value pair by removing a
		 * "remote" value (if it exists).
		 */
		xfs_attr_restore_rmt_blk(args);
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		error = xfs_attr_rmtval_invalidate(args);
		if (error)
			return error;
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		attr->xattri_dela_state++;
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		fallthrough;
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	case XFS_DAS_RM_LBLK:
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	case XFS_DAS_RM_NBLK:
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		if (args->rmtblkno) {
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			error = xfs_attr_rmtval_remove(attr);
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			if (error == -EAGAIN)
				trace_xfs_attr_set_iter_return(
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					attr->xattri_dela_state, args->dp);
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			if (error)
				return error;

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			attr->xattri_dela_state = XFS_DAS_RD_LEAF;
			trace_xfs_attr_set_iter_return(attr->xattri_dela_state,
						       args->dp);
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			return -EAGAIN;
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		}

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		/*
		 * This is the end of the shared leaf/node sequence. We need
		 * to continue at the next state in the sequence, but we can't
		 * easily just fall through. So we increment to the next state
		 * and then jump back to switch statement to evaluate the next
		 * state correctly.
		 */
		attr->xattri_dela_state++;
		goto next_state;

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	case XFS_DAS_RD_LEAF:
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		/*
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		 * This is the last step for leaf format. Read the block with
		 * the old attr, remove the old attr, check for shortform
		 * conversion and return.
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		 */
		error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
					   &bp);
		if (error)
			return error;

		xfs_attr3_leaf_remove(bp, args);

		forkoff = xfs_attr_shortform_allfit(bp, dp);
		if (forkoff)
			error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
			/* bp is gone due to xfs_da_shrink_inode */

		return error;
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	case XFS_DAS_CLR_FLAG:
		/*
		 * The last state for node format. Look up the old attr and
		 * remove it.
		 */
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		error = xfs_attr_node_addname_clear_incomplete(attr);
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		break;
	default:
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		ASSERT(0);
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		break;
	}
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	return error;
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}

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/*
 * Return EEXIST if attr is found, or ENOATTR if not
 */
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static int
xfs_attr_lookup(
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	struct xfs_da_args	*args)
{
	struct xfs_inode	*dp = args->dp;
	struct xfs_buf		*bp = NULL;
	int			error;

	if (!xfs_inode_hasattr(dp))
		return -ENOATTR;

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	if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
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		return xfs_attr_sf_findname(args, NULL, NULL);

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	if (xfs_attr_is_leaf(dp)) {
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		error = xfs_attr_leaf_hasname(args, &bp);

		if (bp)
			xfs_trans_brelse(args->trans, bp);

		return error;
	}

	return xfs_attr_node_hasname(args, NULL);
}

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static int
xfs_attr_item_init(
	struct xfs_da_args	*args,
	unsigned int		op_flags,	/* op flag (set or remove) */
	struct xfs_attr_item	**attr)		/* new xfs_attr_item */
{

	struct xfs_attr_item	*new;

	new = kmem_zalloc(sizeof(struct xfs_attr_item), KM_NOFS);
	new->xattri_op_flags = op_flags;
	new->xattri_da_args = args;

	*attr = new;
	return 0;
}

/* Sets an attribute for an inode as a deferred operation */
static int
xfs_attr_defer_add(
	struct xfs_da_args	*args)
{
	struct xfs_attr_item	*new;
	int			error = 0;

	error = xfs_attr_item_init(args, XFS_ATTR_OP_FLAGS_SET, &new);
	if (error)
		return error;

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	new->xattri_dela_state = xfs_attr_init_add_state(args);
614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631
	xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
	trace_xfs_attr_defer_add(new->xattri_dela_state, args->dp);

	return 0;
}

/* Sets an attribute for an inode as a deferred operation */
static int
xfs_attr_defer_replace(
	struct xfs_da_args	*args)
{
	struct xfs_attr_item	*new;
	int			error = 0;

	error = xfs_attr_item_init(args, XFS_ATTR_OP_FLAGS_REPLACE, &new);
	if (error)
		return error;

632
	new->xattri_dela_state = xfs_attr_init_replace_state(args);
633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658
	xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
	trace_xfs_attr_defer_replace(new->xattri_dela_state, args->dp);

	return 0;
}

/* Removes an attribute for an inode as a deferred operation */
static int
xfs_attr_defer_remove(
	struct xfs_da_args	*args)
{

	struct xfs_attr_item	*new;
	int			error;

	error  = xfs_attr_item_init(args, XFS_ATTR_OP_FLAGS_REMOVE, &new);
	if (error)
		return error;

	new->xattri_dela_state = XFS_DAS_UNINIT;
	xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
	trace_xfs_attr_defer_remove(new->xattri_dela_state, args->dp);

	return 0;
}

659
/*
660
 * Note: If args->value is NULL the attribute will be removed, just like the
661 662
 * Linux ->setattr API.
 */
663 664
int
xfs_attr_set(
665
	struct xfs_da_args	*args)
L
Linus Torvalds 已提交
666
{
667
	struct xfs_inode	*dp = args->dp;
668 669
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_trans_res	tres;
670
	bool			rsvd = (args->attr_filter & XFS_ATTR_ROOT);
671
	int			error, local;
672
	int			rmt_blks = 0;
673
	unsigned int		total;
674
	int			delayed = xfs_has_larp(mp);
675

676
	if (xfs_is_shutdown(dp->i_mount))
D
Dave Chinner 已提交
677
		return -EIO;
678

679 680 681 682
	error = xfs_qm_dqattach(dp);
	if (error)
		return error;

683 684 685
	args->geo = mp->m_attr_geo;
	args->whichfork = XFS_ATTR_FORK;
	args->hashval = xfs_da_hashname(args->name, args->namelen);
L
Linus Torvalds 已提交
686 687

	/*
688 689 690
	 * 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 as well.
L
Linus Torvalds 已提交
691
	 */
692
	args->op_flags = XFS_DA_OP_OKNOENT;
693

694
	if (args->value) {
695 696
		XFS_STATS_INC(mp, xs_attr_set);

697 698
		args->op_flags |= XFS_DA_OP_ADDNAME;
		args->total = xfs_attr_calc_size(args, &local);
699 700 701 702 703 704 705

		/*
		 * 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(struct xfs_attr_sf_hdr) +
706
				xfs_attr_sf_entsize_byname(args->namelen,
707
						args->valuelen);
708 709 710 711 712 713

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

714 715
		if (!local)
			rmt_blks = xfs_attr3_rmt_blocks(mp, args->valuelen);
716 717
	} else {
		XFS_STATS_INC(mp, xs_attr_remove);
718
		rmt_blks = xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX);
719
	}
L
Linus Torvalds 已提交
720

721 722 723 724 725 726
	if (delayed) {
		error = xfs_attr_use_log_assist(mp);
		if (error)
			return error;
	}

L
Linus Torvalds 已提交
727 728 729 730
	/*
	 * Root fork attributes can use reserved data blocks for this
	 * operation if necessary
	 */
731
	xfs_init_attr_trans(args, &tres, &total);
732
	error = xfs_trans_alloc_inode(dp, &tres, total, 0, rsvd, &args->trans);
733
	if (error)
734
		goto drop_incompat;
L
Linus Torvalds 已提交
735

736 737 738
	if (args->value || xfs_inode_hasattr(dp)) {
		error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
				XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
739 740 741
		if (error == -EFBIG)
			error = xfs_iext_count_upgrade(args->trans, dp,
					XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
742 743 744 745
		if (error)
			goto out_trans_cancel;
	}

D
Dave Chinner 已提交
746
	error = xfs_attr_lookup(args);
747 748 749 750 751 752 753 754 755
	switch (error) {
	case -EEXIST:
		/* if no value, we are performing a remove operation */
		if (!args->value) {
			error = xfs_attr_defer_remove(args);
			break;
		}
		/* Pure create fails if the attr already exists */
		if (args->attr_flags & XATTR_CREATE)
756 757
			goto out_trans_cancel;

758 759 760 761 762
		error = xfs_attr_defer_replace(args);
		break;
	case -ENOATTR:
		/* Can't remove what isn't there. */
		if (!args->value)
763
			goto out_trans_cancel;
764

765 766
		/* Pure replace fails if no existing attr to replace. */
		if (args->attr_flags & XATTR_REPLACE)
767 768
			goto out_trans_cancel;

769 770 771 772
		error = xfs_attr_defer_add(args);
		break;
	default:
		goto out_trans_cancel;
773
	}
774 775
	if (error)
		goto out_trans_cancel;
L
Linus Torvalds 已提交
776 777 778 779 780

	/*
	 * If this is a synchronous mount, make sure that the
	 * transaction goes to disk before returning to the user.
	 */
781
	if (xfs_has_wsync(mp))
782
		xfs_trans_set_sync(args->trans);
L
Linus Torvalds 已提交
783

784
	if (!(args->op_flags & XFS_DA_OP_NOTIME))
785
		xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
786

L
Linus Torvalds 已提交
787 788 789
	/*
	 * Commit the last in the sequence of transactions.
	 */
790 791
	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
	error = xfs_trans_commit(args->trans);
792
out_unlock:
L
Linus Torvalds 已提交
793
	xfs_iunlock(dp, XFS_ILOCK_EXCL);
794 795 796
drop_incompat:
	if (delayed)
		xlog_drop_incompat_feat(mp->m_log);
797
	return error;
L
Linus Torvalds 已提交
798

799
out_trans_cancel:
800 801
	if (args->trans)
		xfs_trans_cancel(args->trans);
802
	goto out_unlock;
L
Linus Torvalds 已提交
803 804
}

805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
int __init
xfs_attri_init_cache(void)
{
	xfs_attri_cache = kmem_cache_create("xfs_attri",
					    sizeof(struct xfs_attri_log_item),
					    0, 0, NULL);

	return xfs_attri_cache != NULL ? 0 : -ENOMEM;
}

void
xfs_attri_destroy_cache(void)
{
	kmem_cache_destroy(xfs_attri_cache);
	xfs_attri_cache = NULL;
}

int __init
xfs_attrd_init_cache(void)
{
	xfs_attrd_cache = kmem_cache_create("xfs_attrd",
					    sizeof(struct xfs_attrd_log_item),
					    0, 0, NULL);

	return xfs_attrd_cache != NULL ? 0 : -ENOMEM;
}

void
xfs_attrd_destroy_cache(void)
{
	kmem_cache_destroy(xfs_attrd_cache);
	xfs_attrd_cache = NULL;
}

L
Linus Torvalds 已提交
839 840 841 842
/*========================================================================
 * External routines when attribute list is inside the inode
 *========================================================================*/

843 844 845 846 847 848 849 850
static inline int xfs_attr_sf_totsize(struct xfs_inode *dp)
{
	struct xfs_attr_shortform *sf;

	sf = (struct xfs_attr_shortform *)dp->i_afp->if_u1.if_data;
	return be16_to_cpu(sf->hdr.totsize);
}

L
Linus Torvalds 已提交
851 852 853 854 855 856 857
/*
 * 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)
{
858
	int newsize, forkoff, retval;
L
Linus Torvalds 已提交
859

860 861
	trace_xfs_attr_sf_addname(args);

L
Linus Torvalds 已提交
862
	retval = xfs_attr_shortform_lookup(args);
863
	if (retval == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
E
Eric Sandeen 已提交
864
		return retval;
865
	if (retval == -EEXIST) {
866
		if (args->attr_flags & XATTR_CREATE)
E
Eric Sandeen 已提交
867
			return retval;
868
		retval = xfs_attr_sf_removename(args);
869 870 871 872 873 874 875
		if (retval)
			return retval;
		/*
		 * Since we have removed the old attr, clear ATTR_REPLACE so
		 * that the leaf format add routine won't trip over the attr
		 * not being around.
		 */
876
		args->attr_flags &= ~XATTR_REPLACE;
L
Linus Torvalds 已提交
877 878
	}

879 880
	if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
	    args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
D
Dave Chinner 已提交
881
		return -ENOSPC;
882

883 884
	newsize = xfs_attr_sf_totsize(args->dp);
	newsize += xfs_attr_sf_entsize_byname(args->namelen, args->valuelen);
885 886 887

	forkoff = xfs_attr_shortform_bytesfit(args->dp, newsize);
	if (!forkoff)
D
Dave Chinner 已提交
888
		return -ENOSPC;
889 890

	xfs_attr_shortform_add(args, forkoff);
E
Eric Sandeen 已提交
891
	return 0;
L
Linus Torvalds 已提交
892 893 894 895 896 897 898
}


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

899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922
/* Store info about a remote block */
STATIC void
xfs_attr_save_rmt_blk(
	struct xfs_da_args	*args)
{
	args->blkno2 = args->blkno;
	args->index2 = args->index;
	args->rmtblkno2 = args->rmtblkno;
	args->rmtblkcnt2 = args->rmtblkcnt;
	args->rmtvaluelen2 = args->rmtvaluelen;
}

/* Set stored info about a remote block */
STATIC void
xfs_attr_restore_rmt_blk(
	struct xfs_da_args	*args)
{
	args->blkno = args->blkno2;
	args->index = args->index2;
	args->rmtblkno = args->rmtblkno2;
	args->rmtblkcnt = args->rmtblkcnt2;
	args->rmtvaluelen = args->rmtvaluelen2;
}

L
Linus Torvalds 已提交
923
/*
924
 * Tries to add an attribute to an inode in leaf form
L
Linus Torvalds 已提交
925
 *
926 927 928 929 930 931
 * This function is meant to execute as part of a delayed operation and leaves
 * the transaction handling to the caller.  On success the attribute is added
 * and the inode and transaction are left dirty.  If there is not enough space,
 * the attr data is converted to node format and -ENOSPC is returned. Caller is
 * responsible for handling the dirty inode and transaction or adding the attr
 * in node format.
L
Linus Torvalds 已提交
932
 */
D
David Chinner 已提交
933
STATIC int
934 935 936
xfs_attr_leaf_try_add(
	struct xfs_da_args	*args,
	struct xfs_buf		*bp)
L
Linus Torvalds 已提交
937
{
938
	int			error;
939

L
Linus Torvalds 已提交
940
	/*
941 942 943 944
	 * If the caller provided a buffer to us, it is locked and held in
	 * the transaction because it just did a shortform to leaf conversion.
	 * Hence we don't need to read it again. Otherwise read in the leaf
	 * buffer.
L
Linus Torvalds 已提交
945
	 */
946 947 948 949 950 951 952 953 954 955 956 957 958
	if (bp) {
		xfs_trans_bhold_release(args->trans, bp);
	} else {
		error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
		if (error)
			return error;
	}

	/*
	 * Look up the xattr name to set the insertion point for the new xattr.
	 */
	error = xfs_attr3_leaf_lookup_int(bp, args);
	if (error != -ENOATTR && error != -EEXIST)
959
		goto out_brelse;
960 961 962
	if (error == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
		goto out_brelse;
	if (error == -EEXIST) {
963
		if (args->attr_flags & XATTR_CREATE)
964
			goto out_brelse;
965 966 967

		trace_xfs_attr_leaf_replace(args);

968
		/* save the attribute state for later removal*/
969
		args->op_flags |= XFS_DA_OP_RENAME;	/* an atomic rename */
970
		xfs_attr_save_rmt_blk(args);
971 972 973 974 975 976 977 978 979

		/*
		 * clear the remote attr state now that it is saved so that the
		 * values reflect the state of the attribute we are about to
		 * add, not the attribute we just found and will remove later.
		 */
		args->rmtblkno = 0;
		args->rmtblkcnt = 0;
		args->rmtvaluelen = 0;
L
Linus Torvalds 已提交
980 981
	}

982 983
	return xfs_attr3_leaf_add(bp, args);

984 985
out_brelse:
	xfs_trans_brelse(args->trans, bp);
986
	return error;
987
}
L
Linus Torvalds 已提交
988

989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009
/*
 * Return EEXIST if attr is found, or ENOATTR if not
 */
STATIC int
xfs_attr_leaf_hasname(
	struct xfs_da_args	*args,
	struct xfs_buf		**bp)
{
	int                     error = 0;

	error = xfs_attr3_leaf_read(args->trans, args->dp, 0, bp);
	if (error)
		return error;

	error = xfs_attr3_leaf_lookup_int(*bp, args);
	if (error != -ENOATTR && error != -EEXIST)
		xfs_trans_brelse(args->trans, *bp);

	return error;
}

L
Linus Torvalds 已提交
1010 1011 1012 1013 1014 1015 1016
/*
 * 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
1017 1018
xfs_attr_leaf_removename(
	struct xfs_da_args	*args)
L
Linus Torvalds 已提交
1019
{
1020 1021 1022
	struct xfs_inode	*dp;
	struct xfs_buf		*bp;
	int			error, forkoff;
L
Linus Torvalds 已提交
1023

1024 1025
	trace_xfs_attr_leaf_removename(args);

L
Linus Torvalds 已提交
1026 1027 1028 1029 1030
	/*
	 * Remove the attribute.
	 */
	dp = args->dp;

1031 1032
	error = xfs_attr_leaf_hasname(args, &bp);

D
Dave Chinner 已提交
1033
	if (error == -ENOATTR) {
1034
		xfs_trans_brelse(args->trans, bp);
D
Dave Chinner 已提交
1035
		return error;
1036 1037
	} else if (error != -EEXIST)
		return error;
L
Linus Torvalds 已提交
1038

D
Dave Chinner 已提交
1039
	xfs_attr3_leaf_remove(bp, args);
L
Linus Torvalds 已提交
1040 1041 1042 1043

	/*
	 * If the result is small enough, shrink it all into the inode.
	 */
1044 1045 1046
	forkoff = xfs_attr_shortform_allfit(bp, dp);
	if (forkoff)
		return xfs_attr3_leaf_to_shortform(bp, args, forkoff);
L
Linus Torvalds 已提交
1047
		/* bp is gone due to xfs_da_shrink_inode */
1048

D
Dave Chinner 已提交
1049
	return 0;
L
Linus Torvalds 已提交
1050 1051 1052 1053 1054 1055 1056
}

/*
 * 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).
1057 1058
 *
 * Returns 0 on successful retrieval, otherwise an error.
L
Linus Torvalds 已提交
1059
 */
1060
STATIC int
L
Linus Torvalds 已提交
1061 1062
xfs_attr_leaf_get(xfs_da_args_t *args)
{
1063
	struct xfs_buf *bp;
L
Linus Torvalds 已提交
1064 1065
	int error;

1066 1067
	trace_xfs_attr_leaf_get(args);

1068
	error = xfs_attr_leaf_hasname(args, &bp);
L
Linus Torvalds 已提交
1069

1070
	if (error == -ENOATTR)  {
1071
		xfs_trans_brelse(args->trans, bp);
D
Dave Chinner 已提交
1072
		return error;
1073 1074 1075 1076
	} else if (error != -EEXIST)
		return error;


D
Dave Chinner 已提交
1077
	error = xfs_attr3_leaf_getvalue(bp, args);
1078
	xfs_trans_brelse(args->trans, bp);
1079
	return error;
L
Linus Torvalds 已提交
1080 1081
}

1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096
/*
 * Return EEXIST if attr is found, or ENOATTR if not
 * statep: If not null is set to point at the found state.  Caller will
 *         be responsible for freeing the state in this case.
 */
STATIC int
xfs_attr_node_hasname(
	struct xfs_da_args	*args,
	struct xfs_da_state	**statep)
{
	struct xfs_da_state	*state;
	int			retval, error;

	state = xfs_da_state_alloc(args);
	if (statep != NULL)
1097
		*statep = state;
1098 1099 1100 1101 1102

	/*
	 * Search to see if name exists, and get back a pointer to it.
	 */
	error = xfs_da3_node_lookup_int(state, &retval);
1103 1104
	if (error)
		retval = error;
1105

1106
	if (!statep)
1107
		xfs_da_state_free(state);
1108

1109 1110 1111
	return retval;
}

L
Linus Torvalds 已提交
1112
/*========================================================================
1113
 * External routines when attribute list size > geo->blksize
L
Linus Torvalds 已提交
1114 1115 1116
 *========================================================================*/

STATIC int
1117
xfs_attr_node_addname_find_attr(
1118
	 struct xfs_attr_item		*attr)
L
Linus Torvalds 已提交
1119
{
1120
	struct xfs_da_args		*args = attr->xattri_da_args;
1121
	int				retval;
1122

L
Linus Torvalds 已提交
1123 1124 1125 1126
	/*
	 * Search to see if name already exists, and get back a pointer
	 * to where it should go.
	 */
1127
	retval = xfs_attr_node_hasname(args, &attr->xattri_da_state);
1128
	if (retval != -ENOATTR && retval != -EEXIST)
1129
		goto error;
1130

1131
	if (retval == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
1132
		goto error;
1133
	if (retval == -EEXIST) {
1134
		if (args->attr_flags & XATTR_CREATE)
1135
			goto error;
1136 1137 1138

		trace_xfs_attr_node_replace(args);

1139
		/* save the attribute state for later removal*/
1140
		args->op_flags |= XFS_DA_OP_RENAME;	/* atomic rename op */
1141
		xfs_attr_save_rmt_blk(args);
1142 1143 1144 1145 1146 1147

		/*
		 * clear the remote attr state now that it is saved so that the
		 * values reflect the state of the attribute we are about to
		 * add, not the attribute we just found and will remove later.
		 */
L
Linus Torvalds 已提交
1148 1149
		args->rmtblkno = 0;
		args->rmtblkcnt = 0;
1150
		args->rmtvaluelen = 0;
L
Linus Torvalds 已提交
1151 1152
	}

1153 1154
	return 0;
error:
1155 1156
	if (attr->xattri_da_state)
		xfs_da_state_free(attr->xattri_da_state);
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168
	return retval;
}

/*
 * 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.
1169 1170 1171 1172 1173
 *
 * This routine is meant to function as a delayed operation, and may return
 * -EAGAIN when the transaction needs to be rolled.  Calling functions will need
 * to handle this, and recall the function until a successful error code is
 *returned.
1174
 */
1175 1176
static int
xfs_attr_node_try_addname(
1177
	struct xfs_attr_item		*attr)
1178
{
1179 1180
	struct xfs_da_args		*args = attr->xattri_da_args;
	struct xfs_da_state		*state = attr->xattri_da_state;
1181 1182
	struct xfs_da_state_blk		*blk;
	int				error;
1183 1184 1185 1186 1187 1188

	trace_xfs_attr_node_addname(args);

	blk = &state->path.blk[state->path.active-1];
	ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);

1189 1190
	error = xfs_attr3_leaf_add(blk->bp, state->args);
	if (error == -ENOSPC) {
L
Linus Torvalds 已提交
1191 1192 1193 1194 1195 1196 1197
		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);
1198
			state = NULL;
D
Dave Chinner 已提交
1199
			error = xfs_attr3_leaf_to_node(args);
1200
			if (error)
1201
				goto out;
L
Linus Torvalds 已提交
1202 1203

			/*
1204 1205 1206 1207 1208
			 * Now that we have converted the leaf to a node, we can
			 * roll the transaction, and try xfs_attr3_leaf_add
			 * again on re-entry.  No need to set dela_state to do
			 * this. dela_state is still unset by this function at
			 * this point.
L
Linus Torvalds 已提交
1209
			 */
1210
			trace_xfs_attr_node_addname_return(
1211
					attr->xattri_dela_state, args->dp);
1212
			return -EAGAIN;
L
Linus Torvalds 已提交
1213 1214 1215 1216 1217 1218 1219 1220
		}

		/*
		 * 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.
		 */
1221
		error = xfs_da3_split(state);
1222
		if (error)
1223
			goto out;
L
Linus Torvalds 已提交
1224 1225 1226 1227
	} else {
		/*
		 * Addition succeeded, update Btree hashvals.
		 */
1228
		xfs_da3_fixhashpath(state, &state->path);
L
Linus Torvalds 已提交
1229 1230
	}

1231 1232 1233
out:
	if (state)
		xfs_da_state_free(state);
1234
	return error;
1235 1236 1237 1238 1239
}


STATIC int
xfs_attr_node_addname_clear_incomplete(
1240
	struct xfs_attr_item		*attr)
1241
{
1242
	struct xfs_da_args		*args = attr->xattri_da_args;
1243
	struct xfs_da_state		*state = NULL;
1244
	struct xfs_mount		*mp = args->dp->i_mount;
1245 1246 1247
	int				retval = 0;
	int				error = 0;

1248 1249 1250 1251
	/*
	 * 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.
	 */
1252 1253
	if (!xfs_has_larp(mp))
		args->attr_filter |= XFS_ATTR_INCOMPLETE;
1254 1255 1256 1257 1258
	state = xfs_da_state_alloc(args);
	state->inleaf = 0;
	error = xfs_da3_node_lookup_int(state, &retval);
	if (error)
		goto out;
L
Linus Torvalds 已提交
1259

1260
	error = xfs_attr_node_removename(args, state);
L
Linus Torvalds 已提交
1261

1262 1263 1264 1265 1266
	/*
	 * Check to see if the tree needs to be collapsed.
	 */
	if (retval && (state->path.active > 1)) {
		error = xfs_da3_join(state);
L
Linus Torvalds 已提交
1267 1268 1269 1270 1271 1272 1273 1274 1275
		if (error)
			goto out;
	}
	retval = error = 0;

out:
	if (state)
		xfs_da_state_free(state);
	if (error)
E
Eric Sandeen 已提交
1276 1277
		return error;
	return retval;
L
Linus Torvalds 已提交
1278 1279
}

1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309
/*
 * Shrink an attribute from leaf to shortform
 */
STATIC int
xfs_attr_node_shrink(
	struct xfs_da_args	*args,
	struct xfs_da_state     *state)
{
	struct xfs_inode	*dp = args->dp;
	int			error, forkoff;
	struct xfs_buf		*bp;

	/*
	 * Have to get rid of the copy of this dabuf in the state.
	 */
	ASSERT(state->path.active == 1);
	ASSERT(state->path.blk[0].bp);
	state->path.blk[0].bp = NULL;

	error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
	if (error)
		return error;

	forkoff = xfs_attr_shortform_allfit(bp, dp);
	if (forkoff) {
		error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
		/* bp is gone due to xfs_da_shrink_inode */
	} else
		xfs_trans_brelse(args->trans, bp);

1310
	return error;
1311 1312
}

1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338
/*
 * Mark an attribute entry INCOMPLETE and save pointers to the relevant buffers
 * for later deletion of the entry.
 */
STATIC int
xfs_attr_leaf_mark_incomplete(
	struct xfs_da_args	*args,
	struct xfs_da_state	*state)
{
	int			error;

	/*
	 * 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)
		return error;

	/*
	 * Mark the attribute as INCOMPLETE
	 */
	return xfs_attr3_leaf_setflag(args);
}

1339 1340 1341 1342 1343 1344 1345
/*
 * Initial setup for xfs_attr_node_removename.  Make sure the attr is there and
 * the blocks are valid.  Attr keys with remote blocks will be marked
 * incomplete.
 */
STATIC
int xfs_attr_node_removename_setup(
1346
	struct xfs_attr_item		*attr)
1347
{
1348 1349
	struct xfs_da_args		*args = attr->xattri_da_args;
	struct xfs_da_state		**state = &attr->xattri_da_state;
1350
	int				error;
1351 1352 1353

	error = xfs_attr_node_hasname(args, state);
	if (error != -EEXIST)
1354
		goto out;
1355
	error = 0;
1356 1357 1358 1359 1360 1361 1362 1363

	ASSERT((*state)->path.blk[(*state)->path.active - 1].bp != NULL);
	ASSERT((*state)->path.blk[(*state)->path.active - 1].magic ==
		XFS_ATTR_LEAF_MAGIC);

	if (args->rmtblkno > 0) {
		error = xfs_attr_leaf_mark_incomplete(args, *state);
		if (error)
1364
			goto out;
1365

1366
		error = xfs_attr_rmtval_invalidate(args);
1367
	}
1368 1369 1370
out:
	if (error)
		xfs_da_state_free(*state);
1371

1372
	return error;
1373 1374
}

1375
STATIC int
1376
xfs_attr_node_removename(
1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393
	struct xfs_da_args	*args,
	struct xfs_da_state	*state)
{
	struct xfs_da_state_blk	*blk;
	int			retval;

	/*
	 * 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_attr3_leaf_remove(blk->bp, args);
	xfs_da3_fixhashpath(state, &state->path);

	return retval;
}

L
Linus Torvalds 已提交
1394
/*
1395
 * Remove the attribute specified in @args.
L
Linus Torvalds 已提交
1396 1397 1398 1399
 *
 * 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).
1400 1401 1402 1403 1404
 *
 * This routine is meant to function as either an in-line or delayed operation,
 * and may return -EAGAIN when the transaction needs to be rolled.  Calling
 * functions will need to handle this, and call the function until a
 * successful error code is returned.
L
Linus Torvalds 已提交
1405
 */
1406 1407
int
xfs_attr_remove_iter(
1408
	struct xfs_attr_item		*attr)
L
Linus Torvalds 已提交
1409
{
1410 1411
	struct xfs_da_args		*args = attr->xattri_da_args;
	struct xfs_da_state		*state = attr->xattri_da_state;
1412
	int				retval, error = 0;
1413
	struct xfs_inode		*dp = args->dp;
L
Linus Torvalds 已提交
1414

1415 1416
	trace_xfs_attr_node_removename(args);

1417
	switch (attr->xattri_dela_state) {
1418 1419 1420
	case XFS_DAS_UNINIT:
		if (!xfs_inode_hasattr(dp))
			return -ENOATTR;
L
Linus Torvalds 已提交
1421

1422 1423 1424 1425 1426
		/*
		 * Shortform or leaf formats don't require transaction rolls and
		 * thus state transitions. Call the right helper and return.
		 */
		if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
1427
			return xfs_attr_sf_removename(args);
1428 1429 1430

		if (xfs_attr_is_leaf(dp))
			return xfs_attr_leaf_removename(args);
1431 1432

		/*
1433 1434
		 * Node format may require transaction rolls. Set up the
		 * state context and fall into the state machine.
1435
		 */
1436 1437
		if (!attr->xattri_da_state) {
			error = xfs_attr_node_removename_setup(attr);
1438 1439
			if (error)
				return error;
1440
			state = attr->xattri_da_state;
1441 1442
		}

1443
		fallthrough;
1444
	case XFS_DAS_RMTBLK:
1445
		attr->xattri_dela_state = XFS_DAS_RMTBLK;
L
Linus Torvalds 已提交
1446 1447

		/*
1448 1449 1450 1451
		 * 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.
L
Linus Torvalds 已提交
1452
		 */
1453 1454 1455 1456 1457
		if (args->rmtblkno > 0) {
			/*
			 * May return -EAGAIN. Roll and repeat until all remote
			 * blocks are removed.
			 */
1458
			error = xfs_attr_rmtval_remove(attr);
1459 1460
			if (error == -EAGAIN) {
				trace_xfs_attr_remove_iter_return(
1461
					attr->xattri_dela_state, args->dp);
1462
				return error;
1463
			} else if (error) {
1464
				goto out;
1465
			}
L
Linus Torvalds 已提交
1466

1467 1468 1469 1470 1471 1472 1473 1474 1475
			/*
			 * Refill the state structure with buffers (the prior
			 * calls released our buffers) and close out this
			 * transaction before proceeding.
			 */
			ASSERT(args->rmtblkno == 0);
			error = xfs_attr_refillstate(state);
			if (error)
				goto out;
1476 1477 1478 1479

			attr->xattri_dela_state = XFS_DAS_RM_NAME;
			trace_xfs_attr_remove_iter_return(
					attr->xattri_dela_state, args->dp);
1480 1481 1482
			return -EAGAIN;
		}

1483
		fallthrough;
1484 1485 1486 1487 1488
	case XFS_DAS_RM_NAME:
		/*
		 * If we came here fresh from a transaction roll, reattach all
		 * the buffers to the current transaction.
		 */
1489
		if (attr->xattri_dela_state == XFS_DAS_RM_NAME) {
1490 1491 1492 1493
			error = xfs_attr_refillstate(state);
			if (error)
				goto out;
		}
L
Linus Torvalds 已提交
1494

1495
		retval = xfs_attr_node_removename(args, state);
1496 1497 1498 1499 1500 1501 1502 1503 1504 1505

		/*
		 * Check to see if the tree needs to be collapsed. If so, roll
		 * the transacton and fall into the shrink state.
		 */
		if (retval && (state->path.active > 1)) {
			error = xfs_da3_join(state);
			if (error)
				goto out;

1506
			attr->xattri_dela_state = XFS_DAS_RM_SHRINK;
1507
			trace_xfs_attr_remove_iter_return(
1508
					attr->xattri_dela_state, args->dp);
1509 1510 1511
			return -EAGAIN;
		}

1512
		fallthrough;
1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527
	case XFS_DAS_RM_SHRINK:
		/*
		 * If the result is small enough, push it all into the inode.
		 * This is our final state so it's safe to return a dirty
		 * transaction.
		 */
		if (xfs_attr_is_leaf(dp))
			error = xfs_attr_node_shrink(args, state);
		ASSERT(error != -EAGAIN);
		break;
	default:
		ASSERT(0);
		error = -EINVAL;
		goto out;
	}
L
Linus Torvalds 已提交
1528
out:
1529 1530
	if (state)
		xfs_da_state_free(state);
E
Eric Sandeen 已提交
1531
	return error;
L
Linus Torvalds 已提交
1532 1533 1534 1535 1536 1537
}

/*
 * 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
1538
 * after some set of transaction commits have released these buffers.
L
Linus Torvalds 已提交
1539 1540 1541 1542 1543 1544 1545 1546
 */
STATIC int
xfs_attr_fillstate(xfs_da_state_t *state)
{
	xfs_da_state_path_t *path;
	xfs_da_state_blk_t *blk;
	int level;

1547 1548
	trace_xfs_attr_fillstate(state->args);

L
Linus Torvalds 已提交
1549 1550 1551 1552 1553 1554 1555 1556
	/*
	 * 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) {
D
Dave Chinner 已提交
1557
			blk->disk_blkno = xfs_buf_daddr(blk->bp);
L
Linus Torvalds 已提交
1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571
			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) {
D
Dave Chinner 已提交
1572
			blk->disk_blkno = xfs_buf_daddr(blk->bp);
L
Linus Torvalds 已提交
1573 1574 1575 1576 1577 1578
			blk->bp = NULL;
		} else {
			blk->disk_blkno = 0;
		}
	}

E
Eric Sandeen 已提交
1579
	return 0;
L
Linus Torvalds 已提交
1580 1581 1582 1583 1584
}

/*
 * Reattach the buffers to the state structure based on the disk block
 * numbers stored in the state structure.
1585
 * This is done after some set of transaction commits have released those
L
Linus Torvalds 已提交
1586 1587 1588 1589 1590 1591 1592 1593 1594
 * 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;

1595 1596
	trace_xfs_attr_refillstate(state->args);

L
Linus Torvalds 已提交
1597 1598 1599 1600 1601 1602 1603 1604
	/*
	 * 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) {
C
Christoph Hellwig 已提交
1605 1606 1607
			error = xfs_da3_node_read_mapped(state->args->trans,
					state->args->dp, blk->disk_blkno,
					&blk->bp, XFS_ATTR_FORK);
L
Linus Torvalds 已提交
1608
			if (error)
E
Eric Sandeen 已提交
1609
				return error;
L
Linus Torvalds 已提交
1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622
		} 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) {
C
Christoph Hellwig 已提交
1623 1624 1625
			error = xfs_da3_node_read_mapped(state->args->trans,
					state->args->dp, blk->disk_blkno,
					&blk->bp, XFS_ATTR_FORK);
L
Linus Torvalds 已提交
1626
			if (error)
E
Eric Sandeen 已提交
1627
				return error;
L
Linus Torvalds 已提交
1628 1629 1630 1631 1632
		} else {
			blk->bp = NULL;
		}
	}

E
Eric Sandeen 已提交
1633
	return 0;
L
Linus Torvalds 已提交
1634 1635 1636
}

/*
1637
 * Retrieve the attribute data from a node attribute list.
L
Linus Torvalds 已提交
1638 1639 1640 1641
 *
 * 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.
1642 1643
 *
 * Returns 0 on successful retrieval, otherwise an error.
L
Linus Torvalds 已提交
1644
 */
1645
STATIC int
1646 1647
xfs_attr_node_get(
	struct xfs_da_args	*args)
L
Linus Torvalds 已提交
1648
{
1649 1650 1651 1652
	struct xfs_da_state	*state;
	struct xfs_da_state_blk	*blk;
	int			i;
	int			error;
L
Linus Torvalds 已提交
1653

1654 1655
	trace_xfs_attr_node_get(args);

L
Linus Torvalds 已提交
1656 1657 1658
	/*
	 * Search to see if name exists, and get back a pointer to it.
	 */
1659 1660
	error = xfs_attr_node_hasname(args, &state);
	if (error != -EEXIST)
1661 1662 1663 1664 1665 1666
		goto out_release;

	/*
	 * Get the value, local or "remote"
	 */
	blk = &state->path.blk[state->path.active - 1];
1667
	error = xfs_attr3_leaf_getvalue(blk->bp, args);
L
Linus Torvalds 已提交
1668 1669 1670 1671

	/*
	 * If not in a transaction, we have to release all the buffers.
	 */
1672
out_release:
1673
	for (i = 0; state != NULL && i < state->path.active; i++) {
1674
		xfs_trans_brelse(args->trans, state->path.blk[i].bp);
L
Linus Torvalds 已提交
1675 1676 1677
		state->path.blk[i].bp = NULL;
	}

1678 1679 1680
	if (state)
		xfs_da_state_free(state);
	return error;
L
Linus Torvalds 已提交
1681
}
1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698

/* Returns true if the attribute entry name is valid. */
bool
xfs_attr_namecheck(
	const void	*name,
	size_t		length)
{
	/*
	 * MAXNAMELEN includes the trailing null, but (name/length) leave it
	 * out, so use >= for the length check.
	 */
	if (length >= MAXNAMELEN)
		return false;

	/* There shouldn't be any nulls here */
	return !memchr(name, 0, length);
}