xfs_attr_leaf.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,154 行 · 第 1/5 页

{
	attrlist_cursor_kern_t *cursor;
	xfs_attr_sf_sort_t *sbuf, *sbp;
	xfs_attr_shortform_t *sf;
	xfs_attr_sf_entry_t *sfe;
	xfs_inode_t *dp;
	int sbsize, nsbuf, count, i;

	ASSERT(context != NULL);
	dp = context->dp;
	ASSERT(dp != NULL);
	ASSERT(dp->i_afp != NULL);
	sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
	ASSERT(sf != NULL);
	if (INT_ISZERO(sf->hdr.count, ARCH_CONVERT))
		return(0);
	cursor = context->cursor;
	ASSERT(cursor != NULL);

	xfs_attr_trace_l_c("sf start", context);

	/*
	 * If the buffer is large enough, do not bother with sorting.
	 * Note the generous fudge factor of 16 overhead bytes per entry.
	 */
	if ((dp->i_afp->if_bytes + INT_GET(sf->hdr.count, ARCH_CONVERT) * 16)
							< context->bufsize) {
		for (i = 0, sfe = &sf->list[0];
				i < INT_GET(sf->hdr.count, ARCH_CONVERT); i++) {
			attrnames_t	*namesp;

			if (((context->flags & ATTR_SECURE) != 0) !=
			    ((sfe->flags & XFS_ATTR_SECURE) != 0) &&
			    !(context->flags & ATTR_KERNORMALS)) {
				sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
				continue;
			}
			if (((context->flags & ATTR_ROOT) != 0) !=
			    ((sfe->flags & XFS_ATTR_ROOT) != 0) &&
			    !(context->flags & ATTR_KERNROOTLS)) {
				sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
				continue;
			}
			namesp = (sfe->flags & XFS_ATTR_SECURE) ? &attr_secure:
				((sfe->flags & XFS_ATTR_ROOT) ? &attr_trusted :
				  &attr_user);
			if (context->flags & ATTR_KERNOVAL) {
				ASSERT(context->flags & ATTR_KERNAMELS);
				context->count += namesp->attr_namelen +
					INT_GET(sfe->namelen, ARCH_CONVERT) + 1;
			}
			else {
				if (xfs_attr_put_listent(context, namesp,
						   (char *)sfe->nameval,
						   (int)sfe->namelen,
						   (int)INT_GET(sfe->valuelen,
								ARCH_CONVERT)))
					break;
			}
			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
		}
		xfs_attr_trace_l_c("sf big-gulp", context);
		return(0);
	}

	/*
	 * It didn't all fit, so we have to sort everything on hashval.
	 */
	sbsize = INT_GET(sf->hdr.count, ARCH_CONVERT) * sizeof(*sbuf);
	sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP);

	/*
	 * Scan the attribute list for the rest of the entries, storing
	 * the relevant info from only those that match into a buffer.
	 */
	nsbuf = 0;
	for (i = 0, sfe = &sf->list[0];
			i < INT_GET(sf->hdr.count, ARCH_CONVERT); i++) {
		if (unlikely(
		    ((char *)sfe < (char *)sf) ||
		    ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
					     XFS_ERRLEVEL_LOW,
					     context->dp->i_mount, sfe);
			xfs_attr_trace_l_c("sf corrupted", context);
			kmem_free(sbuf, sbsize);
			return XFS_ERROR(EFSCORRUPTED);
		}
		if (((context->flags & ATTR_SECURE) != 0) !=
		    ((sfe->flags & XFS_ATTR_SECURE) != 0) &&
		    !(context->flags & ATTR_KERNORMALS)) {
			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
			continue;
		}
		if (((context->flags & ATTR_ROOT) != 0) !=
		    ((sfe->flags & XFS_ATTR_ROOT) != 0) &&
		    !(context->flags & ATTR_KERNROOTLS)) {
			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
			continue;
		}
		sbp->entno = i;
		INT_SET(sbp->hash, ARCH_CONVERT,
			xfs_da_hashname((char *)sfe->nameval, sfe->namelen));
		sbp->name = (char *)sfe->nameval;
		sbp->namelen = sfe->namelen;
		/* These are bytes, and both on-disk, don't endian-flip */
		sbp->valuelen = sfe->valuelen;
		sbp->flags = sfe->flags;
		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
		sbp++;
		nsbuf++;
	}

	/*
	 * Sort the entries on hash then entno.
	 */
	qsort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);

	/*
	 * Re-find our place IN THE SORTED LIST.
	 */
	count = 0;
	cursor->initted = 1;
	cursor->blkno = 0;
	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
		if (INT_GET(sbp->hash, ARCH_CONVERT) == cursor->hashval) {
			if (cursor->offset == count) {
				break;
			}
			count++;
		} else if (INT_GET(sbp->hash, ARCH_CONVERT) > cursor->hashval) {
			break;
		}
	}
	if (i == nsbuf) {
		kmem_free(sbuf, sbsize);
		xfs_attr_trace_l_c("blk end", context);
		return(0);
	}

	/*
	 * Loop putting entries into the user buffer.
	 */
	for ( ; i < nsbuf; i++, sbp++) {
		attrnames_t	*namesp;

		namesp = (sbp->flags & XFS_ATTR_SECURE) ? &attr_secure :
			((sbp->flags & XFS_ATTR_ROOT) ? &attr_trusted :
			  &attr_user);

		if (cursor->hashval != INT_GET(sbp->hash, ARCH_CONVERT)) {
			cursor->hashval = INT_GET(sbp->hash, ARCH_CONVERT);
			cursor->offset = 0;
		}
		if (context->flags & ATTR_KERNOVAL) {
			ASSERT(context->flags & ATTR_KERNAMELS);
			context->count += namesp->attr_namelen +
						sbp->namelen + 1;
		} else {
			if (xfs_attr_put_listent(context, namesp,
					sbp->name, sbp->namelen,
					INT_GET(sbp->valuelen, ARCH_CONVERT)))
				break;
		}
		cursor->offset++;
	}

	kmem_free(sbuf, sbsize);
	xfs_attr_trace_l_c("sf E-O-F", context);
	return(0);
}

/*
 * Check a leaf attribute block to see if all the entries would fit into
 * a shortform attribute list.
 */
int
xfs_attr_shortform_allfit(xfs_dabuf_t *bp, xfs_inode_t *dp)
{
	xfs_attr_leafblock_t *leaf;
	xfs_attr_leaf_entry_t *entry;
	xfs_attr_leaf_name_local_t *name_loc;
	int bytes, i;

	leaf = bp->data;
	ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT)
						== XFS_ATTR_LEAF_MAGIC);

	entry = &leaf->entries[0];
	bytes = sizeof(struct xfs_attr_sf_hdr);
	for (i = 0; i < INT_GET(leaf->hdr.count, ARCH_CONVERT); entry++, i++) {
		if (entry->flags & XFS_ATTR_INCOMPLETE)
			continue;		/* don't copy partial entries */
		if (!(entry->flags & XFS_ATTR_LOCAL))
			return(0);
		name_loc = XFS_ATTR_LEAF_NAME_LOCAL(leaf, i);
		if (name_loc->namelen >= XFS_ATTR_SF_ENTSIZE_MAX)
			return(0);
		if (INT_GET(name_loc->valuelen, ARCH_CONVERT) >= XFS_ATTR_SF_ENTSIZE_MAX)
			return(0);
		bytes += sizeof(struct xfs_attr_sf_entry)-1
				+ name_loc->namelen
				+ INT_GET(name_loc->valuelen, ARCH_CONVERT);
	}
	return( bytes < XFS_IFORK_ASIZE(dp) );
}

/*
 * Convert a leaf attribute list to shortform attribute list
 */
int
xfs_attr_leaf_to_shortform(xfs_dabuf_t *bp, xfs_da_args_t *args)
{
	xfs_attr_leafblock_t *leaf;
	xfs_attr_leaf_entry_t *entry;
	xfs_attr_leaf_name_local_t *name_loc;
	xfs_da_args_t nargs;
	xfs_inode_t *dp;
	char *tmpbuffer;
	int error, i;

	dp = args->dp;
	tmpbuffer = kmem_alloc(XFS_LBSIZE(dp->i_mount), KM_SLEEP);
	ASSERT(tmpbuffer != NULL);

	ASSERT(bp != NULL);
	memcpy(tmpbuffer, bp->data, XFS_LBSIZE(dp->i_mount));
	leaf = (xfs_attr_leafblock_t *)tmpbuffer;
	ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT)
						== XFS_ATTR_LEAF_MAGIC);
	memset(bp->data, 0, XFS_LBSIZE(dp->i_mount));

	/*
	 * Clean out the prior contents of the attribute list.
	 */
	error = xfs_da_shrink_inode(args, 0, bp);
	if (error)
		goto out;
	error = xfs_attr_shortform_create(args);
	if (error)
		goto out;

	/*
	 * Copy the attributes
	 */
	memset((char *)&nargs, 0, sizeof(nargs));
	nargs.dp = dp;
	nargs.firstblock = args->firstblock;
	nargs.flist = args->flist;
	nargs.total = args->total;
	nargs.whichfork = XFS_ATTR_FORK;
	nargs.trans = args->trans;
	nargs.oknoent = 1;
	entry = &leaf->entries[0];
	for (i = 0; i < INT_GET(leaf->hdr.count, ARCH_CONVERT); entry++, i++) {
		if (entry->flags & XFS_ATTR_INCOMPLETE)
			continue;	/* don't copy partial entries */
		if (INT_ISZERO(entry->nameidx, ARCH_CONVERT))
			continue;
		ASSERT(entry->flags & XFS_ATTR_LOCAL);
		name_loc = XFS_ATTR_LEAF_NAME_LOCAL(leaf, i);
		nargs.name = (char *)name_loc->nameval;
		nargs.namelen = name_loc->namelen;
		nargs.value = (char *)&name_loc->nameval[nargs.namelen];
		nargs.valuelen = INT_GET(name_loc->valuelen, ARCH_CONVERT);
		nargs.hashval = INT_GET(entry->hashval, ARCH_CONVERT);
		nargs.flags = (entry->flags & XFS_ATTR_SECURE) ? ATTR_SECURE :
			      ((entry->flags & XFS_ATTR_ROOT) ? ATTR_ROOT : 0);
		xfs_attr_shortform_add(&nargs);
	}
	error = 0;

out:
	kmem_free(tmpbuffer, XFS_LBSIZE(dp->i_mount));
	return(error);
}

/*
 * Convert from using a single leaf to a root node and a leaf.
 */
int
xfs_attr_leaf_to_node(xfs_da_args_t *args)
{
	xfs_attr_leafblock_t *leaf;
	xfs_da_intnode_t *node;
	xfs_inode_t *dp;
	xfs_dabuf_t *bp1, *bp2;
	xfs_dablk_t blkno;
	int error;

	dp = args->dp;
	bp1 = bp2 = NULL;
	error = xfs_da_grow_inode(args, &blkno);
	if (error)
		goto out;
	error = xfs_da_read_buf(args->trans, args->dp, 0, -1, &bp1,
					     XFS_ATTR_FORK);
	if (error)
		goto out;
	ASSERT(bp1 != NULL);
	bp2 = NULL;
	error = xfs_da_get_buf(args->trans, args->dp, blkno, -1, &bp2,
					    XFS_ATTR_FORK);
	if (error)
		goto out;
	ASSERT(bp2 != NULL);
	memcpy(bp2->data, bp1->data, XFS_LBSIZE(dp->i_mount));
	xfs_da_buf_done(bp1);
	bp1 = NULL;
	xfs_da_log_buf(args->trans, bp2, 0, XFS_LBSIZE(dp->i_mount) - 1);

	/*
	 * Set up the new root node.
	 */
	error = xfs_da_node_create(args, 0, 1, &bp1, XFS_ATTR_FORK);
	if (error)
		goto out;
	node = bp1->data;
	leaf = bp2->data;
	ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT)
						== XFS_ATTR_LEAF_MAGIC);
	/* both on-disk, don't endian-flip twice */
	node->btree[0].hashval =
		leaf->entries[INT_GET(leaf->hdr.count, ARCH_CONVERT)-1 ].hashval;
	INT_SET(node->btree[0].before, ARCH_CONVERT, blkno);
	INT_SET(node->hdr.count, ARCH_CONVERT, 1);
	xfs_da_log_buf(args->trans, bp1, 0, XFS_LBSIZE(dp->i_mount) - 1);
	error = 0;
out:
	if (bp1)
		xfs_da_buf_done(bp1);
	if (bp2)
		xfs_da_buf_done(bp2);
	return(error);
}


/*========================================================================
 * Routines used for growing the Btree.
 *========================================================================*/

/*
 * Create the initial contents of a leaf attribute list
 * or a leaf in a node attribute list.
 */
int
xfs_attr_leaf_create(xfs_da_args_t *args, xfs_dablk_t blkno, xfs_dabuf_t **bpp)
{
	xfs_attr_leafblock_t *leaf;
	xfs_attr_leaf_hdr_t *hdr;
	xfs_inode_t *dp;
	xfs_dabuf_t *bp;
	int error;

	dp = args->dp;
	ASSERT(dp != NULL);
	error = xfs_da_get_buf(args->trans, args->dp, blkno, -1, &bp,
					    XFS_ATTR_FORK);
	if (error)
		return(error);
	ASSERT(bp != NULL);
	leaf = bp->data;
	memset((char *)leaf, 0, XFS_LBSIZE(dp->i_mount));
	hdr = &leaf->hdr;
	INT_SET(hdr->info.magic, ARCH_CONVERT, XFS_ATTR_LEAF_MAGIC);
	INT_SET(hdr->firstused, ARCH_CONVERT, XFS_LBSIZE(dp->i_mount));
	if (INT_ISZERO(hdr->firstused, ARCH_CONVERT)) {
		INT_SET(hdr->firstused, ARCH_CONVERT,
			XFS_LBSIZE(dp->i_mount) - XFS_ATTR_LEAF_NAME_ALIGN);
	}

	INT_SET(hdr->freemap[0].base, ARCH_CONVERT,
						sizeof(xfs_attr_leaf_hdr_t));
	INT_SET(hdr->freemap[0].size, ARCH_CONVERT,
					  INT_GET(hdr->firstused, ARCH_CONVERT)
					- INT_GET(hdr->freemap[0].base,
								ARCH_CONVERT));

	xfs_da_log_buf(args->trans, bp, 0, XFS_LBSIZE(dp->i_mount) - 1);

	*bpp = bp;
	return(0);
}

/*
 * Split the leaf node, rebalance, then add the new entry.
 */
int
xfs_attr_leaf_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
				   xfs_da_state_blk_t *newblk)
{
	xfs_dablk_t blkno;
	int error;

	/*
	 * Allocate space for a new leaf node.
	 */
	ASSERT(oldblk->magic == XFS_ATTR_LEAF_MAGIC);
	error = xfs_da_grow_inode(state->args, &blkno);
	if (error)
		return(error);
	error = xfs_attr_leaf_create(state->args, blkno, &newblk->bp);
	if (error)
		return(error);
	newblk->blkno = blkno;
	newblk->magic = XFS_ATTR_LEAF_MAGIC;

	/*
	 * Rebalance the entries across the two leaves.
	 * NOTE: rebalance() currently depends on the 2nd block being empty.
	 */
	xfs_attr_leaf_rebalance(state, oldblk, newblk);
	error = xfs_da_blk_link(state, oldblk, newblk);
	if (error)
		return(error);

	/*
	 * Save info on "old" attribute for "atomic rename" ops, leaf_add()
	 * modifies the index/blkno/rmtblk/rmtblkcnt fields to show the
	 * "new" attrs info.  Will need the "old" info to remove it later.
	 *
	 * Insert the "new" entry in the correct block.
	 */
	if (state->inleaf)
		error = xfs_attr_leaf_add(oldblk->bp, state->args);
	else
		error = xfs_attr_leaf_add(newblk->bp, state->args);

	/*
	 * Update last hashval in each block since we added the name.
	 */