1 files changed, 539 insertions, 0 deletions

diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
new file mode 100644
index 000000000..99bbbe1a0
--- /dev/null
+++ b/fs/xfs/xfs_attr_list.c
@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, 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_da_format.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_bmap.h"
+#include "xfs_da_btree.h"
+#include "xfs_attr.h"
+#include "xfs_attr_sf.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_error.h"
+#include "xfs_trace.h"
+#include "xfs_dir2.h"
+
+STATIC int
+xfs_attr_shortform_compare(const void *a, const void *b)
+{
+	xfs_attr_sf_sort_t *sa, *sb;
+
+	sa = (xfs_attr_sf_sort_t *)a;
+	sb = (xfs_attr_sf_sort_t *)b;
+	if (sa->hash < sb->hash) {
+		return -1;
+	} else if (sa->hash > sb->hash) {
+		return 1;
+	} else {
+		return sa->entno - sb->entno;
+	}
+}
+
+#define XFS_ISRESET_CURSOR(cursor) \
+	(!((cursor)->initted) && !((cursor)->hashval) && \
+	 !((cursor)->blkno) && !((cursor)->offset))
+/*
+ * Copy out entries of shortform attribute lists for attr_list().
+ * Shortform attribute lists are not stored in hashval sorted order.
+ * If the output buffer is not large enough to hold them all, then
+ * we have to calculate each entries' hashvalue and sort them before
+ * we can begin returning them to the user.
+ */
+static int
+xfs_attr_shortform_list(
+	struct xfs_attr_list_context	*context)
+{
+	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
+	struct xfs_inode		*dp = context->dp;
+	struct xfs_attr_sf_sort		*sbuf, *sbp;
+	struct xfs_attr_shortform	*sf;
+	struct xfs_attr_sf_entry	*sfe;
+	int				sbsize, nsbuf, count, i;
+	int				error = 0;
+
+	sf = (struct xfs_attr_shortform *)dp->i_af.if_u1.if_data;
+	ASSERT(sf != NULL);
+	if (!sf->hdr.count)
+		return 0;
+
+	trace_xfs_attr_list_sf(context);
+
+	/*
+	 * If the buffer is large enough and the cursor is at the start,
+	 * do not bother with sorting since we will return everything in
+	 * one buffer and another call using the cursor won't need to be
+	 * made.
+	 * Note the generous fudge factor of 16 overhead bytes per entry.
+	 * If bufsize is zero then put_listent must be a search function
+	 * and can just scan through what we have.
+	 */
+	if (context->bufsize == 0 ||
+	    (XFS_ISRESET_CURSOR(cursor) &&
+	     (dp->i_af.if_bytes + sf->hdr.count * 16) < context->bufsize)) {
+		for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
+			if (XFS_IS_CORRUPT(context->dp->i_mount,
+					   !xfs_attr_namecheck(sfe->nameval,
+							       sfe->namelen)))
+				return -EFSCORRUPTED;
+			context->put_listent(context,
+					     sfe->flags,
+					     sfe->nameval,
+					     (int)sfe->namelen,
+					     (int)sfe->valuelen);
+			/*
+			 * Either search callback finished early or
+			 * didn't fit it all in the buffer after all.
+			 */
+			if (context->seen_enough)
+				break;
+			sfe = xfs_attr_sf_nextentry(sfe);
+		}
+		trace_xfs_attr_list_sf_all(context);
+		return 0;
+	}
+
+	/* do no more for a search callback */
+	if (context->bufsize == 0)
+		return 0;
+
+	/*
+	 * It didn't all fit, so we have to sort everything on hashval.
+	 */
+	sbsize = sf->hdr.count * sizeof(*sbuf);
+	sbp = sbuf = kmem_alloc(sbsize, KM_NOFS);
+
+	/*
+	 * 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 < sf->hdr.count; i++) {
+		if (unlikely(
+		    ((char *)sfe < (char *)sf) ||
+		    ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)))) {
+			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
+					     XFS_ERRLEVEL_LOW,
+					     context->dp->i_mount, sfe,
+					     sizeof(*sfe));
+			kmem_free(sbuf);
+			return -EFSCORRUPTED;
+		}
+
+		sbp->entno = i;
+		sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
+		sbp->name = 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.
+	 */
+	xfs_sort(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 (sbp->hash == cursor->hashval) {
+			if (cursor->offset == count) {
+				break;
+			}
+			count++;
+		} else if (sbp->hash > cursor->hashval) {
+			break;
+		}
+	}
+	if (i == nsbuf)
+		goto out;
+
+	/*
+	 * Loop putting entries into the user buffer.
+	 */
+	for ( ; i < nsbuf; i++, sbp++) {
+		if (cursor->hashval != sbp->hash) {
+			cursor->hashval = sbp->hash;
+			cursor->offset = 0;
+		}
+		if (XFS_IS_CORRUPT(context->dp->i_mount,
+				   !xfs_attr_namecheck(sbp->name,
+						       sbp->namelen))) {
+			error = -EFSCORRUPTED;
+			goto out;
+		}
+		context->put_listent(context,
+				     sbp->flags,
+				     sbp->name,
+				     sbp->namelen,
+				     sbp->valuelen);
+		if (context->seen_enough)
+			break;
+		cursor->offset++;
+	}
+out:
+	kmem_free(sbuf);
+	return error;
+}
+
+/*
+ * We didn't find the block & hash mentioned in the cursor state, so
+ * walk down the attr btree looking for the hash.
+ */
+STATIC int
+xfs_attr_node_list_lookup(
+	struct xfs_attr_list_context	*context,
+	struct xfs_attrlist_cursor_kern	*cursor,
+	struct xfs_buf			**pbp)
+{
+	struct xfs_da3_icnode_hdr	nodehdr;
+	struct xfs_da_intnode		*node;
+	struct xfs_da_node_entry	*btree;
+	struct xfs_inode		*dp = context->dp;
+	struct xfs_mount		*mp = dp->i_mount;
+	struct xfs_trans		*tp = context->tp;
+	struct xfs_buf			*bp;
+	int				i;
+	int				error = 0;
+	unsigned int			expected_level = 0;
+	uint16_t			magic;
+
+	ASSERT(*pbp == NULL);
+	cursor->blkno = 0;
+	for (;;) {
+		error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
+				XFS_ATTR_FORK);
+		if (error)
+			return error;
+		node = bp->b_addr;
+		magic = be16_to_cpu(node->hdr.info.magic);
+		if (magic == XFS_ATTR_LEAF_MAGIC ||
+		    magic == XFS_ATTR3_LEAF_MAGIC)
+			break;
+		if (magic != XFS_DA_NODE_MAGIC &&
+		    magic != XFS_DA3_NODE_MAGIC) {
+			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+					node, sizeof(*node));
+			goto out_corruptbuf;
+		}
+
+		xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
+
+		/* Tree taller than we can handle; bail out! */
+		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
+			goto out_corruptbuf;
+
+		/* Check the level from the root node. */
+		if (cursor->blkno == 0)
+			expected_level = nodehdr.level - 1;
+		else if (expected_level != nodehdr.level)
+			goto out_corruptbuf;
+		else
+			expected_level--;
+
+		btree = nodehdr.btree;
+		for (i = 0; i < nodehdr.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;
+			}
+		}
+		xfs_trans_brelse(tp, bp);
+
+		if (i == nodehdr.count)
+			return 0;
+
+		/* We can't point back to the root. */
+		if (XFS_IS_CORRUPT(mp, cursor->blkno == 0))
+			return -EFSCORRUPTED;
+	}
+
+	if (expected_level != 0)
+		goto out_corruptbuf;
+
+	*pbp = bp;
+	return 0;
+
+out_corruptbuf:
+	xfs_buf_mark_corrupt(bp);
+	xfs_trans_brelse(tp, bp);
+	return -EFSCORRUPTED;
+}
+
+STATIC int
+xfs_attr_node_list(
+	struct xfs_attr_list_context	*context)
+{
+	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
+	struct xfs_attr3_icleaf_hdr	leafhdr;
+	struct xfs_attr_leafblock	*leaf;
+	struct xfs_da_intnode		*node;
+	struct xfs_buf			*bp;
+	struct xfs_inode		*dp = context->dp;
+	struct xfs_mount		*mp = dp->i_mount;
+	int				error = 0;
+
+	trace_xfs_attr_node_list(context);
+
+	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_da3_node_read(context->tp, dp, cursor->blkno, &bp,
+				XFS_ATTR_FORK);
+		if ((error != 0) && (error != -EFSCORRUPTED))
+			return error;
+		if (bp) {
+			struct xfs_attr_leaf_entry *entries;
+
+			node = bp->b_addr;
+			switch (be16_to_cpu(node->hdr.info.magic)) {
+			case XFS_DA_NODE_MAGIC:
+			case XFS_DA3_NODE_MAGIC:
+				trace_xfs_attr_list_wrong_blk(context);
+				xfs_trans_brelse(context->tp, bp);
+				bp = NULL;
+				break;
+			case XFS_ATTR_LEAF_MAGIC:
+			case XFS_ATTR3_LEAF_MAGIC:
+				leaf = bp->b_addr;
+				xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
+							     &leafhdr, leaf);
+				entries = xfs_attr3_leaf_entryp(leaf);
+				if (cursor->hashval > be32_to_cpu(
+						entries[leafhdr.count - 1].hashval)) {
+					trace_xfs_attr_list_wrong_blk(context);
+					xfs_trans_brelse(context->tp, bp);
+					bp = NULL;
+				} else if (cursor->hashval <= be32_to_cpu(
+						entries[0].hashval)) {
+					trace_xfs_attr_list_wrong_blk(context);
+					xfs_trans_brelse(context->tp, bp);
+					bp = NULL;
+				}
+				break;
+			default:
+				trace_xfs_attr_list_wrong_blk(context);
+				xfs_trans_brelse(context->tp, 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) {
+		error = xfs_attr_node_list_lookup(context, cursor, &bp);
+		if (error || !bp)
+			return error;
+	}
+	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->b_addr;
+		error = xfs_attr3_leaf_list_int(bp, context);
+		if (error)
+			break;
+		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
+		if (context->seen_enough || leafhdr.forw == 0)
+			break;
+		cursor->blkno = leafhdr.forw;
+		xfs_trans_brelse(context->tp, bp);
+		error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno,
+					    &bp);
+		if (error)
+			return error;
+	}
+	xfs_trans_brelse(context->tp, bp);
+	return error;
+}
+
+/*
+ * Copy out attribute list entries for attr_list(), for leaf attribute lists.
+ */
+int
+xfs_attr3_leaf_list_int(
+	struct xfs_buf			*bp,
+	struct xfs_attr_list_context	*context)
+{
+	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
+	struct xfs_attr_leafblock	*leaf;
+	struct xfs_attr3_icleaf_hdr	ichdr;
+	struct xfs_attr_leaf_entry	*entries;
+	struct xfs_attr_leaf_entry	*entry;
+	int				i;
+	struct xfs_mount		*mp = context->dp->i_mount;
+
+	trace_xfs_attr_list_leaf(context);
+
+	leaf = bp->b_addr;
+	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
+	entries = xfs_attr3_leaf_entryp(leaf);
+
+	cursor->initted = 1;
+
+	/*
+	 * Re-find our place in the leaf block if this is a new syscall.
+	 */
+	if (context->resynch) {
+		entry = &entries[0];
+		for (i = 0; i < ichdr.count; entry++, i++) {
+			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
+				if (cursor->offset == context->dupcnt) {
+					context->dupcnt = 0;
+					break;
+				}
+				context->dupcnt++;
+			} else if (be32_to_cpu(entry->hashval) >
+					cursor->hashval) {
+				context->dupcnt = 0;
+				break;
+			}
+		}
+		if (i == ichdr.count) {
+			trace_xfs_attr_list_notfound(context);
+			return 0;
+		}
+	} else {
+		entry = &entries[0];
+		i = 0;
+	}
+	context->resynch = 0;
+
+	/*
+	 * We have found our place, start copying out the new attributes.
+	 */
+	for (; i < ichdr.count; entry++, i++) {
+		char *name;
+		int namelen, valuelen;
+
+		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
+			cursor->hashval = be32_to_cpu(entry->hashval);
+			cursor->offset = 0;
+		}
+
+		if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
+		    !context->allow_incomplete)
+			continue;
+
+		if (entry->flags & XFS_ATTR_LOCAL) {
+			xfs_attr_leaf_name_local_t *name_loc;
+
+			name_loc = xfs_attr3_leaf_name_local(leaf, i);
+			name = name_loc->nameval;
+			namelen = name_loc->namelen;
+			valuelen = be16_to_cpu(name_loc->valuelen);
+		} else {
+			xfs_attr_leaf_name_remote_t *name_rmt;
+
+			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
+			name = name_rmt->name;
+			namelen = name_rmt->namelen;
+			valuelen = be32_to_cpu(name_rmt->valuelen);
+		}
+
+		if (XFS_IS_CORRUPT(context->dp->i_mount,
+				   !xfs_attr_namecheck(name, namelen)))
+			return -EFSCORRUPTED;
+		context->put_listent(context, entry->flags,
+					      name, namelen, valuelen);
+		if (context->seen_enough)
+			break;
+		cursor->offset++;
+	}
+	trace_xfs_attr_list_leaf_end(context);
+	return 0;
+}
+
+/*
+ * Copy out attribute entries for attr_list(), for leaf attribute lists.
+ */
+STATIC int
+xfs_attr_leaf_list(
+	struct xfs_attr_list_context	*context)
+{
+	struct xfs_buf			*bp;
+	int				error;
+
+	trace_xfs_attr_leaf_list(context);
+
+	context->cursor.blkno = 0;
+	error = xfs_attr3_leaf_read(context->tp, context->dp, 0, &bp);
+	if (error)
+		return error;
+
+	error = xfs_attr3_leaf_list_int(bp, context);
+	xfs_trans_brelse(context->tp, bp);
+	return error;
+}
+
+int
+xfs_attr_list_ilocked(
+	struct xfs_attr_list_context	*context)
+{
+	struct xfs_inode		*dp = context->dp;
+
+	ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
+
+	/*
+	 * Decide on what work routines to call based on the inode size.
+	 */
+	if (!xfs_inode_hasattr(dp))
+		return 0;
+	if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
+		return xfs_attr_shortform_list(context);
+	if (xfs_attr_is_leaf(dp))
+		return xfs_attr_leaf_list(context);
+	return xfs_attr_node_list(context);
+}
+
+int
+xfs_attr_list(
+	struct xfs_attr_list_context	*context)
+{
+	struct xfs_inode		*dp = context->dp;
+	uint				lock_mode;
+	int				error;
+
+	XFS_STATS_INC(dp->i_mount, xs_attr_list);
+
+	if (xfs_is_shutdown(dp->i_mount))
+		return -EIO;
+
+	lock_mode = xfs_ilock_attr_map_shared(dp);
+	error = xfs_attr_list_ilocked(context);
+	xfs_iunlock(dp, lock_mode);
+	return error;
+}