1 files changed, 391 insertions, 0 deletions
diff --git a/fs/xfs/xfs_attr_inactive.c b/fs/xfs/xfs_attr_inactive.c
new file mode 100644
index 000000000..89c7a9f4f
--- /dev/null
+++ b/fs/xfs/xfs_attr_inactive.c
@@ -0,0 +1,391 @@
+// 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_bit.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_inode.h"
+#include "xfs_attr.h"
+#include "xfs_attr_remote.h"
+#include "xfs_trans.h"
+#include "xfs_bmap.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_quota.h"
+#include "xfs_dir2.h"
+#include "xfs_error.h"
+
+/*
+ * Invalidate any incore buffers associated with this remote attribute value
+ * extent.   We never log remote attribute value buffers, which means that they
+ * won't be attached to a transaction and are therefore safe to mark stale.
+ * The actual bunmapi will be taken care of later.
+ */
+STATIC int
+xfs_attr3_rmt_stale(
+	struct xfs_inode	*dp,
+	xfs_dablk_t		blkno,
+	int			blkcnt)
+{
+	struct xfs_bmbt_irec	map;
+	int			nmap;
+	int			error;
+
+	/*
+	 * Roll through the "value", invalidating the attribute value's
+	 * blocks.
+	 */
+	while (blkcnt > 0) {
+		/*
+		 * Try to remember where we decided to put the value.
+		 */
+		nmap = 1;
+		error = xfs_bmapi_read(dp, (xfs_fileoff_t)blkno, blkcnt,
+				       &map, &nmap, XFS_BMAPI_ATTRFORK);
+		if (error)
+			return error;
+		if (XFS_IS_CORRUPT(dp->i_mount, nmap != 1))
+			return -EFSCORRUPTED;
+
+		/*
+		 * Mark any incore buffers for the remote value as stale.  We
+		 * never log remote attr value buffers, so the buffer should be
+		 * easy to kill.
+		 */
+		error = xfs_attr_rmtval_stale(dp, &map, 0);
+		if (error)
+			return error;
+
+		blkno += map.br_blockcount;
+		blkcnt -= map.br_blockcount;
+	}
+
+	return 0;
+}
+
+/*
+ * Invalidate all of the "remote" value regions pointed to by a particular
+ * leaf block.
+ * Note that we must release the lock on the buffer so that we are not
+ * caught holding something that the logging code wants to flush to disk.
+ */
+STATIC int
+xfs_attr3_leaf_inactive(
+	struct xfs_trans		**trans,
+	struct xfs_inode		*dp,
+	struct xfs_buf			*bp)
+{
+	struct xfs_attr3_icleaf_hdr	ichdr;
+	struct xfs_mount		*mp = bp->b_mount;
+	struct xfs_attr_leafblock	*leaf = bp->b_addr;
+	struct xfs_attr_leaf_entry	*entry;
+	struct xfs_attr_leaf_name_remote *name_rmt;
+	int				error = 0;
+	int				i;
+
+	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
+
+	/*
+	 * Find the remote value extents for this leaf and invalidate their
+	 * incore buffers.
+	 */
+	entry = xfs_attr3_leaf_entryp(leaf);
+	for (i = 0; i < ichdr.count; entry++, i++) {
+		int		blkcnt;
+
+		if (!entry->nameidx || (entry->flags & XFS_ATTR_LOCAL))
+			continue;
+
+		name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
+		if (!name_rmt->valueblk)
+			continue;
+
+		blkcnt = xfs_attr3_rmt_blocks(dp->i_mount,
+				be32_to_cpu(name_rmt->valuelen));
+		error = xfs_attr3_rmt_stale(dp,
+				be32_to_cpu(name_rmt->valueblk), blkcnt);
+		if (error)
+			goto err;
+	}
+
+	xfs_trans_brelse(*trans, bp);
+err:
+	return error;
+}
+
+/*
+ * Recurse (gasp!) through the attribute nodes until we find leaves.
+ * We're doing a depth-first traversal in order to invalidate everything.
+ */
+STATIC int
+xfs_attr3_node_inactive(
+	struct xfs_trans	**trans,
+	struct xfs_inode	*dp,
+	struct xfs_buf		*bp,
+	int			level)
+{
+	struct xfs_mount	*mp = dp->i_mount;
+	struct xfs_da_blkinfo	*info;
+	xfs_dablk_t		child_fsb;
+	xfs_daddr_t		parent_blkno, child_blkno;
+	struct xfs_buf		*child_bp;
+	struct xfs_da3_icnode_hdr ichdr;
+	int			error, i;
+
+	/*
+	 * Since this code is recursive (gasp!) we must protect ourselves.
+	 */
+	if (level > XFS_DA_NODE_MAXDEPTH) {
+		xfs_buf_mark_corrupt(bp);
+		xfs_trans_brelse(*trans, bp);	/* no locks for later trans */
+		return -EFSCORRUPTED;
+	}
+
+	xfs_da3_node_hdr_from_disk(dp->i_mount, &ichdr, bp->b_addr);
+	parent_blkno = xfs_buf_daddr(bp);
+	if (!ichdr.count) {
+		xfs_trans_brelse(*trans, bp);
+		return 0;
+	}
+	child_fsb = be32_to_cpu(ichdr.btree[0].before);
+	xfs_trans_brelse(*trans, bp);	/* no locks for later trans */
+	bp = NULL;
+
+	/*
+	 * If this is the node level just above the leaves, simply loop
+	 * over the leaves removing all of them.  If this is higher up
+	 * in the tree, recurse downward.
+	 */
+	for (i = 0; i < ichdr.count; i++) {
+		/*
+		 * Read the subsidiary block to see what we have to work with.
+		 * Don't do this in a transaction.  This is a depth-first
+		 * traversal of the tree so we may deal with many blocks
+		 * before we come back to this one.
+		 */
+		error = xfs_da3_node_read(*trans, dp, child_fsb, &child_bp,
+					  XFS_ATTR_FORK);
+		if (error)
+			return error;
+
+		/* save for re-read later */
+		child_blkno = xfs_buf_daddr(child_bp);
+
+		/*
+		 * Invalidate the subtree, however we have to.
+		 */
+		info = child_bp->b_addr;
+		switch (info->magic) {
+		case cpu_to_be16(XFS_DA_NODE_MAGIC):
+		case cpu_to_be16(XFS_DA3_NODE_MAGIC):
+			error = xfs_attr3_node_inactive(trans, dp, child_bp,
+							level + 1);
+			break;
+		case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
+		case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
+			error = xfs_attr3_leaf_inactive(trans, dp, child_bp);
+			break;
+		default:
+			xfs_buf_mark_corrupt(child_bp);
+			xfs_trans_brelse(*trans, child_bp);
+			error = -EFSCORRUPTED;
+			break;
+		}
+		if (error)
+			return error;
+
+		/*
+		 * Remove the subsidiary block from the cache and from the log.
+		 */
+		error = xfs_trans_get_buf(*trans, mp->m_ddev_targp,
+				child_blkno,
+				XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0,
+				&child_bp);
+		if (error)
+			return error;
+		xfs_trans_binval(*trans, child_bp);
+		child_bp = NULL;
+
+		/*
+		 * If we're not done, re-read the parent to get the next
+		 * child block number.
+		 */
+		if (i + 1 < ichdr.count) {
+			struct xfs_da3_icnode_hdr phdr;
+
+			error = xfs_da3_node_read_mapped(*trans, dp,
+					parent_blkno, &bp, XFS_ATTR_FORK);
+			if (error)
+				return error;
+			xfs_da3_node_hdr_from_disk(dp->i_mount, &phdr,
+						  bp->b_addr);
+			child_fsb = be32_to_cpu(phdr.btree[i + 1].before);
+			xfs_trans_brelse(*trans, bp);
+			bp = NULL;
+		}
+		/*
+		 * Atomically commit the whole invalidate stuff.
+		 */
+		error = xfs_trans_roll_inode(trans, dp);
+		if (error)
+			return  error;
+	}
+
+	return 0;
+}
+
+/*
+ * Indiscriminately delete the entire attribute fork
+ *
+ * Recurse (gasp!) through the attribute nodes until we find leaves.
+ * We're doing a depth-first traversal in order to invalidate everything.
+ */
+static int
+xfs_attr3_root_inactive(
+	struct xfs_trans	**trans,
+	struct xfs_inode	*dp)
+{
+	struct xfs_mount	*mp = dp->i_mount;
+	struct xfs_da_blkinfo	*info;
+	struct xfs_buf		*bp;
+	xfs_daddr_t		blkno;
+	int			error;
+
+	/*
+	 * Read block 0 to see what we have to work with.
+	 * We only get here if we have extents, since we remove
+	 * the extents in reverse order the extent containing
+	 * block 0 must still be there.
+	 */
+	error = xfs_da3_node_read(*trans, dp, 0, &bp, XFS_ATTR_FORK);
+	if (error)
+		return error;
+	blkno = xfs_buf_daddr(bp);
+
+	/*
+	 * Invalidate the tree, even if the "tree" is only a single leaf block.
+	 * This is a depth-first traversal!
+	 */
+	info = bp->b_addr;
+	switch (info->magic) {
+	case cpu_to_be16(XFS_DA_NODE_MAGIC):
+	case cpu_to_be16(XFS_DA3_NODE_MAGIC):
+		error = xfs_attr3_node_inactive(trans, dp, bp, 1);
+		break;
+	case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
+	case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
+		error = xfs_attr3_leaf_inactive(trans, dp, bp);
+		break;
+	default:
+		error = -EFSCORRUPTED;
+		xfs_buf_mark_corrupt(bp);
+		xfs_trans_brelse(*trans, bp);
+		break;
+	}
+	if (error)
+		return error;
+
+	/*
+	 * Invalidate the incore copy of the root block.
+	 */
+	error = xfs_trans_get_buf(*trans, mp->m_ddev_targp, blkno,
+			XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0, &bp);
+	if (error)
+		return error;
+	error = bp->b_error;
+	if (error) {
+		xfs_trans_brelse(*trans, bp);
+		return error;
+	}
+	xfs_trans_binval(*trans, bp);	/* remove from cache */
+	/*
+	 * Commit the invalidate and start the next transaction.
+	 */
+	error = xfs_trans_roll_inode(trans, dp);
+
+	return error;
+}
+
+/*
+ * xfs_attr_inactive kills all traces of an attribute fork on an inode. It
+ * removes both the on-disk and in-memory inode fork. Note that this also has to
+ * handle the condition of inodes without attributes but with an attribute fork
+ * configured, so we can't use xfs_inode_hasattr() here.
+ *
+ * The in-memory attribute fork is removed even on error.
+ */
+int
+xfs_attr_inactive(
+	struct xfs_inode	*dp)
+{
+	struct xfs_trans	*trans;
+	struct xfs_mount	*mp;
+	int			lock_mode = XFS_ILOCK_SHARED;
+	int			error = 0;
+
+	mp = dp->i_mount;
+
+	xfs_ilock(dp, lock_mode);
+	if (!xfs_inode_has_attr_fork(dp))
+		goto out_destroy_fork;
+	xfs_iunlock(dp, lock_mode);
+
+	lock_mode = 0;
+
+	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_attrinval, 0, 0, 0, &trans);
+	if (error)
+		goto out_destroy_fork;
+
+	lock_mode = XFS_ILOCK_EXCL;
+	xfs_ilock(dp, lock_mode);
+
+	if (!xfs_inode_has_attr_fork(dp))
+		goto out_cancel;
+
+	/*
+	 * No need to make quota reservations here. We expect to release some
+	 * blocks, not allocate, in the common case.
+	 */
+	xfs_trans_ijoin(trans, dp, 0);
+
+	/*
+	 * Invalidate and truncate the attribute fork extents. Make sure the
+	 * fork actually has xattr blocks as otherwise the invalidation has no
+	 * blocks to read and returns an error. In this case, just do the fork
+	 * removal below.
+	 */
+	if (dp->i_af.if_nextents > 0) {
+		error = xfs_attr3_root_inactive(&trans, dp);
+		if (error)
+			goto out_cancel;
+
+		error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK, 0);
+		if (error)
+			goto out_cancel;
+	}
+
+	/* Reset the attribute fork - this also destroys the in-core fork */
+	xfs_attr_fork_remove(dp, trans);
+
+	error = xfs_trans_commit(trans);
+	xfs_iunlock(dp, lock_mode);
+	return error;
+
+out_cancel:
+	xfs_trans_cancel(trans);
+out_destroy_fork:
+	/* kill the in-core attr fork before we drop the inode lock */
+	xfs_ifork_zap_attr(dp);
+	if (lock_mode)
+		xfs_iunlock(dp, lock_mode);
+	return error;
+}