Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 648 insertions, 0 deletions

diff --git a/fs/afs/dir_edit.c b/fs/afs/dir_edit.c
new file mode 100644
index 000000000..3ead36a07
--- /dev/null
+++ b/fs/afs/dir_edit.c
@@ -0,0 +1,648 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AFS filesystem directory editing
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/pagemap.h>
+#include <linux/iversion.h>
+#include <linux/folio_queue.h>
+#include "internal.h"
+#include "xdr_fs.h"
+
+/*
+ * Find a number of contiguous clear bits in a directory block bitmask.
+ *
+ * There are 64 slots, which means we can load the entire bitmap into a
+ * variable.  The first bit doesn't count as it corresponds to the block header
+ * slot.  nr_slots is between 1 and 9.
+ */
+static int afs_find_contig_bits(union afs_xdr_dir_block *block, unsigned int nr_slots)
+{
+	u64 bitmap;
+	u32 mask;
+	int bit, n;
+
+	bitmap  = (u64)block->hdr.bitmap[0] << 0 * 8;
+	bitmap |= (u64)block->hdr.bitmap[1] << 1 * 8;
+	bitmap |= (u64)block->hdr.bitmap[2] << 2 * 8;
+	bitmap |= (u64)block->hdr.bitmap[3] << 3 * 8;
+	bitmap |= (u64)block->hdr.bitmap[4] << 4 * 8;
+	bitmap |= (u64)block->hdr.bitmap[5] << 5 * 8;
+	bitmap |= (u64)block->hdr.bitmap[6] << 6 * 8;
+	bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8;
+	bitmap >>= 1; /* The first entry is metadata */
+	bit = 1;
+	mask = (1 << nr_slots) - 1;
+
+	do {
+		if (sizeof(unsigned long) == 8)
+			n = ffz(bitmap);
+		else
+			n = ((u32)bitmap) != 0 ?
+				ffz((u32)bitmap) :
+				ffz((u32)(bitmap >> 32)) + 32;
+		bitmap >>= n;
+		bit += n;
+
+		if ((bitmap & mask) == 0) {
+			if (bit > 64 - nr_slots)
+				return -1;
+			return bit;
+		}
+
+		n = __ffs(bitmap);
+		bitmap >>= n;
+		bit += n;
+	} while (bitmap);
+
+	return -1;
+}
+
+/*
+ * Set a number of contiguous bits in the directory block bitmap.
+ */
+static void afs_set_contig_bits(union afs_xdr_dir_block *block,
+				int bit, unsigned int nr_slots)
+{
+	u64 mask;
+
+	mask = (1 << nr_slots) - 1;
+	mask <<= bit;
+
+	block->hdr.bitmap[0] |= (u8)(mask >> 0 * 8);
+	block->hdr.bitmap[1] |= (u8)(mask >> 1 * 8);
+	block->hdr.bitmap[2] |= (u8)(mask >> 2 * 8);
+	block->hdr.bitmap[3] |= (u8)(mask >> 3 * 8);
+	block->hdr.bitmap[4] |= (u8)(mask >> 4 * 8);
+	block->hdr.bitmap[5] |= (u8)(mask >> 5 * 8);
+	block->hdr.bitmap[6] |= (u8)(mask >> 6 * 8);
+	block->hdr.bitmap[7] |= (u8)(mask >> 7 * 8);
+}
+
+/*
+ * Clear a number of contiguous bits in the directory block bitmap.
+ */
+static void afs_clear_contig_bits(union afs_xdr_dir_block *block,
+				  int bit, unsigned int nr_slots)
+{
+	u64 mask;
+
+	mask = (1 << nr_slots) - 1;
+	mask <<= bit;
+
+	block->hdr.bitmap[0] &= ~(u8)(mask >> 0 * 8);
+	block->hdr.bitmap[1] &= ~(u8)(mask >> 1 * 8);
+	block->hdr.bitmap[2] &= ~(u8)(mask >> 2 * 8);
+	block->hdr.bitmap[3] &= ~(u8)(mask >> 3 * 8);
+	block->hdr.bitmap[4] &= ~(u8)(mask >> 4 * 8);
+	block->hdr.bitmap[5] &= ~(u8)(mask >> 5 * 8);
+	block->hdr.bitmap[6] &= ~(u8)(mask >> 6 * 8);
+	block->hdr.bitmap[7] &= ~(u8)(mask >> 7 * 8);
+}
+
+/*
+ * Get a specific block, extending the directory storage to cover it as needed.
+ */
+static union afs_xdr_dir_block *afs_dir_get_block(struct afs_dir_iter *iter, size_t block)
+{
+	struct folio_queue *fq;
+	struct afs_vnode *dvnode = iter->dvnode;
+	struct folio *folio;
+	size_t blpos = block * AFS_DIR_BLOCK_SIZE;
+	size_t blend = (block + 1) * AFS_DIR_BLOCK_SIZE, fpos = iter->fpos;
+	int ret;
+
+	if (dvnode->directory_size < blend) {
+		size_t cur_size = dvnode->directory_size;
+
+		ret = netfs_alloc_folioq_buffer(
+			NULL, &dvnode->directory, &cur_size, blend,
+			mapping_gfp_mask(dvnode->netfs.inode.i_mapping));
+		dvnode->directory_size = cur_size;
+		if (ret < 0)
+			goto fail;
+	}
+
+	fq = iter->fq;
+	if (!fq)
+		fq = dvnode->directory;
+
+	/* Search the folio queue for the folio containing the block... */
+	for (; fq; fq = fq->next) {
+		for (int s = iter->fq_slot; s < folioq_count(fq); s++) {
+			size_t fsize = folioq_folio_size(fq, s);
+
+			if (blend <= fpos + fsize) {
+				/* ... and then return the mapped block. */
+				folio = folioq_folio(fq, s);
+				if (WARN_ON_ONCE(folio_pos(folio) != fpos))
+					goto fail;
+				iter->fq = fq;
+				iter->fq_slot = s;
+				iter->fpos = fpos;
+				return kmap_local_folio(folio, blpos - fpos);
+			}
+			fpos += fsize;
+		}
+		iter->fq_slot = 0;
+	}
+
+fail:
+	iter->fq = NULL;
+	iter->fq_slot = 0;
+	afs_invalidate_dir(dvnode, afs_dir_invalid_edit_get_block);
+	return NULL;
+}
+
+/*
+ * Scan a directory block looking for a dirent of the right name.
+ */
+static int afs_dir_scan_block(const union afs_xdr_dir_block *block, const struct qstr *name,
+			      unsigned int blocknum)
+{
+	const union afs_xdr_dirent *de;
+	u64 bitmap;
+	int d, len, n;
+
+	_enter("");
+
+	bitmap  = (u64)block->hdr.bitmap[0] << 0 * 8;
+	bitmap |= (u64)block->hdr.bitmap[1] << 1 * 8;
+	bitmap |= (u64)block->hdr.bitmap[2] << 2 * 8;
+	bitmap |= (u64)block->hdr.bitmap[3] << 3 * 8;
+	bitmap |= (u64)block->hdr.bitmap[4] << 4 * 8;
+	bitmap |= (u64)block->hdr.bitmap[5] << 5 * 8;
+	bitmap |= (u64)block->hdr.bitmap[6] << 6 * 8;
+	bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8;
+
+	for (d = (blocknum == 0 ? AFS_DIR_RESV_BLOCKS0 : AFS_DIR_RESV_BLOCKS);
+	     d < AFS_DIR_SLOTS_PER_BLOCK;
+	     d++) {
+		if (!((bitmap >> d) & 1))
+			continue;
+		de = &block->dirents[d];
+		if (de->u.valid != 1)
+			continue;
+
+		/* The block was NUL-terminated by afs_dir_check_page(). */
+		len = strlen(de->u.name);
+		if (len == name->len &&
+		    memcmp(de->u.name, name->name, name->len) == 0)
+			return d;
+
+		n = round_up(12 + len + 1 + 4, AFS_DIR_DIRENT_SIZE);
+		n /= AFS_DIR_DIRENT_SIZE;
+		d += n - 1;
+	}
+
+	return -1;
+}
+
+/*
+ * Initialise a new directory block.  Note that block 0 is special and contains
+ * some extra metadata.
+ */
+static void afs_edit_init_block(union afs_xdr_dir_block *meta,
+				union afs_xdr_dir_block *block, int block_num)
+{
+	memset(block, 0, sizeof(*block));
+	block->hdr.npages = htons(1);
+	block->hdr.magic = AFS_DIR_MAGIC;
+	block->hdr.bitmap[0] = 1;
+
+	if (block_num == 0) {
+		block->hdr.bitmap[0] = 0xff;
+		block->hdr.bitmap[1] = 0x1f;
+		memset(block->meta.alloc_ctrs,
+		       AFS_DIR_SLOTS_PER_BLOCK,
+		       sizeof(block->meta.alloc_ctrs));
+		meta->meta.alloc_ctrs[0] =
+			AFS_DIR_SLOTS_PER_BLOCK - AFS_DIR_RESV_BLOCKS0;
+	}
+
+	if (block_num < AFS_DIR_BLOCKS_WITH_CTR)
+		meta->meta.alloc_ctrs[block_num] =
+			AFS_DIR_SLOTS_PER_BLOCK - AFS_DIR_RESV_BLOCKS;
+}
+
+/*
+ * Edit a directory's file data to add a new directory entry.  Doing this after
+ * create, mkdir, symlink, link or rename if the data version number is
+ * incremented by exactly one avoids the need to re-download the entire
+ * directory contents.
+ *
+ * The caller must hold the inode locked.
+ */
+void afs_edit_dir_add(struct afs_vnode *vnode,
+		      const struct qstr *name, struct afs_fid *new_fid,
+		      enum afs_edit_dir_reason why)
+{
+	union afs_xdr_dir_block *meta, *block;
+	union afs_xdr_dirent *de;
+	struct afs_dir_iter iter = { .dvnode = vnode };
+	unsigned int nr_blocks, b, entry;
+	loff_t i_size;
+	int slot;
+
+	_enter(",,{%d,%s},", name->len, name->name);
+
+	i_size = i_size_read(&vnode->netfs.inode);
+	if (i_size > AFS_DIR_BLOCK_SIZE * AFS_DIR_MAX_BLOCKS ||
+	    (i_size & (AFS_DIR_BLOCK_SIZE - 1))) {
+		afs_invalidate_dir(vnode, afs_dir_invalid_edit_add_bad_size);
+		return;
+	}
+
+	meta = afs_dir_get_block(&iter, 0);
+	if (!meta)
+		return;
+
+	/* Work out how many slots we're going to need. */
+	iter.nr_slots = afs_dir_calc_slots(name->len);
+
+	if (i_size == 0)
+		goto new_directory;
+	nr_blocks = i_size / AFS_DIR_BLOCK_SIZE;
+
+	/* Find a block that has sufficient slots available.  Each folio
+	 * contains two or more directory blocks.
+	 */
+	for (b = 0; b < nr_blocks + 1; b++) {
+		/* If the directory extended into a new folio, then we need to
+		 * tack a new folio on the end.
+		 */
+		if (nr_blocks >= AFS_DIR_MAX_BLOCKS)
+			goto error_too_many_blocks;
+
+		/* Lower dir blocks have a counter in the header we can check. */
+		if (b < AFS_DIR_BLOCKS_WITH_CTR &&
+		    meta->meta.alloc_ctrs[b] < iter.nr_slots)
+			continue;
+
+		block = afs_dir_get_block(&iter, b);
+		if (!block)
+			goto error;
+
+		/* Abandon the edit if we got a callback break. */
+		if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+			goto already_invalidated;
+
+		_debug("block %u: %2u %3u %u",
+		       b,
+		       (b < AFS_DIR_BLOCKS_WITH_CTR) ? meta->meta.alloc_ctrs[b] : 99,
+		       ntohs(block->hdr.npages),
+		       ntohs(block->hdr.magic));
+
+		/* Initialise the block if necessary. */
+		if (b == nr_blocks) {
+			_debug("init %u", b);
+			afs_edit_init_block(meta, block, b);
+			afs_set_i_size(vnode, (b + 1) * AFS_DIR_BLOCK_SIZE);
+		}
+
+		/* We need to try and find one or more consecutive slots to
+		 * hold the entry.
+		 */
+		slot = afs_find_contig_bits(block, iter.nr_slots);
+		if (slot >= 0) {
+			_debug("slot %u", slot);
+			goto found_space;
+		}
+
+		kunmap_local(block);
+	}
+
+	/* There are no spare slots of sufficient size, yet the operation
+	 * succeeded.  Download the directory again.
+	 */
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_create_nospc, 0, 0, 0, 0, name->name);
+	afs_invalidate_dir(vnode, afs_dir_invalid_edit_add_no_slots);
+	goto out_unmap;
+
+new_directory:
+	afs_edit_init_block(meta, meta, 0);
+	i_size = AFS_DIR_BLOCK_SIZE;
+	afs_set_i_size(vnode, i_size);
+	slot = AFS_DIR_RESV_BLOCKS0;
+	block = afs_dir_get_block(&iter, 0);
+	nr_blocks = 1;
+	b = 0;
+
+found_space:
+	/* Set the dirent slot. */
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_create, b, slot,
+			   new_fid->vnode, new_fid->unique, name->name);
+	de = &block->dirents[slot];
+	de->u.valid	= 1;
+	de->u.unused[0]	= 0;
+	de->u.hash_next	= 0; // TODO: Really need to maintain this
+	de->u.vnode	= htonl(new_fid->vnode);
+	de->u.unique	= htonl(new_fid->unique);
+	memcpy(de->u.name, name->name, name->len + 1);
+	de->u.name[name->len] = 0;
+
+	/* Adjust the bitmap. */
+	afs_set_contig_bits(block, slot, iter.nr_slots);
+
+	/* Adjust the allocation counter. */
+	if (b < AFS_DIR_BLOCKS_WITH_CTR)
+		meta->meta.alloc_ctrs[b] -= iter.nr_slots;
+
+	/* Adjust the hash chain. */
+	entry = b * AFS_DIR_SLOTS_PER_BLOCK + slot;
+	iter.bucket = afs_dir_hash_name(name);
+	de->u.hash_next = meta->meta.hashtable[iter.bucket];
+	meta->meta.hashtable[iter.bucket] = htons(entry);
+	kunmap_local(block);
+
+	inode_inc_iversion_raw(&vnode->netfs.inode);
+	afs_stat_v(vnode, n_dir_cr);
+	_debug("Insert %s in %u[%u]", name->name, b, slot);
+
+	netfs_single_mark_inode_dirty(&vnode->netfs.inode);
+
+out_unmap:
+	kunmap_local(meta);
+	_leave("");
+	return;
+
+already_invalidated:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_create_inval, 0, 0, 0, 0, name->name);
+	kunmap_local(block);
+	goto out_unmap;
+
+error_too_many_blocks:
+	afs_invalidate_dir(vnode, afs_dir_invalid_edit_add_too_many_blocks);
+error:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_create_error, 0, 0, 0, 0, name->name);
+	goto out_unmap;
+}
+
+/*
+ * Edit a directory's file data to remove a new directory entry.  Doing this
+ * after unlink, rmdir or rename if the data version number is incremented by
+ * exactly one avoids the need to re-download the entire directory contents.
+ *
+ * The caller must hold the inode locked.
+ */
+void afs_edit_dir_remove(struct afs_vnode *vnode,
+			 const struct qstr *name, enum afs_edit_dir_reason why)
+{
+	union afs_xdr_dir_block *meta, *block, *pblock;
+	union afs_xdr_dirent *de, *pde;
+	struct afs_dir_iter iter = { .dvnode = vnode };
+	struct afs_fid fid;
+	unsigned int b, slot, entry;
+	loff_t i_size;
+	__be16 next;
+	int found;
+
+	_enter(",,{%d,%s},", name->len, name->name);
+
+	i_size = i_size_read(&vnode->netfs.inode);
+	if (i_size < AFS_DIR_BLOCK_SIZE ||
+	    i_size > AFS_DIR_BLOCK_SIZE * AFS_DIR_MAX_BLOCKS ||
+	    (i_size & (AFS_DIR_BLOCK_SIZE - 1))) {
+		afs_invalidate_dir(vnode, afs_dir_invalid_edit_rem_bad_size);
+		return;
+	}
+
+	if (!afs_dir_init_iter(&iter, name))
+		return;
+
+	meta = afs_dir_get_block(&iter, 0);
+	if (!meta)
+		return;
+
+	/* Find the entry in the blob. */
+	found = afs_dir_search_bucket(&iter, name, &fid);
+	if (found < 0) {
+		/* Didn't find the dirent to clobber.  Re-download. */
+		trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_noent,
+				   0, 0, 0, 0, name->name);
+		afs_invalidate_dir(vnode, afs_dir_invalid_edit_rem_wrong_name);
+		goto out_unmap;
+	}
+
+	entry = found;
+	b    = entry / AFS_DIR_SLOTS_PER_BLOCK;
+	slot = entry % AFS_DIR_SLOTS_PER_BLOCK;
+
+	block = afs_dir_find_block(&iter, b);
+	if (!block)
+		goto error;
+	if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+		goto already_invalidated;
+
+	/* Check and clear the entry. */
+	de = &block->dirents[slot];
+	if (de->u.valid != 1)
+		goto error_unmap;
+
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_delete, b, slot,
+			   ntohl(de->u.vnode), ntohl(de->u.unique),
+			   name->name);
+
+	/* Adjust the bitmap. */
+	afs_clear_contig_bits(block, slot, iter.nr_slots);
+
+	/* Adjust the allocation counter. */
+	if (b < AFS_DIR_BLOCKS_WITH_CTR)
+		meta->meta.alloc_ctrs[b] += iter.nr_slots;
+
+	/* Clear the constituent entries. */
+	next = de->u.hash_next;
+	memset(de, 0, sizeof(*de) * iter.nr_slots);
+	kunmap_local(block);
+
+	/* Adjust the hash chain: if iter->prev_entry is 0, the hashtable head
+	 * index is previous; otherwise it's slot number of the previous entry.
+	 */
+	if (!iter.prev_entry) {
+		__be16 prev_next = meta->meta.hashtable[iter.bucket];
+
+		if (unlikely(prev_next != htons(entry))) {
+			pr_warn("%llx:%llx:%x: not head of chain b=%x p=%x,%x e=%x %*s",
+				vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
+				iter.bucket, iter.prev_entry, prev_next, entry,
+				name->len, name->name);
+			goto error;
+		}
+		meta->meta.hashtable[iter.bucket] = next;
+	} else {
+		unsigned int pb = iter.prev_entry / AFS_DIR_SLOTS_PER_BLOCK;
+		unsigned int ps = iter.prev_entry % AFS_DIR_SLOTS_PER_BLOCK;
+		__be16 prev_next;
+
+		pblock = afs_dir_find_block(&iter, pb);
+		if (!pblock)
+			goto error;
+		pde = &pblock->dirents[ps];
+		prev_next = pde->u.hash_next;
+		if (prev_next != htons(entry)) {
+			kunmap_local(pblock);
+			pr_warn("%llx:%llx:%x: not prev in chain b=%x p=%x,%x e=%x %*s",
+				vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
+				iter.bucket, iter.prev_entry, prev_next, entry,
+				name->len, name->name);
+			goto error;
+		}
+		pde->u.hash_next = next;
+		kunmap_local(pblock);
+	}
+
+	netfs_single_mark_inode_dirty(&vnode->netfs.inode);
+
+	inode_set_iversion_raw(&vnode->netfs.inode, vnode->status.data_version);
+	afs_stat_v(vnode, n_dir_rm);
+	_debug("Remove %s from %u[%u]", name->name, b, slot);
+
+out_unmap:
+	kunmap_local(meta);
+	_leave("");
+	return;
+
+already_invalidated:
+	kunmap_local(block);
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_inval,
+			   0, 0, 0, 0, name->name);
+	goto out_unmap;
+
+error_unmap:
+	kunmap_local(block);
+error:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_error,
+			   0, 0, 0, 0, name->name);
+	goto out_unmap;
+}
+
+/*
+ * Edit an entry in a directory to update the vnode it refers to.  This is also
+ * used to update the ".." entry in a directory.
+ */
+void afs_edit_dir_update(struct afs_vnode *vnode, const struct qstr *name,
+			 struct afs_vnode *new_dvnode, enum afs_edit_dir_reason why)
+{
+	union afs_xdr_dir_block *block;
+	union afs_xdr_dirent *de;
+	struct afs_dir_iter iter = { .dvnode = vnode };
+	unsigned int nr_blocks, b;
+	loff_t i_size;
+	int slot;
+
+	_enter("");
+
+	i_size = i_size_read(&vnode->netfs.inode);
+	if (i_size < AFS_DIR_BLOCK_SIZE) {
+		afs_invalidate_dir(vnode, afs_dir_invalid_edit_upd_bad_size);
+		return;
+	}
+
+	nr_blocks = i_size / AFS_DIR_BLOCK_SIZE;
+
+	/* Find a block that has sufficient slots available.  Each folio
+	 * contains two or more directory blocks.
+	 */
+	for (b = 0; b < nr_blocks; b++) {
+		block = afs_dir_get_block(&iter, b);
+		if (!block)
+			goto error;
+
+		/* Abandon the edit if we got a callback break. */
+		if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+			goto already_invalidated;
+
+		slot = afs_dir_scan_block(block, name, b);
+		if (slot >= 0)
+			goto found_dirent;
+
+		kunmap_local(block);
+	}
+
+	/* Didn't find the dirent to clobber.  Download the directory again. */
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_update_nodd,
+			   0, 0, 0, 0, name->name);
+	afs_invalidate_dir(vnode, afs_dir_invalid_edit_upd_no_dd);
+	goto out;
+
+found_dirent:
+	de = &block->dirents[slot];
+	de->u.vnode  = htonl(new_dvnode->fid.vnode);
+	de->u.unique = htonl(new_dvnode->fid.unique);
+
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_update_dd, b, slot,
+			   ntohl(de->u.vnode), ntohl(de->u.unique), name->name);
+
+	kunmap_local(block);
+	netfs_single_mark_inode_dirty(&vnode->netfs.inode);
+	inode_set_iversion_raw(&vnode->netfs.inode, vnode->status.data_version);
+
+out:
+	_leave("");
+	return;
+
+already_invalidated:
+	kunmap_local(block);
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_update_inval,
+			   0, 0, 0, 0, name->name);
+	goto out;
+
+error:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_update_error,
+			   0, 0, 0, 0, name->name);
+	goto out;
+}
+
+/*
+ * Initialise a new directory.  We need to fill in the "." and ".." entries.
+ */
+void afs_mkdir_init_dir(struct afs_vnode *dvnode, struct afs_vnode *parent_dvnode)
+{
+	union afs_xdr_dir_block *meta;
+	struct afs_dir_iter iter = { .dvnode = dvnode };
+	union afs_xdr_dirent *de;
+	unsigned int slot = AFS_DIR_RESV_BLOCKS0;
+	loff_t i_size;
+
+	i_size = i_size_read(&dvnode->netfs.inode);
+	if (i_size != AFS_DIR_BLOCK_SIZE) {
+		afs_invalidate_dir(dvnode, afs_dir_invalid_edit_add_bad_size);
+		return;
+	}
+
+	meta = afs_dir_get_block(&iter, 0);
+	if (!meta)
+		return;
+
+	afs_edit_init_block(meta, meta, 0);
+
+	de = &meta->dirents[slot];
+	de->u.valid  = 1;
+	de->u.vnode  = htonl(dvnode->fid.vnode);
+	de->u.unique = htonl(dvnode->fid.unique);
+	memcpy(de->u.name, ".", 2);
+	trace_afs_edit_dir(dvnode, afs_edit_dir_for_mkdir, afs_edit_dir_mkdir, 0, slot,
+			   dvnode->fid.vnode, dvnode->fid.unique, ".");
+	slot++;
+
+	de = &meta->dirents[slot];
+	de->u.valid  = 1;
+	de->u.vnode  = htonl(parent_dvnode->fid.vnode);
+	de->u.unique = htonl(parent_dvnode->fid.unique);
+	memcpy(de->u.name, "..", 3);
+	trace_afs_edit_dir(dvnode, afs_edit_dir_for_mkdir, afs_edit_dir_mkdir, 0, slot,
+			   parent_dvnode->fid.vnode, parent_dvnode->fid.unique, "..");
+
+	afs_set_contig_bits(meta, AFS_DIR_RESV_BLOCKS0, 2);
+	meta->meta.alloc_ctrs[0] -= 2;
+	kunmap_local(meta);
+
+	netfs_single_mark_inode_dirty(&dvnode->netfs.inode);
+	set_bit(AFS_VNODE_DIR_VALID, &dvnode->flags);
+	set_bit(AFS_VNODE_DIR_READ, &dvnode->flags);
+}