Merge branch 'afs-dh' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull AFS updates from Al Viro:
 "The AFS series posted by dhowells depended upon lookup_one_len()
  rework; now that prereq is in the mainline, that series had been
  rebased on top of it and got some exposure and testing..."

* 'afs-dh' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  afs: Do better accretion of small writes on newly created content
  afs: Add stats for data transfer operations
  afs: Trace protocol errors
  afs: Locally edit directory data for mkdir/create/unlink/...
  afs: Adjust the directory XDR structures
  afs: Split the directory content defs into a header
  afs: Fix directory handling
  afs: Split the dynroot stuff out and give it its own ops tables
  afs: Keep track of invalid-before version for dentry coherency
  afs: Rearrange status mapping
  afs: Make it possible to get the data version in readpage
  afs: Init inode before accessing cache
  afs: Introduce a statistics proc file
  afs: Dump bad status record
  afs: Implement @cell substitution handling
  afs: Implement @sys substitution handling
  afs: Prospectively look up extra files when doing a single lookup
  afs: Don't over-increment the cell usage count when pinning it
  afs: Fix checker warnings
  vfs: Remove the const from dir_context::actor

Documentation/filesystems/afs.txt

@@ -11,7 +11,7 @@ Contents:
  - Proc filesystem.
  - The cell database.
  - Security.
- - Examples.
+ - The @sys substitution.
 
 
 ========
@@ -230,3 +230,29 @@ If a file is opened with a particular key and then the file descriptor is
 passed to a process that doesn't have that key (perhaps over an AF_UNIX
 socket), then the operations on the file will be made with key that was used to
 open the file.
+
+
+=====================
+THE @SYS SUBSTITUTION
+=====================
+
+The list of up to 16 @sys substitutions for the current network namespace can
+be configured by writing a list to /proc/fs/afs/sysname:
+
+	[root@andromeda ~]# echo foo amd64_linux_26 >/proc/fs/afs/sysname
+
+or cleared entirely by writing an empty list:
+
+	[root@andromeda ~]# echo >/proc/fs/afs/sysname
+
+The current list for current network namespace can be retrieved by:
+
+	[root@andromeda ~]# cat /proc/fs/afs/sysname
+	foo
+	amd64_linux_26
+
+When @sys is being substituted for, each element of the list is tried in the
+order given.
+
+By default, the list will contain one item that conforms to the pattern
+"<arch>_linux_26", amd64 being the name for x86_64.

fs/afs/Makefile

@@ -12,6 +12,8 @@ kafs-objs := \
 	cell.o \
 	cmservice.o \
 	dir.o \
+	dir_edit.o \
+	dynroot.o \
 	file.o \
 	flock.o \
 	fsclient.o \

fs/afs/addr_list.c

@@ -243,9 +243,9 @@ void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
 		    xport == a->sin6_port)
 			return;
 		if (xdr == a->sin6_addr.s6_addr32[3] &&
-		    xport < a->sin6_port)
+		    (u16 __force)xport < (u16 __force)a->sin6_port)
 			break;
-		if (xdr < a->sin6_addr.s6_addr32[3])
+		if ((u32 __force)xdr < (u32 __force)a->sin6_addr.s6_addr32[3])
 			break;
 	}
 
@@ -280,7 +280,7 @@ void afs_merge_fs_addr6(struct afs_addr_list *alist, __be32 *xdr, u16 port)
 		    xport == a->sin6_port)
 			return;
 		if (diff == 0 &&
-		    xport < a->sin6_port)
+		    (u16 __force)xport < (u16 __force)a->sin6_port)
 			break;
 		if (diff < 0)
 			break;

fs/afs/afs.h

@@ -67,10 +67,14 @@ typedef enum {
 } afs_callback_type_t;
 
 struct afs_callback {
-	struct afs_fid		fid;		/* file identifier */
-	unsigned		version;	/* callback version */
-	unsigned		expiry;		/* time at which expires */
-	afs_callback_type_t	type;		/* type of callback */
+	unsigned		version;	/* Callback version */
+	unsigned		expiry;		/* Time at which expires */
+	afs_callback_type_t	type;		/* Type of callback */
+};
+
+struct afs_callback_break {
+	struct afs_fid		fid;		/* File identifier */
+	struct afs_callback	cb;		/* Callback details */
 };
 
 #define AFSCBMAX 50	/* maximum callbacks transferred per bulk op */
@@ -123,21 +127,20 @@ typedef u32 afs_access_t;
  * AFS file status information
  */
 struct afs_file_status {
-	unsigned		if_version;	/* interface version */
-#define AFS_FSTATUS_VERSION	1
+	u64			size;		/* file size */
+	afs_dataversion_t	data_version;	/* current data version */
+	time_t			mtime_client;	/* last time client changed data */
+	time_t			mtime_server;	/* last time server changed data */
+	unsigned		abort_code;	/* Abort if bulk-fetching this failed */
 
 	afs_file_type_t		type;		/* file type */
 	unsigned		nlink;		/* link count */
-	u64			size;		/* file size */
-	afs_dataversion_t	data_version;	/* current data version */
 	u32			author;		/* author ID */
-	kuid_t			owner;		/* owner ID */
-	kgid_t			group;		/* group ID */
+	u32			owner;		/* owner ID */
+	u32			group;		/* group ID */
 	afs_access_t		caller_access;	/* access rights for authenticated caller */
 	afs_access_t		anon_access;	/* access rights for unauthenticated caller */
 	umode_t			mode;		/* UNIX mode */
-	time_t			mtime_client;	/* last time client changed data */
-	time_t			mtime_server;	/* last time server changed data */
 	s32			lock_count;	/* file lock count (0=UNLK -1=WRLCK +ve=#RDLCK */
 };
 

fs/afs/afs_fs.h

@@ -31,10 +31,12 @@ enum AFS_FS_Operations {
 	FSGETVOLUMEINFO		= 148,	/* AFS Get information about a volume */
 	FSGETVOLUMESTATUS	= 149,	/* AFS Get volume status information */
 	FSGETROOTVOLUME		= 151,	/* AFS Get root volume name */
+	FSBULKSTATUS		= 155,	/* AFS Fetch multiple file statuses */
 	FSSETLOCK		= 156,	/* AFS Request a file lock */
 	FSEXTENDLOCK		= 157,	/* AFS Extend a file lock */
 	FSRELEASELOCK		= 158,	/* AFS Release a file lock */
 	FSLOOKUP		= 161,	/* AFS lookup file in directory */
+	FSINLINEBULKSTATUS	= 65536, /* AFS Fetch multiple file statuses with inline errors */
 	FSFETCHDATA64		= 65537, /* AFS Fetch file data */
 	FSSTOREDATA64		= 65538, /* AFS Store file data */
 	FSGIVEUPALLCALLBACKS	= 65539, /* AFS Give up all outstanding callbacks on a server */

fs/afs/callback.c

@@ -96,26 +96,6 @@ int afs_register_server_cb_interest(struct afs_vnode *vnode,
 	return 0;
 }
 
-/*
- * Set a vnode's interest on a server.
- */
-void afs_set_cb_interest(struct afs_vnode *vnode, struct afs_cb_interest *cbi)
-{
-	struct afs_cb_interest *old_cbi = NULL;
-
-	if (vnode->cb_interest == cbi)
-		return;
-
-	write_seqlock(&vnode->cb_lock);
-	if (vnode->cb_interest != cbi) {
-		afs_get_cb_interest(cbi);
-		old_cbi = vnode->cb_interest;
-		vnode->cb_interest = cbi;
-	}
-	write_sequnlock(&vnode->cb_lock);
-	afs_put_cb_interest(afs_v2net(vnode), cbi);
-}
-
 /*
  * Remove an interest on a server.
  */
@@ -150,6 +130,7 @@ void afs_break_callback(struct afs_vnode *vnode)
 
 	write_seqlock(&vnode->cb_lock);
 
+	clear_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
 	if (test_and_clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
 		vnode->cb_break++;
 		afs_clear_permits(vnode);
@@ -207,7 +188,7 @@ static void afs_break_one_callback(struct afs_server *server,
  * allow the fileserver to break callback promises
  */
 void afs_break_callbacks(struct afs_server *server, size_t count,
-			 struct afs_callback callbacks[])
+			 struct afs_callback_break *callbacks)
 {
 	_enter("%p,%zu,", server, count);
 
@@ -219,9 +200,9 @@ void afs_break_callbacks(struct afs_server *server, size_t count,
 		       callbacks->fid.vid,
 		       callbacks->fid.vnode,
 		       callbacks->fid.unique,
-		       callbacks->version,
-		       callbacks->expiry,
-		       callbacks->type
+		       callbacks->cb.version,
+		       callbacks->cb.expiry,
+		       callbacks->cb.type
 		       );
 		afs_break_one_callback(server, &callbacks->fid);
 	}

fs/afs/cell.c

@@ -18,7 +18,7 @@
 #include <keys/rxrpc-type.h>
 #include "internal.h"
 
-unsigned __read_mostly afs_cell_gc_delay = 10;
+static unsigned __read_mostly afs_cell_gc_delay = 10;
 
 static void afs_manage_cell(struct work_struct *);
 
@@ -75,7 +75,7 @@ struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net,
 			cell = rcu_dereference_raw(net->ws_cell);
 			if (cell) {
 				afs_get_cell(cell);
-				continue;
+				break;
 			}
 			ret = -EDESTADDRREQ;
 			continue;
@@ -130,6 +130,8 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
 		_leave(" = -ENAMETOOLONG");
 		return ERR_PTR(-ENAMETOOLONG);
 	}
+	if (namelen == 5 && memcmp(name, "@cell", 5) == 0)
+		return ERR_PTR(-EINVAL);
 
 	_enter("%*.*s,%s", namelen, namelen, name, vllist);
 
@@ -334,8 +336,8 @@ int afs_cell_init(struct afs_net *net, const char *rootcell)
 		return PTR_ERR(new_root);
 	}
 
-	set_bit(AFS_CELL_FL_NO_GC, &new_root->flags);
-	afs_get_cell(new_root);
+	if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags))
+		afs_get_cell(new_root);
 
 	/* install the new cell */
 	write_seqlock(&net->cells_lock);
@@ -411,7 +413,7 @@ static void afs_cell_destroy(struct rcu_head *rcu)
 
 	ASSERTCMP(atomic_read(&cell->usage), ==, 0);
 
-	afs_put_addrlist(cell->vl_addrs);
+	afs_put_addrlist(rcu_access_pointer(cell->vl_addrs));
 	key_put(cell->anonymous_key);
 	kfree(cell);
 

fs/afs/cmservice.c

@@ -178,8 +178,8 @@ static void SRXAFSCB_CallBack(struct work_struct *work)
  */
 static int afs_deliver_cb_callback(struct afs_call *call)
 {
+	struct afs_callback_break *cb;
 	struct sockaddr_rxrpc srx;
-	struct afs_callback *cb;
 	struct afs_server *server;
 	__be32 *bp;
 	int ret, loop;
@@ -201,7 +201,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->count = ntohl(call->tmp);
 		_debug("FID count: %u", call->count);
 		if (call->count > AFSCBMAX)
-			return -EBADMSG;
+			return afs_protocol_error(call, -EBADMSG);
 
 		call->buffer = kmalloc(call->count * 3 * 4, GFP_KERNEL);
 		if (!call->buffer)
@@ -218,7 +218,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 
 		_debug("unmarshall FID array");
 		call->request = kcalloc(call->count,
-					sizeof(struct afs_callback),
+					sizeof(struct afs_callback_break),
 					GFP_KERNEL);
 		if (!call->request)
 			return -ENOMEM;
@@ -229,7 +229,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 			cb->fid.vid	= ntohl(*bp++);
 			cb->fid.vnode	= ntohl(*bp++);
 			cb->fid.unique	= ntohl(*bp++);
-			cb->type	= AFSCM_CB_UNTYPED;
+			cb->cb.type	= AFSCM_CB_UNTYPED;
 		}
 
 		call->offset = 0;
@@ -245,7 +245,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->count2 = ntohl(call->tmp);
 		_debug("CB count: %u", call->count2);
 		if (call->count2 != call->count && call->count2 != 0)
-			return -EBADMSG;
+			return afs_protocol_error(call, -EBADMSG);
 		call->offset = 0;
 		call->unmarshall++;
 
@@ -260,9 +260,9 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		cb = call->request;
 		bp = call->buffer;
 		for (loop = call->count2; loop > 0; loop--, cb++) {
-			cb->version	= ntohl(*bp++);
-			cb->expiry	= ntohl(*bp++);
-			cb->type	= ntohl(*bp++);
+			cb->cb.version	= ntohl(*bp++);
+			cb->cb.expiry	= ntohl(*bp++);
+			cb->cb.type	= ntohl(*bp++);
 		}
 
 		call->offset = 0;
@@ -500,9 +500,9 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 
 		b = call->buffer;
 		r = call->request;
-		r->time_low			= ntohl(b[0]);
-		r->time_mid			= ntohl(b[1]);
-		r->time_hi_and_version		= ntohl(b[2]);
+		r->time_low			= b[0];
+		r->time_mid			= htons(ntohl(b[1]));
+		r->time_hi_and_version		= htons(ntohl(b[2]));
 		r->clock_seq_hi_and_reserved 	= ntohl(b[3]);
 		r->clock_seq_low		= ntohl(b[4]);
 

fs/afs/dir_edit.c

+/* AFS filesystem directory editing
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/pagemap.h>
+#include <linux/iversion.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, before, after;
+
+	mask = (1 << nr_slots) - 1;
+	mask <<= bit;
+
+	before = *(u64 *)block->hdr.bitmap;
+
+	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);
+
+	after = *(u64 *)block->hdr.bitmap;
+}
+
+/*
+ * 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, before, after;
+
+	mask = (1 << nr_slots) - 1;
+	mask <<= bit;
+
+	before = *(u64 *)block->hdr.bitmap;
+
+	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);
+
+	after = *(u64 *)block->hdr.bitmap;
+}
+
+/*
+ * Scan a directory block looking for a dirent of the right name.
+ */
+static int afs_dir_scan_block(union afs_xdr_dir_block *block, struct qstr *name,
+			      unsigned int blocknum)
+{
+	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,
+		      struct qstr *name, struct afs_fid *new_fid,
+		      enum afs_edit_dir_reason why)
+{
+	union afs_xdr_dir_block *meta, *block;
+	struct afs_xdr_dir_page *meta_page, *dir_page;
+	union afs_xdr_dirent *de;
+	struct page *page0, *page;
+	unsigned int need_slots, nr_blocks, b;
+	pgoff_t index;
+	loff_t i_size;
+	gfp_t gfp;
+	int slot;
+
+	_enter(",,{%d,%s},", name->len, name->name);
+
+	i_size = i_size_read(&vnode->vfs_inode);
+	if (i_size > AFS_DIR_BLOCK_SIZE * AFS_DIR_MAX_BLOCKS ||
+	    (i_size & (AFS_DIR_BLOCK_SIZE - 1))) {
+		clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+		return;
+	}
+
+	gfp = vnode->vfs_inode.i_mapping->gfp_mask;
+	page0 = find_or_create_page(vnode->vfs_inode.i_mapping, 0, gfp);
+	if (!page0) {
+		clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+		_leave(" [fgp]");
+		return;
+	}
+
+	/* Work out how many slots we're going to need. */
+	need_slots = round_up(12 + name->len + 1 + 4, AFS_DIR_DIRENT_SIZE);
+	need_slots /= AFS_DIR_DIRENT_SIZE;
+
+	meta_page = kmap(page0);
+	meta = &meta_page->blocks[0];
+	if (i_size == 0)
+		goto new_directory;
+	nr_blocks = i_size / AFS_DIR_BLOCK_SIZE;
+
+	/* Find a block that has sufficient slots available.  Each VM page
+	 * contains two or more directory blocks.
+	 */
+	for (b = 0; b < nr_blocks + 1; b++) {
+		/* If the directory extended into a new page, then we need to
+		 * tack a new page on the end.
+		 */
+		index = b / AFS_DIR_BLOCKS_PER_PAGE;
+		if (index == 0) {
+			page = page0;
+			dir_page = meta_page;
+		} else {
+			if (nr_blocks >= AFS_DIR_MAX_BLOCKS)
+				goto error;
+			gfp = vnode->vfs_inode.i_mapping->gfp_mask;
+			page = find_or_create_page(vnode->vfs_inode.i_mapping,
+						   index, gfp);
+			if (!page)
+				goto error;
+			if (!PagePrivate(page)) {
+				set_page_private(page, 1);
+				SetPagePrivate(page);
+			}
+			dir_page = kmap(page);
+		}
+
+		/* Abandon the edit if we got a callback break. */
+		if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+			goto invalidated;
+
+		block = &dir_page->blocks[b % AFS_DIR_BLOCKS_PER_PAGE];
+
+		_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);
+			i_size_write(&vnode->vfs_inode, (b + 1) * AFS_DIR_BLOCK_SIZE);
+		}
+
+		/* Only lower dir pages have a counter in the header. */
+		if (b >= AFS_DIR_BLOCKS_WITH_CTR ||
+		    meta->meta.alloc_ctrs[b] >= need_slots) {
+			/* We need to try and find one or more consecutive
+			 * slots to hold the entry.
+			 */
+			slot = afs_find_contig_bits(block, need_slots);
+			if (slot >= 0) {
+				_debug("slot %u", slot);
+				goto found_space;
+			}
+		}
+
+		if (page != page0) {
+			unlock_page(page);
+			kunmap(page);
+			put_page(page);
+		}
+	}
+
+	/* 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);
+	clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+	goto out_unmap;
+
+new_directory:
+	afs_edit_init_block(meta, meta, 0);
+	i_size = AFS_DIR_BLOCK_SIZE;
+	i_size_write(&vnode->vfs_inode, i_size);
+	slot = AFS_DIR_RESV_BLOCKS0;
+	page = page0;
+	block = meta;
+	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, need_slots);
+	if (page != page0) {
+		unlock_page(page);
+		kunmap(page);
+		put_page(page);
+	}
+
+	/* Adjust the allocation counter. */
+	if (b < AFS_DIR_BLOCKS_WITH_CTR)
+		meta->meta.alloc_ctrs[b] -= need_slots;
+
+	inode_inc_iversion_raw(&vnode->vfs_inode);
+	afs_stat_v(vnode, n_dir_cr);
+	_debug("Insert %s in %u[%u]", name->name, b, slot);
+
+out_unmap:
+	unlock_page(page0);
+	kunmap(page0);
+	put_page(page0);
+	_leave("");
+	return;
+
+invalidated:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_create_inval, 0, 0, 0, 0, name->name);
+	clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+	if (page != page0) {
+		kunmap(page);
+		put_page(page);
+	}
+	goto out_unmap;
+
+error:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_create_error, 0, 0, 0, 0, name->name);
+	clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+	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,
+			 struct qstr *name, enum afs_edit_dir_reason why)
+{
+	struct afs_xdr_dir_page *meta_page, *dir_page;
+	union afs_xdr_dir_block *meta, *block;
+	union afs_xdr_dirent *de;
+	struct page *page0, *page;
+	unsigned int need_slots, nr_blocks, b;
+	pgoff_t index;
+	loff_t i_size;
+	int slot;
+
+	_enter(",,{%d,%s},", name->len, name->name);
+
+	i_size = i_size_read(&vnode->vfs_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))) {
+		clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+		return;
+	}
+	nr_blocks = i_size / AFS_DIR_BLOCK_SIZE;
+
+	page0 = find_lock_page(vnode->vfs_inode.i_mapping, 0);
+	if (!page0) {
+		clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+		_leave(" [fgp]");
+		return;
+	}
+
+	/* Work out how many slots we're going to discard. */
+	need_slots = round_up(12 + name->len + 1 + 4, AFS_DIR_DIRENT_SIZE);
+	need_slots /= AFS_DIR_DIRENT_SIZE;
+
+	meta_page = kmap(page0);
+	meta = &meta_page->blocks[0];
+
+	/* Find a page that has sufficient slots available.  Each VM page
+	 * contains two or more directory blocks.
+	 */
+	for (b = 0; b < nr_blocks; b++) {
+		index = b / AFS_DIR_BLOCKS_PER_PAGE;
+		if (index != 0) {
+			page = find_lock_page(vnode->vfs_inode.i_mapping, index);
+			if (!page)
+				goto error;
+			dir_page = kmap(page);
+		} else {
+			page = page0;
+			dir_page = meta_page;
+		}
+
+		/* Abandon the edit if we got a callback break. */
+		if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+			goto invalidated;
+
+		block = &dir_page->blocks[b % AFS_DIR_BLOCKS_PER_PAGE];
+
+		if (b > AFS_DIR_BLOCKS_WITH_CTR ||
+		    meta->meta.alloc_ctrs[b] <= AFS_DIR_SLOTS_PER_BLOCK - 1 - need_slots) {
+			slot = afs_dir_scan_block(block, name, b);
+			if (slot >= 0)
+				goto found_dirent;
+		}
+
+		if (page != page0) {
+			unlock_page(page);
+			kunmap(page);
+			put_page(page);
+		}
+	}
+
+	/* Didn't find the dirent to clobber.  Download the directory again. */
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_noent,
+			   0, 0, 0, 0, name->name);
+	clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+	goto out_unmap;
+
+found_dirent:
+	de = &block->dirents[slot];
+
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_delete, b, slot,
+			   ntohl(de->u.vnode), ntohl(de->u.unique),
+			   name->name);
+
+	memset(de, 0, sizeof(*de) * need_slots);
+
+	/* Adjust the bitmap. */
+	afs_clear_contig_bits(block, slot, need_slots);
+	if (page != page0) {
+		unlock_page(page);
+		kunmap(page);
+		put_page(page);
+	}
+
+	/* Adjust the allocation counter. */
+	if (b < AFS_DIR_BLOCKS_WITH_CTR)
+		meta->meta.alloc_ctrs[b] += need_slots;
+
+	inode_set_iversion_raw(&vnode->vfs_inode, vnode->status.data_version);
+	afs_stat_v(vnode, n_dir_rm);
+	_debug("Remove %s from %u[%u]", name->name, b, slot);
+
+out_unmap:
+	unlock_page(page0);
+	kunmap(page0);
+	put_page(page0);
+	_leave("");
+	return;
+
+invalidated:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_inval,
+			   0, 0, 0, 0, name->name);
+	clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+	if (page != page0) {
+		unlock_page(page);
+		kunmap(page);
+		put_page(page);
+	}
+	goto out_unmap;
+
+error:
+	trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_error,
+			   0, 0, 0, 0, name->name);
+	clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+	goto out_unmap;
+}

fs/afs/dynroot.c

+/* dir.c: AFS dynamic root handling
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/dns_resolver.h>
+#include "internal.h"
+
+const struct file_operations afs_dynroot_file_operations = {
+	.open		= dcache_dir_open,
+	.release	= dcache_dir_close,
+	.iterate_shared	= dcache_readdir,
+	.llseek		= dcache_dir_lseek,
+};
+
+/*
+ * Probe to see if a cell may exist.  This prevents positive dentries from
+ * being created unnecessarily.
+ */
+static int afs_probe_cell_name(struct dentry *dentry)
+{
+	struct afs_cell *cell;
+	const char *name = dentry->d_name.name;
+	size_t len = dentry->d_name.len;
+	int ret;
+
+	/* Names prefixed with a dot are R/W mounts. */
+	if (name[0] == '.') {
+		if (len == 1)
+			return -EINVAL;
+		name++;
+		len--;
+	}
+
+	cell = afs_lookup_cell_rcu(afs_d2net(dentry), name, len);
+	if (!IS_ERR(cell)) {
+		afs_put_cell(afs_d2net(dentry), cell);
+		return 0;
+	}
+
+	ret = dns_query("afsdb", name, len, "ipv4", NULL, NULL);
+	if (ret == -ENODATA)
+		ret = -EDESTADDRREQ;
+	return ret;
+}
+
+/*
+ * Try to auto mount the mountpoint with pseudo directory, if the autocell
+ * operation is setted.
+ */
+struct inode *afs_try_auto_mntpt(struct dentry *dentry, struct inode *dir)
+{
+	struct afs_vnode *vnode = AFS_FS_I(dir);
+	struct inode *inode;
+	int ret = -ENOENT;
+
+	_enter("%p{%pd}, {%x:%u}",
+	       dentry, dentry, vnode->fid.vid, vnode->fid.vnode);
+
+	if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
+		goto out;
+
+	ret = afs_probe_cell_name(dentry);
+	if (ret < 0)
+		goto out;
+
+	inode = afs_iget_pseudo_dir(dir->i_sb, false);
+	if (IS_ERR(inode)) {
+		ret = PTR_ERR(inode);
+		goto out;
+	}
+
+	_leave("= %p", inode);
+	return inode;
+
+out:
+	_leave("= %d", ret);
+	return ERR_PTR(ret);
+}
+
+/*
+ * Look up @cell in a dynroot directory.  This is a substitution for the
+ * local cell name for the net namespace.
+ */
+static struct dentry *afs_lookup_atcell(struct dentry *dentry)
+{
+	struct afs_cell *cell;
+	struct afs_net *net = afs_d2net(dentry);
+	struct dentry *ret;
+	unsigned int seq = 0;
+	char *name;
+	int len;
+
+	if (!net->ws_cell)
+		return ERR_PTR(-ENOENT);
+
+	ret = ERR_PTR(-ENOMEM);
+	name = kmalloc(AFS_MAXCELLNAME + 1, GFP_KERNEL);
+	if (!name)
+		goto out_p;
+
+	rcu_read_lock();
+	do {
+		read_seqbegin_or_lock(&net->cells_lock, &seq);
+		cell = rcu_dereference_raw(net->ws_cell);
+		if (cell) {
+			len = cell->name_len;
+			memcpy(name, cell->name, len + 1);
+		}
+	} while (need_seqretry(&net->cells_lock, seq));
+	done_seqretry(&net->cells_lock, seq);
+	rcu_read_unlock();
+
+	ret = ERR_PTR(-ENOENT);
+	if (!cell)
+		goto out_n;
+
+	ret = lookup_one_len(name, dentry->d_parent, len);
+
+	/* We don't want to d_add() the @cell dentry here as we don't want to
+	 * the cached dentry to hide changes to the local cell name.
+	 */
+
+out_n:
+	kfree(name);
+out_p:
+	return ret;
+}
+
+/*
+ * Look up an entry in a dynroot directory.
+ */
+static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry,
+					 unsigned int flags)
+{
+	struct afs_vnode *vnode;
+	struct inode *inode;
+	int ret;
+
+	vnode = AFS_FS_I(dir);
+
+	_enter("%pd", dentry);
+
+	ASSERTCMP(d_inode(dentry), ==, NULL);
+
+	if (dentry->d_name.len >= AFSNAMEMAX) {
+		_leave(" = -ENAMETOOLONG");
+		return ERR_PTR(-ENAMETOOLONG);
+	}
+
+	if (dentry->d_name.len == 5 &&
+	    memcmp(dentry->d_name.name, "@cell", 5) == 0)
+		return afs_lookup_atcell(dentry);
+
+	inode = afs_try_auto_mntpt(dentry, dir);
+	if (IS_ERR(inode)) {
+		ret = PTR_ERR(inode);
+		if (ret == -ENOENT) {
+			d_add(dentry, NULL);
+			_leave(" = NULL [negative]");
+			return NULL;
+		}
+		_leave(" = %d [do]", ret);
+		return ERR_PTR(ret);
+	}
+
+	d_add(dentry, inode);
+	_leave(" = 0 { ino=%lu v=%u }",
+	       d_inode(dentry)->i_ino, d_inode(dentry)->i_generation);
+	return NULL;
+}
+
+const struct inode_operations afs_dynroot_inode_operations = {
+	.lookup		= afs_dynroot_lookup,
+};
+
+/*
+ * Dirs in the dynamic root don't need revalidation.
+ */
+static int afs_dynroot_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	return 1;
+}
+
+/*
+ * Allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
+ * sleep)
+ * - called from dput() when d_count is going to 0.
+ * - return 1 to request dentry be unhashed, 0 otherwise
+ */
+static int afs_dynroot_d_delete(const struct dentry *dentry)
+{
+	return d_really_is_positive(dentry);
+}
+
+const struct dentry_operations afs_dynroot_dentry_operations = {
+	.d_revalidate	= afs_dynroot_d_revalidate,
+	.d_delete	= afs_dynroot_d_delete,
+	.d_release	= afs_d_release,
+	.d_automount	= afs_d_automount,
+};

fs/afs/file.c

@@ -30,7 +30,6 @@ static int afs_readpages(struct file *filp, struct address_space *mapping,
 
 const struct file_operations afs_file_operations = {
 	.open		= afs_open,
-	.flush		= afs_flush,
 	.release	= afs_release,
 	.llseek		= generic_file_llseek,
 	.read_iter	= generic_file_read_iter,
@@ -146,6 +145,9 @@ int afs_open(struct inode *inode, struct file *file)
 		if (ret < 0)
 			goto error_af;
 	}
+
+	if (file->f_flags & O_TRUNC)
+		set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
 	
 	file->private_data = af;
 	_leave(" = 0");
@@ -170,6 +172,9 @@ int afs_release(struct inode *inode, struct file *file)
 
 	_enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
 
+	if ((file->f_mode & FMODE_WRITE))
+		return vfs_fsync(file, 0);
+
 	file->private_data = NULL;
 	if (af->wb)
 		afs_put_wb_key(af->wb);
@@ -187,10 +192,12 @@ void afs_put_read(struct afs_read *req)
 {
 	int i;
 
-	if (atomic_dec_and_test(&req->usage)) {
+	if (refcount_dec_and_test(&req->usage)) {
 		for (i = 0; i < req->nr_pages; i++)
 			if (req->pages[i])
 				put_page(req->pages[i]);
+		if (req->pages != req->array)
+			kfree(req->pages);
 		kfree(req);
 	}
 }
@@ -240,6 +247,12 @@ int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *de
 		ret = afs_end_vnode_operation(&fc);
 	}
 
+	if (ret == 0) {
+		afs_stat_v(vnode, n_fetches);
+		atomic_long_add(desc->actual_len,
+				&afs_v2net(vnode)->n_fetch_bytes);
+	}
+
 	_leave(" = %d", ret);
 	return ret;
 }
@@ -297,10 +310,11 @@ int afs_page_filler(void *data, struct page *page)
 		 * end of the file, the server will return a short read and the
 		 * unmarshalling code will clear the unfilled space.
 		 */
-		atomic_set(&req->usage, 1);
+		refcount_set(&req->usage, 1);
 		req->pos = (loff_t)page->index << PAGE_SHIFT;
 		req->len = PAGE_SIZE;
 		req->nr_pages = 1;
+		req->pages = req->array;
 		req->pages[0] = page;
 		get_page(page);
 
@@ -309,10 +323,6 @@ int afs_page_filler(void *data, struct page *page)
 		ret = afs_fetch_data(vnode, key, req);
 		afs_put_read(req);
 
-		if (ret >= 0 && S_ISDIR(inode->i_mode) &&
-		    !afs_dir_check_page(inode, page))
-			ret = -EIO;
-
 		if (ret < 0) {
 			if (ret == -ENOENT) {
 				_debug("got NOENT from server"
@@ -447,10 +457,11 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 	if (!req)
 		return -ENOMEM;
 
-	atomic_set(&req->usage, 1);
+	refcount_set(&req->usage, 1);
 	req->page_done = afs_readpages_page_done;
 	req->pos = first->index;
 	req->pos <<= PAGE_SHIFT;
+	req->pages = req->array;
 
 	/* Transfer the pages to the request.  We add them in until one fails
 	 * to add to the LRU and then we stop (as that'll make a hole in the

fs/afs/flock.c

@@ -613,7 +613,7 @@ static int afs_do_getlk(struct file *file, struct file_lock *fl)
 	posix_test_lock(file, fl);
 	if (fl->fl_type == F_UNLCK) {
 		/* no local locks; consult the server */
-		ret = afs_fetch_status(vnode, key);
+		ret = afs_fetch_status(vnode, key, false);
 		if (ret < 0)
 			goto error;
 

fs/afs/inode.c

@@ -30,12 +30,11 @@ static const struct inode_operations afs_symlink_inode_operations = {
 };
 
 /*
- * map the AFS file status to the inode member variables
+ * Initialise an inode from the vnode status.
  */
-static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
+static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key)
 {
 	struct inode *inode = AFS_VNODE_TO_I(vnode);
-	bool changed;
 
 	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
 	       vnode->status.type,
@@ -46,16 +45,21 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
 
 	read_seqlock_excl(&vnode->cb_lock);
 
+	afs_update_inode_from_status(vnode, &vnode->status, NULL,
+				     AFS_VNODE_NOT_YET_SET);
+
 	switch (vnode->status.type) {
 	case AFS_FTYPE_FILE:
 		inode->i_mode	= S_IFREG | vnode->status.mode;
 		inode->i_op	= &afs_file_inode_operations;
 		inode->i_fop	= &afs_file_operations;
+		inode->i_mapping->a_ops	= &afs_fs_aops;
 		break;
 	case AFS_FTYPE_DIR:
 		inode->i_mode	= S_IFDIR | vnode->status.mode;
 		inode->i_op	= &afs_dir_inode_operations;
 		inode->i_fop	= &afs_dir_file_operations;
+		inode->i_mapping->a_ops	= &afs_dir_aops;
 		break;
 	case AFS_FTYPE_SYMLINK:
 		/* Symlinks with a mode of 0644 are actually mountpoints. */
@@ -67,45 +71,31 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
 			inode->i_mode	= S_IFDIR | 0555;
 			inode->i_op	= &afs_mntpt_inode_operations;
 			inode->i_fop	= &afs_mntpt_file_operations;
+			inode->i_mapping->a_ops	= &afs_fs_aops;
 		} else {
 			inode->i_mode	= S_IFLNK | vnode->status.mode;
 			inode->i_op	= &afs_symlink_inode_operations;
+			inode->i_mapping->a_ops	= &afs_fs_aops;
 		}
 		inode_nohighmem(inode);
 		break;
 	default:
 		printk("kAFS: AFS vnode with undefined type\n");
 		read_sequnlock_excl(&vnode->cb_lock);
-		return -EBADMSG;
+		return afs_protocol_error(NULL, -EBADMSG);
 	}
 
-	changed = (vnode->status.size != inode->i_size);
-
-	set_nlink(inode, vnode->status.nlink);
-	inode->i_uid		= vnode->status.owner;
-	inode->i_gid            = vnode->status.group;
-	inode->i_size		= vnode->status.size;
-	inode->i_ctime.tv_sec	= vnode->status.mtime_client;
-	inode->i_ctime.tv_nsec	= 0;
-	inode->i_atime		= inode->i_mtime = inode->i_ctime;
 	inode->i_blocks		= 0;
-	inode->i_generation	= vnode->fid.unique;
-	inode_set_iversion_raw(inode, vnode->status.data_version);
-	inode->i_mapping->a_ops	= &afs_fs_aops;
+	vnode->invalid_before	= vnode->status.data_version;
 
 	read_sequnlock_excl(&vnode->cb_lock);
-
-#ifdef CONFIG_AFS_FSCACHE
-	if (changed)
-		fscache_attr_changed(vnode->cache);
-#endif
 	return 0;
 }
 
 /*
  * Fetch file status from the volume.
  */
-int afs_fetch_status(struct afs_vnode *vnode, struct key *key)
+int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool new_inode)
 {
 	struct afs_fs_cursor fc;
 	int ret;
@@ -119,7 +109,7 @@ int afs_fetch_status(struct afs_vnode *vnode, struct key *key)
 	if (afs_begin_vnode_operation(&fc, vnode, key)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = vnode->cb_break + vnode->cb_s_break;
-			afs_fs_fetch_file_status(&fc, NULL);
+			afs_fs_fetch_file_status(&fc, NULL, new_inode);
 		}
 
 		afs_check_for_remote_deletion(&fc, fc.vnode);
@@ -255,6 +245,11 @@ static void afs_get_inode_cache(struct afs_vnode *vnode)
 	} __packed key;
 	struct afs_vnode_cache_aux aux;
 
+	if (vnode->status.type == AFS_FTYPE_DIR) {
+		vnode->cache = NULL;
+		return;
+	}
+
 	key.vnode_id		= vnode->fid.vnode;
 	key.unique		= vnode->fid.unique;
 	key.vnode_id_ext[0]	= 0;
@@ -307,7 +302,7 @@ struct inode *afs_iget(struct super_block *sb, struct key *key,
 
 	if (!status) {
 		/* it's a remotely extant inode */
-		ret = afs_fetch_status(vnode, key);
+		ret = afs_fetch_status(vnode, key, true);
 		if (ret < 0)
 			goto bad_inode;
 	} else {
@@ -331,15 +326,12 @@ struct inode *afs_iget(struct super_block *sb, struct key *key,
 		vnode->cb_expires_at += ktime_get_real_seconds();
 	}
 
-	/* set up caching before mapping the status, as map-status reads the
-	 * first page of symlinks to see if they're really mountpoints */
-	inode->i_size = vnode->status.size;
-	afs_get_inode_cache(vnode);
-
-	ret = afs_inode_map_status(vnode, key);
+	ret = afs_inode_init_from_status(vnode, key);
 	if (ret < 0)
 		goto bad_inode;
 
+	afs_get_inode_cache(vnode);
+
 	/* success */
 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
 	inode->i_flags |= S_NOATIME;
@@ -349,10 +341,6 @@ struct inode *afs_iget(struct super_block *sb, struct key *key,
 
 	/* failure */
 bad_inode:
-#ifdef CONFIG_AFS_FSCACHE
-	fscache_relinquish_cookie(vnode->cache, NULL, ret == -ENOENT);
-	vnode->cache = NULL;
-#endif
 	iget_failed(inode);
 	_leave(" = %d [bad]", ret);
 	return ERR_PTR(ret);
@@ -407,8 +395,11 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
 	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
 		if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break) {
 			vnode->cb_s_break = vnode->cb_interest->server->cb_s_break;
-		} else if (!test_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags) &&
-			   !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
+		} else if (vnode->status.type == AFS_FTYPE_DIR &&
+			   test_bit(AFS_VNODE_DIR_VALID, &vnode->flags) &&
+			   vnode->cb_expires_at - 10 > now) {
+				valid = true;
+		} else if (!test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
 			   vnode->cb_expires_at - 10 > now) {
 				valid = true;
 		}
@@ -432,7 +423,7 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
 	 * access */
 	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
 		_debug("not promised");
-		ret = afs_fetch_status(vnode, key);
+		ret = afs_fetch_status(vnode, key, false);
 		if (ret < 0) {
 			if (ret == -ENOENT) {
 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
@@ -453,8 +444,6 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
 	 * different */
 	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
 		afs_zap_data(vnode);
-
-	clear_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags);
 	mutex_unlock(&vnode->validate_lock);
 valid:
 	_leave(" = 0");
@@ -544,7 +533,7 @@ void afs_evict_inode(struct inode *inode)
 	}
 #endif
 
-	afs_put_permits(vnode->permit_cache);
+	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
 	_leave("");
 }
 

fs/afs/internal.h

@@ -122,7 +122,8 @@ struct afs_call {
 	u32			operation_ID;	/* operation ID for an incoming call */
 	u32			count;		/* count for use in unmarshalling */
 	__be32			tmp;		/* place to extract temporary data */
-	afs_dataversion_t	store_version;	/* updated version expected from store */
+	afs_dataversion_t	expected_version; /* Updated version expected from store */
+	afs_dataversion_t	expected_version_2; /* 2nd updated version expected from store */
 };
 
 struct afs_call_type {
@@ -173,11 +174,14 @@ struct afs_read {
 	loff_t			len;		/* How much we're asking for */
 	loff_t			actual_len;	/* How much we're actually getting */
 	loff_t			remain;		/* Amount remaining */
-	atomic_t		usage;
+	loff_t			file_size;	/* File size returned by server */
+	afs_dataversion_t	data_version;	/* Version number returned by server */
+	refcount_t		usage;
 	unsigned int		index;		/* Which page we're reading into */
 	unsigned int		nr_pages;
 	void (*page_done)(struct afs_call *, struct afs_read *);
-	struct page		*pages[];
+	struct page		**pages;
+	struct page		*array[];
 };
 
 /*
@@ -198,6 +202,18 @@ static inline struct afs_super_info *AFS_FS_S(struct super_block *sb)
 
 extern struct file_system_type afs_fs_type;
 
+/*
+ * Set of substitutes for @sys.
+ */
+struct afs_sysnames {
+#define AFS_NR_SYSNAME 16
+	char			*subs[AFS_NR_SYSNAME];
+	refcount_t		usage;
+	unsigned short		nr;
+	short			error;
+	char			blank[1];
+};
+
 /*
  * AFS network namespace record.
  */
@@ -245,9 +261,25 @@ struct afs_net {
 	struct mutex		lock_manager_mutex;
 
 	/* Misc */
-	struct proc_dir_entry	*proc_afs;		/* /proc/net/afs directory */
+	struct proc_dir_entry	*proc_afs;	/* /proc/net/afs directory */
+	struct afs_sysnames	*sysnames;
+	rwlock_t		sysnames_lock;
+
+	/* Statistics counters */
+	atomic_t		n_lookup;	/* Number of lookups done */
+	atomic_t		n_reval;	/* Number of dentries needing revalidation */
+	atomic_t		n_inval;	/* Number of invalidations by the server */
+	atomic_t		n_relpg;	/* Number of invalidations by releasepage */
+	atomic_t		n_read_dir;	/* Number of directory pages read */
+	atomic_t		n_dir_cr;	/* Number of directory entry creation edits */
+	atomic_t		n_dir_rm;	/* Number of directory entry removal edits */
+	atomic_t		n_stores;	/* Number of store ops */
+	atomic_long_t		n_store_bytes;	/* Number of bytes stored */
+	atomic_long_t		n_fetch_bytes;	/* Number of bytes fetched */
+	atomic_t		n_fetches;	/* Number of data fetch ops */
 };
 
+extern const char afs_init_sysname[];
 extern struct afs_net __afs_net;// Dummy AFS network namespace; TODO: replace with real netns
 
 enum afs_cell_state {
@@ -363,6 +395,7 @@ struct afs_server {
 #define AFS_SERVER_FL_UPDATING	4
 #define AFS_SERVER_FL_PROBED	5		/* The fileserver has been probed */
 #define AFS_SERVER_FL_PROBING	6		/* Fileserver is being probed */
+#define AFS_SERVER_FL_NO_IBULK	7		/* Fileserver doesn't support FS.InlineBulkStatus */
 	atomic_t		usage;
 	u32			addr_version;	/* Address list version */
 
@@ -455,10 +488,11 @@ struct afs_vnode {
 	struct afs_volume	*volume;	/* volume on which vnode resides */
 	struct afs_fid		fid;		/* the file identifier for this inode */
 	struct afs_file_status	status;		/* AFS status info for this file */
+	afs_dataversion_t	invalid_before;	/* Child dentries are invalid before this */
 #ifdef CONFIG_AFS_FSCACHE
 	struct fscache_cookie	*cache;		/* caching cookie */
 #endif
-	struct afs_permits	*permit_cache;	/* cache of permits so far obtained */
+	struct afs_permits __rcu *permit_cache;	/* cache of permits so far obtained */
 	struct mutex		io_lock;	/* Lock for serialising I/O on this mutex */
 	struct mutex		validate_lock;	/* lock for validating this vnode */
 	spinlock_t		wb_lock;	/* lock for wb_keys */
@@ -466,12 +500,13 @@ struct afs_vnode {
 	unsigned long		flags;
 #define AFS_VNODE_CB_PROMISED	0		/* Set if vnode has a callback promise */
 #define AFS_VNODE_UNSET		1		/* set if vnode attributes not yet set */
-#define AFS_VNODE_DIR_MODIFIED	2		/* set if dir vnode's data modified */
+#define AFS_VNODE_DIR_VALID	2		/* Set if dir contents are valid */
 #define AFS_VNODE_ZAP_DATA	3		/* set if vnode's data should be invalidated */
 #define AFS_VNODE_DELETED	4		/* set if vnode deleted on server */
 #define AFS_VNODE_MOUNTPOINT	5		/* set if vnode is a mountpoint symlink */
 #define AFS_VNODE_AUTOCELL	6		/* set if Vnode is an auto mount point */
 #define AFS_VNODE_PSEUDODIR	7 		/* set if Vnode is a pseudo directory */
+#define AFS_VNODE_NEW_CONTENT	8		/* Set if file has new content (create/trunc-0) */
 
 	struct list_head	wb_keys;	/* List of keys available for writeback */
 	struct list_head	pending_locks;	/* locks waiting to be granted */
@@ -611,7 +646,7 @@ extern struct fscache_cookie_def afs_vnode_cache_index_def;
  */
 extern void afs_init_callback_state(struct afs_server *);
 extern void afs_break_callback(struct afs_vnode *);
-extern void afs_break_callbacks(struct afs_server *, size_t,struct afs_callback[]);
+extern void afs_break_callbacks(struct afs_server *, size_t, struct afs_callback_break*);
 
 extern int afs_register_server_cb_interest(struct afs_vnode *, struct afs_server_entry *);
 extern void afs_put_cb_interest(struct afs_net *, struct afs_cb_interest *);
@@ -646,11 +681,26 @@ extern bool afs_cm_incoming_call(struct afs_call *);
  */
 extern const struct file_operations afs_dir_file_operations;
 extern const struct inode_operations afs_dir_inode_operations;
+extern const struct address_space_operations afs_dir_aops;
+extern const struct dentry_operations afs_fs_dentry_operations;
+
+extern void afs_d_release(struct dentry *);
+
+/*
+ * dir_edit.c
+ */
+extern void afs_edit_dir_add(struct afs_vnode *, struct qstr *, struct afs_fid *,
+			     enum afs_edit_dir_reason);
+extern void afs_edit_dir_remove(struct afs_vnode *, struct qstr *, enum afs_edit_dir_reason);
+
+/*
+ * dynroot.c
+ */
 extern const struct file_operations afs_dynroot_file_operations;
 extern const struct inode_operations afs_dynroot_inode_operations;
-extern const struct dentry_operations afs_fs_dentry_operations;
+extern const struct dentry_operations afs_dynroot_dentry_operations;
 
-extern bool afs_dir_check_page(struct inode *, struct page *);
+extern struct inode *afs_try_auto_mntpt(struct dentry *, struct inode *);
 
 /*
  * file.c
@@ -680,17 +730,23 @@ extern int afs_flock(struct file *, int, struct file_lock *);
 /*
  * fsclient.c
  */
-extern int afs_fs_fetch_file_status(struct afs_fs_cursor *, struct afs_volsync *);
+#define AFS_VNODE_NOT_YET_SET	0x01
+#define AFS_VNODE_META_CHANGED	0x02
+#define AFS_VNODE_DATA_CHANGED	0x04
+extern void afs_update_inode_from_status(struct afs_vnode *, struct afs_file_status *,
+					 const afs_dataversion_t *, u8);
+
+extern int afs_fs_fetch_file_status(struct afs_fs_cursor *, struct afs_volsync *, bool);
 extern int afs_fs_give_up_callbacks(struct afs_net *, struct afs_server *);
 extern int afs_fs_fetch_data(struct afs_fs_cursor *, struct afs_read *);
-extern int afs_fs_create(struct afs_fs_cursor *, const char *, umode_t,
+extern int afs_fs_create(struct afs_fs_cursor *, const char *, umode_t, u64,
 			 struct afs_fid *, struct afs_file_status *, struct afs_callback *);
-extern int afs_fs_remove(struct afs_fs_cursor *, const char *, bool);
-extern int afs_fs_link(struct afs_fs_cursor *, struct afs_vnode *, const char *);
-extern int afs_fs_symlink(struct afs_fs_cursor *, const char *, const char *,
+extern int afs_fs_remove(struct afs_fs_cursor *, const char *, bool, u64);
+extern int afs_fs_link(struct afs_fs_cursor *, struct afs_vnode *, const char *, u64);
+extern int afs_fs_symlink(struct afs_fs_cursor *, const char *, const char *, u64,
 			  struct afs_fid *, struct afs_file_status *);
 extern int afs_fs_rename(struct afs_fs_cursor *, const char *,
-			 struct afs_vnode *, const char *);
+			 struct afs_vnode *, const char *, u64, u64);
 extern int afs_fs_store_data(struct afs_fs_cursor *, struct address_space *,
 			     pgoff_t, pgoff_t, unsigned, unsigned);
 extern int afs_fs_setattr(struct afs_fs_cursor *, struct iattr *);
@@ -702,11 +758,18 @@ extern int afs_fs_give_up_all_callbacks(struct afs_net *, struct afs_server *,
 					struct afs_addr_cursor *, struct key *);
 extern int afs_fs_get_capabilities(struct afs_net *, struct afs_server *,
 				   struct afs_addr_cursor *, struct key *);
+extern int afs_fs_inline_bulk_status(struct afs_fs_cursor *, struct afs_net *,
+				     struct afs_fid *, struct afs_file_status *,
+				     struct afs_callback *, unsigned int,
+				     struct afs_volsync *);
+extern int afs_fs_fetch_status(struct afs_fs_cursor *, struct afs_net *,
+			       struct afs_fid *, struct afs_file_status *,
+			       struct afs_callback *, struct afs_volsync *);
 
 /*
  * inode.c
  */
-extern int afs_fetch_status(struct afs_vnode *, struct key *);
+extern int afs_fetch_status(struct afs_vnode *, struct key *, bool);
 extern int afs_iget5_test(struct inode *, void *);
 extern struct inode *afs_iget_pseudo_dir(struct super_block *, bool);
 extern struct inode *afs_iget(struct super_block *, struct key *,
@@ -754,6 +817,13 @@ static inline void afs_put_net(struct afs_net *net)
 {
 }
 
+static inline void __afs_stat(atomic_t *s)
+{
+	atomic_inc(s);
+}
+
+#define afs_stat_v(vnode, n) __afs_stat(&afs_v2net(vnode)->n)
+
 /*
  * misc.c
  */
@@ -781,6 +851,7 @@ extern int __net_init afs_proc_init(struct afs_net *);
 extern void __net_exit afs_proc_cleanup(struct afs_net *);
 extern int afs_proc_cell_setup(struct afs_net *, struct afs_cell *);
 extern void afs_proc_cell_remove(struct afs_net *, struct afs_cell *);
+extern void afs_put_sysnames(struct afs_sysnames *);
 
 /*
  * rotate.c
@@ -809,6 +880,7 @@ extern void afs_flat_call_destructor(struct afs_call *);
 extern void afs_send_empty_reply(struct afs_call *);
 extern void afs_send_simple_reply(struct afs_call *, const void *, size_t);
 extern int afs_extract_data(struct afs_call *, void *, size_t, bool);
+extern int afs_protocol_error(struct afs_call *, int);
 
 static inline int afs_transfer_reply(struct afs_call *call)
 {
@@ -955,7 +1027,6 @@ extern int afs_writepage(struct page *, struct writeback_control *);
 extern int afs_writepages(struct address_space *, struct writeback_control *);
 extern void afs_pages_written_back(struct afs_vnode *, struct afs_call *);
 extern ssize_t afs_file_write(struct kiocb *, struct iov_iter *);
-extern int afs_flush(struct file *, fl_owner_t);
 extern int afs_fsync(struct file *, loff_t, loff_t, int);
 extern int afs_page_mkwrite(struct vm_fault *);
 extern void afs_prune_wb_keys(struct afs_vnode *);

fs/afs/main.c

@@ -34,11 +34,42 @@ MODULE_PARM_DESC(rootcell, "root AFS cell name and VL server IP addr list");
 struct workqueue_struct *afs_wq;
 struct afs_net __afs_net;
 
+#if defined(CONFIG_ALPHA)
+const char afs_init_sysname[] = "alpha_linux26";
+#elif defined(CONFIG_X86_64)
+const char afs_init_sysname[] = "amd64_linux26";
+#elif defined(CONFIG_ARM)
+const char afs_init_sysname[] = "arm_linux26";
+#elif defined(CONFIG_ARM64)
+const char afs_init_sysname[] = "aarch64_linux26";
+#elif defined(CONFIG_X86_32)
+const char afs_init_sysname[] = "i386_linux26";
+#elif defined(CONFIG_IA64)
+const char afs_init_sysname[] = "ia64_linux26";
+#elif defined(CONFIG_PPC64)
+const char afs_init_sysname[] = "ppc64_linux26";
+#elif defined(CONFIG_PPC32)
+const char afs_init_sysname[] = "ppc_linux26";
+#elif defined(CONFIG_S390)
+#ifdef CONFIG_64BIT
+const char afs_init_sysname[] = "s390x_linux26";
+#else
+const char afs_init_sysname[] = "s390_linux26";
+#endif
+#elif defined(CONFIG_SPARC64)
+const char afs_init_sysname[] = "sparc64_linux26";
+#elif defined(CONFIG_SPARC32)
+const char afs_init_sysname[] = "sparc_linux26";
+#else
+const char afs_init_sysname[] = "unknown_linux26";
+#endif
+
 /*
  * Initialise an AFS network namespace record.
  */
 static int __net_init afs_net_init(struct afs_net *net)
 {
+	struct afs_sysnames *sysnames;
 	int ret;
 
 	net->live = true;
@@ -67,6 +98,16 @@ static int __net_init afs_net_init(struct afs_net *net)
 	INIT_WORK(&net->fs_manager, afs_manage_servers);
 	timer_setup(&net->fs_timer, afs_servers_timer, 0);
 
+	ret = -ENOMEM;
+	sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
+	if (!sysnames)
+		goto error_sysnames;
+	sysnames->subs[0] = (char *)&afs_init_sysname;
+	sysnames->nr = 1;
+	refcount_set(&sysnames->usage, 1);
+	net->sysnames = sysnames;
+	rwlock_init(&net->sysnames_lock);
+
 	/* Register the /proc stuff */
 	ret = afs_proc_init(net);
 	if (ret < 0)
@@ -92,6 +133,8 @@ static int __net_init afs_net_init(struct afs_net *net)
 	net->live = false;
 	afs_proc_cleanup(net);
 error_proc:
+	afs_put_sysnames(net->sysnames);
+error_sysnames:
 	net->live = false;
 	return ret;
 }
@@ -106,6 +149,7 @@ static void __net_exit afs_net_exit(struct afs_net *net)
 	afs_purge_servers(net);
 	afs_close_socket(net);
 	afs_proc_cleanup(net);
+	afs_put_sysnames(net->sysnames);
 }
 
 /*

fs/afs/proc.c

@@ -126,6 +126,34 @@ static const struct file_operations afs_proc_servers_fops = {
 	.release	= seq_release,
 };
 
+static int afs_proc_sysname_open(struct inode *inode, struct file *file);
+static int afs_proc_sysname_release(struct inode *inode, struct file *file);
+static void *afs_proc_sysname_start(struct seq_file *p, loff_t *pos);
+static void *afs_proc_sysname_next(struct seq_file *p, void *v,
+					loff_t *pos);
+static void afs_proc_sysname_stop(struct seq_file *p, void *v);
+static int afs_proc_sysname_show(struct seq_file *m, void *v);
+static ssize_t afs_proc_sysname_write(struct file *file,
+				      const char __user *buf,
+				      size_t size, loff_t *_pos);
+
+static const struct seq_operations afs_proc_sysname_ops = {
+	.start	= afs_proc_sysname_start,
+	.next	= afs_proc_sysname_next,
+	.stop	= afs_proc_sysname_stop,
+	.show	= afs_proc_sysname_show,
+};
+
+static const struct file_operations afs_proc_sysname_fops = {
+	.open		= afs_proc_sysname_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= afs_proc_sysname_release,
+	.write		= afs_proc_sysname_write,
+};
+
+static const struct file_operations afs_proc_stats_fops;
+
 /*
  * initialise the /proc/fs/afs/ directory
  */
@@ -139,7 +167,9 @@ int afs_proc_init(struct afs_net *net)
 
 	if (!proc_create("cells", 0644, net->proc_afs, &afs_proc_cells_fops) ||
 	    !proc_create("rootcell", 0644, net->proc_afs, &afs_proc_rootcell_fops) ||
-	    !proc_create("servers", 0644, net->proc_afs, &afs_proc_servers_fops))
+	    !proc_create("servers", 0644, net->proc_afs, &afs_proc_servers_fops) ||
+	    !proc_create("stats", 0644, net->proc_afs, &afs_proc_stats_fops) ||
+	    !proc_create("sysname", 0644, net->proc_afs, &afs_proc_sysname_fops))
 		goto error_tree;
 
 	_leave(" = 0");
@@ -183,6 +213,7 @@ static int afs_proc_cells_open(struct inode *inode, struct file *file)
  * first item
  */
 static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
+	__acquires(rcu)
 {
 	struct afs_net *net = afs_seq2net(m);
 
@@ -204,6 +235,7 @@ static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
  * clean up after reading from the cells list
  */
 static void afs_proc_cells_stop(struct seq_file *m, void *v)
+	__releases(rcu)
 {
 	rcu_read_unlock();
 }
@@ -282,7 +314,8 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 			goto done;
 		}
 
-		set_bit(AFS_CELL_FL_NO_GC, &cell->flags);
+		if (test_and_set_bit(AFS_CELL_FL_NO_GC, &cell->flags))
+			afs_put_cell(net, cell);
 		printk("kAFS: Added new cell '%s'\n", name);
 	} else {
 		goto inval;
@@ -304,7 +337,40 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
 				      size_t size, loff_t *_pos)
 {
-	return 0;
+	struct afs_cell *cell;
+	struct afs_net *net = afs_proc2net(file);
+	unsigned int seq = 0;
+	char name[AFS_MAXCELLNAME + 1];
+	int len;
+
+	if (*_pos > 0)
+		return 0;
+	if (!net->ws_cell)
+		return 0;
+
+	rcu_read_lock();
+	do {
+		read_seqbegin_or_lock(&net->cells_lock, &seq);
+		len = 0;
+		cell = rcu_dereference_raw(net->ws_cell);
+		if (cell) {
+			len = cell->name_len;
+			memcpy(name, cell->name, len);
+		}
+	} while (need_seqretry(&net->cells_lock, seq));
+	done_seqretry(&net->cells_lock, seq);
+	rcu_read_unlock();
+
+	if (!len)
+		return 0;
+
+	name[len++] = '\n';
+	if (len > size)
+		len = size;
+	if (copy_to_user(buf, name, len) != 0)
+		return -EFAULT;
+	*_pos = 1;
+	return len;
 }
 
 /*
@@ -327,6 +393,12 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 	if (IS_ERR(kbuf))
 		return PTR_ERR(kbuf);
 
+	ret = -EINVAL;
+	if (kbuf[0] == '.')
+		goto out;
+	if (memchr(kbuf, '/', size))
+		goto out;
+
 	/* trim to first NL */
 	s = memchr(kbuf, '\n', size);
 	if (s)
@@ -339,6 +411,7 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 	if (ret >= 0)
 		ret = size;	/* consume everything, always */
 
+out:
 	kfree(kbuf);
 	_leave(" = %d", ret);
 	return ret;
@@ -413,6 +486,7 @@ static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
  * first item
  */
 static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
+	__acquires(cell->proc_lock)
 {
 	struct afs_cell *cell = m->private;
 
@@ -438,6 +512,7 @@ static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
  * clean up after reading from the cells list
  */
 static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
+	__releases(cell->proc_lock)
 {
 	struct afs_cell *cell = p->private;
 
@@ -500,6 +575,7 @@ static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file)
  * first item
  */
 static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
+	__acquires(rcu)
 {
 	struct afs_addr_list *alist;
 	struct afs_cell *cell = m->private;
@@ -544,6 +620,7 @@ static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
  * clean up after reading from the cells list
  */
 static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
+	__releases(rcu)
 {
 	rcu_read_unlock();
 }
@@ -580,6 +657,7 @@ static int afs_proc_servers_open(struct inode *inode, struct file *file)
  * first item.
  */
 static void *afs_proc_servers_start(struct seq_file *m, loff_t *_pos)
+	__acquires(rcu)
 {
 	struct afs_net *net = afs_seq2net(m);
 
@@ -601,6 +679,7 @@ static void *afs_proc_servers_next(struct seq_file *m, void *v, loff_t *_pos)
  * clean up after reading from the cells list
  */
 static void afs_proc_servers_stop(struct seq_file *p, void *v)
+	__releases(rcu)
 {
 	rcu_read_unlock();
 }
@@ -626,3 +705,244 @@ static int afs_proc_servers_show(struct seq_file *m, void *v)
 		   &alist->addrs[alist->index].transport);
 	return 0;
 }
+
+void afs_put_sysnames(struct afs_sysnames *sysnames)
+{
+	int i;
+
+	if (sysnames && refcount_dec_and_test(&sysnames->usage)) {
+		for (i = 0; i < sysnames->nr; i++)
+			if (sysnames->subs[i] != afs_init_sysname &&
+			    sysnames->subs[i] != sysnames->blank)
+				kfree(sysnames->subs[i]);
+	}
+}
+
+/*
+ * Handle opening of /proc/fs/afs/sysname.  If it is opened for writing, we
+ * assume the caller wants to change the substitution list and we allocate a
+ * buffer to hold the list.
+ */
+static int afs_proc_sysname_open(struct inode *inode, struct file *file)
+{
+	struct afs_sysnames *sysnames;
+	struct seq_file *m;
+	int ret;
+
+	ret = seq_open(file, &afs_proc_sysname_ops);
+	if (ret < 0)
+		return ret;
+
+	if (file->f_mode & FMODE_WRITE) {
+		sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
+		if (!sysnames) {
+			seq_release(inode, file);
+			return -ENOMEM;
+		}
+
+		refcount_set(&sysnames->usage, 1);
+		m = file->private_data;
+		m->private = sysnames;
+	}
+
+	return 0;
+}
+
+/*
+ * Handle writes to /proc/fs/afs/sysname to set the @sys substitution.
+ */
+static ssize_t afs_proc_sysname_write(struct file *file,
+				      const char __user *buf,
+				      size_t size, loff_t *_pos)
+{
+	struct afs_sysnames *sysnames;
+	struct seq_file *m = file->private_data;
+	char *kbuf = NULL, *s, *p, *sub;
+	int ret, len;
+
+	sysnames = m->private;
+	if (!sysnames)
+		return -EINVAL;
+	if (sysnames->error)
+		return sysnames->error;
+
+	if (size >= PAGE_SIZE - 1) {
+		sysnames->error = -EINVAL;
+		return -EINVAL;
+	}
+	if (size == 0)
+		return 0;
+
+	kbuf = memdup_user_nul(buf, size);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
+
+	inode_lock(file_inode(file));
+
+	p = kbuf;
+	while ((s = strsep(&p, " \t\n"))) {
+		len = strlen(s);
+		if (len == 0)
+			continue;
+		ret = -ENAMETOOLONG;
+		if (len >= AFSNAMEMAX)
+			goto error;
+
+		if (len >= 4 &&
+		    s[len - 4] == '@' &&
+		    s[len - 3] == 's' &&
+		    s[len - 2] == 'y' &&
+		    s[len - 1] == 's')
+			/* Protect against recursion */
+			goto invalid;
+
+		if (s[0] == '.' &&
+		    (len < 2 || (len == 2 && s[1] == '.')))
+			goto invalid;
+
+		if (memchr(s, '/', len))
+			goto invalid;
+
+		ret = -EFBIG;
+		if (sysnames->nr >= AFS_NR_SYSNAME)
+			goto out;
+
+		if (strcmp(s, afs_init_sysname) == 0) {
+			sub = (char *)afs_init_sysname;
+		} else {
+			ret = -ENOMEM;
+			sub = kmemdup(s, len + 1, GFP_KERNEL);
+			if (!sub)
+				goto out;
+		}
+
+		sysnames->subs[sysnames->nr] = sub;
+		sysnames->nr++;
+	}
+
+	ret = size;	/* consume everything, always */
+out:
+	inode_unlock(file_inode(file));
+	kfree(kbuf);
+	return ret;
+
+invalid:
+	ret = -EINVAL;
+error:
+	sysnames->error = ret;
+	goto out;
+}
+
+static int afs_proc_sysname_release(struct inode *inode, struct file *file)
+{
+	struct afs_sysnames *sysnames, *kill = NULL;
+	struct seq_file *m = file->private_data;
+	struct afs_net *net = afs_seq2net(m);
+
+	sysnames = m->private;
+	if (sysnames) {
+		if (!sysnames->error) {
+			kill = sysnames;
+			if (sysnames->nr == 0) {
+				sysnames->subs[0] = sysnames->blank;
+				sysnames->nr++;
+			}
+			write_lock(&net->sysnames_lock);
+			kill = net->sysnames;
+			net->sysnames = sysnames;
+			write_unlock(&net->sysnames_lock);
+		}
+		afs_put_sysnames(kill);
+	}
+
+	return seq_release(inode, file);
+}
+
+static void *afs_proc_sysname_start(struct seq_file *m, loff_t *pos)
+	__acquires(&net->sysnames_lock)
+{
+	struct afs_net *net = afs_seq2net(m);
+	struct afs_sysnames *names = net->sysnames;
+
+	read_lock(&net->sysnames_lock);
+
+	if (*pos >= names->nr)
+		return NULL;
+	return (void *)(unsigned long)(*pos + 1);
+}
+
+static void *afs_proc_sysname_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct afs_net *net = afs_seq2net(m);
+	struct afs_sysnames *names = net->sysnames;
+
+	*pos += 1;
+	if (*pos >= names->nr)
+		return NULL;
+	return (void *)(unsigned long)(*pos + 1);
+}
+
+static void afs_proc_sysname_stop(struct seq_file *m, void *v)
+	__releases(&net->sysnames_lock)
+{
+	struct afs_net *net = afs_seq2net(m);
+
+	read_unlock(&net->sysnames_lock);
+}
+
+static int afs_proc_sysname_show(struct seq_file *m, void *v)
+{
+	struct afs_net *net = afs_seq2net(m);
+	struct afs_sysnames *sysnames = net->sysnames;
+	unsigned int i = (unsigned long)v - 1;
+
+	if (i < sysnames->nr)
+		seq_printf(m, "%s\n", sysnames->subs[i]);
+	return 0;
+}
+
+/*
+ * Display general per-net namespace statistics
+ */
+static int afs_proc_stats_show(struct seq_file *m, void *v)
+{
+	struct afs_net *net = afs_seq2net(m);
+
+	seq_puts(m, "kAFS statistics\n");
+
+	seq_printf(m, "dir-mgmt: look=%u reval=%u inval=%u relpg=%u\n",
+		   atomic_read(&net->n_lookup),
+		   atomic_read(&net->n_reval),
+		   atomic_read(&net->n_inval),
+		   atomic_read(&net->n_relpg));
+
+	seq_printf(m, "dir-data: rdpg=%u\n",
+		   atomic_read(&net->n_read_dir));
+
+	seq_printf(m, "dir-edit: cr=%u rm=%u\n",
+		   atomic_read(&net->n_dir_cr),
+		   atomic_read(&net->n_dir_rm));
+
+	seq_printf(m, "file-rd : n=%u nb=%lu\n",
+		   atomic_read(&net->n_fetches),
+		   atomic_long_read(&net->n_fetch_bytes));
+	seq_printf(m, "file-wr : n=%u nb=%lu\n",
+		   atomic_read(&net->n_stores),
+		   atomic_long_read(&net->n_store_bytes));
+	return 0;
+}
+
+/*
+ * Open "/proc/fs/afs/stats" to allow reading of the stat counters.
+ */
+static int afs_proc_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, afs_proc_stats_show, NULL);
+}
+
+static const struct file_operations afs_proc_stats_fops = {
+	.open		= afs_proc_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release        = single_release,
+};

fs/afs/rotate.c

@@ -21,7 +21,7 @@
 /*
  * Initialise a filesystem server cursor for iterating over FS servers.
  */
-void afs_init_fs_cursor(struct afs_fs_cursor *fc, struct afs_vnode *vnode)
+static void afs_init_fs_cursor(struct afs_fs_cursor *fc, struct afs_vnode *vnode)
 {
 	memset(fc, 0, sizeof(*fc));
 }

fs/afs/rxrpc.c

@@ -926,3 +926,12 @@ int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 	afs_set_call_complete(call, ret, remote_abort);
 	return ret;
 }
+
+/*
+ * Log protocol error production.
+ */
+noinline int afs_protocol_error(struct afs_call *call, int error)
+{
+	trace_afs_protocol_error(call, error, __builtin_return_address(0));
+	return error;
+}