[RFC PATCH 10/11] afs: Overhaul cell database management

From: David Howells
Date: Fri Sep 01 2017 - 11:42:12 EST

Overhaul the way that the in-kernel AFS client keeps track of cells in the
following manner:

(1) Cells are now held in an rbtree to make walking them quicker and RCU
managed (though this is probably overkill).

(2) Cells now have a manager work item that:

(A) Looks after fetching and refreshing the VL server list.

(B) Manages cell record lifetime, including initialising and
destruction.

(B) Manages cell record caching whereby threads are kept around for a
certain time after last use and then destroyed.

(C) Manages the FS-Cache index cookie for a cell. It is not permitted
for a cookie to be in use twice, so we have to be careful to not
allow a new cell record to exist at the same time as an old record
of the same name.

(3) Each AFS network namespace is given a manager work item that manages
the cells within it, maintaining a single timer to prod cells into
updating their DNS records.

This uses the reduce_timer() facility to make the timer expire at the
soonest timed event that needs happening.

(4) When a module is being unloaded, cells and cell managers are now
counted out using dec_after_work() to make sure the module text is
pinned until after the data structures have been cleaned up.

(5) Each cell's VL server list is now protected by a seqlock rather than a
semaphore.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/afs/callback.c | 2
fs/afs/cell.c | 913 ++++++++++++++++++++++++++++++++++++----------------
fs/afs/internal.h | 62 +++-
fs/afs/main.c | 16 +
fs/afs/proc.c | 15 -
fs/afs/server.c | 3
fs/afs/super.c | 20 +
fs/afs/vlocation.c | 6
fs/afs/xattr.c | 2
9 files changed, 710 insertions(+), 329 deletions(-)

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index d12dffb76b67..bdccc4e72c0e 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -341,7 +341,7 @@ void afs_dispatch_give_up_callbacks(struct work_struct *work)
* had callbacks entirely, and the server will call us later to break
* them
*/
- afs_fs_give_up_callbacks(server->cell->net, server, true);
+ afs_fs_give_up_callbacks(server->net, server, true);
}

/*
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 6c49532a79de..078ffd90e5f4 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -1,6 +1,6 @@
/* AFS cell and server record management
*
- * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2002, 2017 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@xxxxxxxxxx)
*
* This program is free software; you can redistribute it and/or
@@ -19,128 +19,192 @@
#include <keys/rxrpc-type.h>
#include "internal.h"

+unsigned __read_mostly afs_cell_gc_delay = 10;
+
+static void afs_manage_cell(struct work_struct *);
+
+static void afs_dec_cells_outstanding(struct afs_net *net)
+{
+ if (atomic_dec_and_test(&net->cells_outstanding))
+ wake_up_atomic_t(&net->cells_outstanding);
+}
+
/*
- * allocate a cell record and fill in its name, VL server address list and
- * allocate an anonymous key
+ * Set the cell timer to fire after a given delay, assuming it's not already
+ * set for an earlier time.
*/
-static struct afs_cell *afs_cell_alloc(struct afs_net *net,
- const char *name, unsigned namelen,
- char *vllist)
+static void afs_set_cell_timer(struct afs_net *net, time64_t delay)
{
- struct afs_cell *cell;
- struct key *key;
- char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next;
- char *dvllist = NULL, *_vllist = NULL;
- char delimiter = ':';
- int ret, i;
+ if (net->live) {
+ atomic_inc(&net->cells_outstanding);
+ if (reduce_timer(&net->cells_timer, jiffies + delay * HZ))
+ afs_dec_cells_outstanding(net);
+ }
+}
+
+/*
+ * Look up and get an activation reference on a cell record under RCU
+ * conditions. The caller must hold the RCU read lock.
+ */
+struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net,
+ const char *name, unsigned int namesz)
+{
+ struct afs_cell *cell = NULL;
+ struct rb_node *p;
+ unsigned int seq = 0, n;
+ int ret = 0;
+
+ _enter("%*.*s", namesz, namesz, name);
+
+ if (name && namesz == 0)
+ return ERR_PTR(-EINVAL);
+ if (namesz > AFS_MAXCELLNAME)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ do {
+ /* Unfortunately, rbtree walking doesn't give reliable results
+ * under just the RCU read lock, so we have to check for
+ * changes.
+ */
+ read_seqbegin_or_lock(&net->cells_lock, &seq);
+
+ if (!name) {
+ ret = -EDESTADDRREQ;
+ cell = rcu_dereference_raw(net->ws_cell);
+ if (!cell)
+ goto done;
+
+ afs_get_cell(cell);
+ goto done;
+ }
+
+ p = rcu_dereference_raw(net->cells.rb_node);
+ while (p) {
+ cell = rb_entry(p, struct afs_cell, net_node);
+
+ n = strncasecmp(cell->name, name,
+ min_t(size_t, cell->name_len, namesz));
+ if (n == 0)
+ n = cell->name_len - namesz;
+ if (n < 0) {
+ p = rcu_dereference_raw(p->rb_left);
+ } else if (n > 0) {
+ p = rcu_dereference_raw(p->rb_right);
+ } else {
+ if (refcount_inc_not_zero(&cell->usage))
+ goto done;
+ /* We want to repeat the search, this time with
+ * the lock properly locked.
+ */
+ }
+ cell = NULL;
+ }
+ } while (need_seqretry(&net->cells_lock, seq));
+
+ ret = -ENOENT;

- _enter("%*.*s,%s", namelen, namelen, name ?: "", vllist);
+done:
+ done_seqretry(&net->cells_lock, seq);

- BUG_ON(!name); /* TODO: want to look up "this cell" in the cache */
+ return ret == 0 ? cell : ERR_PTR(ret);
+}
+
+/*
+ * Set up a cell record and fill in its name, VL server address list and
+ * allocate an anonymous key
+ */
+static struct afs_cell *afs_alloc_cell(struct afs_net *net,
+ const char *name, unsigned int namelen,
+ const char *vllist)
+{
+ struct afs_cell *cell;
+ int i, ret;

+ ASSERT(name);
+ if (namelen == 0)
+ return ERR_PTR(-EINVAL);
if (namelen > AFS_MAXCELLNAME) {
_leave(" = -ENAMETOOLONG");
return ERR_PTR(-ENAMETOOLONG);
}

- /* allocate and initialise a cell record */
- cell = kzalloc(sizeof(struct afs_cell) + namelen + 1, GFP_KERNEL);
+ _enter("%*.*s,%s", namelen, namelen, name, vllist);
+
+ cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL);
if (!cell) {
_leave(" = -ENOMEM");
return ERR_PTR(-ENOMEM);
}

- memcpy(cell->name, name, namelen);
- cell->name[namelen] = 0;
-
- atomic_set(&cell->usage, 1);
- INIT_LIST_HEAD(&cell->link);
cell->net = net;
+ cell->name_len = namelen;
+ for (i = 0; i < namelen; i++)
+ cell->name[i] = tolower(name[i]);
+
+ refcount_set(&cell->usage, 2);
+ INIT_WORK(&cell->manager, afs_manage_cell);
rwlock_init(&cell->servers_lock);
INIT_LIST_HEAD(&cell->servers);
init_rwsem(&cell->vl_sem);
INIT_LIST_HEAD(&cell->vl_list);
spin_lock_init(&cell->vl_lock);
+ seqlock_init(&cell->vl_addrs_lock);
+ cell->flags = (1 << AFS_CELL_FL_NOT_READY);

for (i = 0; i < AFS_CELL_MAX_ADDRS; i++) {
struct sockaddr_rxrpc *srx = &cell->vl_addrs[i];
srx->srx_family = AF_RXRPC;
srx->srx_service = VL_SERVICE;
srx->transport_type = SOCK_DGRAM;
- srx->transport.sin.sin_port = htons(AFS_VL_PORT);
+ srx->transport.sin6.sin6_family = AF_INET6;
+ srx->transport.sin6.sin6_port = htons(AFS_VL_PORT);
}

- /* if the ip address is invalid, try dns query */
- if (!vllist || strlen(vllist) < 7) {
- ret = dns_query("afsdb", name, namelen, "ipv4", &dvllist, NULL);
- if (ret < 0) {
- if (ret == -ENODATA || ret == -EAGAIN || ret == -ENOKEY)
- /* translate these errors into something
- * userspace might understand */
- ret = -EDESTADDRREQ;
- _leave(" = %d", ret);
- return ERR_PTR(ret);
- }
- _vllist = dvllist;
+ /* Fill in the VL server list if we were given a list of addresses to
+ * use.
+ */
+ if (vllist) {
+ char delim = ':';

- /* change the delimiter for user-space reply */
- delimiter = ',';
-
- } else {
if (strchr(vllist, ',') || !strchr(vllist, '.'))
- delimiter = ',';
- _vllist = vllist;
- }
-
- /* fill in the VL server list from the rest of the string */
- do {
- struct sockaddr_rxrpc *srx = &cell->vl_addrs[cell->vl_naddrs];
- const char *end;
-
- next = strchr(_vllist, delimiter);
- if (next)
- *next++ = 0;
+ delim = ',';
+
+ do {
+ struct sockaddr_rxrpc *srx = &cell->vl_addrs[cell->vl_naddrs];
+
+ if (in4_pton(vllist, -1,
+ (u8 *)&srx->transport.sin6.sin6_addr.s6_addr32[3],
+ delim, &vllist)) {
+ srx->transport_len = sizeof(struct sockaddr_in6);
+ srx->transport.sin6.sin6_addr.s6_addr32[0] = 0;
+ srx->transport.sin6.sin6_addr.s6_addr32[1] = 0;
+ srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
+ } else if (in6_pton(vllist, -1,
+ srx->transport.sin6.sin6_addr.s6_addr,
+ delim, &vllist)) {
+ srx->transport_len = sizeof(struct sockaddr_in6);
+ srx->transport.sin6.sin6_family = AF_INET6;
+ } else {
+ goto bad_address;
+ }

- if (in4_pton(_vllist, -1, (u8 *)&srx->transport.sin6.sin6_addr.s6_addr32[3],
- -1, &end)) {
- srx->transport_len = sizeof(struct sockaddr_in6);
- srx->transport.sin6.sin6_family = AF_INET6;
- srx->transport.sin6.sin6_flowinfo = 0;
- srx->transport.sin6.sin6_scope_id = 0;
- srx->transport.sin6.sin6_addr.s6_addr32[0] = 0;
- srx->transport.sin6.sin6_addr.s6_addr32[1] = 0;
- srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
- } else if (in6_pton(_vllist, -1, srx->transport.sin6.sin6_addr.s6_addr,
- -1, &end)) {
- srx->transport_len = sizeof(struct sockaddr_in6);
- srx->transport.sin6.sin6_family = AF_INET6;
- srx->transport.sin6.sin6_flowinfo = 0;
- srx->transport.sin6.sin6_scope_id = 0;
- } else {
- goto bad_address;
- }
+ cell->vl_naddrs++;
+ if (!*vllist)
+ break;
+ vllist++;

- } while (cell->vl_naddrs++,
- cell->vl_naddrs < AFS_CELL_MAX_ADDRS && (_vllist = next));
+ } while (cell->vl_naddrs < AFS_CELL_MAX_ADDRS && vllist);

- /* create a key to represent an anonymous user */
- memcpy(keyname, "afs@", 4);
- dp = keyname + 4;
- cp = cell->name;
- do {
- *dp++ = toupper(*cp);
- } while (*cp++);
-
- key = rxrpc_get_null_key(keyname);
- if (IS_ERR(key)) {
- _debug("no key");
- ret = PTR_ERR(key);
- goto error;
+ /* Disable DNS refresh for manually-specified cells and set the
+ * no-garbage collect flag (which pins the active count).
+ */
+ cell->dns_expiry = TIME64_MAX;
+ } else {
+ /* We're going to need to 'refresh' this cell's VL server list
+ * from the DNS before we can use it.
+ */
+ cell->dns_expiry = S64_MIN;
}
- cell->anonymous_key = key;
-
- _debug("anon key %p{%x}",
- cell->anonymous_key, key_serial(cell->anonymous_key));

_leave(" = %p", cell);
return cell;
@@ -148,92 +212,128 @@ static struct afs_cell *afs_cell_alloc(struct afs_net *net,
bad_address:
printk(KERN_ERR "kAFS: bad VL server IP address\n");
ret = -EINVAL;
-error:
- key_put(cell->anonymous_key);
- kfree(dvllist);
kfree(cell);
_leave(" = %d", ret);
return ERR_PTR(ret);
}

/*
- * afs_cell_crate() - create a cell record
+ * afs_lookup_cell - Look up or create a cell record.
* @net: The network namespace
- * @name: is the name of the cell.
- * @namsesz: is the strlen of the cell name.
- * @vllist: is a colon separated list of IP addresses in "a.b.c.d" format.
- * @retref: is T to return the cell reference when the cell exists.
+ * @name: The name of the cell.
+ * @namesz: The strlen of the cell name.
+ * @vllist: A colon/comma separated list of numeric IP addresses or NULL.
+ * @excl: T if an error should be given if the cell name already exists.
+ *
+ * Look up a cell record by name and query the DNS for VL server addresses if
+ * needed. Note that that actual DNS query is punted off to the manager thread
+ * so that this function can return immediately if interrupted whilst allowing
+ * cell records to be shared even if not yet fully constructed.
*/
-struct afs_cell *afs_cell_create(struct afs_net *net,
- const char *name, unsigned namesz,
- char *vllist, bool retref)
+struct afs_cell *afs_lookup_cell(struct afs_net *net,
+ const char *name, unsigned int namesz,
+ const char *vllist, bool excl)
{
- struct afs_cell *cell;
- int ret;
-
- _enter("%*.*s,%s", namesz, namesz, name ?: "", vllist);
+ struct afs_cell *cell, *candidate, *cursor;
+ struct rb_node *parent, **pp;
+ int ret, n;
+
+ _enter("%s,%s", name, vllist);
+
+ if (!excl) {
+ rcu_read_lock();
+ cell = afs_lookup_cell_rcu(net, name, namesz);
+ rcu_read_unlock();
+ if (!IS_ERR(cell)) {
+ if (excl) {
+ afs_put_cell(net, cell);
+ return ERR_PTR(-EEXIST);
+ }
+ goto wait_for_cell;
+ }
+ }

- down_write(&net->cells_sem);
- read_lock(&net->cells_lock);
- list_for_each_entry(cell, &net->cells, link) {
- if (strncasecmp(cell->name, name, namesz) == 0)
- goto duplicate_name;
+ /* Assume we're probably going to create a cell and preallocate and
+ * mostly set up a candidate record. We can then use this to stash the
+ * name, the net namespace and VL server addresses.
+ *
+ * We also want to do this before we hold any locks as it may involve
+ * upcalling to userspace to make DNS queries.
+ */
+ candidate = afs_alloc_cell(net, name, namesz, vllist);
+ if (IS_ERR(candidate)) {
+ _leave(" = %ld", PTR_ERR(candidate));
+ return candidate;
}
- read_unlock(&net->cells_lock);

- cell = afs_cell_alloc(net, name, namesz, vllist);
- if (IS_ERR(cell)) {
- _leave(" = %ld", PTR_ERR(cell));
- up_write(&net->cells_sem);
- return cell;
+ /* Find the insertion point and check to see if someone else added a
+ * cell whilst we were allocating.
+ */
+ write_seqlock(&net->cells_lock);
+
+ pp = &net->cells.rb_node;
+ parent = NULL;
+ while (*pp) {
+ parent = *pp;
+ cursor = rb_entry(parent, struct afs_cell, net_node);
+
+ n = strncasecmp(cursor->name, name,
+ min_t(size_t, cursor->name_len, namesz));
+ if (n == 0)
+ n = cursor->name_len - namesz;
+ if (n < 0)
+ pp = &(*pp)->rb_left;
+ else if (n > 0)
+ pp = &(*pp)->rb_right;
+ else
+ goto cell_already_exists;
}

- /* add a proc directory for this cell */
- ret = afs_proc_cell_setup(net, cell);
- if (ret < 0)
+ cell = candidate;
+ candidate = NULL;
+ rb_link_node_rcu(&cell->net_node, parent, pp);
+ rb_insert_color(&cell->net_node, &net->cells);
+ atomic_inc(&net->cells_outstanding);
+ write_sequnlock(&net->cells_lock);
+
+ schedule_work(&cell->manager);
+
+wait_for_cell:
+ _debug("wait_for_cell");
+ ret = wait_on_bit(&cell->flags, AFS_CELL_FL_NOT_READY, TASK_INTERRUPTIBLE);
+ smp_rmb();
+
+ switch (READ_ONCE(cell->state)) {
+ case AFS_CELL_FAILED:
+ ret = cell->error;
+ default:
+ _debug("weird %u %d", cell->state, cell->error);
goto error;
+ case AFS_CELL_ACTIVE:
+ break;
+ }

-#ifdef CONFIG_AFS_FSCACHE
- /* put it up for caching (this never returns an error) */
- cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index,
- &afs_cell_cache_index_def,
- cell, true);
-#endif
-
- /* add to the cell lists */
- write_lock(&net->cells_lock);
- list_add_tail(&cell->link, &net->cells);
- write_unlock(&net->cells_lock);
-
- down_write(&net->proc_cells_sem);
- list_add_tail(&cell->proc_link, &net->proc_cells);
- up_write(&net->proc_cells_sem);
- up_write(&net->cells_sem);
-
- _leave(" = %p", cell);
+ _leave(" = %p [cell]", cell);
return cell;

+cell_already_exists:
+ _debug("cell exists");
+ cell = cursor;
+ if (excl) {
+ ret = -EEXIST;
+ } else {
+ ASSERTCMP(refcount_read(&cursor->usage), >=, 1);
+ refcount_inc(&cursor->usage);
+ ret = 0;
+ }
+ write_sequnlock(&net->cells_lock);
+ kfree(candidate);
+ if (ret == 0)
+ goto wait_for_cell;
error:
- up_write(&net->cells_sem);
- key_put(cell->anonymous_key);
- kfree(cell);
- _leave(" = %d", ret);
+ afs_put_cell(net, cell);
+ _leave(" = %d [error]", ret);
return ERR_PTR(ret);
-
-duplicate_name:
- if (retref && !IS_ERR(cell))
- afs_get_cell(cell);
-
- read_unlock(&net->cells_lock);
- up_write(&net->cells_sem);
-
- if (retref) {
- _leave(" = %p", cell);
- return cell;
- }
-
- _leave(" = -EEXIST");
- return ERR_PTR(-EEXIST);
}

/*
@@ -241,10 +341,11 @@ struct afs_cell *afs_cell_create(struct afs_net *net,
* - can be called with a module parameter string
* - can be called from a write to /proc/fs/afs/rootcell
*/
-int afs_cell_init(struct afs_net *net, char *rootcell)
+int afs_cell_init(struct afs_net *net, const char *rootcell)
{
struct afs_cell *old_root, *new_root;
- char *cp;
+ const char *cp, *vllist;
+ size_t len;

_enter("");

@@ -257,223 +358,467 @@ int afs_cell_init(struct afs_net *net, char *rootcell)
}

cp = strchr(rootcell, ':');
- if (!cp)
+ if (!cp) {
_debug("kAFS: no VL server IP addresses specified");
- else
- *cp++ = 0;
+ vllist = NULL;
+ len = strlen(rootcell);
+ } else {
+ vllist = cp + 1;
+ len = cp - rootcell;
+ }

/* allocate a cell record for the root cell */
- new_root = afs_cell_create(net, rootcell, strlen(rootcell), cp, false);
+ new_root = afs_lookup_cell(net, rootcell, len, vllist, false);
if (IS_ERR(new_root)) {
_leave(" = %ld", PTR_ERR(new_root));
return PTR_ERR(new_root);
}

+ set_bit(AFS_CELL_FL_NO_GC, &new_root->flags);
+ afs_get_cell(new_root);
+
/* install the new cell */
- write_lock(&net->cells_lock);
+ write_seqlock(&net->cells_lock);
old_root = net->ws_cell;
net->ws_cell = new_root;
- write_unlock(&net->cells_lock);
- afs_put_cell(old_root);
+ write_sequnlock(&net->cells_lock);

+ afs_put_cell(net, old_root);
_leave(" = 0");
return 0;
}

/*
- * lookup a cell record
+ * Update a cell's VL server address list from the DNS.
*/
-struct afs_cell *afs_cell_lookup(struct afs_net *net,
- const char *name, unsigned namesz,
- bool dns_cell)
+static void afs_update_cell(struct afs_cell *cell)
{
- struct afs_cell *cell;
+ time64_t now, expiry;
+ char *vllist = NULL;
+ int ret;

- _enter("\"%*.*s\",", namesz, namesz, name ?: "");
+ _enter("%s", cell->name);
+
+ ret = dns_query("afsdb", cell->name, cell->name_len,
+ "ipv4", &vllist, &expiry);
+ _debug("query %d", ret);
+ switch (ret) {
+ case 0 ... INT_MAX:
+ clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
+ clear_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
+ goto parse_dns_data;
+
+ case -ENODATA:
+ clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
+ set_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
+ cell->dns_expiry = ktime_get_real_seconds() + 61;
+ cell->error = -EDESTADDRREQ;
+ goto out;
+
+ case -EAGAIN:
+ case -ECONNREFUSED:
+ default:
+ /* Unable to query DNS. */
+ set_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
+ cell->dns_expiry = ktime_get_real_seconds() + 10;
+ cell->error = -EDESTADDRREQ;
+ goto out;
+ }

- down_read(&net->cells_sem);
- read_lock(&net->cells_lock);
+parse_dns_data:
+ write_seqlock(&cell->vl_addrs_lock);

- if (name) {
- /* if the cell was named, look for it in the cell record list */
- list_for_each_entry(cell, &net->cells, link) {
- if (strncmp(cell->name, name, namesz) == 0) {
- afs_get_cell(cell);
- goto found;
- }
- }
- cell = ERR_PTR(-ENOENT);
- if (dns_cell)
- goto create_cell;
- found:
- ;
- } else {
- cell = net->ws_cell;
- if (!cell) {
- /* this should not happen unless user tries to mount
- * when root cell is not set. Return an impossibly
- * bizarre errno to alert the user. Things like
- * ENOENT might be "more appropriate" but they happen
- * for other reasons.
- */
- cell = ERR_PTR(-EDESTADDRREQ);
+ ret = -EINVAL;
+ do {
+ struct sockaddr_rxrpc *srx = &cell->vl_addrs[cell->vl_naddrs];
+
+ if (in4_pton(vllist, -1,
+ (u8 *)&srx->transport.sin6.sin6_addr.s6_addr32[3],
+ ',', (const char **)&vllist)) {
+ srx->transport_len = sizeof(struct sockaddr_in6);
+ srx->transport.sin6.sin6_addr.s6_addr32[0] = 0;
+ srx->transport.sin6.sin6_addr.s6_addr32[1] = 0;
+ srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
+ } else if (in6_pton(vllist, -1,
+ srx->transport.sin6.sin6_addr.s6_addr,
+ ',', (const char **)&vllist)) {
+ srx->transport_len = sizeof(struct sockaddr_in6);
+ srx->transport.sin6.sin6_family = AF_INET6;
} else {
- afs_get_cell(cell);
+ goto bad_address;
}

- }
-
- read_unlock(&net->cells_lock);
- up_read(&net->cells_sem);
- _leave(" = %p", cell);
- return cell;
+ cell->vl_naddrs++;
+ if (!*vllist)
+ break;
+ vllist++;

-create_cell:
- read_unlock(&net->cells_lock);
- up_read(&net->cells_sem);
+ } while (cell->vl_naddrs < AFS_CELL_MAX_ADDRS);

- cell = afs_cell_create(net, name, namesz, NULL, true);
+ if (cell->vl_naddrs < AFS_CELL_MAX_ADDRS)
+ memset(cell->vl_addrs + cell->vl_naddrs, 0,
+ (AFS_CELL_MAX_ADDRS - cell->vl_naddrs) * sizeof(cell->vl_addrs[0]));

- _leave(" = %p", cell);
- return cell;
+ now = ktime_get_real_seconds();
+ cell->dns_expiry = expiry;
+ afs_set_cell_timer(cell->net, expiry - now);
+bad_address:
+ write_sequnlock(&cell->vl_addrs_lock);
+out:
+ _leave("");
}

-#if 0
/*
- * try and get a cell record
+ * Destroy a cell record
*/
-struct afs_cell *afs_get_cell_maybe(struct afs_cell *cell)
+static void afs_cell_destroy(struct rcu_head *rcu)
{
- write_lock(&net->cells_lock);
+ struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu);

- if (cell && !list_empty(&cell->link))
- afs_get_cell(cell);
- else
- cell = NULL;
+ _enter("%p{%s}", cell, cell->name);

- write_unlock(&net->cells_lock);
- return cell;
+ ASSERTCMP(refcount_read(&cell->usage), ==, 0);
+
+ key_put(cell->anonymous_key);
+ kfree(cell);
+
+ _leave(" [destroyed]");
}
-#endif /* 0 */

/*
- * destroy a cell record
+ * Queue the cell manager.
*/
-void afs_put_cell(struct afs_cell *cell)
+static void afs_queue_cell_manager(struct afs_net *net)
{
- if (!cell)
- return;
+ int outstanding = atomic_inc_return(&net->cells_outstanding);
+
+ _enter("%d", outstanding);

- _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name);
+ if (!schedule_work(&net->cells_manager))
+ afs_dec_cells_outstanding(net);
+}

- ASSERTCMP(atomic_read(&cell->usage), >, 0);
+/*
+ * Cell management timer. We have an increment on cells_outstanding that we
+ * need to pass along to the work item.
+ */
+void afs_cells_timer(unsigned long data)
+{
+ struct afs_net *net = (struct afs_net *)data;
+
+ _enter("");
+ if (!schedule_work(&net->cells_manager))
+ afs_dec_cells_outstanding(net);
+}

- /* to prevent a race, the decrement and the dequeue must be effectively
- * atomic */
- write_lock(&cell->net->cells_lock);
+/*
+ * Drop a reference on a cell record.
+ */
+void afs_put_cell(struct afs_net *net, struct afs_cell *cell)
+{
+ time64_t now, expire_delay;

- if (likely(!atomic_dec_and_test(&cell->usage))) {
- write_unlock(&cell->net->cells_lock);
- _leave("");
+ if (!cell)
return;
- }

- ASSERT(list_empty(&cell->servers));
- ASSERT(list_empty(&cell->vl_list));
+ _enter("%s", cell->name);

- wake_up(&cell->net->cells_freeable_wq);
+ now = ktime_get_real_seconds();
+ cell->last_inactive = now;
+ expire_delay = 0;
+ if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
+ !test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
+ expire_delay = afs_cell_gc_delay;

- write_unlock(&cell->net->cells_lock);
+ if (refcount_dec_return(&cell->usage) > 1)
+ return;

- _leave(" [unused]");
+ /* 'cell' may now be garbage collected. */
+ afs_set_cell_timer(net, expire_delay);
}

/*
- * destroy a cell record
- * - must be called with the net->cells_sem write-locked
- * - cell->link should have been broken by the caller
+ * Allocate a key to use as a placeholder for anonymous user security.
*/
-static void afs_cell_destroy(struct afs_net *net, struct afs_cell *cell)
+static int afs_alloc_anon_key(struct afs_cell *cell)
{
- _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name);
+ struct key *key;
+ char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp;

- ASSERTCMP(atomic_read(&cell->usage), >=, 0);
- ASSERT(list_empty(&cell->link));
+ /* Create a key to represent an anonymous user. */
+ memcpy(keyname, "afs@", 4);
+ dp = keyname + 4;
+ cp = cell->name;
+ do {
+ *dp++ = toupper(*cp);
+ } while (*cp++);

- /* wait for everyone to stop using the cell */
- if (atomic_read(&cell->usage) > 0) {
- DECLARE_WAITQUEUE(myself, current);
+ key = rxrpc_get_null_key(keyname);
+ if (IS_ERR(key))
+ return PTR_ERR(key);

- _debug("wait for cell %s", cell->name);
- set_current_state(TASK_UNINTERRUPTIBLE);
- add_wait_queue(&net->cells_freeable_wq, &myself);
+ cell->anonymous_key = key;

- while (atomic_read(&cell->usage) > 0) {
- schedule();
- set_current_state(TASK_UNINTERRUPTIBLE);
- }
+ _debug("anon key %p{%x}",
+ cell->anonymous_key, key_serial(cell->anonymous_key));
+ return 0;
+}

- remove_wait_queue(&net->cells_freeable_wq, &myself);
- set_current_state(TASK_RUNNING);
+/*
+ * Activate a cell.
+ */
+static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell)
+{
+ int ret;
+
+ if (!cell->anonymous_key) {
+ ret = afs_alloc_anon_key(cell);
+ if (ret < 0)
+ return ret;
}

- _debug("cell dead");
- ASSERTCMP(atomic_read(&cell->usage), ==, 0);
- ASSERT(list_empty(&cell->servers));
- ASSERT(list_empty(&cell->vl_list));
+#ifdef CONFIG_AFS_FSCACHE
+ cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index,
+ &afs_cell_cache_index_def,
+ cell, true);
+#endif
+ ret = afs_proc_cell_setup(net, cell);
+ if (ret < 0)
+ return ret;
+ spin_lock(&net->proc_cells_lock);
+ list_add_tail(&cell->proc_link, &net->proc_cells);
+ spin_unlock(&net->proc_cells_lock);
+ return 0;
+}
+
+/*
+ * Deactivate a cell.
+ */
+static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell)
+{
+ _enter("%s", cell->name);

afs_proc_cell_remove(net, cell);

- down_write(&net->proc_cells_sem);
+ spin_lock(&net->proc_cells_lock);
list_del_init(&cell->proc_link);
- up_write(&net->proc_cells_sem);
+ spin_unlock(&net->proc_cells_lock);

#ifdef CONFIG_AFS_FSCACHE
fscache_relinquish_cookie(cell->cache, 0);
+ cell->cache = NULL;
#endif
- key_put(cell->anonymous_key);
- kfree(cell);

- _leave(" [destroyed]");
+ _leave("");
}

/*
- * purge in-memory cell database on module unload or afs_init() failure
- * - the timeout daemon is stopped before calling this
+ * Manage a cell record, initialising and destroying it, maintaining its DNS
+ * records.
*/
-void afs_cell_purge(struct afs_net *net)
+static void afs_manage_cell(struct work_struct *work)
{
- struct afs_cell *cell;
+ struct afs_cell *cell = container_of(work, struct afs_cell, manager);
+ struct afs_net *net = cell->net;
+ bool deleted;
+ int ret;
+
+ _enter("%s", cell->name);
+
+again:
+ _debug("state %u", cell->state);
+ switch (cell->state) {
+ case AFS_CELL_INACTIVE:
+ case AFS_CELL_FAILED:
+ write_seqlock(&net->cells_lock);
+ deleted = refcount_dec_if_one(&cell->usage);
+ if (deleted)
+ rb_erase(&cell->net_node, &net->cells);
+ write_sequnlock(&net->cells_lock);
+ if (deleted)
+ goto final_destruction;
+ if (cell->state == AFS_CELL_FAILED)
+ goto done;
+ cell->state = AFS_CELL_UNSET;
+ goto again;
+
+ case AFS_CELL_UNSET:
+ cell->state = AFS_CELL_ACTIVATING;
+ goto again;
+
+ case AFS_CELL_ACTIVATING:
+ ret = afs_activate_cell(net, cell);
+ if (ret < 0)
+ goto activation_failed;
+
+ cell->state = AFS_CELL_ACTIVE;
+ smp_wmb();
+ clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
+ wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+ goto again;
+
+ case AFS_CELL_ACTIVE:
+ if (refcount_read(&cell->usage) > 1) {
+ time64_t now = ktime_get_real_seconds();
+ if (cell->dns_expiry <= now && net->live)
+ afs_update_cell(cell);
+ goto done;
+ }
+ cell->state = AFS_CELL_DEACTIVATING;
+ goto again;
+
+ case AFS_CELL_DEACTIVATING:
+ set_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
+ if (refcount_read(&cell->usage) > 1)
+ goto reverse_deactivation;
+ afs_deactivate_cell(net, cell);
+ cell->state = AFS_CELL_INACTIVE;
+ goto again;
+
+ default:
+ break;
+ }
+ _debug("bad state %u", cell->state);
+ BUG(); /* Unhandled state */
+
+activation_failed:
+ cell->error = ret;
+ afs_deactivate_cell(net, cell);
+
+ cell->state = AFS_CELL_FAILED;
+ smp_wmb();
+ if (test_and_clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags))
+ wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+ goto again;
+
+reverse_deactivation:
+ cell->state = AFS_CELL_ACTIVE;
+ smp_wmb();
+ clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
+ wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+ _leave(" [deact->act]");
+ return;
+
+done:
+ _leave(" [done %u]", cell->state);
+ return;
+
+final_destruction:
+ call_rcu(&cell->rcu, afs_cell_destroy);
+ dec_after_work(&net->cells_outstanding);
+ _leave(" [destruct %d]", atomic_read(&net->cells_outstanding));
+}
+
+/*
+ * Manage the records of cells known to a network namespace. This includes
+ * updating the DNS records and garbage collecting unused cells that were
+ * automatically added.
+ *
+ * Note that constructed cell records may only be removed from net->cells by
+ * this work item, so it is safe for this work item to stash a cursor pointing
+ * into the tree and then return to caller (provided it skips cells that are
+ * still under construction).
+ *
+ * Note also that we were given an increment on net->cells_outstanding by
+ * whoever queued us that we need to deal with before returning.
+ */
+void afs_manage_cells(struct work_struct *work)
+{
+ struct afs_net *net = container_of(work, struct afs_net, cells_manager);
+ struct rb_node *cursor;
+ time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX;
+ bool purging = !net->live;

_enter("");

- afs_put_cell(net->ws_cell);
+ /* Trawl the cell database looking for cells that have expired from
+ * lack of use and cells whose DNS results have expired and dispatch
+ * their managers.
+ */
+ read_seqlock_excl(&net->cells_lock);

- down_write(&net->cells_sem);
+ for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) {
+ struct afs_cell *cell =
+ rb_entry(cursor, struct afs_cell, net_node);
+ bool sched_cell = false;

- while (!list_empty(&net->cells)) {
- cell = NULL;
+ _debug("manage %s %u", cell->name, refcount_read(&cell->usage));

- /* remove the next cell from the front of the list */
- write_lock(&net->cells_lock);
+ ASSERTCMP(refcount_read(&cell->usage), >=, 1);

- if (!list_empty(&net->cells)) {
- cell = list_entry(net->cells.next,
- struct afs_cell, link);
- list_del_init(&cell->link);
+ if (purging && test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags))
+ refcount_dec(&cell->usage);
+
+ ASSERTIFCMP(purging, refcount_read(&cell->usage), ==, 1);
+
+ if (refcount_read(&cell->usage) == 1) {
+ time64_t expire_at = cell->last_inactive;
+
+ if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
+ !test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
+ expire_at += afs_cell_gc_delay;
+ if (purging || expire_at <= now)
+ sched_cell = true;
+ else if (expire_at < next_manage)
+ next_manage = expire_at;
}

- write_unlock(&net->cells_lock);
+ if (!purging) {
+ if (cell->dns_expiry <= now)
+ sched_cell = true;
+ else if (cell->dns_expiry <= next_manage)
+ next_manage = cell->dns_expiry;
+ }
+
+ if (sched_cell)
+ schedule_work(&cell->manager);
+ }
+
+ read_sequnlock_excl(&net->cells_lock);

- if (cell) {
- _debug("PURGING CELL %s (%d)",
- cell->name, atomic_read(&cell->usage));
+ /* Update the timer on the way out. We have to pass an increment on
+ * cells_outstanding in the namespace that we are in to the timer or
+ * the work scheduler.
+ */
+ if (!purging && next_manage < TIME64_MAX) {
+ now = ktime_get_real_seconds();

- /* now the cell should be left with no references */
- afs_cell_destroy(net, cell);
+ if (next_manage - now <= 0) {
+ if (schedule_work(&net->cells_manager))
+ atomic_inc(&net->cells_outstanding);
+ } else {
+ afs_set_cell_timer(net, next_manage - now);
}
}

- up_write(&net->cells_sem);
+ dec_after_work(&net->cells_outstanding);
+ _leave(" [%d]", atomic_read(&net->cells_outstanding));
+}
+
+/*
+ * Purge in-memory cell database.
+ */
+void afs_cell_purge(struct afs_net *net)
+{
+ struct afs_cell *ws;
+
+ _enter("");
+
+ write_seqlock(&net->cells_lock);
+ ws = net->ws_cell;
+ net->ws_cell = NULL;
+ write_sequnlock(&net->cells_lock);
+ afs_put_cell(net, ws);
+
+ _debug("del timer");
+ if (del_timer_sync(&net->cells_timer))
+ atomic_dec(&net->cells_outstanding);
+
+ _debug("kick mgr");
+ afs_queue_cell_manager(net);
+
+ _debug("wait");
+ wait_on_atomic_t(&net->cells_outstanding, atomic_t_wait,
+ TASK_UNINTERRUPTIBLE);
_leave("");
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 47d5ae08f071..f96398163a68 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -202,13 +202,14 @@ struct afs_net {
atomic_t nr_superblocks;

/* Cell database */
- struct list_head cells;
+ struct rb_root cells;
struct afs_cell *ws_cell;
- rwlock_t cells_lock;
- struct rw_semaphore cells_sem;
- wait_queue_head_t cells_freeable_wq;
+ struct work_struct cells_manager;
+ struct timer_list cells_timer;
+ atomic_t cells_outstanding;
+ seqlock_t cells_lock;

- struct rw_semaphore proc_cells_sem;
+ spinlock_t proc_cells_lock;
struct list_head proc_cells;

/* Volume location database */
@@ -235,14 +236,26 @@ struct afs_net {

extern struct afs_net __afs_net;// Dummy AFS network namespace; TODO: replace with real netns

+enum afs_cell_state {
+ AFS_CELL_UNSET,
+ AFS_CELL_ACTIVATING,
+ AFS_CELL_ACTIVE,
+ AFS_CELL_DEACTIVATING,
+ AFS_CELL_INACTIVE,
+ AFS_CELL_FAILED,
+};
+
/*
* AFS cell record
*/
struct afs_cell {
- atomic_t usage;
- struct list_head link; /* main cell list link */
- struct afs_net *net; /* The network namespace */
+ union {
+ struct rcu_head rcu;
+ struct rb_node net_node; /* Node in net->cells */
+ };
+ struct afs_net *net;
struct key *anonymous_key; /* anonymous user key for this cell */
+ struct work_struct manager; /* Manager for init/deinit/dns */
struct list_head proc_link; /* /proc cell list link */
#ifdef CONFIG_AFS_FSCACHE
struct fscache_cookie *cache; /* caching cookie */
@@ -255,12 +268,26 @@ struct afs_cell {
/* volume location record management */
struct rw_semaphore vl_sem; /* volume management serialisation semaphore */
struct list_head vl_list; /* cell's active VL record list */
+ time64_t dns_expiry; /* Time AFSDB/SRV record expires */
+ time64_t last_inactive; /* Time of last drop of usage count */
+ refcount_t usage;
+ unsigned long flags;
+#define AFS_CELL_FL_NOT_READY 0 /* The cell record is not ready for use */
+#define AFS_CELL_FL_NO_GC 1 /* The cell was added manually, don't auto-gc */
+#define AFS_CELL_FL_NOT_FOUND 2 /* Permanent DNS error */
+#define AFS_CELL_FL_DNS_FAIL 3 /* Failed to access DNS */
+ enum afs_cell_state state;
+ short error;
+
spinlock_t vl_lock; /* vl_list lock */
+
+ /* VLDB server list. */
+ seqlock_t vl_addrs_lock;
unsigned short vl_naddrs; /* number of VL servers in addr list */
unsigned short vl_curr_svix; /* current server index */
struct sockaddr_rxrpc vl_addrs[AFS_CELL_MAX_ADDRS]; /* cell VL server addresses */
-
- char name[0]; /* cell name - must go last */
+ u8 name_len; /* Length of name */
+ char name[64 + 1]; /* Cell name, case-flattened and NUL-padded */
};

/*
@@ -310,6 +337,7 @@ struct afs_server {
atomic_t usage;
time64_t time_of_death; /* time at which put reduced usage to 0 */
struct sockaddr_rxrpc addr; /* server address */
+ struct afs_net *net; /* The network namespace */
struct afs_cell *cell; /* cell in which server resides */
struct list_head link; /* link in cell's server list */
struct list_head grave; /* link in master graveyard list */
@@ -476,12 +504,14 @@ extern void afs_flush_callback_breaks(struct afs_server *);
/*
* cell.c
*/
-#define afs_get_cell(C) do { atomic_inc(&(C)->usage); } while(0)
-extern int __net_init afs_cell_init(struct afs_net *, char *);
-extern struct afs_cell *afs_cell_create(struct afs_net *, const char *, unsigned, char *, bool);
-extern struct afs_cell *afs_cell_lookup(struct afs_net *, const char *, unsigned, bool);
-extern struct afs_cell *afs_grab_cell(struct afs_cell *);
-extern void afs_put_cell(struct afs_cell *);
+#define afs_get_cell(C) do { refcount_inc(&(C)->usage); } while(0)
+extern int __net_init afs_cell_init(struct afs_net *, const char *);
+extern struct afs_cell *afs_lookup_cell_rcu(struct afs_net *, const char *, unsigned);
+extern struct afs_cell *afs_lookup_cell(struct afs_net *, const char *, unsigned,
+ const char *, bool);
+extern void afs_put_cell(struct afs_net *, struct afs_cell *);
+extern void afs_manage_cells(struct work_struct *);
+extern void afs_cells_timer(unsigned long);
extern void __net_exit afs_cell_purge(struct afs_net *);

/*
diff --git a/fs/afs/main.c b/fs/afs/main.c
index 87b1a9c8000d..e0342e445099 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -46,12 +46,15 @@ static int __net_init afs_net_init(struct afs_net *net)

INIT_WORK(&net->charge_preallocation_work, afs_charge_preallocation);
mutex_init(&net->socket_mutex);
- INIT_LIST_HEAD(&net->cells);
- rwlock_init(&net->cells_lock);
- init_rwsem(&net->cells_sem);
- init_waitqueue_head(&net->cells_freeable_wq);
- init_rwsem(&net->proc_cells_sem);
+
+ net->cells = RB_ROOT;
+ seqlock_init(&net->cells_lock);
+ INIT_WORK(&net->cells_manager, afs_manage_cells);
+ setup_timer(&net->cells_timer, afs_cells_timer, (unsigned long)net);
+
+ spin_lock_init(&net->proc_cells_lock);
INIT_LIST_HEAD(&net->proc_cells);
+
INIT_LIST_HEAD(&net->vl_updates);
INIT_LIST_HEAD(&net->vl_graveyard);
INIT_DELAYED_WORK(&net->vl_reaper, afs_vlocation_reaper);
@@ -82,11 +85,14 @@ static int __net_init afs_net_init(struct afs_net *net)
return 0;

error_open_socket:
+ net->live = false;
afs_vlocation_purge(net);
afs_cell_purge(net);
error_cell_init:
+ net->live = false;
afs_proc_cleanup(net);
error_proc:
+ net->live = false;
return ret;
}

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index ee10f0089d87..df3614306056 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -186,7 +186,7 @@ static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
{
struct afs_net *net = afs_seq2net(m);

- down_read(&net->proc_cells_sem);
+ rcu_read_lock();
return seq_list_start_head(&net->proc_cells, *_pos);
}

@@ -205,9 +205,7 @@ static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
*/
static void afs_proc_cells_stop(struct seq_file *m, void *v)
{
- struct afs_net *net = afs_seq2net(m);
-
- up_read(&net->proc_cells_sem);
+ rcu_read_unlock();
}

/*
@@ -225,8 +223,7 @@ static int afs_proc_cells_show(struct seq_file *m, void *v)
}

/* display one cell per line on subsequent lines */
- seq_printf(m, "%3d %s\n",
- atomic_read(&cell->usage), cell->name);
+ seq_printf(m, "%3u %s\n", refcount_read(&cell->usage), cell->name);
return 0;
}

@@ -279,13 +276,13 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
if (strcmp(kbuf, "add") == 0) {
struct afs_cell *cell;

- cell = afs_cell_create(net, name, strlen(name), args, false);
+ cell = afs_lookup_cell(net, name, strlen(name), args, true);
if (IS_ERR(cell)) {
ret = PTR_ERR(cell);
goto done;
}

- afs_put_cell(cell);
+ set_bit(AFS_CELL_FL_NO_GC, &cell->flags);
printk("kAFS: Added new cell '%s'\n", name);
} else {
goto inval;
@@ -354,7 +351,7 @@ int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
{
struct proc_dir_entry *dir;

- _enter("%p{%s}", cell, cell->name);
+ _enter("%p{%s},%p", cell, cell->name, net->proc_afs);

dir = proc_mkdir(cell->name, net->proc_afs);
if (!dir)
diff --git a/fs/afs/server.c b/fs/afs/server.c
index 9b38f386a142..57c2f605e11b 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -68,6 +68,7 @@ static struct afs_server *afs_alloc_server(struct afs_cell *cell,
server = kzalloc(sizeof(struct afs_server), GFP_KERNEL);
if (server) {
atomic_set(&server->usage, 1);
+ server->net = cell->net;
server->cell = cell;

INIT_LIST_HEAD(&server->link);
@@ -254,7 +255,7 @@ static void afs_destroy_server(struct afs_server *server)
ASSERTCMP(server->cb_break_head, ==, server->cb_break_tail);
ASSERTCMP(atomic_read(&server->cb_break_n), ==, 0);

- afs_put_cell(server->cell);
+ afs_put_cell(server->net, server->cell);
kfree(server);
}

diff --git a/fs/afs/super.c b/fs/afs/super.c
index 1bfc7b28700b..5113a48f907d 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -200,13 +200,14 @@ static int afs_parse_options(struct afs_mount_params *params,
token = match_token(p, afs_options_list, args);
switch (token) {
case afs_opt_cell:
- cell = afs_cell_lookup(params->net,
- args[0].from,
- args[0].to - args[0].from,
- false);
+ rcu_read_lock();
+ cell = afs_lookup_cell_rcu(params->net,
+ args[0].from,
+ args[0].to - args[0].from);
+ rcu_read_unlock();
if (IS_ERR(cell))
return PTR_ERR(cell);
- afs_put_cell(params->cell);
+ afs_put_cell(params->net, params->cell);
params->cell = cell;
break;

@@ -308,13 +309,14 @@ static int afs_parse_device_name(struct afs_mount_params *params,

/* lookup the cell record */
if (cellname || !params->cell) {
- cell = afs_cell_lookup(params->net, cellname, cellnamesz, true);
+ cell = afs_lookup_cell(params->net, cellname, cellnamesz,
+ NULL, false);
if (IS_ERR(cell)) {
printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
cellnamesz, cellnamesz, cellname ?: "");
return PTR_ERR(cell);
}
- afs_put_cell(params->cell);
+ afs_put_cell(params->net, params->cell);
params->cell = cell;
}

@@ -474,7 +476,7 @@ static struct dentry *afs_mount(struct file_system_type *fs_type,
kfree(as);
}

- afs_put_cell(params.cell);
+ afs_put_cell(params.net, params.cell);
kfree(new_opts);
_leave(" = 0 [%p]", sb);
return dget(sb->s_root);
@@ -488,7 +490,7 @@ static struct dentry *afs_mount(struct file_system_type *fs_type,
error_vol:
afs_put_volume(params.net, vol);
error:
- afs_put_cell(params.cell);
+ afs_put_cell(params.net, params.cell);
key_put(params.key);
kfree(new_opts);
_leave(" = %d", ret);
diff --git a/fs/afs/vlocation.c b/fs/afs/vlocation.c
index 4f8c15c09a6d..ec5ab8dc9bc8 100644
--- a/fs/afs/vlocation.c
+++ b/fs/afs/vlocation.c
@@ -480,11 +480,11 @@ void afs_put_vlocation(struct afs_net *net, struct afs_vlocation *vl)
/*
* destroy a dead volume location record
*/
-static void afs_vlocation_destroy(struct afs_vlocation *vl)
+static void afs_vlocation_destroy(struct afs_net *net, struct afs_vlocation *vl)
{
_enter("%p", vl);

- afs_put_cell(vl->cell);
+ afs_put_cell(net, vl->cell);
kfree(vl);
}

@@ -539,7 +539,7 @@ void afs_vlocation_reaper(struct work_struct *work)
while (!list_empty(&corpses)) {
vl = list_entry(corpses.next, struct afs_vlocation, grave);
list_del(&vl->grave);
- afs_vlocation_destroy(vl);
+ afs_vlocation_destroy(net, vl);
}

_leave("");
diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
index 2830e4f48d85..e58e00ee9747 100644
--- a/fs/afs/xattr.c
+++ b/fs/afs/xattr.c
@@ -45,7 +45,7 @@ static int afs_xattr_get_cell(const struct xattr_handler *handler,
struct afs_cell *cell = vnode->volume->cell;
size_t namelen;

- namelen = strlen(cell->name);
+ namelen = cell->name_len;
if (size == 0)
return namelen;
if (namelen > size)