From 9999e48639b3cecb08ffb37358bcba3b48161b29 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 08:50:17 +0000
Subject: [PATCH] add ax88772_rst
---
kernel/fs/afs/callback.c | 357 +++++++++++++++++-----------------------------------------
1 files changed, 106 insertions(+), 251 deletions(-)
diff --git a/kernel/fs/afs/callback.c b/kernel/fs/afs/callback.c
index 97283b0..7d9b23d 100644
--- a/kernel/fs/afs/callback.c
+++ b/kernel/fs/afs/callback.c
@@ -21,200 +21,25 @@
#include "internal.h"
/*
- * Create volume and callback interests on a server.
- */
-static struct afs_cb_interest *afs_create_interest(struct afs_server *server,
- struct afs_vnode *vnode)
-{
- struct afs_vol_interest *new_vi, *vi;
- struct afs_cb_interest *new;
- struct hlist_node **pp;
-
- new_vi = kzalloc(sizeof(struct afs_vol_interest), GFP_KERNEL);
- if (!new_vi)
- return NULL;
-
- new = kzalloc(sizeof(struct afs_cb_interest), GFP_KERNEL);
- if (!new) {
- kfree(new_vi);
- return NULL;
- }
-
- new_vi->usage = 1;
- new_vi->vid = vnode->volume->vid;
- INIT_HLIST_NODE(&new_vi->srv_link);
- INIT_HLIST_HEAD(&new_vi->cb_interests);
-
- refcount_set(&new->usage, 1);
- new->sb = vnode->vfs_inode.i_sb;
- new->vid = vnode->volume->vid;
- new->server = afs_get_server(server);
- INIT_HLIST_NODE(&new->cb_vlink);
-
- write_lock(&server->cb_break_lock);
-
- for (pp = &server->cb_volumes.first; *pp; pp = &(*pp)->next) {
- vi = hlist_entry(*pp, struct afs_vol_interest, srv_link);
- if (vi->vid < new_vi->vid)
- continue;
- if (vi->vid > new_vi->vid)
- break;
- vi->usage++;
- goto found_vi;
- }
-
- new_vi->srv_link.pprev = pp;
- new_vi->srv_link.next = *pp;
- if (*pp)
- (*pp)->pprev = &new_vi->srv_link.next;
- *pp = &new_vi->srv_link;
- vi = new_vi;
- new_vi = NULL;
-found_vi:
-
- new->vol_interest = vi;
- hlist_add_head(&new->cb_vlink, &vi->cb_interests);
-
- write_unlock(&server->cb_break_lock);
- kfree(new_vi);
- return new;
-}
-
-/*
- * Set up an interest-in-callbacks record for a volume on a server and
- * register it with the server.
- * - Called with vnode->io_lock held.
- */
-int afs_register_server_cb_interest(struct afs_vnode *vnode,
- struct afs_server_list *slist,
- unsigned int index)
-{
- struct afs_server_entry *entry = &slist->servers[index];
- struct afs_cb_interest *cbi, *vcbi, *new, *old;
- struct afs_server *server = entry->server;
-
-again:
- if (vnode->cb_interest &&
- likely(vnode->cb_interest == entry->cb_interest))
- return 0;
-
- read_lock(&slist->lock);
- cbi = afs_get_cb_interest(entry->cb_interest);
- read_unlock(&slist->lock);
-
- vcbi = vnode->cb_interest;
- if (vcbi) {
- if (vcbi == cbi) {
- afs_put_cb_interest(afs_v2net(vnode), cbi);
- return 0;
- }
-
- /* Use a new interest in the server list for the same server
- * rather than an old one that's still attached to a vnode.
- */
- if (cbi && vcbi->server == cbi->server) {
- write_seqlock(&vnode->cb_lock);
- old = vnode->cb_interest;
- vnode->cb_interest = cbi;
- write_sequnlock(&vnode->cb_lock);
- afs_put_cb_interest(afs_v2net(vnode), old);
- return 0;
- }
-
- /* Re-use the one attached to the vnode. */
- if (!cbi && vcbi->server == server) {
- write_lock(&slist->lock);
- if (entry->cb_interest) {
- write_unlock(&slist->lock);
- afs_put_cb_interest(afs_v2net(vnode), cbi);
- goto again;
- }
-
- entry->cb_interest = cbi;
- write_unlock(&slist->lock);
- return 0;
- }
- }
-
- if (!cbi) {
- new = afs_create_interest(server, vnode);
- if (!new)
- return -ENOMEM;
-
- write_lock(&slist->lock);
- if (!entry->cb_interest) {
- entry->cb_interest = afs_get_cb_interest(new);
- cbi = new;
- new = NULL;
- } else {
- cbi = afs_get_cb_interest(entry->cb_interest);
- }
- write_unlock(&slist->lock);
- afs_put_cb_interest(afs_v2net(vnode), new);
- }
-
- ASSERT(cbi);
-
- /* Change the server the vnode is using. This entails scrubbing any
- * interest the vnode had in the previous server it was using.
- */
- write_seqlock(&vnode->cb_lock);
-
- old = vnode->cb_interest;
- vnode->cb_interest = cbi;
- vnode->cb_s_break = cbi->server->cb_s_break;
- vnode->cb_v_break = vnode->volume->cb_v_break;
- clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
-
- write_sequnlock(&vnode->cb_lock);
- afs_put_cb_interest(afs_v2net(vnode), old);
- return 0;
-}
-
-/*
- * Remove an interest on a server.
- */
-void afs_put_cb_interest(struct afs_net *net, struct afs_cb_interest *cbi)
-{
- struct afs_vol_interest *vi;
-
- if (cbi && refcount_dec_and_test(&cbi->usage)) {
- if (!hlist_unhashed(&cbi->cb_vlink)) {
- write_lock(&cbi->server->cb_break_lock);
-
- hlist_del_init(&cbi->cb_vlink);
- vi = cbi->vol_interest;
- cbi->vol_interest = NULL;
- if (--vi->usage == 0)
- hlist_del(&vi->srv_link);
- else
- vi = NULL;
-
- write_unlock(&cbi->server->cb_break_lock);
- kfree(vi);
- afs_put_server(net, cbi->server);
- }
- kfree(cbi);
- }
-}
-
-/*
- * allow the fileserver to request callback state (re-)initialisation
+ * Allow the fileserver to request callback state (re-)initialisation.
+ * Unfortunately, UUIDs are not guaranteed unique.
*/
void afs_init_callback_state(struct afs_server *server)
{
- if (!test_and_clear_bit(AFS_SERVER_FL_NEW, &server->flags))
+ rcu_read_lock();
+ do {
server->cb_s_break++;
+ server = rcu_dereference(server->uuid_next);
+ } while (0);
+ rcu_read_unlock();
}
/*
* actually break a callback
*/
-void afs_break_callback(struct afs_vnode *vnode)
+void __afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)
{
_enter("");
-
- write_seqlock(&vnode->cb_lock);
clear_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
if (test_and_clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
@@ -223,9 +48,54 @@
if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB)
afs_lock_may_be_available(vnode);
- }
+ trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, true);
+ } else {
+ trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, false);
+ }
+}
+
+void afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)
+{
+ write_seqlock(&vnode->cb_lock);
+ __afs_break_callback(vnode, reason);
write_sequnlock(&vnode->cb_lock);
+}
+
+/*
+ * Look up a volume by volume ID under RCU conditions.
+ */
+static struct afs_volume *afs_lookup_volume_rcu(struct afs_cell *cell,
+ afs_volid_t vid)
+{
+ struct afs_volume *volume = NULL;
+ struct rb_node *p;
+ int seq = 0;
+
+ 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(&cell->volume_lock, &seq);
+
+ p = rcu_dereference_raw(cell->volumes.rb_node);
+ while (p) {
+ volume = rb_entry(p, struct afs_volume, cell_node);
+
+ if (volume->vid < vid)
+ p = rcu_dereference_raw(p->rb_left);
+ else if (volume->vid > vid)
+ p = rcu_dereference_raw(p->rb_right);
+ else
+ break;
+ volume = NULL;
+ }
+
+ } while (need_seqretry(&cell->volume_lock, seq));
+
+ done_seqretry(&cell->volume_lock, seq);
+ return volume;
}
/*
@@ -234,60 +104,68 @@
* - the backing file is changed
* - a lock is released
*/
-static void afs_break_one_callback(struct afs_server *server,
+static void afs_break_one_callback(struct afs_volume *volume,
struct afs_fid *fid)
{
- struct afs_vol_interest *vi;
- struct afs_cb_interest *cbi;
- struct afs_iget_data data;
+ struct super_block *sb;
struct afs_vnode *vnode;
struct inode *inode;
- read_lock(&server->cb_break_lock);
- hlist_for_each_entry(vi, &server->cb_volumes, srv_link) {
- if (vi->vid < fid->vid)
- continue;
- if (vi->vid > fid->vid) {
- vi = NULL;
- break;
- }
- //atomic_inc(&vi->usage);
- break;
+ if (fid->vnode == 0 && fid->unique == 0) {
+ /* The callback break applies to an entire volume. */
+ write_lock(&volume->cb_v_break_lock);
+ volume->cb_v_break++;
+ trace_afs_cb_break(fid, volume->cb_v_break,
+ afs_cb_break_for_volume_callback, false);
+ write_unlock(&volume->cb_v_break_lock);
+ return;
}
+
+ /* See if we can find a matching inode - even an I_NEW inode needs to
+ * be marked as it can have its callback broken before we finish
+ * setting up the local inode.
+ */
+ sb = rcu_dereference(volume->sb);
+ if (!sb)
+ return;
+
+ inode = find_inode_rcu(sb, fid->vnode, afs_ilookup5_test_by_fid, fid);
+ if (inode) {
+ vnode = AFS_FS_I(inode);
+ afs_break_callback(vnode, afs_cb_break_for_callback);
+ } else {
+ trace_afs_cb_miss(fid, afs_cb_break_for_callback);
+ }
+}
+
+static void afs_break_some_callbacks(struct afs_server *server,
+ struct afs_callback_break *cbb,
+ size_t *_count)
+{
+ struct afs_callback_break *residue = cbb;
+ struct afs_volume *volume;
+ afs_volid_t vid = cbb->fid.vid;
+ size_t i;
+
+ volume = afs_lookup_volume_rcu(server->cell, vid);
/* TODO: Find all matching volumes if we couldn't match the server and
* break them anyway.
*/
- if (!vi)
- goto out;
- /* Step through all interested superblocks. There may be more than one
- * because of cell aliasing.
- */
- hlist_for_each_entry(cbi, &vi->cb_interests, cb_vlink) {
- if (fid->vnode == 0 && fid->unique == 0) {
- /* The callback break applies to an entire volume. */
- struct afs_super_info *as = AFS_FS_S(cbi->sb);
- struct afs_volume *volume = as->volume;
-
- write_lock(&volume->cb_v_break_lock);
- volume->cb_v_break++;
- write_unlock(&volume->cb_v_break_lock);
+ for (i = *_count; i > 0; cbb++, i--) {
+ if (cbb->fid.vid == vid) {
+ _debug("- Fid { vl=%08llx n=%llu u=%u }",
+ cbb->fid.vid,
+ cbb->fid.vnode,
+ cbb->fid.unique);
+ --*_count;
+ if (volume)
+ afs_break_one_callback(volume, &cbb->fid);
} else {
- data.volume = NULL;
- data.fid = *fid;
- inode = ilookup5_nowait(cbi->sb, fid->vnode,
- afs_iget5_test, &data);
- if (inode) {
- vnode = AFS_FS_I(inode);
- afs_break_callback(vnode);
- iput(inode);
- }
+ *residue++ = *cbb;
}
}
-
-out:
- read_unlock(&server->cb_break_lock);
}
/*
@@ -299,35 +177,12 @@
_enter("%p,%zu,", server, count);
ASSERT(server != NULL);
- ASSERTCMP(count, <=, AFSCBMAX);
- /* TODO: Sort the callback break list by volume ID */
+ rcu_read_lock();
- for (; count > 0; callbacks++, count--) {
- _debug("- Fid { vl=%08x n=%u u=%u } CB { v=%u x=%u t=%u }",
- callbacks->fid.vid,
- callbacks->fid.vnode,
- callbacks->fid.unique,
- callbacks->cb.version,
- callbacks->cb.expiry,
- callbacks->cb.type
- );
- afs_break_one_callback(server, &callbacks->fid);
- }
+ while (count > 0)
+ afs_break_some_callbacks(server, callbacks, &count);
- _leave("");
+ rcu_read_unlock();
return;
-}
-
-/*
- * Clear the callback interests in a server list.
- */
-void afs_clear_callback_interests(struct afs_net *net, struct afs_server_list *slist)
-{
- int i;
-
- for (i = 0; i < slist->nr_servers; i++) {
- afs_put_cb_interest(net, slist->servers[i].cb_interest);
- slist->servers[i].cb_interest = NULL;
- }
}
--
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