^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * This software may be freely redistributed under the terms of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * GNU General Public License.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * You should have received a copy of the GNU General Public License
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * along with this program; if not, write to the Free Software
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * Authors: David Woodhouse <dwmw2@infradead.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * David Howells <dhowells@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/circ_buf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * Allow the fileserver to request callback state (re-)initialisation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * Unfortunately, UUIDs are not guaranteed unique.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) void afs_init_callback_state(struct afs_server *server)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) server->cb_s_break++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) server = rcu_dereference(server->uuid_next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) } while (0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * actually break a callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) void __afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) _enter("");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) clear_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (test_and_clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) vnode->cb_break++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) afs_clear_permits(vnode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) afs_lock_may_be_available(vnode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) void afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) write_seqlock(&vnode->cb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) __afs_break_callback(vnode, reason);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) write_sequnlock(&vnode->cb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * Look up a volume by volume ID under RCU conditions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) static struct afs_volume *afs_lookup_volume_rcu(struct afs_cell *cell,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) afs_volid_t vid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) struct afs_volume *volume = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) struct rb_node *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) int seq = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) /* Unfortunately, rbtree walking doesn't give reliable results
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * under just the RCU read lock, so we have to check for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * changes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) read_seqbegin_or_lock(&cell->volume_lock, &seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) p = rcu_dereference_raw(cell->volumes.rb_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) while (p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) volume = rb_entry(p, struct afs_volume, cell_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) if (volume->vid < vid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) p = rcu_dereference_raw(p->rb_left);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) else if (volume->vid > vid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) p = rcu_dereference_raw(p->rb_right);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) volume = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) } while (need_seqretry(&cell->volume_lock, seq));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) done_seqretry(&cell->volume_lock, seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return volume;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) * allow the fileserver to explicitly break one callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * - happens when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * - the backing file is changed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * - a lock is released
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) static void afs_break_one_callback(struct afs_volume *volume,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) struct afs_fid *fid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) struct afs_vnode *vnode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) if (fid->vnode == 0 && fid->unique == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /* The callback break applies to an entire volume. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) write_lock(&volume->cb_v_break_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) volume->cb_v_break++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) trace_afs_cb_break(fid, volume->cb_v_break,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) afs_cb_break_for_volume_callback, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) write_unlock(&volume->cb_v_break_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) /* See if we can find a matching inode - even an I_NEW inode needs to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * be marked as it can have its callback broken before we finish
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * setting up the local inode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) sb = rcu_dereference(volume->sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) if (!sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) inode = find_inode_rcu(sb, fid->vnode, afs_ilookup5_test_by_fid, fid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if (inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) vnode = AFS_FS_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) afs_break_callback(vnode, afs_cb_break_for_callback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) trace_afs_cb_miss(fid, afs_cb_break_for_callback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) static void afs_break_some_callbacks(struct afs_server *server,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) struct afs_callback_break *cbb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) size_t *_count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) struct afs_callback_break *residue = cbb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) struct afs_volume *volume;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) afs_volid_t vid = cbb->fid.vid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) size_t i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) volume = afs_lookup_volume_rcu(server->cell, vid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) /* TODO: Find all matching volumes if we couldn't match the server and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * break them anyway.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) for (i = *_count; i > 0; cbb++, i--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) if (cbb->fid.vid == vid) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) _debug("- Fid { vl=%08llx n=%llu u=%u }",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) cbb->fid.vid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) cbb->fid.vnode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) cbb->fid.unique);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) --*_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) if (volume)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) afs_break_one_callback(volume, &cbb->fid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) *residue++ = *cbb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * allow the fileserver to break callback promises
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) void afs_break_callbacks(struct afs_server *server, size_t count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) struct afs_callback_break *callbacks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) _enter("%p,%zu,", server, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) ASSERT(server != NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) while (count > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) afs_break_some_callbacks(server, callbacks, &count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags