Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /* AFS cell alias detection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Written by David Howells (dhowells@redhat.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/namei.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <keys/rxrpc-type.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include "internal.h"
^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)  * Sample a volume.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) static struct afs_volume *afs_sample_volume(struct afs_cell *cell, struct key *key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 					    const char *name, unsigned int namelen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 	struct afs_volume *volume;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 	struct afs_fs_context fc = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 		.type		= 0, /* Explicitly leave it to the VLDB */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 		.volnamesz	= namelen,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 		.volname	= name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 		.net		= cell->net,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 		.cell		= cell,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 		.key		= key, /* This might need to be something */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	volume = afs_create_volume(&fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	_leave(" = %p", volume);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	return volume;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)  * Compare two addresses.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) static int afs_compare_addrs(const struct sockaddr_rxrpc *srx_a,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 			     const struct sockaddr_rxrpc *srx_b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	short port_a, port_b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	int addr_a, addr_b, diff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	diff = (short)srx_a->transport_type - (short)srx_b->transport_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	if (diff)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	switch (srx_a->transport_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	case AF_INET: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		const struct sockaddr_in *a = &srx_a->transport.sin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 		const struct sockaddr_in *b = &srx_b->transport.sin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		addr_a = ntohl(a->sin_addr.s_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		addr_b = ntohl(b->sin_addr.s_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		diff = addr_a - addr_b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		if (diff == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 			port_a = ntohs(a->sin_port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 			port_b = ntohs(b->sin_port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 			diff = port_a - port_b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	case AF_INET6: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 		const struct sockaddr_in6 *a = &srx_a->transport.sin6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 		const struct sockaddr_in6 *b = &srx_b->transport.sin6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		diff = memcmp(&a->sin6_addr, &b->sin6_addr, 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		if (diff == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 			port_a = ntohs(a->sin6_port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 			port_b = ntohs(b->sin6_port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 			diff = port_a - port_b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 		WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 		diff = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	return diff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85)  * Compare the address lists of a pair of fileservers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) static int afs_compare_fs_alists(const struct afs_server *server_a,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 				 const struct afs_server *server_b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	const struct afs_addr_list *la, *lb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	int a = 0, b = 0, addr_matches = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	la = rcu_dereference(server_a->addresses);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	lb = rcu_dereference(server_b->addresses);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	while (a < la->nr_addrs && b < lb->nr_addrs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		const struct sockaddr_rxrpc *srx_a = &la->addrs[a];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		const struct sockaddr_rxrpc *srx_b = &lb->addrs[b];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		int diff = afs_compare_addrs(srx_a, srx_b);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		if (diff < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 			a++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		} else if (diff > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 			b++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 			addr_matches++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 			a++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 			b++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	return addr_matches;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)  * Compare the fileserver lists of two volumes.  The server lists are sorted in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)  * order of ascending UUID.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) static int afs_compare_volume_slists(const struct afs_volume *vol_a,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 				     const struct afs_volume *vol_b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	const struct afs_server_list *la, *lb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	int i, a = 0, b = 0, uuid_matches = 0, addr_matches = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	la = rcu_dereference(vol_a->servers);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	lb = rcu_dereference(vol_b->servers);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	for (i = 0; i < AFS_MAXTYPES; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		if (la->vids[i] != lb->vids[i])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	while (a < la->nr_servers && b < lb->nr_servers) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 		const struct afs_server *server_a = la->servers[a].server;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 		const struct afs_server *server_b = lb->servers[b].server;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		int diff = memcmp(&server_a->uuid, &server_b->uuid, sizeof(uuid_t));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		if (diff < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 			a++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		} else if (diff > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 			b++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 			uuid_matches++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 			addr_matches += afs_compare_fs_alists(server_a, server_b);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 			a++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			b++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	_leave(" = %d [um %d]", addr_matches, uuid_matches);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	return addr_matches;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)  * Compare root.cell volumes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) static int afs_compare_cell_roots(struct afs_cell *cell)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	struct afs_cell *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	_enter("");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	hlist_for_each_entry_rcu(p, &cell->net->proc_cells, proc_link) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		if (p == cell || p->alias_of)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		if (!p->root_volume)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 			continue; /* Ignore cells that don't have a root.cell volume. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		if (afs_compare_volume_slists(cell->root_volume, p->root_volume) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 			goto is_alias;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	_leave(" = 0");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) is_alias:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	cell->alias_of = afs_use_cell(p, afs_cell_trace_use_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)  * Query the new cell for a volume from a cell we're already using.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) static int afs_query_for_alias_one(struct afs_cell *cell, struct key *key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 				   struct afs_cell *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	struct afs_volume *volume, *pvol = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	/* Arbitrarily pick a volume from the list. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	read_seqlock_excl(&p->volume_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	if (!RB_EMPTY_ROOT(&p->volumes))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		pvol = afs_get_volume(rb_entry(p->volumes.rb_node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 					       struct afs_volume, cell_node),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 				      afs_volume_trace_get_query_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	read_sequnlock_excl(&p->volume_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	if (!pvol)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	_enter("%s:%s", cell->name, pvol->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	/* And see if it's in the new cell. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	volume = afs_sample_volume(cell, key, pvol->name, pvol->name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	if (IS_ERR(volume)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		afs_put_volume(cell->net, pvol, afs_volume_trace_put_query_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		if (PTR_ERR(volume) != -ENOMEDIUM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 			return PTR_ERR(volume);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 		/* That volume is not in the new cell, so not an alias */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	/* The new cell has a like-named volume also - compare volume ID,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	 * server and address lists.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	if (pvol->vid == volume->vid) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 		if (afs_compare_volume_slists(volume, pvol))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 			ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 		rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	afs_put_volume(cell->net, volume, afs_volume_trace_put_query_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	afs_put_volume(cell->net, pvol, afs_volume_trace_put_query_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)  * Query the new cell for volumes we know exist in cells we're already using.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) static int afs_query_for_alias(struct afs_cell *cell, struct key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	struct afs_cell *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	_enter("%s", cell->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	if (mutex_lock_interruptible(&cell->net->proc_cells_lock) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 		return -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	hlist_for_each_entry(p, &cell->net->proc_cells, proc_link) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 		if (p == cell || p->alias_of)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		if (RB_EMPTY_ROOT(&p->volumes))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		if (p->root_volume)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 			continue; /* Ignore cells that have a root.cell volume. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		afs_use_cell(p, afs_cell_trace_use_check_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 		mutex_unlock(&cell->net->proc_cells_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 		if (afs_query_for_alias_one(cell, key, p) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 			goto is_alias;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 		if (mutex_lock_interruptible(&cell->net->proc_cells_lock) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 			afs_unuse_cell(cell->net, p, afs_cell_trace_unuse_check_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 			return -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 		afs_unuse_cell(cell->net, p, afs_cell_trace_unuse_check_alias);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	mutex_unlock(&cell->net->proc_cells_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	_leave(" = 0");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) is_alias:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	cell->alias_of = p; /* Transfer our ref */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)  * Look up a VLDB record for a volume.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) static char *afs_vl_get_cell_name(struct afs_cell *cell, struct key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	struct afs_vl_cursor vc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	char *cell_name = ERR_PTR(-EDESTADDRREQ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	bool skipped = false, not_skipped = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	if (!afs_begin_vlserver_operation(&vc, cell, key))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		return ERR_PTR(-ERESTARTSYS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	while (afs_select_vlserver(&vc)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		if (!test_bit(AFS_VLSERVER_FL_IS_YFS, &vc.server->flags)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 			vc.ac.error = -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 			skipped = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		not_skipped = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		cell_name = afs_yfsvl_get_cell_name(&vc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	ret = afs_end_vlserver_operation(&vc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	if (skipped && !not_skipped)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		ret = -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 	return ret < 0 ? ERR_PTR(ret) : cell_name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) static int yfs_check_canonical_cell_name(struct afs_cell *cell, struct key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 	struct afs_cell *master;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	char *cell_name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	cell_name = afs_vl_get_cell_name(cell, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	if (IS_ERR(cell_name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 		return PTR_ERR(cell_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	if (strcmp(cell_name, cell->name) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 		kfree(cell_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	master = afs_lookup_cell(cell->net, cell_name, strlen(cell_name),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 				 NULL, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 	kfree(cell_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	if (IS_ERR(master))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 		return PTR_ERR(master);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 	cell->alias_of = master; /* Transfer our ref */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) static int afs_do_cell_detect_alias(struct afs_cell *cell, struct key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 	struct afs_volume *root_volume;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	_enter("%s", cell->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	ret = yfs_check_canonical_cell_name(cell, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 	if (ret != -EOPNOTSUPP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 	/* Try and get the root.cell volume for comparison with other cells */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 	root_volume = afs_sample_volume(cell, key, "root.cell", 9);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 	if (!IS_ERR(root_volume)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 		cell->root_volume = root_volume;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 		return afs_compare_cell_roots(cell);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	if (PTR_ERR(root_volume) != -ENOMEDIUM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 		return PTR_ERR(root_volume);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	/* Okay, this cell doesn't have an root.cell volume.  We need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	 * locate some other random volume and use that to check.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 	return afs_query_for_alias(cell, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)  * Check to see if a new cell is an alias of a cell we already have.  At this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355)  * point we have the cell's volume server list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)  * Returns 0 if we didn't detect an alias, 1 if we found an alias and an error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)  * if we had problems gathering the data required.  In the case the we did
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359)  * detect an alias, cell->alias_of is set to point to the assumed master.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) int afs_cell_detect_alias(struct afs_cell *cell, struct key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	struct afs_net *net = cell->net;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 	if (mutex_lock_interruptible(&net->cells_alias_lock) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 		return -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 	if (test_bit(AFS_CELL_FL_CHECK_ALIAS, &cell->flags)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 		ret = afs_do_cell_detect_alias(cell, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 		if (ret >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 			clear_bit_unlock(AFS_CELL_FL_CHECK_ALIAS, &cell->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 		ret = cell->alias_of ? 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 	mutex_unlock(&net->cells_alias_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 	if (ret == 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 		pr_notice("kAFS: Cell %s is an alias of %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 			  cell->name, cell->alias_of->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) }