From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/afs/volume.c | 452 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 452 insertions(+) create mode 100644 fs/afs/volume.c (limited to 'fs/afs/volume.c') diff --git a/fs/afs/volume.c b/fs/afs/volume.c new file mode 100644 index 000000000..1c9144e3e --- /dev/null +++ b/fs/afs/volume.c @@ -0,0 +1,452 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* AFS volume management + * + * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include "internal.h" + +static unsigned __read_mostly afs_volume_record_life = 60 * 60; + +/* + * Insert a volume into a cell. If there's an existing volume record, that is + * returned instead with a ref held. + */ +static struct afs_volume *afs_insert_volume_into_cell(struct afs_cell *cell, + struct afs_volume *volume) +{ + struct afs_volume *p; + struct rb_node *parent = NULL, **pp; + + write_seqlock(&cell->volume_lock); + + pp = &cell->volumes.rb_node; + while (*pp) { + parent = *pp; + p = rb_entry(parent, struct afs_volume, cell_node); + if (p->vid < volume->vid) { + pp = &(*pp)->rb_left; + } else if (p->vid > volume->vid) { + pp = &(*pp)->rb_right; + } else { + if (afs_try_get_volume(p, afs_volume_trace_get_cell_insert)) { + volume = p; + goto found; + } + + set_bit(AFS_VOLUME_RM_TREE, &volume->flags); + rb_replace_node_rcu(&p->cell_node, &volume->cell_node, &cell->volumes); + } + } + + rb_link_node_rcu(&volume->cell_node, parent, pp); + rb_insert_color(&volume->cell_node, &cell->volumes); + hlist_add_head_rcu(&volume->proc_link, &cell->proc_volumes); + +found: + write_sequnlock(&cell->volume_lock); + return volume; + +} + +static void afs_remove_volume_from_cell(struct afs_volume *volume) +{ + struct afs_cell *cell = volume->cell; + + if (!hlist_unhashed(&volume->proc_link)) { + trace_afs_volume(volume->vid, refcount_read(&cell->ref), + afs_volume_trace_remove); + write_seqlock(&cell->volume_lock); + hlist_del_rcu(&volume->proc_link); + if (!test_and_set_bit(AFS_VOLUME_RM_TREE, &volume->flags)) + rb_erase(&volume->cell_node, &cell->volumes); + write_sequnlock(&cell->volume_lock); + } +} + +/* + * Allocate a volume record and load it up from a vldb record. + */ +static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params, + struct afs_vldb_entry *vldb, + unsigned long type_mask) +{ + struct afs_server_list *slist; + struct afs_volume *volume; + int ret = -ENOMEM, nr_servers = 0, i; + + for (i = 0; i < vldb->nr_servers; i++) + if (vldb->fs_mask[i] & type_mask) + nr_servers++; + + volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL); + if (!volume) + goto error_0; + + volume->vid = vldb->vid[params->type]; + volume->update_at = ktime_get_real_seconds() + afs_volume_record_life; + volume->cell = afs_get_cell(params->cell, afs_cell_trace_get_vol); + volume->type = params->type; + volume->type_force = params->force; + volume->name_len = vldb->name_len; + + refcount_set(&volume->ref, 1); + INIT_HLIST_NODE(&volume->proc_link); + rwlock_init(&volume->servers_lock); + rwlock_init(&volume->cb_v_break_lock); + memcpy(volume->name, vldb->name, vldb->name_len + 1); + + slist = afs_alloc_server_list(params->cell, params->key, vldb, type_mask); + if (IS_ERR(slist)) { + ret = PTR_ERR(slist); + goto error_1; + } + + refcount_set(&slist->usage, 1); + rcu_assign_pointer(volume->servers, slist); + trace_afs_volume(volume->vid, 1, afs_volume_trace_alloc); + return volume; + +error_1: + afs_put_cell(volume->cell, afs_cell_trace_put_vol); + kfree(volume); +error_0: + return ERR_PTR(ret); +} + +/* + * Look up or allocate a volume record. + */ +static struct afs_volume *afs_lookup_volume(struct afs_fs_context *params, + struct afs_vldb_entry *vldb, + unsigned long type_mask) +{ + struct afs_volume *candidate, *volume; + + candidate = afs_alloc_volume(params, vldb, type_mask); + if (IS_ERR(candidate)) + return candidate; + + volume = afs_insert_volume_into_cell(params->cell, candidate); + if (volume != candidate) + afs_put_volume(params->net, candidate, afs_volume_trace_put_cell_dup); + return volume; +} + +/* + * Look up a VLDB record for a volume. + */ +static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell, + struct key *key, + const char *volname, + size_t volnamesz) +{ + struct afs_vldb_entry *vldb = ERR_PTR(-EDESTADDRREQ); + struct afs_vl_cursor vc; + int ret; + + if (!afs_begin_vlserver_operation(&vc, cell, key)) + return ERR_PTR(-ERESTARTSYS); + + while (afs_select_vlserver(&vc)) { + vldb = afs_vl_get_entry_by_name_u(&vc, volname, volnamesz); + } + + ret = afs_end_vlserver_operation(&vc); + return ret < 0 ? ERR_PTR(ret) : vldb; +} + +/* + * Look up a volume in the VL server and create a candidate volume record for + * it. + * + * The volume name can be one of the following: + * "%[cell:]volume[.]" R/W volume + * "#[cell:]volume[.]" R/O or R/W volume (rwparent=0), + * or R/W (rwparent=1) volume + * "%[cell:]volume.readonly" R/O volume + * "#[cell:]volume.readonly" R/O volume + * "%[cell:]volume.backup" Backup volume + * "#[cell:]volume.backup" Backup volume + * + * The cell name is optional, and defaults to the current cell. + * + * See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin + * Guide + * - Rule 1: Explicit type suffix forces access of that type or nothing + * (no suffix, then use Rule 2 & 3) + * - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W + * if not available + * - Rule 3: If parent volume is R/W, then only mount R/W volume unless + * explicitly told otherwise + */ +struct afs_volume *afs_create_volume(struct afs_fs_context *params) +{ + struct afs_vldb_entry *vldb; + struct afs_volume *volume; + unsigned long type_mask = 1UL << params->type; + + vldb = afs_vl_lookup_vldb(params->cell, params->key, + params->volname, params->volnamesz); + if (IS_ERR(vldb)) + return ERR_CAST(vldb); + + if (test_bit(AFS_VLDB_QUERY_ERROR, &vldb->flags)) { + volume = ERR_PTR(vldb->error); + goto error; + } + + /* Make the final decision on the type we want */ + volume = ERR_PTR(-ENOMEDIUM); + if (params->force) { + if (!(vldb->flags & type_mask)) + goto error; + } else if (test_bit(AFS_VLDB_HAS_RO, &vldb->flags)) { + params->type = AFSVL_ROVOL; + } else if (test_bit(AFS_VLDB_HAS_RW, &vldb->flags)) { + params->type = AFSVL_RWVOL; + } else { + goto error; + } + + type_mask = 1UL << params->type; + volume = afs_lookup_volume(params, vldb, type_mask); + +error: + kfree(vldb); + return volume; +} + +/* + * Destroy a volume record + */ +static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume) +{ + _enter("%p", volume); + +#ifdef CONFIG_AFS_FSCACHE + ASSERTCMP(volume->cache, ==, NULL); +#endif + + afs_remove_volume_from_cell(volume); + afs_put_serverlist(net, rcu_access_pointer(volume->servers)); + afs_put_cell(volume->cell, afs_cell_trace_put_vol); + trace_afs_volume(volume->vid, refcount_read(&volume->ref), + afs_volume_trace_free); + kfree_rcu(volume, rcu); + + _leave(" [destroyed]"); +} + +/* + * Try to get a reference on a volume record. + */ +bool afs_try_get_volume(struct afs_volume *volume, enum afs_volume_trace reason) +{ + int r; + + if (__refcount_inc_not_zero(&volume->ref, &r)) { + trace_afs_volume(volume->vid, r + 1, reason); + return true; + } + return false; +} + +/* + * Get a reference on a volume record. + */ +struct afs_volume *afs_get_volume(struct afs_volume *volume, + enum afs_volume_trace reason) +{ + if (volume) { + int r; + + __refcount_inc(&volume->ref, &r); + trace_afs_volume(volume->vid, r + 1, reason); + } + return volume; +} + + +/* + * Drop a reference on a volume record. + */ +void afs_put_volume(struct afs_net *net, struct afs_volume *volume, + enum afs_volume_trace reason) +{ + if (volume) { + afs_volid_t vid = volume->vid; + bool zero; + int r; + + zero = __refcount_dec_and_test(&volume->ref, &r); + trace_afs_volume(vid, r - 1, reason); + if (zero) + afs_destroy_volume(net, volume); + } +} + +/* + * Activate a volume. + */ +int afs_activate_volume(struct afs_volume *volume) +{ +#ifdef CONFIG_AFS_FSCACHE + struct fscache_volume *vcookie; + char *name; + + name = kasprintf(GFP_KERNEL, "afs,%s,%llx", + volume->cell->name, volume->vid); + if (!name) + return -ENOMEM; + + vcookie = fscache_acquire_volume(name, NULL, NULL, 0); + if (IS_ERR(vcookie)) { + if (vcookie != ERR_PTR(-EBUSY)) { + kfree(name); + return PTR_ERR(vcookie); + } + pr_err("AFS: Cache volume key already in use (%s)\n", name); + vcookie = NULL; + } + volume->cache = vcookie; + kfree(name); +#endif + return 0; +} + +/* + * Deactivate a volume. + */ +void afs_deactivate_volume(struct afs_volume *volume) +{ + _enter("%s", volume->name); + +#ifdef CONFIG_AFS_FSCACHE + fscache_relinquish_volume(volume->cache, NULL, + test_bit(AFS_VOLUME_DELETED, &volume->flags)); + volume->cache = NULL; +#endif + + _leave(""); +} + +/* + * Query the VL service to update the volume status. + */ +static int afs_update_volume_status(struct afs_volume *volume, struct key *key) +{ + struct afs_server_list *new, *old, *discard; + struct afs_vldb_entry *vldb; + char idbuf[16]; + int ret, idsz; + + _enter(""); + + /* We look up an ID by passing it as a decimal string in the + * operation's name parameter. + */ + idsz = sprintf(idbuf, "%llu", volume->vid); + + vldb = afs_vl_lookup_vldb(volume->cell, key, idbuf, idsz); + if (IS_ERR(vldb)) { + ret = PTR_ERR(vldb); + goto error; + } + + /* See if the volume got renamed. */ + if (vldb->name_len != volume->name_len || + memcmp(vldb->name, volume->name, vldb->name_len) != 0) { + /* TODO: Use RCU'd string. */ + memcpy(volume->name, vldb->name, AFS_MAXVOLNAME); + volume->name_len = vldb->name_len; + } + + /* See if the volume's server list got updated. */ + new = afs_alloc_server_list(volume->cell, key, + vldb, (1 << volume->type)); + if (IS_ERR(new)) { + ret = PTR_ERR(new); + goto error_vldb; + } + + write_lock(&volume->servers_lock); + + discard = new; + old = rcu_dereference_protected(volume->servers, + lockdep_is_held(&volume->servers_lock)); + if (afs_annotate_server_list(new, old)) { + new->seq = volume->servers_seq + 1; + rcu_assign_pointer(volume->servers, new); + smp_wmb(); + volume->servers_seq++; + discard = old; + } + + volume->update_at = ktime_get_real_seconds() + afs_volume_record_life; + write_unlock(&volume->servers_lock); + ret = 0; + + afs_put_serverlist(volume->cell->net, discard); +error_vldb: + kfree(vldb); +error: + _leave(" = %d", ret); + return ret; +} + +/* + * Make sure the volume record is up to date. + */ +int afs_check_volume_status(struct afs_volume *volume, struct afs_operation *op) +{ + int ret, retries = 0; + + _enter(""); + +retry: + if (test_bit(AFS_VOLUME_WAIT, &volume->flags)) + goto wait; + if (volume->update_at <= ktime_get_real_seconds() || + test_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags)) + goto update; + _leave(" = 0"); + return 0; + +update: + if (!test_and_set_bit_lock(AFS_VOLUME_UPDATING, &volume->flags)) { + clear_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags); + ret = afs_update_volume_status(volume, op->key); + if (ret < 0) + set_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags); + clear_bit_unlock(AFS_VOLUME_WAIT, &volume->flags); + clear_bit_unlock(AFS_VOLUME_UPDATING, &volume->flags); + wake_up_bit(&volume->flags, AFS_VOLUME_WAIT); + _leave(" = %d", ret); + return ret; + } + +wait: + if (!test_bit(AFS_VOLUME_WAIT, &volume->flags)) { + _leave(" = 0 [no wait]"); + return 0; + } + + ret = wait_on_bit(&volume->flags, AFS_VOLUME_WAIT, + (op->flags & AFS_OPERATION_UNINTR) ? + TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE); + if (ret == -ERESTARTSYS) { + _leave(" = %d", ret); + return ret; + } + + retries++; + if (retries == 4) { + _leave(" = -ESTALE"); + return -ESTALE; + } + goto retry; +} -- cgit v1.2.3