/* AFS superblock handling * * Copyright (c) 2002, 2007, 2018 Red Hat, Inc. All rights reserved. * * This software may be freely redistributed under the terms of the * GNU General Public License. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * Authors: David Howells <dhowells@redhat.com> * David Woodhouse <dwmw2@infradead.org> * */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/mount.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/fs_parser.h> #include <linux/statfs.h> #include <linux/sched.h> #include <linux/nsproxy.h> #include <linux/magic.h> #include <net/net_namespace.h> #include "internal.h" static void afs_i_init_once(void *foo); static void afs_kill_super(struct super_block *sb); static struct inode *afs_alloc_inode(struct super_block *sb); static void afs_destroy_inode(struct inode *inode); static void afs_free_inode(struct inode *inode); static int afs_statfs(struct dentry *dentry, struct kstatfs *buf); static int afs_show_devname(struct seq_file *m, struct dentry *root); static int afs_show_options(struct seq_file *m, struct dentry *root); static int afs_init_fs_context(struct fs_context *fc); static const struct fs_parameter_spec afs_fs_parameters[]; struct file_system_type afs_fs_type = { .owner = THIS_MODULE, .name = "afs", .init_fs_context = afs_init_fs_context, .parameters = afs_fs_parameters, .kill_sb = afs_kill_super, .fs_flags = FS_RENAME_DOES_D_MOVE, }; MODULE_ALIAS_FS("afs"); int afs_net_id; static const struct super_operations afs_super_ops = { .statfs = afs_statfs, .alloc_inode = afs_alloc_inode, .drop_inode = afs_drop_inode, .destroy_inode = afs_destroy_inode, .free_inode = afs_free_inode, .evict_inode = afs_evict_inode, .show_devname = afs_show_devname, .show_options = afs_show_options, }; static struct kmem_cache *afs_inode_cachep; static atomic_t afs_count_active_inodes; enum afs_param { Opt_autocell, Opt_dyn, Opt_flock, Opt_source, }; static const struct constant_table afs_param_flock[] = { {"local", afs_flock_mode_local }, {"openafs", afs_flock_mode_openafs }, {"strict", afs_flock_mode_strict }, {"write", afs_flock_mode_write }, {} }; static const struct fs_parameter_spec afs_fs_parameters[] = { fsparam_flag ("autocell", Opt_autocell), fsparam_flag ("dyn", Opt_dyn), fsparam_enum ("flock", Opt_flock, afs_param_flock), fsparam_string("source", Opt_source), {} }; /* * initialise the filesystem */ int __init afs_fs_init(void) { int ret; _enter(""); /* create ourselves an inode cache */ atomic_set(&afs_count_active_inodes, 0); ret = -ENOMEM; afs_inode_cachep = kmem_cache_create("afs_inode_cache", sizeof(struct afs_vnode), 0, SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, afs_i_init_once); if (!afs_inode_cachep) { printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n"); return ret; } /* now export our filesystem to lesser mortals */ ret = register_filesystem(&afs_fs_type); if (ret < 0) { kmem_cache_destroy(afs_inode_cachep); _leave(" = %d", ret); return ret; } _leave(" = 0"); return 0; } /* * clean up the filesystem */ void afs_fs_exit(void) { _enter(""); afs_mntpt_kill_timer(); unregister_filesystem(&afs_fs_type); if (atomic_read(&afs_count_active_inodes) != 0) { printk("kAFS: %d active inode objects still present\n", atomic_read(&afs_count_active_inodes)); BUG(); } /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(afs_inode_cachep); _leave(""); } /* * Display the mount device name in /proc/mounts. */ static int afs_show_devname(struct seq_file *m, struct dentry *root) { struct afs_super_info *as = AFS_FS_S(root->d_sb); struct afs_volume *volume = as->volume; struct afs_cell *cell = as->cell; const char *suf = ""; char pref = '%'; if (as->dyn_root) { seq_puts(m, "none"); return 0; } switch (volume->type) { case AFSVL_RWVOL: break; case AFSVL_ROVOL: pref = '#'; if (volume->type_force) suf = ".readonly"; break; case AFSVL_BACKVOL: pref = '#'; suf = ".backup"; break; } seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf); return 0; } /* * Display the mount options in /proc/mounts. */ static int afs_show_options(struct seq_file *m, struct dentry *root) { struct afs_super_info *as = AFS_FS_S(root->d_sb); const char *p = NULL; if (as->dyn_root) seq_puts(m, ",dyn"); if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags)) seq_puts(m, ",autocell"); switch (as->flock_mode) { case afs_flock_mode_unset: break; case afs_flock_mode_local: p = "local"; break; case afs_flock_mode_openafs: p = "openafs"; break; case afs_flock_mode_strict: p = "strict"; break; case afs_flock_mode_write: p = "write"; break; } if (p) seq_printf(m, ",flock=%s", p); return 0; } /* * Parse the source name to get cell name, volume name, volume type and R/W * selector. * * This can be one of the following: * "%[cell:]volume[.]" R/W volume * "#[cell:]volume[.]" R/O or R/W volume (R/O parent), * or R/W (R/W parent) volume * "%[cell:]volume.readonly" R/O volume * "#[cell:]volume.readonly" R/O volume * "%[cell:]volume.backup" Backup volume * "#[cell:]volume.backup" Backup volume */ static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param) { struct afs_fs_context *ctx = fc->fs_private; struct afs_cell *cell; const char *cellname, *suffix, *name = param->string; int cellnamesz; _enter(",%s", name); if (fc->source) return invalf(fc, "kAFS: Multiple sources not supported"); if (!name) { printk(KERN_ERR "kAFS: no volume name specified\n"); return -EINVAL; } if ((name[0] != '%' && name[0] != '#') || !name[1]) { /* To use dynroot, we don't want to have to provide a source */ if (strcmp(name, "none") == 0) { ctx->no_cell = true; return 0; } printk(KERN_ERR "kAFS: unparsable volume name\n"); return -EINVAL; } /* determine the type of volume we're looking for */ if (name[0] == '%') { ctx->type = AFSVL_RWVOL; ctx->force = true; } name++; /* split the cell name out if there is one */ ctx->volname = strchr(name, ':'); if (ctx->volname) { cellname = name; cellnamesz = ctx->volname - name; ctx->volname++; } else { ctx->volname = name; cellname = NULL; cellnamesz = 0; } /* the volume type is further affected by a possible suffix */ suffix = strrchr(ctx->volname, '.'); if (suffix) { if (strcmp(suffix, ".readonly") == 0) { ctx->type = AFSVL_ROVOL; ctx->force = true; } else if (strcmp(suffix, ".backup") == 0) { ctx->type = AFSVL_BACKVOL; ctx->force = true; } else if (suffix[1] == 0) { } else { suffix = NULL; } } ctx->volnamesz = suffix ? suffix - ctx->volname : strlen(ctx->volname); _debug("cell %*.*s [%p]", cellnamesz, cellnamesz, cellname ?: "", ctx->cell); /* lookup the cell record */ if (cellname) { cell = afs_lookup_cell(ctx->net, cellname, cellnamesz, NULL, false); if (IS_ERR(cell)) { pr_err("kAFS: unable to lookup cell '%*.*s'\n", cellnamesz, cellnamesz, cellname ?: ""); return PTR_ERR(cell); } afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_parse); afs_see_cell(cell, afs_cell_trace_see_source); ctx->cell = cell; } _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s", ctx->cell->name, ctx->cell, ctx->volnamesz, ctx->volnamesz, ctx->volname, suffix ?: "-", ctx->type, ctx->force ? " FORCE" : ""); fc->source = param->string; param->string = NULL; return 0; } /* * Parse a single mount parameter. */ static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct fs_parse_result result; struct afs_fs_context *ctx = fc->fs_private; int opt; opt = fs_parse(fc, afs_fs_parameters, param, &result); if (opt < 0) return opt; switch (opt) { case Opt_source: return afs_parse_source(fc, param); case Opt_autocell: ctx->autocell = true; break; case Opt_dyn: ctx->dyn_root = true; break; case Opt_flock: ctx->flock_mode = result.uint_32; break; default: return -EINVAL; } _leave(" = 0"); return 0; } /* * Validate the options, get the cell key and look up the volume. */ static int afs_validate_fc(struct fs_context *fc) { struct afs_fs_context *ctx = fc->fs_private; struct afs_volume *volume; struct afs_cell *cell; struct key *key; int ret; if (!ctx->dyn_root) { if (ctx->no_cell) { pr_warn("kAFS: Can only specify source 'none' with -o dyn\n"); return -EINVAL; } if (!ctx->cell) { pr_warn("kAFS: No cell specified\n"); return -EDESTADDRREQ; } reget_key: /* We try to do the mount securely. */ key = afs_request_key(ctx->cell); if (IS_ERR(key)) return PTR_ERR(key); ctx->key = key; if (ctx->volume) { afs_put_volume(ctx->net, ctx->volume, afs_volume_trace_put_validate_fc); ctx->volume = NULL; } if (test_bit(AFS_CELL_FL_CHECK_ALIAS, &ctx->cell->flags)) { ret = afs_cell_detect_alias(ctx->cell, key); if (ret < 0) return ret; if (ret == 1) { _debug("switch to alias"); key_put(ctx->key); ctx->key = NULL; cell = afs_use_cell(ctx->cell->alias_of, afs_cell_trace_use_fc_alias); afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc); ctx->cell = cell; goto reget_key; } } volume = afs_create_volume(ctx); if (IS_ERR(volume)) return PTR_ERR(volume); ctx->volume = volume; } return 0; } /* * check a superblock to see if it's the one we're looking for */ static int afs_test_super(struct super_block *sb, struct fs_context *fc) { struct afs_fs_context *ctx = fc->fs_private; struct afs_super_info *as = AFS_FS_S(sb); return (as->net_ns == fc->net_ns && as->volume && as->volume->vid == ctx->volume->vid && as->cell == ctx->cell && !as->dyn_root); } static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc) { struct afs_super_info *as = AFS_FS_S(sb); return (as->net_ns == fc->net_ns && as->dyn_root); } static int afs_set_super(struct super_block *sb, struct fs_context *fc) { return set_anon_super(sb, NULL); } /* * fill in the superblock */ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx) { struct afs_super_info *as = AFS_FS_S(sb); struct inode *inode = NULL; int ret; _enter(""); /* fill in the superblock */ sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_magic = AFS_FS_MAGIC; sb->s_op = &afs_super_ops; if (!as->dyn_root) sb->s_xattr = afs_xattr_handlers; ret = super_setup_bdi(sb); if (ret) return ret; /* allocate the root inode and dentry */ if (as->dyn_root) { inode = afs_iget_pseudo_dir(sb, true); } else { sprintf(sb->s_id, "%llu", as->volume->vid); afs_activate_volume(as->volume); inode = afs_root_iget(sb, ctx->key); } if (IS_ERR(inode)) return PTR_ERR(inode); if (ctx->autocell || as->dyn_root) set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags); ret = -ENOMEM; sb->s_root = d_make_root(inode); if (!sb->s_root) goto error; if (as->dyn_root) { sb->s_d_op = &afs_dynroot_dentry_operations; ret = afs_dynroot_populate(sb); if (ret < 0) goto error; } else { sb->s_d_op = &afs_fs_dentry_operations; rcu_assign_pointer(as->volume->sb, sb); } _leave(" = 0"); return 0; error: _leave(" = %d", ret); return ret; } static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc) { struct afs_fs_context *ctx = fc->fs_private; struct afs_super_info *as; as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL); if (as) { as->net_ns = get_net(fc->net_ns); as->flock_mode = ctx->flock_mode; if (ctx->dyn_root) { as->dyn_root = true; } else { as->cell = afs_use_cell(ctx->cell, afs_cell_trace_use_sbi); as->volume = afs_get_volume(ctx->volume, afs_volume_trace_get_alloc_sbi); } } return as; } static void afs_destroy_sbi(struct afs_super_info *as) { if (as) { struct afs_net *net = afs_net(as->net_ns); afs_put_volume(net, as->volume, afs_volume_trace_put_destroy_sbi); afs_unuse_cell(net, as->cell, afs_cell_trace_unuse_sbi); put_net(as->net_ns); kfree(as); } } static void afs_kill_super(struct super_block *sb) { struct afs_super_info *as = AFS_FS_S(sb); if (as->dyn_root) afs_dynroot_depopulate(sb); /* Clear the callback interests (which will do ilookup5) before * deactivating the superblock. */ if (as->volume) rcu_assign_pointer(as->volume->sb, NULL); kill_anon_super(sb); if (as->volume) afs_deactivate_volume(as->volume); afs_destroy_sbi(as); } /* * Get an AFS superblock and root directory. */ static int afs_get_tree(struct fs_context *fc) { struct afs_fs_context *ctx = fc->fs_private; struct super_block *sb; struct afs_super_info *as; int ret; ret = afs_validate_fc(fc); if (ret) goto error; _enter(""); /* allocate a superblock info record */ ret = -ENOMEM; as = afs_alloc_sbi(fc); if (!as) goto error; fc->s_fs_info = as; /* allocate a deviceless superblock */ sb = sget_fc(fc, as->dyn_root ? afs_dynroot_test_super : afs_test_super, afs_set_super); if (IS_ERR(sb)) { ret = PTR_ERR(sb); goto error; } if (!sb->s_root) { /* initial superblock/root creation */ _debug("create"); ret = afs_fill_super(sb, ctx); if (ret < 0) goto error_sb; sb->s_flags |= SB_ACTIVE; } else { _debug("reuse"); ASSERTCMP(sb->s_flags, &, SB_ACTIVE); } fc->root = dget(sb->s_root); trace_afs_get_tree(as->cell, as->volume); _leave(" = 0 [%p]", sb); return 0; error_sb: deactivate_locked_super(sb); error: _leave(" = %d", ret); return ret; } static void afs_free_fc(struct fs_context *fc) { struct afs_fs_context *ctx = fc->fs_private; afs_destroy_sbi(fc->s_fs_info); afs_put_volume(ctx->net, ctx->volume, afs_volume_trace_put_free_fc); afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc); key_put(ctx->key); kfree(ctx); } static const struct fs_context_operations afs_context_ops = { .free = afs_free_fc, .parse_param = afs_parse_param, .get_tree = afs_get_tree, }; /* * Set up the filesystem mount context. */ static int afs_init_fs_context(struct fs_context *fc) { struct afs_fs_context *ctx; struct afs_cell *cell; ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL); if (!ctx) return -ENOMEM; ctx->type = AFSVL_ROVOL; ctx->net = afs_net(fc->net_ns); /* Default to the workstation cell. */ cell = afs_find_cell(ctx->net, NULL, 0, afs_cell_trace_use_fc); if (IS_ERR(cell)) cell = NULL; ctx->cell = cell; fc->fs_private = ctx; fc->ops = &afs_context_ops; return 0; } /* * Initialise an inode cache slab element prior to any use. Note that * afs_alloc_inode() *must* reset anything that could incorrectly leak from one * inode to another. */ static void afs_i_init_once(void *_vnode) { struct afs_vnode *vnode = _vnode; memset(vnode, 0, sizeof(*vnode)); inode_init_once(&vnode->vfs_inode); mutex_init(&vnode->io_lock); init_rwsem(&vnode->validate_lock); spin_lock_init(&vnode->wb_lock); spin_lock_init(&vnode->lock); INIT_LIST_HEAD(&vnode->wb_keys); INIT_LIST_HEAD(&vnode->pending_locks); INIT_LIST_HEAD(&vnode->granted_locks); INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work); seqlock_init(&vnode->cb_lock); } /* * allocate an AFS inode struct from our slab cache */ static struct inode *afs_alloc_inode(struct super_block *sb) { struct afs_vnode *vnode; vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL); if (!vnode) return NULL; atomic_inc(&afs_count_active_inodes); /* Reset anything that shouldn't leak from one inode to the next. */ memset(&vnode->fid, 0, sizeof(vnode->fid)); memset(&vnode->status, 0, sizeof(vnode->status)); vnode->volume = NULL; vnode->lock_key = NULL; vnode->permit_cache = NULL; #ifdef CONFIG_AFS_FSCACHE vnode->cache = NULL; #endif vnode->flags = 1 << AFS_VNODE_UNSET; vnode->lock_state = AFS_VNODE_LOCK_NONE; init_rwsem(&vnode->rmdir_lock); _leave(" = %p", &vnode->vfs_inode); return &vnode->vfs_inode; } static void afs_free_inode(struct inode *inode) { kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode)); } /* * destroy an AFS inode struct */ static void afs_destroy_inode(struct inode *inode) { struct afs_vnode *vnode = AFS_FS_I(inode); _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode); _debug("DESTROY INODE %p", inode); atomic_dec(&afs_count_active_inodes); } static void afs_get_volume_status_success(struct afs_operation *op) { struct afs_volume_status *vs = &op->volstatus.vs; struct kstatfs *buf = op->volstatus.buf; if (vs->max_quota == 0) buf->f_blocks = vs->part_max_blocks; else buf->f_blocks = vs->max_quota; if (buf->f_blocks > vs->blocks_in_use) buf->f_bavail = buf->f_bfree = buf->f_blocks - vs->blocks_in_use; } static const struct afs_operation_ops afs_get_volume_status_operation = { .issue_afs_rpc = afs_fs_get_volume_status, .issue_yfs_rpc = yfs_fs_get_volume_status, .success = afs_get_volume_status_success, }; /* * return information about an AFS volume */ static int afs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct afs_super_info *as = AFS_FS_S(dentry->d_sb); struct afs_operation *op; struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry)); buf->f_type = dentry->d_sb->s_magic; buf->f_bsize = AFS_BLOCK_SIZE; buf->f_namelen = AFSNAMEMAX - 1; if (as->dyn_root) { buf->f_blocks = 1; buf->f_bavail = 0; buf->f_bfree = 0; return 0; } op = afs_alloc_operation(NULL, as->volume); if (IS_ERR(op)) return PTR_ERR(op); afs_op_set_vnode(op, 0, vnode); op->nr_files = 1; op->volstatus.buf = buf; op->ops = &afs_get_volume_status_operation; return afs_do_sync_operation(op); }