/* * Copyright (c) 2002 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 Woodhouse <dwmw2@infradead.org> * David Howells <dhowells@redhat.com> * */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/sched.h> #include <linux/mount.h> #include <linux/namei.h> #include <linux/iversion.h> #include "internal.h" static const struct inode_operations afs_symlink_inode_operations = { .get_link = page_get_link, .listxattr = afs_listxattr, }; /* * Initialise an inode from the vnode status. */ static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key) { struct inode *inode = AFS_VNODE_TO_I(vnode); _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu", vnode->status.type, vnode->status.nlink, (unsigned long long) vnode->status.size, vnode->status.data_version, vnode->status.mode); read_seqlock_excl(&vnode->cb_lock); afs_update_inode_from_status(vnode, &vnode->status, NULL, AFS_VNODE_NOT_YET_SET); switch (vnode->status.type) { case AFS_FTYPE_FILE: inode->i_mode = S_IFREG | vnode->status.mode; inode->i_op = &afs_file_inode_operations; inode->i_fop = &afs_file_operations; inode->i_mapping->a_ops = &afs_fs_aops; break; case AFS_FTYPE_DIR: inode->i_mode = S_IFDIR | vnode->status.mode; inode->i_op = &afs_dir_inode_operations; inode->i_fop = &afs_dir_file_operations; inode->i_mapping->a_ops = &afs_dir_aops; break; case AFS_FTYPE_SYMLINK: /* Symlinks with a mode of 0644 are actually mountpoints. */ if ((vnode->status.mode & 0777) == 0644) { inode->i_flags |= S_AUTOMOUNT; set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags); inode->i_mode = S_IFDIR | 0555; inode->i_op = &afs_mntpt_inode_operations; inode->i_fop = &afs_mntpt_file_operations; inode->i_mapping->a_ops = &afs_fs_aops; } else { inode->i_mode = S_IFLNK | vnode->status.mode; inode->i_op = &afs_symlink_inode_operations; inode->i_mapping->a_ops = &afs_fs_aops; } inode_nohighmem(inode); break; default: printk("kAFS: AFS vnode with undefined type\n"); read_sequnlock_excl(&vnode->cb_lock); return afs_protocol_error(NULL, -EBADMSG, afs_eproto_file_type); } inode->i_blocks = 0; vnode->invalid_before = vnode->status.data_version; read_sequnlock_excl(&vnode->cb_lock); return 0; } /* * Fetch file status from the volume. */ int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool new_inode) { struct afs_fs_cursor fc; int ret; _enter("%s,{%llx:%llu.%u,S=%lx}", vnode->volume->name, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique, vnode->flags); ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, vnode, key)) { while (afs_select_fileserver(&fc)) { fc.cb_break = afs_calc_vnode_cb_break(vnode); afs_fs_fetch_file_status(&fc, NULL, new_inode); } afs_check_for_remote_deletion(&fc, fc.vnode); afs_vnode_commit_status(&fc, vnode, fc.cb_break); ret = afs_end_vnode_operation(&fc); } _leave(" = %d", ret); return ret; } /* * iget5() comparator */ int afs_iget5_test(struct inode *inode, void *opaque) { struct afs_iget_data *data = opaque; struct afs_vnode *vnode = AFS_FS_I(inode); return memcmp(&vnode->fid, &data->fid, sizeof(data->fid)) == 0; } /* * iget5() comparator for inode created by autocell operations * * These pseudo inodes don't match anything. */ static int afs_iget5_pseudo_dir_test(struct inode *inode, void *opaque) { return 0; } /* * iget5() inode initialiser */ static int afs_iget5_set(struct inode *inode, void *opaque) { struct afs_iget_data *data = opaque; struct afs_vnode *vnode = AFS_FS_I(inode); vnode->fid = data->fid; vnode->volume = data->volume; /* YFS supports 96-bit vnode IDs, but Linux only supports * 64-bit inode numbers. */ inode->i_ino = data->fid.vnode; inode->i_generation = data->fid.unique; return 0; } /* * Create an inode for a dynamic root directory or an autocell dynamic * automount dir. */ struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root) { struct afs_iget_data data; struct afs_super_info *as; struct afs_vnode *vnode; struct inode *inode; static atomic_t afs_autocell_ino; _enter(""); as = sb->s_fs_info; if (as->volume) { data.volume = as->volume; data.fid.vid = as->volume->vid; } if (root) { data.fid.vnode = 1; data.fid.unique = 1; } else { data.fid.vnode = atomic_inc_return(&afs_autocell_ino); data.fid.unique = 0; } inode = iget5_locked(sb, data.fid.vnode, afs_iget5_pseudo_dir_test, afs_iget5_set, &data); if (!inode) { _leave(" = -ENOMEM"); return ERR_PTR(-ENOMEM); } _debug("GOT INODE %p { ino=%lu, vl=%llx, vn=%llx, u=%x }", inode, inode->i_ino, data.fid.vid, data.fid.vnode, data.fid.unique); vnode = AFS_FS_I(inode); /* there shouldn't be an existing inode */ BUG_ON(!(inode->i_state & I_NEW)); inode->i_size = 0; inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; if (root) { inode->i_op = &afs_dynroot_inode_operations; inode->i_fop = &afs_dynroot_file_operations; } else { inode->i_op = &afs_autocell_inode_operations; } set_nlink(inode, 2); inode->i_uid = GLOBAL_ROOT_UID; inode->i_gid = GLOBAL_ROOT_GID; inode->i_ctime.tv_sec = get_seconds(); inode->i_ctime.tv_nsec = 0; inode->i_atime = inode->i_mtime = inode->i_ctime; inode->i_blocks = 0; inode_set_iversion_raw(inode, 0); inode->i_generation = 0; set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags); if (!root) { set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags); inode->i_flags |= S_AUTOMOUNT; } inode->i_flags |= S_NOATIME; unlock_new_inode(inode); _leave(" = %p", inode); return inode; } /* * Get a cache cookie for an inode. */ static void afs_get_inode_cache(struct afs_vnode *vnode) { #ifdef CONFIG_AFS_FSCACHE struct { u32 vnode_id; u32 unique; u32 vnode_id_ext[2]; /* Allow for a 96-bit key */ } __packed key; struct afs_vnode_cache_aux aux; if (vnode->status.type == AFS_FTYPE_DIR) { vnode->cache = NULL; return; } key.vnode_id = vnode->fid.vnode; key.unique = vnode->fid.unique; key.vnode_id_ext[0] = vnode->fid.vnode >> 32; key.vnode_id_ext[1] = vnode->fid.vnode_hi; aux.data_version = vnode->status.data_version; vnode->cache = fscache_acquire_cookie(vnode->volume->cache, &afs_vnode_cache_index_def, &key, sizeof(key), &aux, sizeof(aux), vnode, vnode->status.size, true); #endif } /* * inode retrieval */ struct inode *afs_iget(struct super_block *sb, struct key *key, struct afs_fid *fid, struct afs_file_status *status, struct afs_callback *cb, struct afs_cb_interest *cbi) { struct afs_iget_data data = { .fid = *fid }; struct afs_super_info *as; struct afs_vnode *vnode; struct inode *inode; int ret; _enter(",{%llx:%llu.%u},,", fid->vid, fid->vnode, fid->unique); as = sb->s_fs_info; data.volume = as->volume; inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set, &data); if (!inode) { _leave(" = -ENOMEM"); return ERR_PTR(-ENOMEM); } _debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }", inode, fid->vid, fid->vnode, fid->unique); vnode = AFS_FS_I(inode); /* deal with an existing inode */ if (!(inode->i_state & I_NEW)) { _leave(" = %p", inode); return inode; } if (!status) { /* it's a remotely extant inode */ ret = afs_fetch_status(vnode, key, true); if (ret < 0) goto bad_inode; } else { /* it's an inode we just created */ memcpy(&vnode->status, status, sizeof(vnode->status)); if (!cb) { /* it's a symlink we just created (the fileserver * didn't give us a callback) */ vnode->cb_version = 0; vnode->cb_type = 0; vnode->cb_expires_at = ktime_get(); } else { vnode->cb_version = cb->version; vnode->cb_type = cb->type; vnode->cb_expires_at = cb->expires_at; vnode->cb_interest = afs_get_cb_interest(cbi); set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags); } vnode->cb_expires_at += ktime_get_real_seconds(); } ret = afs_inode_init_from_status(vnode, key); if (ret < 0) goto bad_inode; afs_get_inode_cache(vnode); /* success */ clear_bit(AFS_VNODE_UNSET, &vnode->flags); inode->i_flags |= S_NOATIME; unlock_new_inode(inode); _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type); return inode; /* failure */ bad_inode: iget_failed(inode); _leave(" = %d [bad]", ret); return ERR_PTR(ret); } /* * mark the data attached to an inode as obsolete due to a write on the server * - might also want to ditch all the outstanding writes and dirty pages */ void afs_zap_data(struct afs_vnode *vnode) { _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode); #ifdef CONFIG_AFS_FSCACHE fscache_invalidate(vnode->cache); #endif /* nuke all the non-dirty pages that aren't locked, mapped or being * written back in a regular file and completely discard the pages in a * directory or symlink */ if (S_ISREG(vnode->vfs_inode.i_mode)) invalidate_remote_inode(&vnode->vfs_inode); else invalidate_inode_pages2(vnode->vfs_inode.i_mapping); } /* * validate a vnode/inode * - there are several things we need to check * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, * symlink) * - parent dir metadata changed (security changes) * - dentry data changed (write, truncate) * - dentry metadata changed (security changes) */ int afs_validate(struct afs_vnode *vnode, struct key *key) { time64_t now = ktime_get_real_seconds(); bool valid; int ret; _enter("{v={%llx:%llu} fl=%lx},%x", vnode->fid.vid, vnode->fid.vnode, vnode->flags, key_serial(key)); /* Quickly check the callback state. Ideally, we'd use read_seqbegin * here, but we have no way to pass the net namespace to the RCU * cleanup for the server record. */ read_seqlock_excl(&vnode->cb_lock); if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break || vnode->cb_v_break != vnode->volume->cb_v_break) { vnode->cb_s_break = vnode->cb_interest->server->cb_s_break; vnode->cb_v_break = vnode->volume->cb_v_break; valid = false; } else if (vnode->status.type == AFS_FTYPE_DIR && (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags) || vnode->cb_expires_at - 10 <= now)) { valid = false; } else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) || vnode->cb_expires_at - 10 <= now) { valid = false; } else { valid = true; } } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { valid = true; } else { vnode->cb_v_break = vnode->volume->cb_v_break; valid = false; } read_sequnlock_excl(&vnode->cb_lock); if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) clear_nlink(&vnode->vfs_inode); if (valid) goto valid; down_write(&vnode->validate_lock); /* if the promise has expired, we need to check the server again to get * a new promise - note that if the (parent) directory's metadata was * changed then the security may be different and we may no longer have * access */ if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { _debug("not promised"); ret = afs_fetch_status(vnode, key, false); if (ret < 0) { if (ret == -ENOENT) { set_bit(AFS_VNODE_DELETED, &vnode->flags); ret = -ESTALE; } goto error_unlock; } _debug("new promise [fl=%lx]", vnode->flags); } if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { _debug("file already deleted"); ret = -ESTALE; goto error_unlock; } /* if the vnode's data version number changed then its contents are * different */ if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) afs_zap_data(vnode); up_write(&vnode->validate_lock); valid: _leave(" = 0"); return 0; error_unlock: up_write(&vnode->validate_lock); _leave(" = %d", ret); return ret; } /* * read the attributes of an inode */ int afs_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *inode = d_inode(path->dentry); struct afs_vnode *vnode = AFS_FS_I(inode); int seq = 0; _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation); do { read_seqbegin_or_lock(&vnode->cb_lock, &seq); generic_fillattr(inode, stat); } while (need_seqretry(&vnode->cb_lock, seq)); done_seqretry(&vnode->cb_lock, seq); return 0; } /* * discard an AFS inode */ int afs_drop_inode(struct inode *inode) { _enter(""); if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags)) return generic_delete_inode(inode); else return generic_drop_inode(inode); } /* * clear an AFS inode */ void afs_evict_inode(struct inode *inode) { struct afs_vnode *vnode; vnode = AFS_FS_I(inode); _enter("{%llx:%llu.%d}", vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique); _debug("CLEAR INODE %p", inode); ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); truncate_inode_pages_final(&inode->i_data); clear_inode(inode); if (vnode->cb_interest) { afs_put_cb_interest(afs_i2net(inode), vnode->cb_interest); vnode->cb_interest = NULL; } while (!list_empty(&vnode->wb_keys)) { struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next, struct afs_wb_key, vnode_link); list_del(&wbk->vnode_link); afs_put_wb_key(wbk); } #ifdef CONFIG_AFS_FSCACHE { struct afs_vnode_cache_aux aux; aux.data_version = vnode->status.data_version; fscache_relinquish_cookie(vnode->cache, &aux, test_bit(AFS_VNODE_DELETED, &vnode->flags)); vnode->cache = NULL; } #endif afs_put_permits(rcu_access_pointer(vnode->permit_cache)); key_put(vnode->lock_key); vnode->lock_key = NULL; _leave(""); } /* * set the attributes of an inode */ int afs_setattr(struct dentry *dentry, struct iattr *attr) { struct afs_fs_cursor fc; struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry)); struct key *key; int ret; _enter("{%llx:%llu},{n=%pd},%x", vnode->fid.vid, vnode->fid.vnode, dentry, attr->ia_valid); if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_MTIME))) { _leave(" = 0 [unsupported]"); return 0; } /* flush any dirty data outstanding on a regular file */ if (S_ISREG(vnode->vfs_inode.i_mode)) filemap_write_and_wait(vnode->vfs_inode.i_mapping); if (attr->ia_valid & ATTR_FILE) { key = afs_file_key(attr->ia_file); } else { key = afs_request_key(vnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } } ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, vnode, key)) { while (afs_select_fileserver(&fc)) { fc.cb_break = afs_calc_vnode_cb_break(vnode); afs_fs_setattr(&fc, attr); } afs_check_for_remote_deletion(&fc, fc.vnode); afs_vnode_commit_status(&fc, vnode, fc.cb_break); ret = afs_end_vnode_operation(&fc); } if (!(attr->ia_valid & ATTR_FILE)) key_put(key); error: _leave(" = %d", ret); return ret; }