b4d0d230ccfb5 (Thomas Gleixner 2019-05-20 19:08:01 +0200 1) // SPDX-License-Identifier: GPL-2.0-or-later
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 2) /* AFS dynamic root handling
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 3) *
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 4) * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 5) * Written by David Howells (dhowells@redhat.com)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 6) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 7)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 8) #include <linux/fs.h>
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 9) #include <linux/namei.h>
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 10) #include <linux/dns_resolver.h>
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 11) #include "internal.h"
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 12)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 13) static atomic_t afs_autocell_ino;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 14)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 15) /*
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 16) * iget5() comparator for inode created by autocell operations
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 17) *
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 18) * These pseudo inodes don't match anything.
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 19) */
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 20) static int afs_iget5_pseudo_test(struct inode *inode, void *opaque)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 21) {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 22) return 0;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 23) }
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 24)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 25) /*
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 26) * iget5() inode initialiser
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 27) */
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 28) static int afs_iget5_pseudo_set(struct inode *inode, void *opaque)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 29) {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 30) struct afs_super_info *as = AFS_FS_S(inode->i_sb);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 31) struct afs_vnode *vnode = AFS_FS_I(inode);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 32) struct afs_fid *fid = opaque;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 33)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 34) vnode->volume = as->volume;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 35) vnode->fid = *fid;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 36) inode->i_ino = fid->vnode;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 37) inode->i_generation = fid->unique;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 38) return 0;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 39) }
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 40)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 41) /*
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 42) * Create an inode for a dynamic root directory or an autocell dynamic
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 43) * automount dir.
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 44) */
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 45) struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 46) {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 47) struct afs_super_info *as = AFS_FS_S(sb);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 48) struct afs_vnode *vnode;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 49) struct inode *inode;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 50) struct afs_fid fid = {};
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 51)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 52) _enter("");
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 53)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 54) if (as->volume)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 55) fid.vid = as->volume->vid;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 56) if (root) {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 57) fid.vnode = 1;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 58) fid.unique = 1;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 59) } else {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 60) fid.vnode = atomic_inc_return(&afs_autocell_ino);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 61) fid.unique = 0;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 62) }
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 63)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 64) inode = iget5_locked(sb, fid.vnode,
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 65) afs_iget5_pseudo_test, afs_iget5_pseudo_set, &fid);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 66) if (!inode) {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 67) _leave(" = -ENOMEM");
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 68) return ERR_PTR(-ENOMEM);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 69) }
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 70)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 71) _debug("GOT INODE %p { ino=%lu, vl=%llx, vn=%llx, u=%x }",
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 72) inode, inode->i_ino, fid.vid, fid.vnode, fid.unique);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 73)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 74) vnode = AFS_FS_I(inode);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 75)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 76) /* there shouldn't be an existing inode */
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 77) BUG_ON(!(inode->i_state & I_NEW));
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 78)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 79) inode->i_size = 0;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 80) inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 81) if (root) {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 82) inode->i_op = &afs_dynroot_inode_operations;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 83) inode->i_fop = &simple_dir_operations;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 84) } else {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 85) inode->i_op = &afs_autocell_inode_operations;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 86) }
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 87) set_nlink(inode, 2);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 88) inode->i_uid = GLOBAL_ROOT_UID;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 89) inode->i_gid = GLOBAL_ROOT_GID;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 90) inode->i_ctime = inode->i_atime = inode->i_mtime = current_time(inode);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 91) inode->i_blocks = 0;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 92) inode->i_generation = 0;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 93)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 94) set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 95) if (!root) {
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 96) set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 97) inode->i_flags |= S_AUTOMOUNT;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 98) }
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 99)
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 100) inode->i_flags |= S_NOATIME;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 101) unlock_new_inode(inode);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 102) _leave(" = %p", inode);
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 103) return inode;
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 104) }
e49c7b2f6de7f (David Howells 2020-04-10 20:51:51 +0100 105)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 106) /*
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 107) * Probe to see if a cell may exist. This prevents positive dentries from
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 108) * being created unnecessarily.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 109) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 110) static int afs_probe_cell_name(struct dentry *dentry)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 111) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 112) struct afs_cell *cell;
a58946c158a04 (David Howells 2019-06-26 21:02:33 +0100 113) struct afs_net *net = afs_d2net(dentry);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 114) const char *name = dentry->d_name.name;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 115) size_t len = dentry->d_name.len;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 116) int ret;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 117)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 118) /* Names prefixed with a dot are R/W mounts. */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 119) if (name[0] == '.') {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 120) if (len == 1)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 121) return -EINVAL;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 122) name++;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 123) len--;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 124) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 125)
dca54a7bbb8ca (David Howells 2020-10-13 20:51:59 +0100 126) cell = afs_find_cell(net, name, len, afs_cell_trace_use_probe);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 127) if (!IS_ERR(cell)) {
dca54a7bbb8ca (David Howells 2020-10-13 20:51:59 +0100 128) afs_unuse_cell(net, cell, afs_cell_trace_unuse_probe);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 129) return 0;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 130) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 131)
a58946c158a04 (David Howells 2019-06-26 21:02:33 +0100 132) ret = dns_query(net->net, "afsdb", name, len, "srv=1",
a58946c158a04 (David Howells 2019-06-26 21:02:33 +0100 133) NULL, NULL, false);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 134) if (ret == -ENODATA)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 135) ret = -EDESTADDRREQ;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 136) return ret;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 137) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 138)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 139) /*
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 140) * Try to auto mount the mountpoint with pseudo directory, if the autocell
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 141) * operation is setted.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 142) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 143) struct inode *afs_try_auto_mntpt(struct dentry *dentry, struct inode *dir)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 144) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 145) struct afs_vnode *vnode = AFS_FS_I(dir);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 146) struct inode *inode;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 147) int ret = -ENOENT;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 148)
3b6492df4153b (David Howells 2018-10-20 00:57:57 +0100 149) _enter("%p{%pd}, {%llx:%llu}",
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 150) dentry, dentry, vnode->fid.vid, vnode->fid.vnode);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 151)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 152) if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 153) goto out;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 154)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 155) ret = afs_probe_cell_name(dentry);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 156) if (ret < 0)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 157) goto out;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 158)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 159) inode = afs_iget_pseudo_dir(dir->i_sb, false);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 160) if (IS_ERR(inode)) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 161) ret = PTR_ERR(inode);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 162) goto out;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 163) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 164)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 165) _leave("= %p", inode);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 166) return inode;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 167)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 168) out:
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 169) _leave("= %d", ret);
1401a0fc2d479 (Al Viro 2018-06-24 10:45:44 -0400 170) return ret == -ENOENT ? NULL : ERR_PTR(ret);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 171) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 172)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 173) /*
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 174) * Look up @cell in a dynroot directory. This is a substitution for the
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 175) * local cell name for the net namespace.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 176) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 177) static struct dentry *afs_lookup_atcell(struct dentry *dentry)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 178) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 179) struct afs_cell *cell;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 180) struct afs_net *net = afs_d2net(dentry);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 181) struct dentry *ret;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 182) char *name;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 183) int len;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 184)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 185) if (!net->ws_cell)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 186) return ERR_PTR(-ENOENT);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 187)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 188) ret = ERR_PTR(-ENOMEM);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 189) name = kmalloc(AFS_MAXCELLNAME + 1, GFP_KERNEL);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 190) if (!name)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 191) goto out_p;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 192)
92e3cc91d8f51 (David Howells 2020-10-09 14:11:58 +0100 193) down_read(&net->cells_lock);
92e3cc91d8f51 (David Howells 2020-10-09 14:11:58 +0100 194) cell = net->ws_cell;
92e3cc91d8f51 (David Howells 2020-10-09 14:11:58 +0100 195) if (cell) {
92e3cc91d8f51 (David Howells 2020-10-09 14:11:58 +0100 196) len = cell->name_len;
92e3cc91d8f51 (David Howells 2020-10-09 14:11:58 +0100 197) memcpy(name, cell->name, len + 1);
92e3cc91d8f51 (David Howells 2020-10-09 14:11:58 +0100 198) }
92e3cc91d8f51 (David Howells 2020-10-09 14:11:58 +0100 199) up_read(&net->cells_lock);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 200)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 201) ret = ERR_PTR(-ENOENT);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 202) if (!cell)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 203) goto out_n;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 204)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 205) ret = lookup_one_len(name, dentry->d_parent, len);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 206)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 207) /* We don't want to d_add() the @cell dentry here as we don't want to
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 208) * the cached dentry to hide changes to the local cell name.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 209) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 210)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 211) out_n:
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 212) kfree(name);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 213) out_p:
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 214) return ret;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 215) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 216)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 217) /*
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 218) * Look up an entry in a dynroot directory.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 219) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 220) static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry,
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 221) unsigned int flags)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 222) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 223) _enter("%pd", dentry);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 224)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 225) ASSERTCMP(d_inode(dentry), ==, NULL);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 226)
1da4bd9f9d187 (David Howells 2019-12-11 08:56:04 +0000 227) if (flags & LOOKUP_CREATE)
1da4bd9f9d187 (David Howells 2019-12-11 08:56:04 +0000 228) return ERR_PTR(-EOPNOTSUPP);
1da4bd9f9d187 (David Howells 2019-12-11 08:56:04 +0000 229)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 230) if (dentry->d_name.len >= AFSNAMEMAX) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 231) _leave(" = -ENAMETOOLONG");
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 232) return ERR_PTR(-ENAMETOOLONG);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 233) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 234)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 235) if (dentry->d_name.len == 5 &&
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 236) memcmp(dentry->d_name.name, "@cell", 5) == 0)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 237) return afs_lookup_atcell(dentry);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 238)
1401a0fc2d479 (Al Viro 2018-06-24 10:45:44 -0400 239) return d_splice_alias(afs_try_auto_mntpt(dentry, dir), dentry);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 240) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 241)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 242) const struct inode_operations afs_dynroot_inode_operations = {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 243) .lookup = afs_dynroot_lookup,
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 244) };
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 245)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 246) /*
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 247) * Dirs in the dynamic root don't need revalidation.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 248) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 249) static int afs_dynroot_d_revalidate(struct dentry *dentry, unsigned int flags)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 250) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 251) return 1;
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 252) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 253)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 254) /*
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 255) * Allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 256) * sleep)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 257) * - called from dput() when d_count is going to 0.
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 258) * - return 1 to request dentry be unhashed, 0 otherwise
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 259) */
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 260) static int afs_dynroot_d_delete(const struct dentry *dentry)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 261) {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 262) return d_really_is_positive(dentry);
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 263) }
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 264)
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 265) const struct dentry_operations afs_dynroot_dentry_operations = {
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 266) .d_revalidate = afs_dynroot_d_revalidate,
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 267) .d_delete = afs_dynroot_d_delete,
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 268) .d_release = afs_d_release,
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 269) .d_automount = afs_d_automount,
66c7e1d319a5b (David Howells 2018-04-06 14:17:25 +0100 270) };
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 271)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 272) /*
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 273) * Create a manually added cell mount directory.
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 274) * - The caller must hold net->proc_cells_lock
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 275) */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 276) int afs_dynroot_mkdir(struct afs_net *net, struct afs_cell *cell)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 277) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 278) struct super_block *sb = net->dynroot_sb;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 279) struct dentry *root, *subdir;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 280) int ret;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 281)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 282) if (!sb || atomic_read(&sb->s_active) == 0)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 283) return 0;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 284)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 285) /* Let the ->lookup op do the creation */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 286) root = sb->s_root;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 287) inode_lock(root->d_inode);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 288) subdir = lookup_one_len(cell->name, root, cell->name_len);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 289) if (IS_ERR(subdir)) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 290) ret = PTR_ERR(subdir);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 291) goto unlock;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 292) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 293)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 294) /* Note that we're retaining an extra ref on the dentry */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 295) subdir->d_fsdata = (void *)1UL;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 296) ret = 0;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 297) unlock:
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 298) inode_unlock(root->d_inode);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 299) return ret;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 300) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 301)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 302) /*
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 303) * Remove a manually added cell mount directory.
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 304) * - The caller must hold net->proc_cells_lock
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 305) */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 306) void afs_dynroot_rmdir(struct afs_net *net, struct afs_cell *cell)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 307) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 308) struct super_block *sb = net->dynroot_sb;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 309) struct dentry *root, *subdir;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 310)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 311) if (!sb || atomic_read(&sb->s_active) == 0)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 312) return;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 313)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 314) root = sb->s_root;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 315) inode_lock(root->d_inode);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 316)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 317) /* Don't want to trigger a lookup call, which will re-add the cell */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 318) subdir = try_lookup_one_len(cell->name, root, cell->name_len);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 319) if (IS_ERR_OR_NULL(subdir)) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 320) _debug("lookup %ld", PTR_ERR(subdir));
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 321) goto no_dentry;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 322) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 323)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 324) _debug("rmdir %pd %u", subdir, d_count(subdir));
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 325)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 326) if (subdir->d_fsdata) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 327) _debug("unpin %u", d_count(subdir));
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 328) subdir->d_fsdata = NULL;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 329) dput(subdir);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 330) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 331) dput(subdir);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 332) no_dentry:
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 333) inode_unlock(root->d_inode);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 334) _leave("");
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 335) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 336)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 337) /*
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 338) * Populate a newly created dynamic root with cell names.
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 339) */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 340) int afs_dynroot_populate(struct super_block *sb)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 341) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 342) struct afs_cell *cell;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 343) struct afs_net *net = afs_sb2net(sb);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 344) int ret;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 345)
3b05e528cb9ef (David Howells 2019-05-09 09:17:08 +0100 346) mutex_lock(&net->proc_cells_lock);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 347)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 348) net->dynroot_sb = sb;
6b3944e42e2e5 (David Howells 2018-10-11 22:45:49 +0100 349) hlist_for_each_entry(cell, &net->proc_cells, proc_link) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 350) ret = afs_dynroot_mkdir(net, cell);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 351) if (ret < 0)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 352) goto error;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 353) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 354)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 355) ret = 0;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 356) out:
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 357) mutex_unlock(&net->proc_cells_lock);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 358) return ret;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 359)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 360) error:
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 361) net->dynroot_sb = NULL;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 362) goto out;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 363) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 364)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 365) /*
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 366) * When a dynamic root that's in the process of being destroyed, depopulate it
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 367) * of pinned directories.
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 368) */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 369) void afs_dynroot_depopulate(struct super_block *sb)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 370) {
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 371) struct afs_net *net = afs_sb2net(sb);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 372) struct dentry *root = sb->s_root, *subdir, *tmp;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 373)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 374) /* Prevent more subdirs from being created */
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 375) mutex_lock(&net->proc_cells_lock);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 376) if (net->dynroot_sb == sb)
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 377) net->dynroot_sb = NULL;
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 378) mutex_unlock(&net->proc_cells_lock);
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 379)
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 380) if (root) {
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 381) inode_lock(root->d_inode);
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 382)
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 383) /* Remove all the pins for dirs created for manually added cells */
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 384) list_for_each_entry_safe(subdir, tmp, &root->d_subdirs, d_child) {
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 385) if (subdir->d_fsdata) {
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 386) subdir->d_fsdata = NULL;
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 387) dput(subdir);
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 388) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 389) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 390)
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 391) inode_unlock(root->d_inode);
5e0b17b026eb7 (David Howells 2020-08-21 10:15:12 +0100 392) }
0da0b7fd73e4f (David Howells 2018-06-15 15:19:22 +0100 393) }
VisionFive2 Linux kernel
StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)
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