/* * linux/fs/nfs/namespace.c * * Copyright (C) 2005 Trond Myklebust * - Modified by David Howells * * NFS namespace */ #include #include #include #include #include #include #include #include #include #include "internal.h" #define NFSDBG_FACILITY NFSDBG_VFS static void nfs_expire_automounts(struct work_struct *work); static LIST_HEAD(nfs_automount_list); static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts); int nfs_mountpoint_expiry_timeout = 500 * HZ; static struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr, rpc_authflavor_t authflavor); /* * nfs_path - reconstruct the path given an arbitrary dentry * @base - used to return pointer to the end of devname part of path * @dentry - pointer to dentry * @buffer - result buffer * @buflen - length of buffer * * Helper function for constructing the server pathname * by arbitrary hashed dentry. * * This is mainly for use in figuring out the path on the * server side when automounting on top of an existing partition * and in generating /proc/mounts and friends. */ char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen) { char *end; int namelen; unsigned seq; const char *base; rename_retry: end = buffer+buflen; *--end = '\0'; buflen--; seq = read_seqbegin(&rename_lock); rcu_read_lock(); while (1) { spin_lock(&dentry->d_lock); if (IS_ROOT(dentry)) break; namelen = dentry->d_name.len; buflen -= namelen + 1; if (buflen < 0) goto Elong_unlock; end -= namelen; memcpy(end, dentry->d_name.name, namelen); *--end = '/'; spin_unlock(&dentry->d_lock); dentry = dentry->d_parent; } if (read_seqretry(&rename_lock, seq)) { spin_unlock(&dentry->d_lock); rcu_read_unlock(); goto rename_retry; } if (*end != '/') { if (--buflen < 0) { spin_unlock(&dentry->d_lock); rcu_read_unlock(); goto Elong; } *--end = '/'; } *p = end; base = dentry->d_fsdata; if (!base) { spin_unlock(&dentry->d_lock); rcu_read_unlock(); WARN_ON(1); return end; } namelen = strlen(base); /* Strip off excess slashes in base string */ while (namelen > 0 && base[namelen - 1] == '/') namelen--; buflen -= namelen; if (buflen < 0) { spin_unlock(&dentry->d_lock); rcu_read_unlock(); goto Elong; } end -= namelen; memcpy(end, base, namelen); spin_unlock(&dentry->d_lock); rcu_read_unlock(); return end; Elong_unlock: spin_unlock(&dentry->d_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; Elong: return ERR_PTR(-ENAMETOOLONG); } #ifdef CONFIG_NFS_V4 static rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors) { struct gss_api_mech *mech; struct xdr_netobj oid; int i; rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX; for (i = 0; i < flavors->num_flavors; i++) { struct nfs4_secinfo_flavor *flavor; flavor = &flavors->flavors[i]; if (flavor->flavor == RPC_AUTH_NULL || flavor->flavor == RPC_AUTH_UNIX) { pseudoflavor = flavor->flavor; break; } else if (flavor->flavor == RPC_AUTH_GSS) { oid.len = flavor->gss.sec_oid4.len; oid.data = flavor->gss.sec_oid4.data; mech = gss_mech_get_by_OID(&oid); if (!mech) continue; pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service); gss_mech_put(mech); break; } } return pseudoflavor; } static int nfs_negotiate_security(const struct dentry *parent, const struct dentry *dentry, rpc_authflavor_t *flavor) { struct page *page; struct nfs4_secinfo_flavors *flavors; int (*secinfo)(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *); int ret = -EPERM; secinfo = NFS_PROTO(parent->d_inode)->secinfo; if (secinfo != NULL) { page = alloc_page(GFP_KERNEL); if (!page) { ret = -ENOMEM; goto out; } flavors = page_address(page); ret = secinfo(parent->d_inode, &dentry->d_name, flavors); *flavor = nfs_find_best_sec(flavors); put_page(page); } out: return ret; } static int nfs_lookup_with_sec(struct nfs_server *server, struct dentry *parent, struct dentry *dentry, struct path *path, struct nfs_fh *fh, struct nfs_fattr *fattr, rpc_authflavor_t *flavor) { struct rpc_clnt *clone; struct rpc_auth *auth; int err; err = nfs_negotiate_security(parent, path->dentry, flavor); if (err < 0) goto out; clone = rpc_clone_client(server->client); auth = rpcauth_create(*flavor, clone); if (!auth) { err = -EIO; goto out_shutdown; } err = server->nfs_client->rpc_ops->lookup(clone, parent->d_inode, &path->dentry->d_name, fh, fattr); out_shutdown: rpc_shutdown_client(clone); out: return err; } #else /* CONFIG_NFS_V4 */ static inline int nfs_lookup_with_sec(struct nfs_server *server, struct dentry *parent, struct dentry *dentry, struct path *path, struct nfs_fh *fh, struct nfs_fattr *fattr, rpc_authflavor_t *flavor) { return -EPERM; } #endif /* CONFIG_NFS_V4 */ /* * nfs_d_automount - Handle crossing a mountpoint on the server * @path - The mountpoint * * When we encounter a mountpoint on the server, we want to set up * a mountpoint on the client too, to prevent inode numbers from * colliding, and to allow "df" to work properly. * On NFSv4, we also want to allow for the fact that different * filesystems may be migrated to different servers in a failover * situation, and that different filesystems may want to use * different security flavours. */ struct vfsmount *nfs_d_automount(struct path *path) { struct vfsmount *mnt; struct nfs_server *server = NFS_SERVER(path->dentry->d_inode); struct dentry *parent; struct nfs_fh *fh = NULL; struct nfs_fattr *fattr = NULL; int err; rpc_authflavor_t flavor = RPC_AUTH_UNIX; dprintk("--> nfs_d_automount()\n"); mnt = ERR_PTR(-ESTALE); if (IS_ROOT(path->dentry)) goto out_nofree; mnt = ERR_PTR(-ENOMEM); fh = nfs_alloc_fhandle(); fattr = nfs_alloc_fattr(); if (fh == NULL || fattr == NULL) goto out; dprintk("%s: enter\n", __func__); /* Look it up again to get its attributes */ parent = dget_parent(path->dentry); err = server->nfs_client->rpc_ops->lookup(server->client, parent->d_inode, &path->dentry->d_name, fh, fattr); if (err == -EPERM && NFS_PROTO(parent->d_inode)->secinfo != NULL) err = nfs_lookup_with_sec(server, parent, path->dentry, path, fh, fattr, &flavor); dput(parent); if (err != 0) { mnt = ERR_PTR(err); goto out; } if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) mnt = nfs_do_refmount(path->dentry); else mnt = nfs_do_submount(path->dentry, fh, fattr, flavor); if (IS_ERR(mnt)) goto out; dprintk("%s: done, success\n", __func__); mntget(mnt); /* prevent immediate expiration */ mnt_set_expiry(mnt, &nfs_automount_list); schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout); out: nfs_free_fattr(fattr); nfs_free_fhandle(fh); out_nofree: dprintk("<-- nfs_follow_mountpoint() = %p\n", mnt); return mnt; } const struct inode_operations nfs_mountpoint_inode_operations = { .getattr = nfs_getattr, }; const struct inode_operations nfs_referral_inode_operations = { }; static void nfs_expire_automounts(struct work_struct *work) { struct list_head *list = &nfs_automount_list; mark_mounts_for_expiry(list); if (!list_empty(list)) schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout); } void nfs_release_automount_timer(void) { if (list_empty(&nfs_automount_list)) cancel_delayed_work(&nfs_automount_task); } /* * Clone a mountpoint of the appropriate type */ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server, const char *devname, struct nfs_clone_mount *mountdata) { #ifdef CONFIG_NFS_V4 struct vfsmount *mnt = ERR_PTR(-EINVAL); switch (server->nfs_client->rpc_ops->version) { case 2: case 3: mnt = vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata); break; case 4: mnt = vfs_kern_mount(&nfs4_xdev_fs_type, 0, devname, mountdata); } return mnt; #else return vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata); #endif } /** * nfs_do_submount - set up mountpoint when crossing a filesystem boundary * @dentry - parent directory * @fh - filehandle for new root dentry * @fattr - attributes for new root inode * @authflavor - security flavor to use when performing the mount * */ static struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr, rpc_authflavor_t authflavor) { struct nfs_clone_mount mountdata = { .sb = dentry->d_sb, .dentry = dentry, .fh = fh, .fattr = fattr, .authflavor = authflavor, }; struct vfsmount *mnt = ERR_PTR(-ENOMEM); char *page = (char *) __get_free_page(GFP_USER); char *devname; dprintk("--> nfs_do_submount()\n"); dprintk("%s: submounting on %s/%s\n", __func__, dentry->d_parent->d_name.name, dentry->d_name.name); if (page == NULL) goto out; devname = nfs_devname(dentry, page, PAGE_SIZE); mnt = (struct vfsmount *)devname; if (IS_ERR(devname)) goto free_page; mnt = nfs_do_clone_mount(NFS_SB(dentry->d_sb), devname, &mountdata); free_page: free_page((unsigned long)page); out: dprintk("%s: done\n", __func__); dprintk("<-- nfs_do_submount() = %p\n", mnt); return mnt; } 2017-12-08media: cec-core.rst: document the new adap_monitor_pin_enable opHans Verkuil Document what this op does. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-09-23media: cec-core.rst/cec-ioc-receive.rst: clarify CEC_TX_STATUS_ERRORHans Verkuil CEC_TX_STATUS_ERROR can be used if the HW cannot tell LOST_ARB and LOW_DRIVE apart, or when some other error occurs. It is not a replacement for NACK. So the hardware must be able to tell the difference between OK, NACK and 'something else'. Clarify the documentation (both public and kernel API) on this point. Also fix two small typos (this messages -> this message). Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-07-19media: cec-core: fix a Sphinx warningMauro Carvalho Chehab /devel/v4l/patchwork/Documentation/media/kapi/cec-core.rst:369: WARNING: Title underline too short. CEC Notifier framework ----------------- Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-07-18media: cec-core.rst: include cec-pin.h and cec-notifier.hHans Verkuil Include the CEC pin framework documentation by reading cec-pin.h. Include the CEC notifier framework documentation by reading cec-notifier.h. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-07-18media: cec-core.rst: document the adap_free callbackHans Verkuil Document what this callback does. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-06-20[media] cec: add cec_transmit_attempt_done helper functionHans Verkuil A simpler variant of cec_transmit_done to be used where the HW does just a single attempt at a transmit. So if the status indicates an error, then the corresponding error count will always be 1 and this function figures that out based on the status argument. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-06-20[media] cec: add cec_s_phys_addr_from_edid helper functionHans Verkuil This function simplifies the integration of CEC in DRM drivers. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-04-05[media] cec-core.rst: document the new cec_get_drvdata() helperHans Verkuil Document the new cec_get_drvdata() helper function. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-03-22[media] docs-rst: media: Push CEC documentation under CEC sectionSakari Ailus The CEC documentation added two sections on the main media kAPI level. There should be only one. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-11-29[media] cec: pass parent device in register(), not allocate()Hans Verkuil The cec_allocate_adapter function doesn't need the parent device, only the cec_register_adapter function needs it. Drop the cec_devnode parent field, since devnode.dev.parent can be used instead. This change makes the framework consistent with other frameworks where the parent device is not used until the device is registered. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-11-16[media] cec-core.rst: improve documentationHans Verkuil Improve the internal CEC documentation. In particular add a section that specifies that transmit-related interrupts should be processed before receive interrupts. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-08-22[media] cec-core: Convert it to ReST formatMauro Carvalho Chehab There are some things there that aren't ok for ReST format. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-08-22[media] docs-rst: move cec kAPI documentation to the media bookMauro Carvalho Chehab The CEC kAPI documentation should also be part of the media book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>