On Thu, 06 Apr 2017, NeilBrown wrote:
> On Wed, Apr 05 2017, Scott Mayhew wrote:
>
> > The nfs.conf has config options for the rpc_pipefs mountpoint.
> > Currently, changing these from the default also requires manually
> > overriding the systemd unit files that are hard-coded to mount the
> > filesystem on /var/lib/nfs/rpc_pipefs.
> >
> > This patch adds a generator that creates a mount unit file for the
> > rpc_pipefs when a non-default value is specified in /etc/nfs.conf, as
> > well as a target unit file to override the dependencies for the systemd
> > units using the rpc_pipefs. The blkmapd, idmapd, and gssd service unit
> > files have been modified to define their dependencies on the rpc_pipefs
> > mountpoint indirectly via the rpc_pipefs target unit file.
> >
> > This patch also removes the dependency on the rpc_pipefs from the
> > rpc-svcgssd.service unit file. rpc.svcgssd uses the sunrpc cache
> > mechanism to exchange data with the kernel, not the rpc_pipefs.
> >
> > Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
>
> I was reading through this, which I really thought would be a good patch
> that I would give an Ack to, and looking at some of the detail involved,
> I started to wonder if we were really doing the right thing here.
> You go to some trouble to make the name of the .mount unit file match
> the name of the location of the mountpoint. Is that really necessary?
>
> Unit files created by systemd-fstab-generator do follow that pattern,
> but they don't have to.
I didn't know that.
>
> Maybe we should just:
>
> 1/ rename var-lib-nfs-rpc_pipefs.mount to rpc_pipefs.mount,
> and modify the dependencies accordingly.
>
> 2/ write a generator which (if necessary) creates a drop-in for
> rpc_pipefs.mount which simply overrides "Where".
>
> i.e /run/systemd/generator/rpc_pipefs.mount.d/pipefs.conf
> would contain
>
> [Mount]
> Where=/foo/bar
Sounds good to me, I'll take a look.
-Scott
>
> I'm sorry to discard your good work, but I now think that a lot of it is
> unnecessary. Sorry for not seeing that earlier.
>
> Thanks,
> NeilBrown
>
>
> > ---
> > .gitignore | 1 +
> > systemd/Makefile.am | 5 +-
> > systemd/nfs-blkmap.service | 4 +-
> > systemd/nfs-idmapd.service | 4 +-
> > systemd/rpc-gssd.service.in | 4 +-
> > systemd/rpc-pipefs-generator.c | 216 +++++++++++++++++++++++++++++++++++++++++
> > systemd/rpc-svcgssd.service | 3 +-
> > systemd/rpc_pipefs.target | 3 +
> > 8 files changed, 231 insertions(+), 9 deletions(-)
> > create mode 100644 systemd/rpc-pipefs-generator.c
> > create mode 100644 systemd/rpc_pipefs.target
> >
> > diff --git a/.gitignore b/.gitignore
> > index 126d12c..941aca0 100644
> > --- a/.gitignore
> > +++ b/.gitignore
> > @@ -70,6 +70,7 @@ tests/nsm_client/nlm_sm_inter_svc.c
> > tests/nsm_client/nlm_sm_inter_xdr.c
> > utils/nfsidmap/nfsidmap
> > systemd/nfs-server-generator
> > +systemd/rpc-pipefs-generator
> > systemd/nfs-config.service
> > systemd/rpc-gssd.service
> > # cscope database files
> > diff --git a/systemd/Makefile.am b/systemd/Makefile.am
> > index 0d15b9f..4becb77 100644
> > --- a/systemd/Makefile.am
> > +++ b/systemd/Makefile.am
> > @@ -4,6 +4,7 @@ MAINTAINERCLEANFILES = Makefile.in
> >
> > unit_files = \
> > nfs-client.target \
> > + rpc_pipefs.target \
> > \
> > nfs-mountd.service \
> > nfs-server.service \
> > @@ -42,12 +43,14 @@ EXTRA_DIST = $(unit_files) $(man5_MANS) $(man7_MANS)
> > unit_dir = /usr/lib/systemd/system
> > generator_dir = /usr/lib/systemd/system-generators
> >
> > -EXTRA_PROGRAMS = nfs-server-generator
> > +EXTRA_PROGRAMS = nfs-server-generator rpc-pipefs-generator
> > genexecdir = $(generator_dir)
> > nfs_server_generator_LDADD = ../support/export/libexport.a \
> > ../support/nfs/libnfs.a \
> > ../support/misc/libmisc.a
> >
> > +rpc_pipefs_generator_LDADD = ../support/nfs/libnfs.a
> > +
> > if INSTALL_SYSTEMD
> > genexec_PROGRAMS = nfs-server-generator
> > install-data-hook: $(unit_files)
> > diff --git a/systemd/nfs-blkmap.service b/systemd/nfs-blkmap.service
> > index ddc324e..2bbcee6 100644
> > --- a/systemd/nfs-blkmap.service
> > +++ b/systemd/nfs-blkmap.service
> > @@ -2,8 +2,8 @@
> > Description=pNFS block layout mapping daemon
> > DefaultDependencies=no
> > Conflicts=umount.target
> > -After=var-lib-nfs-rpc_pipefs.mount
> > -Requires=var-lib-nfs-rpc_pipefs.mount
> > +After=rpc_pipefs.target
> > +Requires=rpc_pipefs.target
> >
> > PartOf=nfs-utils.service
> >
> > diff --git a/systemd/nfs-idmapd.service b/systemd/nfs-idmapd.service
> > index acca86b..f38fe52 100644
> > --- a/systemd/nfs-idmapd.service
> > +++ b/systemd/nfs-idmapd.service
> > @@ -1,8 +1,8 @@
> > [Unit]
> > Description=NFSv4 ID-name mapping service
> > DefaultDependencies=no
> > -Requires=var-lib-nfs-rpc_pipefs.mount
> > -After=var-lib-nfs-rpc_pipefs.mount local-fs.target
> > +Requires=rpc_pipefs.target
> > +After=rpc_pipefs.target local-fs.target
> >
> > BindsTo=nfs-server.service
> >
> > diff --git a/systemd/rpc-gssd.service.in b/systemd/rpc-gssd.service.in
> > index b353027..6807db3 100644
> > --- a/systemd/rpc-gssd.service.in
> > +++ b/systemd/rpc-gssd.service.in
> > @@ -2,8 +2,8 @@
> > Description=RPC security service for NFS client and server
> > DefaultDependencies=no
> > Conflicts=umount.target
> > -Requires=var-lib-nfs-rpc_pipefs.mount
> > -After=var-lib-nfs-rpc_pipefs.mount
> > +Requires=rpc_pipefs.target
> > +After=rpc_pipefs.target
> >
> > ConditionPathExists=@_sysconfdir@/krb5.keytab
> >
> > diff --git a/systemd/rpc-pipefs-generator.c b/systemd/rpc-pipefs-generator.c
> > new file mode 100644
> > index 0000000..b0a6c19
> > --- /dev/null
> > +++ b/systemd/rpc-pipefs-generator.c
> > @@ -0,0 +1,216 @@
> > +/*
> > + * rpc-pipefs-generator:
> > + * systemd generator to create ordering dependencies between
> > + * nfs services and the rpc_pipefs mountpoint
> > + */
> > +
> > +#ifdef HAVE_CONFIG_H
> > +#include <config.h>
> > +#endif
> > +
> > +#include <sys/stat.h>
> > +#include <sys/types.h>
> > +#include <unistd.h>
> > +#include <stdlib.h>
> > +#include <string.h>
> > +#include <ctype.h>
> > +#include <stdio.h>
> > +#include <mntent.h>
> > +
> > +#include "nfslib.h"
> > +#include "conffile.h"
> > +
> > +#define RPC_PIPEFS_DEFAULT "/var/lib/nfs/rpc_pipefs"
> > +char *conf_path = NFS_CONFFILE;
> > +
> > +int systemd_len(char *path)
> > +{
> > + char *p;
> > + int len = 0;
> > +
> > + p = path;
> > + while (*p == '/')
> > + p++;
> > +
> > + if (!*p)
> > + /* "/" becomes "-", otherwise leading "/" is ignored */
> > + return 1;
> > +
> > + while (*p) {
> > + unsigned char c = *p++;
> > +
> > + if (c == '/') {
> > + /* multiple non-trailing slashes become '-' */
> > + while (*p == '/')
> > + p++;
> > + if (*p)
> > + len++;
> > + } else if (isalnum(c) || c == ':' || c == '.' || c == '_')
> > + len++;
> > + else {
> > + len += 4;
> > + }
> > + }
> > +
> > + return len;
> > +}
> > +
> > +char *systemd_escape(char *path)
> > +{
> > + char *result = NULL;
> > + char *p;
> > + int len;
> > +
> > + len = systemd_len(path);
> > + if (!len)
> > + goto out;
> > +
> > + result = malloc(len + strlen(".mount") + 1);
> > + if (!result)
> > + goto out;
> > +
> > + p = result;
> > + while (*path == '/')
> > + path++;
> > + if (!*path) {
> > + /* "/" becomes "-", otherwise leading "/" is ignored */
> > + *p++ = '-';
> > + goto out_append;
> > + }
> > + while (*path) {
> > + unsigned char c = *path++;
> > +
> > + if (c == '/') {
> > + /* multiple non-trailing slashes become '-' */
> > + while (*path == '/')
> > + path++;
> > + if (*path)
> > + *p++ = '-';
> > + } else if (isalnum(c) || c == ':' || c == '.' || c == '_')
> > + *p++ = c;
> > + else {
> > + *p++ = '\\';
> > + *p++ = 'x';
> > + *p++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
> > + *p++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
> > + }
> > + }
> > +
> > +out_append:
> > + sprintf(p, ".mount");
> > +out:
> > + return result;
> > +}
> > +
> > +static int generate_mount_unit(const char *pipefs_path, const char *pipefs_unit,
> > + const char *dirname)
> > +{
> > + char *path;
> > + FILE *f;
> > +
> > + path = malloc(strlen(dirname) + 1 + strlen(pipefs_unit));
> > + if (!path)
> > + return 1;
> > + sprintf(path, "%s/%s", dirname, pipefs_unit);
> > + f = fopen(path, "w");
> > + if (!f)
> > + return 1;
> > +
> > + fprintf(f, "# Automatically generated by rpc-pipefs-generator\n\n[Unit]\n");
> > + fprintf(f, "Description=RPC Pipe File System\n");
> > + fprintf(f, "DefaultDependencies=no\n");
> > + fprintf(f, "After=systemd-tmpfiles-setup.service\n");
> > + fprintf(f, "Conflicts=umount.target\n");
> > + fprintf(f, "\n[Mount]\n");
> > + fprintf(f, "What=sunrpc\n");
> > + fprintf(f, "Where=%s\n", pipefs_path);
> > + fprintf(f, "Type=rpc_pipefs\n");
> > +
> > + fclose(f);
> > + return 0;
> > +}
> > +
> > +static
> > +int generate_target(char *pipefs_path, const char *dirname)
> > +{
> > + char *path;
> > + char filebase[] = "/rpc_pipefs.target";
> > + char *pipefs_unit;
> > + FILE *f;
> > + int ret = 0;
> > +
> > + pipefs_unit = systemd_escape(pipefs_path);
> > + if (!pipefs_unit)
> > + return 1;
> > +
> > + ret = generate_mount_unit(pipefs_path, pipefs_unit, dirname);
> > + if (ret)
> > + return ret;
> > +
> > + path = malloc(strlen(dirname) + 1 + sizeof(filebase));
> > + if (!path)
> > + return 2;
> > + sprintf(path, "%s", dirname);
> > + mkdir(path, 0755);
> > + strcat(path, filebase);
> > + f = fopen(path, "w");
> > + if (!f)
> > + return 1;
> > +
> > + fprintf(f, "# Automatically generated by rpc-pipefs-generator\n\n[Unit]\n");
> > + fprintf(f, "Requires=%s\n", pipefs_unit);
> > + fprintf(f, "After=%s\n", pipefs_unit);
> > + fclose(f);
> > +
> > + return 0;
> > +}
> > +
> > +static int is_non_pipefs_mountpoint(char *path)
> > +{
> > + FILE *mtab;
> > + struct mntent *mnt;
> > +
> > + mtab = setmntent("/etc/mtab", "r");
> > + if (!mtab)
> > + return 0;
> > +
> > + while ((mnt = getmntent(mtab)) != NULL) {
> > + if (strlen(mnt->mnt_dir) != strlen(path))
> > + continue;
> > + if (strncmp(mnt->mnt_dir, path, strlen(mnt->mnt_dir)))
> > + continue;
> > + if (strncmp(mnt->mnt_type, "rpc_pipefs", strlen(mnt->mnt_type)))
> > + break;
> > + }
> > + fclose(mtab);
> > + return mnt != NULL;
> > +}
> > +
> > +int main(int argc, char *argv[])
> > +{
> > + int ret;
> > + char *s;
> > +
> > + /* Avoid using any external services */
> > + xlog_syslog(0);
> > +
> > + if (argc != 4 || argv[1][0] != '/') {
> > + fprintf(stderr, "rpc-pipefs-generator: create systemd dependencies for nfs services\n");
> > + fprintf(stderr, "Usage: normal-dir early-dir late-dir\n");
> > + exit(1);
> > + }
> > +
> > + conf_init();
> > + s = conf_get_str("global", "pipefs-directory");
> > + if (!s)
> > + exit(0);
> > + if (strlen(s) == strlen(RPC_PIPEFS_DEFAULT) &&
> > + strcmp(s, RPC_PIPEFS_DEFAULT) == 0)
> > + exit(0);
> > +
> > + if (is_non_pipefs_mountpoint(s))
> > + exit(1);
> > +
> > + ret = generate_target(s, argv[1]);
> > + exit(ret);
> > +}
> > diff --git a/systemd/rpc-svcgssd.service b/systemd/rpc-svcgssd.service
> > index 7187e3c..cb2bcd4 100644
> > --- a/systemd/rpc-svcgssd.service
> > +++ b/systemd/rpc-svcgssd.service
> > @@ -1,8 +1,7 @@
> > [Unit]
> > Description=RPC security service for NFS server
> > DefaultDependencies=no
> > -Requires=var-lib-nfs-rpc_pipefs.mount
> > -After=var-lib-nfs-rpc_pipefs.mount local-fs.target
> > +After=local-fs.target
> > PartOf=nfs-server.service
> > PartOf=nfs-utils.service
> >
> > diff --git a/systemd/rpc_pipefs.target b/systemd/rpc_pipefs.target
> > new file mode 100644
> > index 0000000..01d4d27
> > --- /dev/null
> > +++ b/systemd/rpc_pipefs.target
> > @@ -0,0 +1,3 @@
> > +[Unit]
> > +Requires=var-lib-nfs-rpc_pipefs.mount
> > +After=var-lib-nfs-rpc_pipefs.mount
> > --
> > 2.9.3
> >
> > --
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