| Message ID | 20220502085045.13038-3-richard@nod.at (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | nfs-utils: Improving NFS re-exports | expand |
Hey, A compile error... On 5/2/22 4:50 AM, Richard Weinberger wrote: > When re-exporting a NFS volume it is mandatory to specify > either a UUID or numerical fsid= option because nfsd is unable > to derive a identifier on its own. > > For NFS cross mounts this becomes a problem because nfsd also > needs a identifier for every crossed mount. > A common workaround is stating every single subvolume in the > exports list too. > But this defeats the purpose of the crossmnt option and is tedious. > > This is where the reexport= tries to help. > It offers various strategies to automatically derive a identifier > for NFS volumes and sub volumes. > Each have their pros and cons. > > Currently two modes are implemented: > > 1. auto-fsidnum > In this mode mountd/exportd will create a new numerical fsid > for a NFS volume and subvolume. The numbers are stored in a database > such that the server will always use the same fsid. > The entry in the exports file allowed to skip fsid= entiry but > stating a UUID is allowed, if needed. > > This mode has the obvious downside that load balancing is not > possible since multiple re-exporting NFS servers would generate > different ids. > > 2. predefined-fsidnum > This mode works just like auto-fsidnum but does not generate ids > for you. It helps in the load balancing case. A system administrator > has to manually maintain the database and install it on all re-exporting > NFS servers. If you have a massive amount of subvolumes this mode > will help because you don't have to bloat the exports list. > > Signed-off-by: Richard Weinberger <richard@nod.at> > --- > support/export/Makefile.am | 2 ++ > support/include/nfslib.h | 1 + > support/nfs/Makefile.am | 1 + > support/nfs/exports.c | 68 +++++++++++++++++++++++++++++++++++++ > support/reexport/reexport.c | 65 +++++++++++++++++++++++++++++++++++ > systemd/Makefile.am | 4 +++ > utils/exportfs/Makefile.am | 6 ++++ > utils/exportfs/exportfs.c | 11 ++++++ > utils/exportfs/exports.man | 31 +++++++++++++++++ > utils/mount/Makefile.am | 7 ++++ > 10 files changed, 196 insertions(+) > > diff --git a/support/export/Makefile.am b/support/export/Makefile.am > index eec737f6..7338e1c7 100644 > --- a/support/export/Makefile.am > +++ b/support/export/Makefile.am > @@ -14,6 +14,8 @@ libexport_a_SOURCES = client.c export.c hostname.c \ > xtab.c mount_clnt.c mount_xdr.c \ > cache.c auth.c v4root.c fsloc.c \ > v4clients.c > +libexport_a_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) -I$(top_srcdir)/support/reexport > + > BUILT_SOURCES = $(GENFILES) > > noinst_HEADERS = mount.h > diff --git a/support/include/nfslib.h b/support/include/nfslib.h > index 6faba71b..0465a1ff 100644 > --- a/support/include/nfslib.h > +++ b/support/include/nfslib.h > @@ -85,6 +85,7 @@ struct exportent { > struct sec_entry e_secinfo[SECFLAVOR_COUNT+1]; > unsigned int e_ttl; > char * e_realpath; > + int e_reexport; > }; > > struct rmtabent { > diff --git a/support/nfs/Makefile.am b/support/nfs/Makefile.am > index 67e3a8e1..2e1577cc 100644 > --- a/support/nfs/Makefile.am > +++ b/support/nfs/Makefile.am > @@ -9,6 +9,7 @@ libnfs_la_SOURCES = exports.c rmtab.c xio.c rpcmisc.c rpcdispatch.c \ > svc_socket.c cacheio.c closeall.c nfs_mntent.c \ > svc_create.c atomicio.c strlcat.c strlcpy.c > libnfs_la_LIBADD = libnfsconf.la > +libnfs_la_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) -I$(top_srcdir)/support/reexport > > libnfsconf_la_SOURCES = conffile.c xlog.c > > diff --git a/support/nfs/exports.c b/support/nfs/exports.c > index 2c8f0752..bc2b1d93 100644 > --- a/support/nfs/exports.c > +++ b/support/nfs/exports.c > @@ -31,6 +31,7 @@ > #include "xlog.h" > #include "xio.h" > #include "pseudoflavors.h" > +#include "reexport.h" > > #define EXPORT_DEFAULT_FLAGS \ > (NFSEXP_READONLY|NFSEXP_ROOTSQUASH|NFSEXP_GATHERED_WRITES|NFSEXP_NOSUBTREECHECK) > @@ -103,6 +104,7 @@ static void init_exportent (struct exportent *ee, int fromkernel) > ee->e_nsqgids = 0; > ee->e_uuid = NULL; > ee->e_ttl = default_ttl; > + ee->e_reexport = REEXP_NONE; > } > > struct exportent * > @@ -302,6 +304,23 @@ putexportent(struct exportent *ep) > } > if (ep->e_uuid) > fprintf(fp, "fsid=%s,", ep->e_uuid); > + > + if (ep->e_reexport) { > + fprintf(fp, "reexport="); > + switch (ep->e_reexport) { > + case REEXP_AUTO_FSIDNUM: > + fprintf(fp, "auto-fsidnum"); > + break; > + case REEXP_PREDEFINED_FSIDNUM: > + fprintf(fp, "predefined-fsidnum"); > + break; > + default: > + xlog(L_ERROR, "unknown reexport method %i", ep->e_reexport); > + fprintf(fp, "none"); > + } > + fprintf(fp, ","); > + } > + > if (ep->e_mountpoint) > fprintf(fp, "mountpoint%s%s,", > ep->e_mountpoint[0]?"=":"", ep->e_mountpoint); > @@ -538,6 +557,7 @@ parseopts(char *cp, struct exportent *ep, int warn, int *had_subtree_opt_ptr) > char *flname = efname?efname:"command line"; > int flline = efp?efp->x_line:0; > unsigned int active = 0; > + int saw_reexport = 0; > > squids = ep->e_squids; nsquids = ep->e_nsquids; > sqgids = ep->e_sqgids; nsqgids = ep->e_nsqgids; > @@ -644,6 +664,13 @@ bad_option: > } > } else if (strncmp(opt, "fsid=", 5) == 0) { > char *oe; > + > + if (saw_reexport) { > + xlog(L_ERROR, "%s:%d: 'fsid=' has to be before 'reexport=' %s\n", > + flname, flline, opt); > + goto bad_option; > + } > + > if (strcmp(opt+5, "root") == 0) { > ep->e_fsid = 0; > setflags(NFSEXP_FSID, active, ep); > @@ -688,6 +715,47 @@ bad_option: > active = parse_flavors(opt+4, ep); > if (!active) > goto bad_option; > + } else if (strncmp(opt, "reexport=", 9) == 0) { > +#ifdef HAVE_REEXPORT_SUPPORT > + char *strategy = strchr(opt, '='); > + > + if (!strategy) { > + xlog(L_ERROR, "%s:%d: bad option %s\n", > + flname, flline, opt); > + goto bad_option; > + } > + strategy++; > + > + if (saw_reexport) { > + xlog(L_ERROR, "%s:%d: only one 'reexport=' is allowed%s\n", > + flname, flline, opt); > + goto bad_option; > + } > + > + if (strcmp(strategy, "auto-fsidnum") == 0) { > + ep->e_reexport = REEXP_AUTO_FSIDNUM; > + } else if (strcmp(strategy, "predefined-fsidnum") == 0) { > + ep->e_reexport = REEXP_PREDEFINED_FSIDNUM; > + } else if (strcmp(strategy, "none") == 0) { > + ep->e_reexport = REEXP_NONE; > + } else { > + xlog(L_ERROR, "%s:%d: bad option %s\n", > + flname, flline, strategy); > + goto bad_option; > + } > + > + if (reexpdb_apply_reexport_settings(ep, flname, flline) != 0) > + goto bad_option; > + > + if (ep->e_fsid) > + setflags(NFSEXP_FSID, active, ep); > + > + saw_reexport = 1; > +#else > + xlog(L_ERROR, "%s:%d: 'reexport=' not available, rebuild with --enable-reexport\n", > + flname, flline); > + goto bad_option; > +#endif > } else { > xlog(L_ERROR, "%s:%d: unknown keyword \"%s\"\n", > flname, flline, opt); > diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c > index 5474a21f..a9529b2b 100644 > --- a/support/reexport/reexport.c > +++ b/support/reexport/reexport.c > @@ -283,3 +283,68 @@ void reexpdb_uncover_subvolume(uint32_t fsidnum) > > free(path); > } > + > +/* > + * reexpdb_apply_reexport_settings - Apply reexport specific settings to an exportent > + * > + * @ep: exportent to apply to > + * @flname: Current export file, only useful for logging > + * @flline: Current line, only useful for logging > + * > + * This is a helper function for applying reexport specific settings to an exportent. > + * It searches a suitable fsid an sets @ep->e_fsid. > + */ > +int reexpdb_apply_reexport_settings(struct exportent *ep, char *flname, int flline) > +{ > + uint32_t fsidnum; > + int found; > + int ret = 0; > + > + if (ep->e_reexport == REEXP_NONE) > + goto out; > + > + if (ep->e_uuid) > + goto out; > + > + /* > + * We do a lazy database init because we want to init the db only > + * when at least one reexport= option is present. > + */ > + if (reexpdb_init() != 0) { > + ret = -1; > + goto out; > + } > + > + found = reexpdb_fsidnum_by_path(ep->e_path, &fsidnum, 0); > + if (!found) { > + if (ep->e_reexport == REEXP_AUTO_FSIDNUM) { > + found = reexpdb_fsidnum_by_path(ep->e_path, &fsidnum, 1); > + if (!found) { > + xlog(L_ERROR, "%s:%i: Unable to generate fsid for %s", > + flname, flline, ep->e_path); > + ret = -1; > + goto out; > + } > + } else { > + if (!ep->e_fsid) { > + xlog(L_ERROR, "%s:%i: Selected 'reexport=' mode requires either a UUID 'fsid=' or a numerical 'fsid=' or a reexport db entry %d", > + flname, flline, ep->e_fsid); > + ret = -1; > + } > + > + goto out; reexport.c: In function ‘reexpdb_apply_reexport_settings’: reexport.c:335:25: error: label ‘out’ used but not defined 335 | goto out; | ^~~~ > + } > + } > + > + if (ep->e_fsid) { > + if (ep->e_fsid != fsidnum) { > + xlog(L_ERROR, "%s:%i: Selected 'reexport=' mode requires configured numerical 'fsid=' to agree with reexport db entry", > + flname, flline); > + ret = -1; > + } > + } else { > + ep->e_fsid = fsidnum; > + } I'm assuming this is where the out needs to be out: > + return ret; > +} > diff --git a/systemd/Makefile.am b/systemd/Makefile.am > index e7f5d818..f254b218 100644 > --- a/systemd/Makefile.am > +++ b/systemd/Makefile.am > @@ -69,6 +69,10 @@ nfs_server_generator_LDADD = ../support/export/libexport.a \ > ../support/misc/libmisc.a \ > $(LIBPTHREAD) > > +if CONFIG_REEXPORT > +nfs_server_generator_LDADD += ../support/reexport/libreexport.a $(LIBSQLITE) -lrt > +endif > + > rpc_pipefs_generator_LDADD = ../support/nfs/libnfs.la > > if INSTALL_SYSTEMD > diff --git a/utils/exportfs/Makefile.am b/utils/exportfs/Makefile.am > index 96524c72..451637a0 100644 > --- a/utils/exportfs/Makefile.am > +++ b/utils/exportfs/Makefile.am > @@ -12,4 +12,10 @@ exportfs_LDADD = ../../support/export/libexport.a \ > ../../support/misc/libmisc.a \ > $(LIBWRAP) $(LIBNSL) $(LIBPTHREAD) > > +if CONFIG_REEXPORT > +exportfs_LDADD += ../../support/reexport/libreexport.a $(LIBSQLITE) -lrt > +endif > + > +exportfs_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) -I$(top_srcdir)/support/reexport > + > MAINTAINERCLEANFILES = Makefile.in > diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c > index 6ba615d1..7f21edcf 100644 > --- a/utils/exportfs/exportfs.c > +++ b/utils/exportfs/exportfs.c > @@ -38,6 +38,7 @@ > #include "exportfs.h" > #include "xlog.h" > #include "conffile.h" > +#include "reexport.h" > > static void export_all(int verbose); > static void exportfs(char *arg, char *options, int verbose); > @@ -719,6 +720,16 @@ dump(int verbose, int export_format) > c = dumpopt(c, "fsid=%d", ep->e_fsid); > if (ep->e_uuid) > c = dumpopt(c, "fsid=%s", ep->e_uuid); > + if (ep->e_reexport) { > + switch (ep->e_reexport) { > + case REEXP_AUTO_FSIDNUM: > + c = dumpopt(c, "reexport=%s", "auto-fsidnum"); > + break; > + case REEXP_PREDEFINED_FSIDNUM: > + c = dumpopt(c, "reexport=%s", "predefined-fsidnum"); > + break; > + } > + } > if (ep->e_mountpoint) > c = dumpopt(c, "mountpoint%s%s", > ep->e_mountpoint[0]?"=":"", > diff --git a/utils/exportfs/exports.man b/utils/exportfs/exports.man > index 54b3f877..ad2c2c59 100644 > --- a/utils/exportfs/exports.man > +++ b/utils/exportfs/exports.man > @@ -420,6 +420,37 @@ will only work if all clients use a consistent security policy. Note > that early kernels did not support this export option, and instead > enabled security labels by default. > > +.TP > +.IR reexport= auto-fsidnum|predefined-fsidnum > +This option helps when a NFS share is re-exported. Since the NFS server > +needs a unique identifier for each exported filesystem and a NFS share > +cannot provide such, usually a manual fsid is needed. > +As soon > +.IR crossmnt > +is used manually assigning fsid won't work anymore. This is where this > +option becomes handy. It will automatically assign a numerical fsid > +to exported NFS shares. The fsid and path relations are stored in a SQLite > +database. If > +.IR auto-fsidnum > +is selected, the fsid is also autmatically allocated. > +.IR predefined-fsidnum > +assumes pre-allocated fsid numbers and will just look them up. > +This option depends also on the kernel, you will need at least kernel version > +5.19. > +Since > +.IR reexport= > +can automatically allocate and assign numerical fsids, it is no longer possible > +to have numerical fsids in other exports as soon this option is used in at least > +one export entry. > + > +The association between fsid numbers and paths is stored in a SQLite database. > +Don't edit or remove the database unless you know exactly what you're doing. > +.IR predefined-fsidnum > +is useful when you have used > +.IR auto-fsidnum > +before and don't want further entries stored. > + > + > .SS User ID Mapping > .PP > .B nfsd > diff --git a/utils/mount/Makefile.am b/utils/mount/Makefile.am > index 3101f7ab..0268488c 100644 > --- a/utils/mount/Makefile.am > +++ b/utils/mount/Makefile.am > @@ -32,6 +32,13 @@ mount_nfs_LDADD = ../../support/nfs/libnfs.la \ > ../../support/misc/libmisc.a \ > $(LIBTIRPC) > > +if CONFIG_REEXPORT > +mount_nfs_LDADD += ../../support/reexport/libreexport.a \ > + ../../support/misc/libmisc.a \ > + $(LIBSQLITE) -lrt $(LIBPTHREAD) > +endif > + > + > mount_nfs_SOURCES = $(mount_common) > > if CONFIG_LIBMOUNT
----- Ursprüngliche Mail ----- > Von: "Steve Dickson" <steved@redhat.com> > A compile error... > reexport.c: In function ‘reexpdb_apply_reexport_settings’: > reexport.c:335:25: error: label ‘out’ used but not defined > 335 | goto out; > | ^~~~ > > >> + } >> + } >> + >> + if (ep->e_fsid) { >> + if (ep->e_fsid != fsidnum) { >> + xlog(L_ERROR, "%s:%i: Selected 'reexport=' mode requires configured >> numerical 'fsid=' to agree with reexport db entry", >> + flname, flline); >> + ret = -1; >> + } >> + } else { >> + ep->e_fsid = fsidnum; >> + } > I'm assuming this is where the out needs to be > > out: Patch 3/5 adds the label. Looks like I messed up something while reordering patches. ;-\ Do you want me to resend the patch series immediately or shall I want for further comments? Thanks, //richard
On 5/10/22 12:06 PM, Richard Weinberger wrote: > ----- Ursprüngliche Mail ----- >> Von: "Steve Dickson" <steved@redhat.com> >> A compile error... >> reexport.c: In function ‘reexpdb_apply_reexport_settings’: >> reexport.c:335:25: error: label ‘out’ used but not defined >> 335 | goto out; >> | ^~~~ >> >> >>> + } >>> + } >>> + >>> + if (ep->e_fsid) { >>> + if (ep->e_fsid != fsidnum) { >>> + xlog(L_ERROR, "%s:%i: Selected 'reexport=' mode requires configured >>> numerical 'fsid=' to agree with reexport db entry", >>> + flname, flline); >>> + ret = -1; >>> + } >>> + } else { >>> + ep->e_fsid = fsidnum; >>> + } >> I'm assuming this is where the out needs to be >> >> out: > > Patch 3/5 adds the label. > Looks like I messed up something while reordering patches. ;-\ NP... there were a couple linking errors that also fixed in patch 3... I figured it out. > > Do you want me to resend the patch series immediately or shall I want for further comments? No... I have the on a branch and at least the compile... cleanly... Now on to testing! :-) steved. > > Thanks, > //richard >
diff --git a/support/export/Makefile.am b/support/export/Makefile.am index eec737f6..7338e1c7 100644 --- a/support/export/Makefile.am +++ b/support/export/Makefile.am @@ -14,6 +14,8 @@ libexport_a_SOURCES = client.c export.c hostname.c \ xtab.c mount_clnt.c mount_xdr.c \ cache.c auth.c v4root.c fsloc.c \ v4clients.c +libexport_a_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) -I$(top_srcdir)/support/reexport + BUILT_SOURCES = $(GENFILES) noinst_HEADERS = mount.h diff --git a/support/include/nfslib.h b/support/include/nfslib.h index 6faba71b..0465a1ff 100644 --- a/support/include/nfslib.h +++ b/support/include/nfslib.h @@ -85,6 +85,7 @@ struct exportent { struct sec_entry e_secinfo[SECFLAVOR_COUNT+1]; unsigned int e_ttl; char * e_realpath; + int e_reexport; }; struct rmtabent { diff --git a/support/nfs/Makefile.am b/support/nfs/Makefile.am index 67e3a8e1..2e1577cc 100644 --- a/support/nfs/Makefile.am +++ b/support/nfs/Makefile.am @@ -9,6 +9,7 @@ libnfs_la_SOURCES = exports.c rmtab.c xio.c rpcmisc.c rpcdispatch.c \ svc_socket.c cacheio.c closeall.c nfs_mntent.c \ svc_create.c atomicio.c strlcat.c strlcpy.c libnfs_la_LIBADD = libnfsconf.la +libnfs_la_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) -I$(top_srcdir)/support/reexport libnfsconf_la_SOURCES = conffile.c xlog.c diff --git a/support/nfs/exports.c b/support/nfs/exports.c index 2c8f0752..bc2b1d93 100644 --- a/support/nfs/exports.c +++ b/support/nfs/exports.c @@ -31,6 +31,7 @@ #include "xlog.h" #include "xio.h" #include "pseudoflavors.h" +#include "reexport.h" #define EXPORT_DEFAULT_FLAGS \ (NFSEXP_READONLY|NFSEXP_ROOTSQUASH|NFSEXP_GATHERED_WRITES|NFSEXP_NOSUBTREECHECK) @@ -103,6 +104,7 @@ static void init_exportent (struct exportent *ee, int fromkernel) ee->e_nsqgids = 0; ee->e_uuid = NULL; ee->e_ttl = default_ttl; + ee->e_reexport = REEXP_NONE; } struct exportent * @@ -302,6 +304,23 @@ putexportent(struct exportent *ep) } if (ep->e_uuid) fprintf(fp, "fsid=%s,", ep->e_uuid); + + if (ep->e_reexport) { + fprintf(fp, "reexport="); + switch (ep->e_reexport) { + case REEXP_AUTO_FSIDNUM: + fprintf(fp, "auto-fsidnum"); + break; + case REEXP_PREDEFINED_FSIDNUM: + fprintf(fp, "predefined-fsidnum"); + break; + default: + xlog(L_ERROR, "unknown reexport method %i", ep->e_reexport); + fprintf(fp, "none"); + } + fprintf(fp, ","); + } + if (ep->e_mountpoint) fprintf(fp, "mountpoint%s%s,", ep->e_mountpoint[0]?"=":"", ep->e_mountpoint); @@ -538,6 +557,7 @@ parseopts(char *cp, struct exportent *ep, int warn, int *had_subtree_opt_ptr) char *flname = efname?efname:"command line"; int flline = efp?efp->x_line:0; unsigned int active = 0; + int saw_reexport = 0; squids = ep->e_squids; nsquids = ep->e_nsquids; sqgids = ep->e_sqgids; nsqgids = ep->e_nsqgids; @@ -644,6 +664,13 @@ bad_option: } } else if (strncmp(opt, "fsid=", 5) == 0) { char *oe; + + if (saw_reexport) { + xlog(L_ERROR, "%s:%d: 'fsid=' has to be before 'reexport=' %s\n", + flname, flline, opt); + goto bad_option; + } + if (strcmp(opt+5, "root") == 0) { ep->e_fsid = 0; setflags(NFSEXP_FSID, active, ep); @@ -688,6 +715,47 @@ bad_option: active = parse_flavors(opt+4, ep); if (!active) goto bad_option; + } else if (strncmp(opt, "reexport=", 9) == 0) { +#ifdef HAVE_REEXPORT_SUPPORT + char *strategy = strchr(opt, '='); + + if (!strategy) { + xlog(L_ERROR, "%s:%d: bad option %s\n", + flname, flline, opt); + goto bad_option; + } + strategy++; + + if (saw_reexport) { + xlog(L_ERROR, "%s:%d: only one 'reexport=' is allowed%s\n", + flname, flline, opt); + goto bad_option; + } + + if (strcmp(strategy, "auto-fsidnum") == 0) { + ep->e_reexport = REEXP_AUTO_FSIDNUM; + } else if (strcmp(strategy, "predefined-fsidnum") == 0) { + ep->e_reexport = REEXP_PREDEFINED_FSIDNUM; + } else if (strcmp(strategy, "none") == 0) { + ep->e_reexport = REEXP_NONE; + } else { + xlog(L_ERROR, "%s:%d: bad option %s\n", + flname, flline, strategy); + goto bad_option; + } + + if (reexpdb_apply_reexport_settings(ep, flname, flline) != 0) + goto bad_option; + + if (ep->e_fsid) + setflags(NFSEXP_FSID, active, ep); + + saw_reexport = 1; +#else + xlog(L_ERROR, "%s:%d: 'reexport=' not available, rebuild with --enable-reexport\n", + flname, flline); + goto bad_option; +#endif } else { xlog(L_ERROR, "%s:%d: unknown keyword \"%s\"\n", flname, flline, opt); diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c index 5474a21f..a9529b2b 100644 --- a/support/reexport/reexport.c +++ b/support/reexport/reexport.c @@ -283,3 +283,68 @@ void reexpdb_uncover_subvolume(uint32_t fsidnum) free(path); } + +/* + * reexpdb_apply_reexport_settings - Apply reexport specific settings to an exportent + * + * @ep: exportent to apply to + * @flname: Current export file, only useful for logging + * @flline: Current line, only useful for logging + * + * This is a helper function for applying reexport specific settings to an exportent. + * It searches a suitable fsid an sets @ep->e_fsid. + */ +int reexpdb_apply_reexport_settings(struct exportent *ep, char *flname, int flline) +{ + uint32_t fsidnum; + int found; + int ret = 0; + + if (ep->e_reexport == REEXP_NONE) + goto out; + + if (ep->e_uuid) + goto out; + + /* + * We do a lazy database init because we want to init the db only + * when at least one reexport= option is present. + */ + if (reexpdb_init() != 0) { + ret = -1; + goto out; + } + + found = reexpdb_fsidnum_by_path(ep->e_path, &fsidnum, 0); + if (!found) { + if (ep->e_reexport == REEXP_AUTO_FSIDNUM) { + found = reexpdb_fsidnum_by_path(ep->e_path, &fsidnum, 1); + if (!found) { + xlog(L_ERROR, "%s:%i: Unable to generate fsid for %s", + flname, flline, ep->e_path); + ret = -1; + goto out; + } + } else { + if (!ep->e_fsid) { + xlog(L_ERROR, "%s:%i: Selected 'reexport=' mode requires either a UUID 'fsid=' or a numerical 'fsid=' or a reexport db entry %d", + flname, flline, ep->e_fsid); + ret = -1; + } + + goto out; + } + } + + if (ep->e_fsid) { + if (ep->e_fsid != fsidnum) { + xlog(L_ERROR, "%s:%i: Selected 'reexport=' mode requires configured numerical 'fsid=' to agree with reexport db entry", + flname, flline); + ret = -1; + } + } else { + ep->e_fsid = fsidnum; + } + + return ret; +} diff --git a/systemd/Makefile.am b/systemd/Makefile.am index e7f5d818..f254b218 100644 --- a/systemd/Makefile.am +++ b/systemd/Makefile.am @@ -69,6 +69,10 @@ nfs_server_generator_LDADD = ../support/export/libexport.a \ ../support/misc/libmisc.a \ $(LIBPTHREAD) +if CONFIG_REEXPORT +nfs_server_generator_LDADD += ../support/reexport/libreexport.a $(LIBSQLITE) -lrt +endif + rpc_pipefs_generator_LDADD = ../support/nfs/libnfs.la if INSTALL_SYSTEMD diff --git a/utils/exportfs/Makefile.am b/utils/exportfs/Makefile.am index 96524c72..451637a0 100644 --- a/utils/exportfs/Makefile.am +++ b/utils/exportfs/Makefile.am @@ -12,4 +12,10 @@ exportfs_LDADD = ../../support/export/libexport.a \ ../../support/misc/libmisc.a \ $(LIBWRAP) $(LIBNSL) $(LIBPTHREAD) +if CONFIG_REEXPORT +exportfs_LDADD += ../../support/reexport/libreexport.a $(LIBSQLITE) -lrt +endif + +exportfs_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) -I$(top_srcdir)/support/reexport + MAINTAINERCLEANFILES = Makefile.in diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c index 6ba615d1..7f21edcf 100644 --- a/utils/exportfs/exportfs.c +++ b/utils/exportfs/exportfs.c @@ -38,6 +38,7 @@ #include "exportfs.h" #include "xlog.h" #include "conffile.h" +#include "reexport.h" static void export_all(int verbose); static void exportfs(char *arg, char *options, int verbose); @@ -719,6 +720,16 @@ dump(int verbose, int export_format) c = dumpopt(c, "fsid=%d", ep->e_fsid); if (ep->e_uuid) c = dumpopt(c, "fsid=%s", ep->e_uuid); + if (ep->e_reexport) { + switch (ep->e_reexport) { + case REEXP_AUTO_FSIDNUM: + c = dumpopt(c, "reexport=%s", "auto-fsidnum"); + break; + case REEXP_PREDEFINED_FSIDNUM: + c = dumpopt(c, "reexport=%s", "predefined-fsidnum"); + break; + } + } if (ep->e_mountpoint) c = dumpopt(c, "mountpoint%s%s", ep->e_mountpoint[0]?"=":"", diff --git a/utils/exportfs/exports.man b/utils/exportfs/exports.man index 54b3f877..ad2c2c59 100644 --- a/utils/exportfs/exports.man +++ b/utils/exportfs/exports.man @@ -420,6 +420,37 @@ will only work if all clients use a consistent security policy. Note that early kernels did not support this export option, and instead enabled security labels by default. +.TP +.IR reexport= auto-fsidnum|predefined-fsidnum +This option helps when a NFS share is re-exported. Since the NFS server +needs a unique identifier for each exported filesystem and a NFS share +cannot provide such, usually a manual fsid is needed. +As soon +.IR crossmnt +is used manually assigning fsid won't work anymore. This is where this +option becomes handy. It will automatically assign a numerical fsid +to exported NFS shares. The fsid and path relations are stored in a SQLite +database. If +.IR auto-fsidnum +is selected, the fsid is also autmatically allocated. +.IR predefined-fsidnum +assumes pre-allocated fsid numbers and will just look them up. +This option depends also on the kernel, you will need at least kernel version +5.19. +Since +.IR reexport= +can automatically allocate and assign numerical fsids, it is no longer possible +to have numerical fsids in other exports as soon this option is used in at least +one export entry. + +The association between fsid numbers and paths is stored in a SQLite database. +Don't edit or remove the database unless you know exactly what you're doing. +.IR predefined-fsidnum +is useful when you have used +.IR auto-fsidnum +before and don't want further entries stored. + + .SS User ID Mapping .PP .B nfsd diff --git a/utils/mount/Makefile.am b/utils/mount/Makefile.am index 3101f7ab..0268488c 100644 --- a/utils/mount/Makefile.am +++ b/utils/mount/Makefile.am @@ -32,6 +32,13 @@ mount_nfs_LDADD = ../../support/nfs/libnfs.la \ ../../support/misc/libmisc.a \ $(LIBTIRPC) +if CONFIG_REEXPORT +mount_nfs_LDADD += ../../support/reexport/libreexport.a \ + ../../support/misc/libmisc.a \ + $(LIBSQLITE) -lrt $(LIBPTHREAD) +endif + + mount_nfs_SOURCES = $(mount_common) if CONFIG_LIBMOUNT
When re-exporting a NFS volume it is mandatory to specify either a UUID or numerical fsid= option because nfsd is unable to derive a identifier on its own. For NFS cross mounts this becomes a problem because nfsd also needs a identifier for every crossed mount. A common workaround is stating every single subvolume in the exports list too. But this defeats the purpose of the crossmnt option and is tedious. This is where the reexport= tries to help. It offers various strategies to automatically derive a identifier for NFS volumes and sub volumes. Each have their pros and cons. Currently two modes are implemented: 1. auto-fsidnum In this mode mountd/exportd will create a new numerical fsid for a NFS volume and subvolume. The numbers are stored in a database such that the server will always use the same fsid. The entry in the exports file allowed to skip fsid= entiry but stating a UUID is allowed, if needed. This mode has the obvious downside that load balancing is not possible since multiple re-exporting NFS servers would generate different ids. 2. predefined-fsidnum This mode works just like auto-fsidnum but does not generate ids for you. It helps in the load balancing case. A system administrator has to manually maintain the database and install it on all re-exporting NFS servers. If you have a massive amount of subvolumes this mode will help because you don't have to bloat the exports list. Signed-off-by: Richard Weinberger <richard@nod.at> --- support/export/Makefile.am | 2 ++ support/include/nfslib.h | 1 + support/nfs/Makefile.am | 1 + support/nfs/exports.c | 68 +++++++++++++++++++++++++++++++++++++ support/reexport/reexport.c | 65 +++++++++++++++++++++++++++++++++++ systemd/Makefile.am | 4 +++ utils/exportfs/Makefile.am | 6 ++++ utils/exportfs/exportfs.c | 11 ++++++ utils/exportfs/exports.man | 31 +++++++++++++++++ utils/mount/Makefile.am | 7 ++++ 10 files changed, 196 insertions(+)