| Message ID | 162122673178.19062.96081788305923933@noble.neil.brown.name (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PATCH/RFC,v2,nfs-utils] Fix NFSv4 export of tmpfs filesystems. | expand |
Hi Neil, > Some filesystems cannot be exported without an fsid or uuid. > tmpfs is the main example. > When mountd (or exportd) creates nfsv4 pseudo-root exports for the path > leading down to an export point it exports each directory without any > fsid or uuid. If one of these directories is on tmp, that will fail. > The net result is that exporting a subdirectory of a tmpfs filesystem > will not work over NFSv4 as the parents within the filesystem cannot be > exported. It will either fail, or fall-back to NFSv3 (depending on the > version of the mount.nfs program). > To fix this we need to provide an fsid or uuid for these pseudo-root > exports. This patch does that by creating an RFC-4122 V5 compatible > UUID based on an arbitrary seed and the path to the export. > To check if an export needs a uuid, text_export() is moved from exportfs > to libexport.a, modified slightly and renamed to export_test(). > Signed-off-by: NeilBrown <neilb@suse.de> Tested-by: Petr Vorel <pvorel@suse.cz> tmpfs and btrfs via LTP test nfs01 on openSUSE. Kind regards, Petr
Hi Neil, > Some filesystems cannot be exported without an fsid or uuid. > tmpfs is the main example. > When mountd (or exportd) creates nfsv4 pseudo-root exports for the path > leading down to an export point it exports each directory without any > fsid or uuid. If one of these directories is on tmp, that will fail. ^ nit: you probably mean tmpfs > The net result is that exporting a subdirectory of a tmpfs filesystem > will not work over NFSv4 as the parents within the filesystem cannot be > exported. It will either fail, or fall-back to NFSv3 (depending on the > version of the mount.nfs program). > To fix this we need to provide an fsid or uuid for these pseudo-root > exports. This patch does that by creating an RFC-4122 V5 compatible > UUID based on an arbitrary seed and the path to the export. > To check if an export needs a uuid, text_export() is moved from exportfs > to libexport.a, modified slightly and renamed to export_test(). > Signed-off-by: NeilBrown <neilb@suse.de> Reported-by: Petr Vorel <pvorel@suse.cz> Reviewed-by: Petr Vorel <pvorel@suse.cz> Tested-by: Petr Vorel <pvorel@suse.cz> LGTM, thanks for fixing it. ... > --- a/support/include/exportfs.h > +++ b/support/include/exportfs.h > @@ -173,5 +173,6 @@ struct export_features { > struct export_features *get_export_features(void); > void fix_pseudoflavor_flags(struct exportent *ep); > char *exportent_realpath(struct exportent *eep); > +int export_test(struct exportent *eep, int with_fsid); > #endif /* EXPORTFS_H */ > diff --git a/utils/exportd/Makefile.am b/utils/exportd/Makefile.am > index eb521f15032d..c95bdee76d3f 100644 > --- a/utils/exportd/Makefile.am > +++ b/utils/exportd/Makefile.am > @@ -16,7 +16,7 @@ exportd_SOURCES = exportd.c > exportd_LDADD = ../../support/export/libexport.a \ > ../../support/nfs/libnfs.la \ > ../../support/misc/libmisc.a \ > - $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) > + $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) -luuid I wonder if configure.ac should have libuuid check as it's now mandatory, e.g.: AC_CHECK_LIB[uuid], uuid_parse, [LIBUUID="-luuid"], AC_MSG_ERROR([libuuid needed])) Kind regards, Petr
Hey! On 5/17/21 12:45 AM, NeilBrown wrote: > > Some filesystems cannot be exported without an fsid or uuid. > tmpfs is the main example. > > When mountd (or exportd) creates nfsv4 pseudo-root exports for the path > leading down to an export point it exports each directory without any > fsid or uuid. If one of these directories is on tmp, that will fail. > > The net result is that exporting a subdirectory of a tmpfs filesystem > will not work over NFSv4 as the parents within the filesystem cannot be > exported. It will either fail, or fall-back to NFSv3 (depending on the > version of the mount.nfs program). > > To fix this we need to provide an fsid or uuid for these pseudo-root > exports. This patch does that by creating an RFC-4122 V5 compatible > UUID based on an arbitrary seed and the path to the export. > > To check if an export needs a uuid, text_export() is moved from exportfs > to libexport.a, modified slightly and renamed to export_test(). Well.... it appears you guys did not compile with the --with-systemd config flag... Because if you did you would have seeing this compile error the in systemd code: /usr/bin/ld: ../support/nfs/.libs/libnfs.a(cacheio.o): in function `stat': /usr/include/sys/stat.h:455: undefined reference to `etab' collect2: error: ld returned 1 exit status make[1]: *** [Makefile:560: nfs-server-generator] Error 1 make[1]: Leaving directory '/home/src/up/nfs-utils/systemd' make: *** [Makefile:479: all-recursive] Error 1 It turns out the moving of export_test() in to the libexport.a is causing any binary linking with libexport.a to have a global definition of struct state_paths etab; The reason is export_test() calls qword_add(). Now qword_add() does not use an etab, but the file qword_add() lives in is cacheio.c which does have a extern struct state_paths etab which is the reason libnfs.a(cacheio.o) is mentioned in the error. At least that is what I *think* is going on... The extern came from commit a15bd94. Now the work around is to simply define a struct state_paths etab; in nfs-server-generator.c which will not be used at least by the systemd code. Now is that something we want continue doing... make any binaries linking with libexport.a define a global etab. It seems a little messy but the interface is not documented and the alternative, moving a bunch of code around see a lot more messy that simple adding one definition. Other than not compiling... Things looks good! ;-) Thoughts? steved. > > Signed-off-by: NeilBrown <neilb@suse.de> > --- > > This version contains Chuck's suggestion for improving the uuid, and > general clean-up. > > support/export/cache.c | 3 ++- > support/export/export.c | 29 +++++++++++++++++++++++++++++ > support/export/v4root.c | 23 ++++++++++++++++++++++- > support/include/exportfs.h | 1 + > utils/exportd/Makefile.am | 2 +- > utils/exportfs/exportfs.c | 38 +++----------------------------------- > utils/mountd/Makefile.am | 2 +- > 7 files changed, 59 insertions(+), 39 deletions(-) > > diff --git a/support/export/cache.c b/support/export/cache.c > index 3e4f53c0a32e..a5823e92e9f2 100644 > --- a/support/export/cache.c > +++ b/support/export/cache.c > @@ -981,7 +981,8 @@ static int dump_to_cache(int f, char *buf, int blen, char *domain, > write_secinfo(&bp, &blen, exp, flag_mask); > if (exp->e_uuid == NULL || different_fs) { > char u[16]; > - if (uuid_by_path(path, 0, 16, u)) { > + if ((exp->e_flags & flag_mask & NFSEXP_FSID) == 0 && > + uuid_by_path(path, 0, 16, u)) { > qword_add(&bp, &blen, "uuid"); > qword_addhex(&bp, &blen, u, 16); > } > diff --git a/support/export/export.c b/support/export/export.c > index c753f68e4d63..03390dfc1de8 100644 > --- a/support/export/export.c > +++ b/support/export/export.c > @@ -10,9 +10,11 @@ > #include <config.h> > #endif > > +#include <unistd.h> > #include <string.h> > #include <sys/types.h> > #include <sys/param.h> > +#include <fcntl.h> > #include <netinet/in.h> > #include <limits.h> > #include <stdlib.h> > @@ -420,3 +422,30 @@ export_hash(char *str) > > return num % HASH_TABLE_SIZE; > } > + > +int export_test(struct exportent *eep, int with_fsid) > +{ > + char *path = eep->e_path; > + int flags = eep->e_flags | (with_fsid ? NFSEXP_FSID : 0); > + /* beside max path, buf size should take protocol str into account */ > + char buf[NFS_MAXPATHLEN+1+64] = { 0 }; > + char *bp = buf; > + int len = sizeof(buf); > + int fd, n; > + > + n = snprintf(buf, len, "-test-client- "); > + bp += n; > + len -= n; > + qword_add(&bp, &len, path); > + if (len < 1) > + return 0; > + snprintf(bp, len, " 3 %d 65534 65534 0\n", flags); > + fd = open("/proc/net/rpc/nfsd.export/channel", O_WRONLY); > + if (fd < 0) > + return 0; > + n = nfsd_path_write(fd, buf, strlen(buf)); > + close(fd); > + if (n < 0) > + return 0; > + return 1; > +} > diff --git a/support/export/v4root.c b/support/export/v4root.c > index 3654bd7c10c0..c12a7d8562b2 100644 > --- a/support/export/v4root.c > +++ b/support/export/v4root.c > @@ -20,6 +20,7 @@ > > #include <unistd.h> > #include <errno.h> > +#include <uuid/uuid.h> > > #include "xlog.h" > #include "exportfs.h" > @@ -89,11 +90,31 @@ v4root_create(char *path, nfs_export *export) > strncpy(eep.e_path, path, sizeof(eep.e_path)-1); > if (strcmp(path, "/") != 0) > eep.e_flags &= ~NFSEXP_FSID; > + > + if (strcmp(path, "/") != 0 && > + !export_test(&eep, 0)) { > + /* Need a uuid - base it on path using a fixed seed that > + * was generated randomly. > + */ > + const char seed_s[] = "39c6b5c1-3f24-4f4e-977c-7fe6546b8a25"; > + uuid_t seed, uuid; > + char uuid_s[UUID_STR_LEN]; > + unsigned int i, j; > + > + uuid_parse(seed_s, seed); > + uuid_generate_sha1(uuid, seed, path, strlen(path)); > + uuid_unparse_upper(uuid, uuid_s); > + /* strip hyhens */ > + for (i = j = 0; uuid_s[i]; i++) > + if (uuid_s[i] != '-') > + uuid_s[j++] = uuid_s[i]; > + eep.e_uuid = uuid_s; > + } > set_pseudofs_security(&eep); > exp = export_create(&eep, 0); > if (exp == NULL) > return NULL; > - xlog(D_CALL, "v4root_create: path '%s' flags 0x%x", > + xlog(D_CALL, "v4root_create: path '%s' flags 0x%x", > exp->m_export.e_path, exp->m_export.e_flags); > return &exp->m_export; > } > diff --git a/support/include/exportfs.h b/support/include/exportfs.h > index 81d137210862..7c1b74537186 100644 > --- a/support/include/exportfs.h > +++ b/support/include/exportfs.h > @@ -173,5 +173,6 @@ struct export_features { > struct export_features *get_export_features(void); > void fix_pseudoflavor_flags(struct exportent *ep); > char *exportent_realpath(struct exportent *eep); > +int export_test(struct exportent *eep, int with_fsid); > > #endif /* EXPORTFS_H */ > diff --git a/utils/exportd/Makefile.am b/utils/exportd/Makefile.am > index eb521f15032d..c95bdee76d3f 100644 > --- a/utils/exportd/Makefile.am > +++ b/utils/exportd/Makefile.am > @@ -16,7 +16,7 @@ exportd_SOURCES = exportd.c > exportd_LDADD = ../../support/export/libexport.a \ > ../../support/nfs/libnfs.la \ > ../../support/misc/libmisc.a \ > - $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) > + $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) -luuid > > exportd_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) \ > -I$(top_srcdir)/support/export > diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c > index 25d757d8b4b4..bc76aaaf8714 100644 > --- a/utils/exportfs/exportfs.c > +++ b/utils/exportfs/exportfs.c > @@ -54,11 +54,6 @@ static int _lockfd = -1; > > struct state_paths etab; > > -static ssize_t exportfs_write(int fd, const char *buf, size_t len) > -{ > - return nfsd_path_write(fd, buf, len); > -} > - > /* > * If we aren't careful, changes made by exportfs can be lost > * when multiple exports process run at once: > @@ -510,33 +505,6 @@ static int can_test(void) > return 1; > } > > -static int test_export(nfs_export *exp, int with_fsid) > -{ > - char *path = exp->m_export.e_path; > - int flags = exp->m_export.e_flags | (with_fsid ? NFSEXP_FSID : 0); > - /* beside max path, buf size should take protocol str into account */ > - char buf[NFS_MAXPATHLEN+1+64] = { 0 }; > - char *bp = buf; > - int len = sizeof(buf); > - int fd, n; > - > - n = snprintf(buf, len, "-test-client- "); > - bp += n; > - len -= n; > - qword_add(&bp, &len, path); > - if (len < 1) > - return 0; > - snprintf(bp, len, " 3 %d 65534 65534 0\n", flags); > - fd = open("/proc/net/rpc/nfsd.export/channel", O_WRONLY); > - if (fd < 0) > - return 0; > - n = exportfs_write(fd, buf, strlen(buf)); > - close(fd); > - if (n < 0) > - return 0; > - return 1; > -} > - > static void > validate_export(nfs_export *exp) > { > @@ -568,12 +536,12 @@ validate_export(nfs_export *exp) > > if ((exp->m_export.e_flags & NFSEXP_FSID) || exp->m_export.e_uuid || > fs_has_fsid) { > - if ( !test_export(exp, 1)) { > + if ( !export_test(&exp->m_export, 1)) { > xlog(L_ERROR, "%s does not support NFS export", path); > return; > } > - } else if ( !test_export(exp, 0)) { > - if (test_export(exp, 1)) > + } else if ( !export_test(&exp->m_export, 0)) { > + if (export_test(&exp->m_export, 1)) > xlog(L_ERROR, "%s requires fsid= for NFS export", path); > else > xlog(L_ERROR, "%s does not support NFS export", path); > diff --git a/utils/mountd/Makefile.am b/utils/mountd/Makefile.am > index 859f28ecd6f3..13b25c90f06e 100644 > --- a/utils/mountd/Makefile.am > +++ b/utils/mountd/Makefile.am > @@ -18,7 +18,7 @@ mountd_LDADD = ../../support/export/libexport.a \ > ../../support/nfs/libnfs.la \ > ../../support/misc/libmisc.a \ > $(OPTLIBS) \ > - $(LIBBSD) $(LIBWRAP) $(LIBNSL) $(LIBBLKID) $(LIBTIRPC) \ > + $(LIBBSD) $(LIBWRAP) $(LIBNSL) $(LIBBLKID) -luuid $(LIBTIRPC) \ > $(LIBPTHREAD) > mountd_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) \ > -I$(top_builddir)/support/include \ >
Hi Steve, all, > Hey! > On 5/17/21 12:45 AM, NeilBrown wrote: > > Some filesystems cannot be exported without an fsid or uuid. > > tmpfs is the main example. > > When mountd (or exportd) creates nfsv4 pseudo-root exports for the path > > leading down to an export point it exports each directory without any > > fsid or uuid. If one of these directories is on tmp, that will fail. > > The net result is that exporting a subdirectory of a tmpfs filesystem > > will not work over NFSv4 as the parents within the filesystem cannot be > > exported. It will either fail, or fall-back to NFSv3 (depending on the > > version of the mount.nfs program). > > To fix this we need to provide an fsid or uuid for these pseudo-root > > exports. This patch does that by creating an RFC-4122 V5 compatible > > UUID based on an arbitrary seed and the path to the export. > > To check if an export needs a uuid, text_export() is moved from exportfs > > to libexport.a, modified slightly and renamed to export_test(). > Well.... it appears you guys did not compile with the --with-systemd > config flag... Because if you did you would have seeing this compile error > the in systemd code: You're right, I didn't :(. > /usr/bin/ld: ../support/nfs/.libs/libnfs.a(cacheio.o): in function `stat': > /usr/include/sys/stat.h:455: undefined reference to `etab' > collect2: error: ld returned 1 exit status > make[1]: *** [Makefile:560: nfs-server-generator] Error 1 > make[1]: Leaving directory '/home/src/up/nfs-utils/systemd' > make: *** [Makefile:479: all-recursive] Error 1 > It turns out the moving of export_test() in to the libexport.a > is causing any binary linking with libexport.a to have a > global definition of struct state_paths etab; > The reason is export_test() calls qword_add(). Now qword_add() > does not use an etab, but the file qword_add() lives in is > cacheio.c which does have a extern struct state_paths etab > which is the reason libnfs.a(cacheio.o) is mentioned in > the error. At least that is what I *think* is going on... > The extern came from commit a15bd94. > Now the work around is to simply define a > struct state_paths etab; in nfs-server-generator.c > which will not be used at least by the systemd code. > Now is that something we want continue doing... make any > binaries linking with libexport.a define a global etab. > It seems a little messy but the interface is not documented > and the alternative, moving a bunch of code around see a lot > more messy that simple adding one definition. +1 Kind regards, Petr > Other than not compiling... Things looks good! ;-) > Thoughts? > steved. ...
On Fri, 21 May 2021, Steve Dickson wrote: > Well.... it appears you guys did not compile with the --with-systemd > config flag... Because if you did you would have seeing this compile error > the in systemd code: > > /usr/bin/ld: ../support/nfs/.libs/libnfs.a(cacheio.o): in function `stat': > /usr/include/sys/stat.h:455: undefined reference to `etab' > collect2: error: ld returned 1 exit status > make[1]: *** [Makefile:560: nfs-server-generator] Error 1 > make[1]: Leaving directory '/home/src/up/nfs-utils/systemd' > make: *** [Makefile:479: all-recursive] Error 1 > > It turns out the moving of export_test() in to the libexport.a > is causing any binary linking with libexport.a to have a > global definition of struct state_paths etab; > > The reason is export_test() calls qword_add(). Now qword_add() > does not use an etab, but the file qword_add() lives in is > cacheio.c which does have a extern struct state_paths etab > which is the reason libnfs.a(cacheio.o) is mentioned in > the error. At least that is what I *think* is going on... > The extern came from commit a15bd94. Thanks for finding and analysis that! I'd rather fix this "properly" so we don't more pointless declaration of "etab". We already have one in svcgssd.c. I have two patches which make this problem go away. I'll post them as a followup. Thanks, NeilBrown
On 5/17/21 12:45 AM, NeilBrown wrote: > > Some filesystems cannot be exported without an fsid or uuid. > tmpfs is the main example. > > When mountd (or exportd) creates nfsv4 pseudo-root exports for the path > leading down to an export point it exports each directory without any > fsid or uuid. If one of these directories is on tmp, that will fail. > > The net result is that exporting a subdirectory of a tmpfs filesystem > will not work over NFSv4 as the parents within the filesystem cannot be > exported. It will either fail, or fall-back to NFSv3 (depending on the > version of the mount.nfs program). > > To fix this we need to provide an fsid or uuid for these pseudo-root > exports. This patch does that by creating an RFC-4122 V5 compatible > UUID based on an arbitrary seed and the path to the export. > > To check if an export needs a uuid, text_export() is moved from exportfs > to libexport.a, modified slightly and renamed to export_test(). > > Signed-off-by: NeilBrown <neilb@suse.de> Committed... (tag: nfs-utils-2-5-4-rc4) Thanks! steved. > --- > > This version contains Chuck's suggestion for improving the uuid, and > general clean-up. > > support/export/cache.c | 3 ++- > support/export/export.c | 29 +++++++++++++++++++++++++++++ > support/export/v4root.c | 23 ++++++++++++++++++++++- > support/include/exportfs.h | 1 + > utils/exportd/Makefile.am | 2 +- > utils/exportfs/exportfs.c | 38 +++----------------------------------- > utils/mountd/Makefile.am | 2 +- > 7 files changed, 59 insertions(+), 39 deletions(-) > > diff --git a/support/export/cache.c b/support/export/cache.c > index 3e4f53c0a32e..a5823e92e9f2 100644 > --- a/support/export/cache.c > +++ b/support/export/cache.c > @@ -981,7 +981,8 @@ static int dump_to_cache(int f, char *buf, int blen, char *domain, > write_secinfo(&bp, &blen, exp, flag_mask); > if (exp->e_uuid == NULL || different_fs) { > char u[16]; > - if (uuid_by_path(path, 0, 16, u)) { > + if ((exp->e_flags & flag_mask & NFSEXP_FSID) == 0 && > + uuid_by_path(path, 0, 16, u)) { > qword_add(&bp, &blen, "uuid"); > qword_addhex(&bp, &blen, u, 16); > } > diff --git a/support/export/export.c b/support/export/export.c > index c753f68e4d63..03390dfc1de8 100644 > --- a/support/export/export.c > +++ b/support/export/export.c > @@ -10,9 +10,11 @@ > #include <config.h> > #endif > > +#include <unistd.h> > #include <string.h> > #include <sys/types.h> > #include <sys/param.h> > +#include <fcntl.h> > #include <netinet/in.h> > #include <limits.h> > #include <stdlib.h> > @@ -420,3 +422,30 @@ export_hash(char *str) > > return num % HASH_TABLE_SIZE; > } > + > +int export_test(struct exportent *eep, int with_fsid) > +{ > + char *path = eep->e_path; > + int flags = eep->e_flags | (with_fsid ? NFSEXP_FSID : 0); > + /* beside max path, buf size should take protocol str into account */ > + char buf[NFS_MAXPATHLEN+1+64] = { 0 }; > + char *bp = buf; > + int len = sizeof(buf); > + int fd, n; > + > + n = snprintf(buf, len, "-test-client- "); > + bp += n; > + len -= n; > + qword_add(&bp, &len, path); > + if (len < 1) > + return 0; > + snprintf(bp, len, " 3 %d 65534 65534 0\n", flags); > + fd = open("/proc/net/rpc/nfsd.export/channel", O_WRONLY); > + if (fd < 0) > + return 0; > + n = nfsd_path_write(fd, buf, strlen(buf)); > + close(fd); > + if (n < 0) > + return 0; > + return 1; > +} > diff --git a/support/export/v4root.c b/support/export/v4root.c > index 3654bd7c10c0..c12a7d8562b2 100644 > --- a/support/export/v4root.c > +++ b/support/export/v4root.c > @@ -20,6 +20,7 @@ > > #include <unistd.h> > #include <errno.h> > +#include <uuid/uuid.h> > > #include "xlog.h" > #include "exportfs.h" > @@ -89,11 +90,31 @@ v4root_create(char *path, nfs_export *export) > strncpy(eep.e_path, path, sizeof(eep.e_path)-1); > if (strcmp(path, "/") != 0) > eep.e_flags &= ~NFSEXP_FSID; > + > + if (strcmp(path, "/") != 0 && > + !export_test(&eep, 0)) { > + /* Need a uuid - base it on path using a fixed seed that > + * was generated randomly. > + */ > + const char seed_s[] = "39c6b5c1-3f24-4f4e-977c-7fe6546b8a25"; > + uuid_t seed, uuid; > + char uuid_s[UUID_STR_LEN]; > + unsigned int i, j; > + > + uuid_parse(seed_s, seed); > + uuid_generate_sha1(uuid, seed, path, strlen(path)); > + uuid_unparse_upper(uuid, uuid_s); > + /* strip hyhens */ > + for (i = j = 0; uuid_s[i]; i++) > + if (uuid_s[i] != '-') > + uuid_s[j++] = uuid_s[i]; > + eep.e_uuid = uuid_s; > + } > set_pseudofs_security(&eep); > exp = export_create(&eep, 0); > if (exp == NULL) > return NULL; > - xlog(D_CALL, "v4root_create: path '%s' flags 0x%x", > + xlog(D_CALL, "v4root_create: path '%s' flags 0x%x", > exp->m_export.e_path, exp->m_export.e_flags); > return &exp->m_export; > } > diff --git a/support/include/exportfs.h b/support/include/exportfs.h > index 81d137210862..7c1b74537186 100644 > --- a/support/include/exportfs.h > +++ b/support/include/exportfs.h > @@ -173,5 +173,6 @@ struct export_features { > struct export_features *get_export_features(void); > void fix_pseudoflavor_flags(struct exportent *ep); > char *exportent_realpath(struct exportent *eep); > +int export_test(struct exportent *eep, int with_fsid); > > #endif /* EXPORTFS_H */ > diff --git a/utils/exportd/Makefile.am b/utils/exportd/Makefile.am > index eb521f15032d..c95bdee76d3f 100644 > --- a/utils/exportd/Makefile.am > +++ b/utils/exportd/Makefile.am > @@ -16,7 +16,7 @@ exportd_SOURCES = exportd.c > exportd_LDADD = ../../support/export/libexport.a \ > ../../support/nfs/libnfs.la \ > ../../support/misc/libmisc.a \ > - $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) > + $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) -luuid > > exportd_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) \ > -I$(top_srcdir)/support/export > diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c > index 25d757d8b4b4..bc76aaaf8714 100644 > --- a/utils/exportfs/exportfs.c > +++ b/utils/exportfs/exportfs.c > @@ -54,11 +54,6 @@ static int _lockfd = -1; > > struct state_paths etab; > > -static ssize_t exportfs_write(int fd, const char *buf, size_t len) > -{ > - return nfsd_path_write(fd, buf, len); > -} > - > /* > * If we aren't careful, changes made by exportfs can be lost > * when multiple exports process run at once: > @@ -510,33 +505,6 @@ static int can_test(void) > return 1; > } > > -static int test_export(nfs_export *exp, int with_fsid) > -{ > - char *path = exp->m_export.e_path; > - int flags = exp->m_export.e_flags | (with_fsid ? NFSEXP_FSID : 0); > - /* beside max path, buf size should take protocol str into account */ > - char buf[NFS_MAXPATHLEN+1+64] = { 0 }; > - char *bp = buf; > - int len = sizeof(buf); > - int fd, n; > - > - n = snprintf(buf, len, "-test-client- "); > - bp += n; > - len -= n; > - qword_add(&bp, &len, path); > - if (len < 1) > - return 0; > - snprintf(bp, len, " 3 %d 65534 65534 0\n", flags); > - fd = open("/proc/net/rpc/nfsd.export/channel", O_WRONLY); > - if (fd < 0) > - return 0; > - n = exportfs_write(fd, buf, strlen(buf)); > - close(fd); > - if (n < 0) > - return 0; > - return 1; > -} > - > static void > validate_export(nfs_export *exp) > { > @@ -568,12 +536,12 @@ validate_export(nfs_export *exp) > > if ((exp->m_export.e_flags & NFSEXP_FSID) || exp->m_export.e_uuid || > fs_has_fsid) { > - if ( !test_export(exp, 1)) { > + if ( !export_test(&exp->m_export, 1)) { > xlog(L_ERROR, "%s does not support NFS export", path); > return; > } > - } else if ( !test_export(exp, 0)) { > - if (test_export(exp, 1)) > + } else if ( !export_test(&exp->m_export, 0)) { > + if (export_test(&exp->m_export, 1)) > xlog(L_ERROR, "%s requires fsid= for NFS export", path); > else > xlog(L_ERROR, "%s does not support NFS export", path); > diff --git a/utils/mountd/Makefile.am b/utils/mountd/Makefile.am > index 859f28ecd6f3..13b25c90f06e 100644 > --- a/utils/mountd/Makefile.am > +++ b/utils/mountd/Makefile.am > @@ -18,7 +18,7 @@ mountd_LDADD = ../../support/export/libexport.a \ > ../../support/nfs/libnfs.la \ > ../../support/misc/libmisc.a \ > $(OPTLIBS) \ > - $(LIBBSD) $(LIBWRAP) $(LIBNSL) $(LIBBLKID) $(LIBTIRPC) \ > + $(LIBBSD) $(LIBWRAP) $(LIBNSL) $(LIBBLKID) -luuid $(LIBTIRPC) \ > $(LIBPTHREAD) > mountd_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) \ > -I$(top_builddir)/support/include \ >
diff --git a/support/export/cache.c b/support/export/cache.c index 3e4f53c0a32e..a5823e92e9f2 100644 --- a/support/export/cache.c +++ b/support/export/cache.c @@ -981,7 +981,8 @@ static int dump_to_cache(int f, char *buf, int blen, char *domain, write_secinfo(&bp, &blen, exp, flag_mask); if (exp->e_uuid == NULL || different_fs) { char u[16]; - if (uuid_by_path(path, 0, 16, u)) { + if ((exp->e_flags & flag_mask & NFSEXP_FSID) == 0 && + uuid_by_path(path, 0, 16, u)) { qword_add(&bp, &blen, "uuid"); qword_addhex(&bp, &blen, u, 16); } diff --git a/support/export/export.c b/support/export/export.c index c753f68e4d63..03390dfc1de8 100644 --- a/support/export/export.c +++ b/support/export/export.c @@ -10,9 +10,11 @@ #include <config.h> #endif +#include <unistd.h> #include <string.h> #include <sys/types.h> #include <sys/param.h> +#include <fcntl.h> #include <netinet/in.h> #include <limits.h> #include <stdlib.h> @@ -420,3 +422,30 @@ export_hash(char *str) return num % HASH_TABLE_SIZE; } + +int export_test(struct exportent *eep, int with_fsid) +{ + char *path = eep->e_path; + int flags = eep->e_flags | (with_fsid ? NFSEXP_FSID : 0); + /* beside max path, buf size should take protocol str into account */ + char buf[NFS_MAXPATHLEN+1+64] = { 0 }; + char *bp = buf; + int len = sizeof(buf); + int fd, n; + + n = snprintf(buf, len, "-test-client- "); + bp += n; + len -= n; + qword_add(&bp, &len, path); + if (len < 1) + return 0; + snprintf(bp, len, " 3 %d 65534 65534 0\n", flags); + fd = open("/proc/net/rpc/nfsd.export/channel", O_WRONLY); + if (fd < 0) + return 0; + n = nfsd_path_write(fd, buf, strlen(buf)); + close(fd); + if (n < 0) + return 0; + return 1; +} diff --git a/support/export/v4root.c b/support/export/v4root.c index 3654bd7c10c0..c12a7d8562b2 100644 --- a/support/export/v4root.c +++ b/support/export/v4root.c @@ -20,6 +20,7 @@ #include <unistd.h> #include <errno.h> +#include <uuid/uuid.h> #include "xlog.h" #include "exportfs.h" @@ -89,11 +90,31 @@ v4root_create(char *path, nfs_export *export) strncpy(eep.e_path, path, sizeof(eep.e_path)-1); if (strcmp(path, "/") != 0) eep.e_flags &= ~NFSEXP_FSID; + + if (strcmp(path, "/") != 0 && + !export_test(&eep, 0)) { + /* Need a uuid - base it on path using a fixed seed that + * was generated randomly. + */ + const char seed_s[] = "39c6b5c1-3f24-4f4e-977c-7fe6546b8a25"; + uuid_t seed, uuid; + char uuid_s[UUID_STR_LEN]; + unsigned int i, j; + + uuid_parse(seed_s, seed); + uuid_generate_sha1(uuid, seed, path, strlen(path)); + uuid_unparse_upper(uuid, uuid_s); + /* strip hyhens */ + for (i = j = 0; uuid_s[i]; i++) + if (uuid_s[i] != '-') + uuid_s[j++] = uuid_s[i]; + eep.e_uuid = uuid_s; + } set_pseudofs_security(&eep); exp = export_create(&eep, 0); if (exp == NULL) return NULL; - xlog(D_CALL, "v4root_create: path '%s' flags 0x%x", + xlog(D_CALL, "v4root_create: path '%s' flags 0x%x", exp->m_export.e_path, exp->m_export.e_flags); return &exp->m_export; } diff --git a/support/include/exportfs.h b/support/include/exportfs.h index 81d137210862..7c1b74537186 100644 --- a/support/include/exportfs.h +++ b/support/include/exportfs.h @@ -173,5 +173,6 @@ struct export_features { struct export_features *get_export_features(void); void fix_pseudoflavor_flags(struct exportent *ep); char *exportent_realpath(struct exportent *eep); +int export_test(struct exportent *eep, int with_fsid); #endif /* EXPORTFS_H */ diff --git a/utils/exportd/Makefile.am b/utils/exportd/Makefile.am index eb521f15032d..c95bdee76d3f 100644 --- a/utils/exportd/Makefile.am +++ b/utils/exportd/Makefile.am @@ -16,7 +16,7 @@ exportd_SOURCES = exportd.c exportd_LDADD = ../../support/export/libexport.a \ ../../support/nfs/libnfs.la \ ../../support/misc/libmisc.a \ - $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) + $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) -luuid exportd_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) \ -I$(top_srcdir)/support/export diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c index 25d757d8b4b4..bc76aaaf8714 100644 --- a/utils/exportfs/exportfs.c +++ b/utils/exportfs/exportfs.c @@ -54,11 +54,6 @@ static int _lockfd = -1; struct state_paths etab; -static ssize_t exportfs_write(int fd, const char *buf, size_t len) -{ - return nfsd_path_write(fd, buf, len); -} - /* * If we aren't careful, changes made by exportfs can be lost * when multiple exports process run at once: @@ -510,33 +505,6 @@ static int can_test(void) return 1; } -static int test_export(nfs_export *exp, int with_fsid) -{ - char *path = exp->m_export.e_path; - int flags = exp->m_export.e_flags | (with_fsid ? NFSEXP_FSID : 0); - /* beside max path, buf size should take protocol str into account */ - char buf[NFS_MAXPATHLEN+1+64] = { 0 }; - char *bp = buf; - int len = sizeof(buf); - int fd, n; - - n = snprintf(buf, len, "-test-client- "); - bp += n; - len -= n; - qword_add(&bp, &len, path); - if (len < 1) - return 0; - snprintf(bp, len, " 3 %d 65534 65534 0\n", flags); - fd = open("/proc/net/rpc/nfsd.export/channel", O_WRONLY); - if (fd < 0) - return 0; - n = exportfs_write(fd, buf, strlen(buf)); - close(fd); - if (n < 0) - return 0; - return 1; -} - static void validate_export(nfs_export *exp) { @@ -568,12 +536,12 @@ validate_export(nfs_export *exp) if ((exp->m_export.e_flags & NFSEXP_FSID) || exp->m_export.e_uuid || fs_has_fsid) { - if ( !test_export(exp, 1)) { + if ( !export_test(&exp->m_export, 1)) { xlog(L_ERROR, "%s does not support NFS export", path); return; } - } else if ( !test_export(exp, 0)) { - if (test_export(exp, 1)) + } else if ( !export_test(&exp->m_export, 0)) { + if (export_test(&exp->m_export, 1)) xlog(L_ERROR, "%s requires fsid= for NFS export", path); else xlog(L_ERROR, "%s does not support NFS export", path); diff --git a/utils/mountd/Makefile.am b/utils/mountd/Makefile.am index 859f28ecd6f3..13b25c90f06e 100644 --- a/utils/mountd/Makefile.am +++ b/utils/mountd/Makefile.am @@ -18,7 +18,7 @@ mountd_LDADD = ../../support/export/libexport.a \ ../../support/nfs/libnfs.la \ ../../support/misc/libmisc.a \ $(OPTLIBS) \ - $(LIBBSD) $(LIBWRAP) $(LIBNSL) $(LIBBLKID) $(LIBTIRPC) \ + $(LIBBSD) $(LIBWRAP) $(LIBNSL) $(LIBBLKID) -luuid $(LIBTIRPC) \ $(LIBPTHREAD) mountd_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) \ -I$(top_builddir)/support/include \
Some filesystems cannot be exported without an fsid or uuid. tmpfs is the main example. When mountd (or exportd) creates nfsv4 pseudo-root exports for the path leading down to an export point it exports each directory without any fsid or uuid. If one of these directories is on tmp, that will fail. The net result is that exporting a subdirectory of a tmpfs filesystem will not work over NFSv4 as the parents within the filesystem cannot be exported. It will either fail, or fall-back to NFSv3 (depending on the version of the mount.nfs program). To fix this we need to provide an fsid or uuid for these pseudo-root exports. This patch does that by creating an RFC-4122 V5 compatible UUID based on an arbitrary seed and the path to the export. To check if an export needs a uuid, text_export() is moved from exportfs to libexport.a, modified slightly and renamed to export_test(). Signed-off-by: NeilBrown <neilb@suse.de> --- This version contains Chuck's suggestion for improving the uuid, and general clean-up. support/export/cache.c | 3 ++- support/export/export.c | 29 +++++++++++++++++++++++++++++ support/export/v4root.c | 23 ++++++++++++++++++++++- support/include/exportfs.h | 1 + utils/exportd/Makefile.am | 2 +- utils/exportfs/exportfs.c | 38 +++----------------------------------- utils/mountd/Makefile.am | 2 +- 7 files changed, 59 insertions(+), 39 deletions(-)