From fd9097110f74f39bce89ec3a341fd9b686a68719 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 9 May 2007 10:19:33 -0400 Subject: [PATCH] nfs-utils: have mountd hold open etab file to force inode number to change This patch changes mountd to hold the etab file open so that when it's changed by exportfs, the inode number should change. We then change auth_reload to reload the file based on whether st_ino is different from the last time it was checked. It also changes auth_reload to maintain a static counter value and return it instead of a timestamp and fixes up get_exportlist accordingly. Finally, it adds some comments to xtab_write to warn people about editing the etab in place. Signed-off-by: Jeff Layton Signed-off-by: NeilBrown --- support/export/xtab.c | 6 ++++++ utils/mountd/auth.c | 29 ++++++++++++++++++++--------- utils/mountd/mountd.c | 10 +++++----- utils/mountd/mountd.h | 2 +- 4 files changed, 32 insertions(+), 15 deletions(-) diff --git a/support/export/xtab.c b/support/export/xtab.c index 0ddb251..292087b 100644 --- a/support/export/xtab.c +++ b/support/export/xtab.c @@ -80,6 +80,12 @@ xtab_export_read(void) return xtab_read(_PATH_ETAB, 1); } +/* + * mountd now keeps an open fd for the etab at all times to make sure that the + * inode number changes when the xtab_export_write is done. If you change the + * routine below such that the files are edited in place, then you'll need to + * fix the auth_reload logic as well... + */ static int xtab_write(char *xtab, char *xtabtmp, int is_export) { diff --git a/utils/mountd/auth.c b/utils/mountd/auth.c index 183c9ea..f7fe23d 100644 --- a/utils/mountd/auth.c +++ b/utils/mountd/auth.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "misc.h" #include "nfslib.h" #include "exportfs.h" @@ -46,24 +47,34 @@ auth_init(char *exports) xtab_mount_write(); } -time_t +unsigned int auth_reload() { struct stat stb; - static time_t last_modified = 0; - - if (stat(_PATH_ETAB, &stb) < 0) + static ino_t last_inode; + static int last_fd; + static unsigned int counter; + int fd; + + if ((fd = open(_PATH_ETAB, O_RDONLY)) < 0) { + xlog(L_FATAL, "couldn't open %s", _PATH_ETAB); + } else if (fstat(fd, &stb) < 0) { xlog(L_FATAL, "couldn't stat %s", _PATH_ETAB); - if (stb.st_mtime == last_modified) - return last_modified; - last_modified = stb.st_mtime; + } else if (stb.st_ino == last_inode) { + close(fd); + return counter; + } else { + close(last_fd); + last_fd = fd; + last_inode = stb.st_ino; + } export_freeall(); memset(&my_client, 0, sizeof(my_client)); - // export_read(export_file); xtab_export_read(); + ++counter; - return last_modified; + return counter; } static nfs_export * diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c index 04141d1..999f035 100644 --- a/utils/mountd/mountd.c +++ b/utils/mountd/mountd.c @@ -465,18 +465,18 @@ static exports get_exportlist(void) { static exports elist = NULL; - static time_t etime = 0; - time_t atime; struct exportnode *e, *ne; struct groupnode *g, *ng, *c, **cp; nfs_export *exp; int i; + static unsigned int ecounter; + unsigned int acounter; - atime = auth_reload(); - if (elist && atime == etime) + acounter = auth_reload(); + if (elist && acounter == ecounter) return elist; - etime = atime; + ecounter = acounter; for (e = elist; e != NULL; e = ne) { ne = e->ex_next; diff --git a/utils/mountd/mountd.h b/utils/mountd/mountd.h index b539278..31bacb5 100644 --- a/utils/mountd/mountd.h +++ b/utils/mountd/mountd.h @@ -40,7 +40,7 @@ bool_t mount_mnt_3_svc(struct svc_req *, dirpath *, mountres3 *); void mount_dispatch(struct svc_req *, SVCXPRT *); void auth_init(char *export_file); -time_t auth_reload(void); +unsigned int auth_reload(void); nfs_export * auth_authenticate(char *what, struct sockaddr_in *sin, char *path); void auth_export(nfs_export *exp); -- 2.39.2