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authorCsaba Henk <csaba@gluster.com>2011-05-15 04:52:33 +0000
committerAnand Avati <avati@gluster.com>2011-05-19 15:41:47 -0700
commitc5d781e05599e9e7ad736d42c9c1033992c76ded (patch)
treeaff88649bc98a6c8babc3d75760fae2ef36b4cc3
parent357df32e16dd21e7aedb699c7bd99cac9b95a040 (diff)
upon daemonizing, wait on mtab update to terminate in parent
This fixes the race in between the mtab update attempts of mount and umount when we do a lazy umount right after mounting, in order to hide the given fs instance; yet this way we still avoid the deadlock of the fs and mount which we can hit if we wait unconditionally for the mtab update to terminate (cf. bz #511). Signed-off-by: Csaba Henk <csaba@gluster.com> Signed-off-by: Anand Avati <avati@gluster.com> BUG: 2690 (race between mtab updates of mount and umount) URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2690
-rw-r--r--contrib/apple/daemon.c26
-rw-r--r--contrib/apple/daemon.h1
-rw-r--r--contrib/fuse-include/fuse-mount.h3
-rw-r--r--contrib/fuse-lib/mount.c52
-rw-r--r--contrib/macfuse/mount_darwin.c3
-rw-r--r--glusterfsd/src/Makefile.am10
-rw-r--r--glusterfsd/src/glusterfsd.c33
-rw-r--r--libglusterfs/src/glusterfs.h1
-rw-r--r--xlators/mount/fuse/src/fuse-bridge.c20
9 files changed, 101 insertions, 48 deletions
diff --git a/contrib/apple/daemon.c b/contrib/apple/daemon.c
index 9389201a1..07dbbc400 100644
--- a/contrib/apple/daemon.c
+++ b/contrib/apple/daemon.c
@@ -44,7 +44,7 @@
#include <unistd.h>
int
-os_daemon(nochdir, noclose)
+os_daemon_return(nochdir, noclose)
int nochdir, noclose;
{
struct sigaction osa, sa;
@@ -52,6 +52,7 @@ os_daemon(nochdir, noclose)
pid_t newgrp;
int oerrno;
int osa_ok;
+ int ret;
/* A SIGHUP may be thrown when the parent exits below. */
sigemptyset(&sa.sa_mask);
@@ -59,14 +60,9 @@ os_daemon(nochdir, noclose)
sa.sa_flags = 0;
osa_ok = sigaction(SIGHUP, &sa, &osa);
- switch (fork()) {
- case -1:
- return (-1);
- case 0:
- break;
- default:
- _exit(0);
- }
+ ret = fork();
+ if (ret)
+ return ret;
newgrp = setsid();
oerrno = errno;
@@ -90,3 +86,15 @@ os_daemon(nochdir, noclose)
}
return (0);
}
+
+int
+os_daemon(int nochdir, int noclose)
+{
+ int ret;
+
+ ret = os_daemon_return(nochdir, noclose);
+ if (ret <= 0)
+ return ret;
+
+ _exit(0);
+}
diff --git a/contrib/apple/daemon.h b/contrib/apple/daemon.h
index 7a2824b6a..aa88d9baa 100644
--- a/contrib/apple/daemon.h
+++ b/contrib/apple/daemon.h
@@ -17,4 +17,5 @@
<http://www.gnu.org/licenses/>.
*/
+int os_daemon_return(int nochdir, int noclose);
int os_daemon(int nochdir, int noclose);
diff --git a/contrib/fuse-include/fuse-mount.h b/contrib/fuse-include/fuse-mount.h
index ca571ce5e..9f83faf02 100644
--- a/contrib/fuse-include/fuse-mount.h
+++ b/contrib/fuse-include/fuse-mount.h
@@ -8,4 +8,5 @@
*/
void gf_fuse_unmount (const char *mountpoint, int fd);
-int gf_fuse_mount (const char *mountpoint, char *fsname, char *mnt_param);
+int gf_fuse_mount (const char *mountpoint, char *fsname, char *mnt_param,
+ pid_t *mtab_pid);
diff --git a/contrib/fuse-lib/mount.c b/contrib/fuse-lib/mount.c
index 47592a62d..f922b07d4 100644
--- a/contrib/fuse-lib/mount.c
+++ b/contrib/fuse-lib/mount.c
@@ -97,7 +97,8 @@ static
#endif
int
fuse_mnt_add_mount (const char *progname, const char *fsname,
- const char *mnt, const char *type, const char *opts)
+ const char *mnt, const char *type, const char *opts,
+ pid_t *mtab_pid)
{
int res;
int status;
@@ -125,19 +126,22 @@ fuse_mnt_add_mount (const char *progname, const char *fsname,
char templ[] = "/tmp/fusermountXXXXXX";
char *tmp;
- /* mtab update done async, just log if fails */
- res = fork ();
- if (res)
- exit (res == -1 ? 1 : 0);
- res = fork ();
- if (res) {
- if (res != -1)
- res = waitpid (res, &status, 0);
- if (res == -1)
- GFFUSE_LOGERR ("%s: /etc/mtab update failed",
- progname);
-
- exit (0);
+ if (!mtab_pid) {
+ /* mtab update done async, just log if fails */
+ res = fork ();
+ if (res)
+ exit (res == -1 ? 1 : 0);
+ res = fork ();
+ if (res) {
+ if (res != -1) {
+ if (!(res == waitpid (res, &status, 0)
+ && status == 0))
+ GFFUSE_LOGERR ("%s: /etc/mtab "
+ "update failed",
+ progname);
+ }
+ exit (0);
+ }
}
sigprocmask (SIG_SETMASK, &oldmask, NULL);
@@ -165,13 +169,16 @@ fuse_mnt_add_mount (const char *progname, const char *fsname,
progname, strerror (errno));
exit (1);
}
- res = waitpid (res, &status, 0);
+ if (mtab_pid) {
+ *mtab_pid = res;
+ res = 0;
+ } else {
+ if (!(res == waitpid (res, &status, 0) && status == 0))
+ res = -1;
+ }
if (res == -1)
GFFUSE_LOGERR ("%s: waitpid: %s", progname, strerror (errno));
- if (status != 0)
- res = -1;
-
out_restore:
sigprocmask (SIG_SETMASK, &oldmask, NULL);
return res;
@@ -519,7 +526,7 @@ gf_fuse_unmount (const char *mountpoint, int fd)
#ifndef FUSE_UTIL
static int
-fuse_mount_sys (const char *mountpoint, char *fsname, char *mnt_param)
+fuse_mount_sys (const char *mountpoint, char *fsname, char *mnt_param, pid_t *mtab_pid)
{
int fd = -1, ret = -1;
unsigned mounted = 0;
@@ -573,7 +580,7 @@ fuse_mount_sys (const char *mountpoint, char *fsname, char *mnt_param)
}
ret = fuse_mnt_add_mount ("fuse", source, newmnt, fstype,
- mnt_param);
+ mnt_param, mtab_pid);
FREE (newmnt);
if (ret == -1) {
GFFUSE_LOGERR ("failed to add mtab entry");
@@ -625,13 +632,14 @@ escape (char *s)
}
int
-gf_fuse_mount (const char *mountpoint, char *fsname, char *mnt_param)
+gf_fuse_mount (const char *mountpoint, char *fsname, char *mnt_param,
+ pid_t *mtab_pid)
{
int fd = -1, rv = -1;
char *fm_mnt_params = NULL, *p = NULL;
char *efsname = NULL;
- fd = fuse_mount_sys (mountpoint, fsname, mnt_param);
+ fd = fuse_mount_sys (mountpoint, fsname, mnt_param, mtab_pid);
if (fd == -1) {
gf_log ("glusterfs-fuse", GF_LOG_INFO,
"direct mount failed (%s), "
diff --git a/contrib/macfuse/mount_darwin.c b/contrib/macfuse/mount_darwin.c
index 9d87fca35..c485583e9 100644
--- a/contrib/macfuse/mount_darwin.c
+++ b/contrib/macfuse/mount_darwin.c
@@ -133,7 +133,8 @@ Return:
}
int
-gf_fuse_mount (const char *mountpoint, char *fsname, char *mnt_param)
+gf_fuse_mount (const char *mountpoint, char *fsname, char *mnt_param,
+ pid_t *mtab_pid /* not used on OS X */)
{
int fd, pid;
int result;
diff --git a/glusterfsd/src/Makefile.am b/glusterfsd/src/Makefile.am
index 537eda0bb..2056ca898 100644
--- a/glusterfsd/src/Makefile.am
+++ b/glusterfsd/src/Makefile.am
@@ -1,9 +1,6 @@
sbin_PROGRAMS = glusterfsd
-glusterfsd_SOURCES = glusterfsd.c glusterfsd-mgmt.c
-if GF_DARWIN_HOST_OS
-glusterfsd_SOURCES += $(CONTRIBDIR)/apple/daemon.c
-endif
+glusterfsd_SOURCES = glusterfsd.c glusterfsd-mgmt.c $(CONTRIBDIR)/apple/daemon.c
glusterfsd_LDADD = $(top_builddir)/libglusterfs/src/libglusterfs.la \
$(top_builddir)/rpc/rpc-lib/src/libgfrpc.la \
$(top_builddir)/rpc/xdr/src/libgfxdr.la \
@@ -14,10 +11,7 @@ noinst_HEADERS = glusterfsd.h glusterfsd-mem-types.h
AM_CFLAGS = -fPIC -Wall -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -D$(GF_HOST_OS)\
-I$(top_srcdir)/libglusterfs/src -DDATADIR=\"$(localstatedir)\" \
-DCONFDIR=\"$(sysconfdir)/glusterfs\" $(GF_GLUSTERFS_CFLAGS) \
- -I$(top_srcdir)/rpc/rpc-lib/src -I$(top_srcdir)/rpc/xdr/src
-if GF_DARWIN_HOST_OS
-AM_CFLAGS += -I$(CONTRIBDIR)/apple
-endif
+ -I$(top_srcdir)/rpc/rpc-lib/src -I$(top_srcdir)/rpc/xdr/src -I$(CONTRIBDIR)/apple
CLEANFILES =
diff --git a/glusterfsd/src/glusterfsd.c b/glusterfsd/src/glusterfsd.c
index 9406d74ac..2d2024409 100644
--- a/glusterfsd/src/glusterfsd.c
+++ b/glusterfsd/src/glusterfsd.c
@@ -25,6 +25,7 @@
#include <sys/types.h>
#include <sys/resource.h>
#include <sys/file.h>
+#include <sys/wait.h>
#include <netdb.h>
#include <signal.h>
#include <libgen.h>
@@ -75,11 +76,7 @@
#include <fnmatch.h>
#include "rpc-clnt.h"
-#ifdef GF_DARWIN_HOST_OS
#include "daemon.h"
-#else
-#define os_daemon(u, v) daemon (u, v)
-#endif
/* using argp for command line parsing */
@@ -315,6 +312,16 @@ create_fuse_mount (glusterfs_ctx_t *ctx)
break;
}
+ if (!cmd_args->no_daemon_mode) {
+ ret = dict_set_static_ptr (master->options, "sync-mtab",
+ "enable");
+ if (ret < 0) {
+ gf_log ("glusterfsd", GF_LOG_ERROR,
+ "failed to set dict value for key sync-mtab");
+ goto err;
+ }
+ }
+
ret = xlator_init (master);
if (ret) {
gf_log ("", GF_LOG_DEBUG, "failed to initialize fuse translator");
@@ -1310,6 +1317,7 @@ daemonize (glusterfs_ctx_t *ctx)
{
int ret = -1;
cmd_args_t *cmd_args = NULL;
+ int cstatus = 0;
cmd_args = &ctx->cmd_args;
@@ -1323,11 +1331,24 @@ daemonize (glusterfs_ctx_t *ctx)
if (cmd_args->debug_mode)
goto postfork;
- ret = os_daemon (0, 0);
- if (ret == -1) {
+ ret = os_daemon_return (0, 0);
+ switch (ret) {
+ case -1:
gf_log ("daemonize", GF_LOG_ERROR,
"Daemonization failed: %s", strerror(errno));
goto out;
+ case 0:
+ break;
+ default:
+ if (ctx->mtab_pid > 0) {
+ ret = waitpid (ctx->mtab_pid, &cstatus, 0);
+ if (!(ret == ctx->mtab_pid && cstatus == 0)) {
+ gf_log ("daemonize", GF_LOG_ERROR,
+ "/etc/mtab update failed");
+ exit (1);
+ }
+ }
+ _exit (0);
}
postfork:
diff --git a/libglusterfs/src/glusterfs.h b/libglusterfs/src/glusterfs.h
index 56b5e2b9c..5553009b1 100644
--- a/libglusterfs/src/glusterfs.h
+++ b/libglusterfs/src/glusterfs.h
@@ -340,6 +340,7 @@ struct _glusterfs_ctx {
int graph_id; /* Incremented per graph, value should
indicate how many times the graph has
got changed */
+ pid_t mtab_pid; /* pid of the process which updates the mtab */
};
typedef struct _glusterfs_ctx glusterfs_ctx_t;
diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index d34a747f4..dafc0a93c 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -3485,6 +3485,8 @@ init (xlator_t *this_xl)
int i = 0;
int xl_name_allocated = 0;
int fsname_allocated = 0;
+ glusterfs_ctx_t *ctx = NULL;
+ gf_boolean_t sync_mtab = _gf_false;
if (this_xl == NULL)
return -1;
@@ -3492,6 +3494,10 @@ init (xlator_t *this_xl)
if (this_xl->options == NULL)
return -1;
+ ctx = glusterfs_ctx_get ();
+ if (!ctx)
+ return -1;
+
options = this_xl->options;
if (this_xl->name == NULL) {
@@ -3604,6 +3610,14 @@ init (xlator_t *this_xl)
priv->fuse_dump_fd = ret;
}
+ sync_mtab = _gf_false;
+ ret = dict_get_str (options, "sync-mtab", &value_string);
+ if (ret == 0) {
+ ret = gf_string2boolean (value_string,
+ &sync_mtab);
+ GF_ASSERT (ret == 0);
+ }
+
cmd_args = &this_xl->ctx->cmd_args;
fsname = cmd_args->volfile;
if (!fsname && cmd_args->volfile_server) {
@@ -3630,7 +3644,8 @@ init (xlator_t *this_xl)
priv->fd = gf_fuse_mount (priv->mount_point, fsname,
"allow_other,default_permissions,"
- "max_read=131072");
+ "max_read=131072",
+ sync_mtab ? &ctx->mtab_pid : NULL);
if (priv->fd == -1)
goto cleanup_exit;
@@ -3727,5 +3742,8 @@ struct volume_options options[] = {
{ .key = {"client-pid"},
.type = GF_OPTION_TYPE_INT
},
+ { .key = {"sync-mtab"},
+ .type = GF_OPTION_TYPE_BOOL
+ },
{ .key = {NULL} },
};