diff options
Diffstat (limited to 'contrib/fuse-lib/mount.c')
| -rw-r--r-- | contrib/fuse-lib/mount.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/contrib/fuse-lib/mount.c b/contrib/fuse-lib/mount.c new file mode 100644 index 000000000..922d9e464 --- /dev/null +++ b/contrib/fuse-lib/mount.c @@ -0,0 +1,313 @@ +/* + FUSE: Filesystem in Userspace + Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu> + Copyright (c) 2010 Gluster, Inc. <http://www.gluster.com> + + This program can be distributed under the terms of the GNU LGPLv2. + See the file COPYING.LIB. +*/ + +#include "mount_util.h" +#include "mount-gluster-compat.h" + +#ifdef GF_FUSERMOUNT +#define FUSERMOUNT_PROG FUSERMOUNT_DIR "/fusermount-glusterfs" +#else +#define FUSERMOUNT_PROG "fusermount" +#endif +#define FUSE_DEVFD_ENV "_FUSE_DEVFD" + + +/* FUSE: function is called fuse_kern_unmount() */ +void +gf_fuse_unmount (const char *mountpoint, int fd) +{ + int res; + int pid; + + if (!mountpoint) + return; + + if (fd != -1) { + struct pollfd pfd; + + pfd.fd = fd; + pfd.events = 0; + res = poll (&pfd, 1, 0); + /* If file poll returns POLLERR on the device file descriptor, + then the filesystem is already unmounted */ + if (res == 1 && (pfd.revents & POLLERR)) + return; + + /* Need to close file descriptor, otherwise synchronous umount + would recurse into filesystem, and deadlock */ + close (fd); + } + + if (geteuid () == 0) { + fuse_mnt_umount ("fuse", mountpoint, mountpoint, 1); + return; + } + + res = umount2 (mountpoint, 2); + if (res == 0) + return; + + pid = fork (); + if (pid == -1) + return; + + if (pid == 0) { + const char *argv[] = { FUSERMOUNT_PROG, "-u", "-q", "-z", + "--", mountpoint, NULL }; + + execvp (FUSERMOUNT_PROG, (char **)argv); + _exit (1); + } + waitpid (pid, NULL, 0); +} + + +/* gluster-specific routines */ + +static char * +escape (char *s) +{ + size_t len = 0; + char *p = NULL; + char *q = NULL; + char *e = NULL; + + for (p = s; *p; p++) { + if (*p == ',') + len++; + len++; + } + + e = CALLOC (1, len + 1); + if (!e) + return NULL; + + for (p = s, q = e; *p; p++, q++) { + if (*p == ',') { + *q = '\\'; + q++; + } + *q = *p; + } + + return e; +} + +static int +fuse_mount_fusermount (const char *mountpoint, char *fsname, + unsigned long mountflags, char *mnt_param, + int fd) +{ + int pid = -1; + int res = 0; + int ret = -1; + char *fm_mnt_params = NULL; + char *efsname = NULL; + +#ifndef GF_FUSERMOUNT + GFFUSE_LOGERR ("Mounting via helper utility " + "(unprivileged mounting) is supported " + "only if glusterfs is compiled with " + "--enable-fusermount"); + return -1; +#endif + + efsname = escape (fsname); + if (!efsname) { + GFFUSE_LOGERR ("Out of memory"); + + return -1; + } + ret = asprintf (&fm_mnt_params, + "%s%s,fsname=%s,nonempty,subtype=glusterfs", + (mountflags & MS_RDONLY) ? "ro," : "", + mnt_param, efsname); + FREE (efsname); + if (ret == -1) { + GFFUSE_LOGERR ("Out of memory"); + + goto out; + } + + /* fork to exec fusermount */ + pid = fork (); + if (pid == -1) { + GFFUSE_LOGERR ("fork() failed: %s", strerror (errno)); + ret = -1; + goto out; + } + + if (pid == 0) { + char env[10]; + const char *argv[32]; + int a = 0; + + argv[a++] = FUSERMOUNT_PROG; + argv[a++] = "-o"; + argv[a++] = fm_mnt_params; + argv[a++] = "--"; + argv[a++] = mountpoint; + argv[a++] = NULL; + + snprintf (env, sizeof (env), "%i", fd); + setenv (FUSE_DEVFD_ENV, env, 1); + execvp (FUSERMOUNT_PROG, (char **)argv); + GFFUSE_LOGERR ("failed to exec fusermount: %s", + strerror (errno)); + _exit (1); + } + + ret = waitpid (pid, &res, 0); + ret = (ret == pid && res == 0) ? 0 : -1; + out: + FREE (fm_mnt_params); + return ret; +} + +static int +fuse_mount_sys (const char *mountpoint, char *fsname, + unsigned long mountflags, char *mnt_param, int fd) +{ + int ret = -1; + unsigned mounted = 0; + char *mnt_param_mnt = NULL; + char *fstype = "fuse.glusterfs"; + char *source = fsname; + + ret = asprintf (&mnt_param_mnt, + "%s,fd=%i,rootmode=%o,user_id=%i,group_id=%i", + mnt_param, fd, S_IFDIR, getuid (), getgid ()); + if (ret == -1) { + GFFUSE_LOGERR ("Out of memory"); + + goto out; + } + ret = mount (source, mountpoint, fstype, mountflags, + mnt_param_mnt); + if (ret == -1 && errno == ENODEV) { + /* fs subtype support was added by 79c0b2df aka + v2.6.21-3159-g79c0b2d. Probably we have an + older kernel ... */ + fstype = "fuse"; + ret = asprintf (&source, "glusterfs#%s", fsname); + if (ret == -1) { + GFFUSE_LOGERR ("Out of memory"); + + goto out; + } + ret = mount (source, mountpoint, fstype, mountflags, + mnt_param_mnt); + } + if (ret == -1) + goto out; + else + mounted = 1; + +#ifndef __NetBSD__ + if (geteuid () == 0) { + char *newmnt = fuse_mnt_resolve_path ("fuse", mountpoint); + char *mnt_param_mtab = NULL; + + if (!newmnt) { + ret = -1; + + goto out; + } + + ret = asprintf (&mnt_param_mtab, "%s%s", + mountflags & MS_RDONLY ? "ro," : "", + mnt_param); + if (ret == -1) + GFFUSE_LOGERR ("Out of memory"); + else { + ret = fuse_mnt_add_mount ("fuse", source, newmnt, + fstype, mnt_param_mtab); + FREE (mnt_param_mtab); + } + + FREE (newmnt); + if (ret == -1) { + GFFUSE_LOGERR ("failed to add mtab entry"); + + goto out; + } + } +#endif /* __NetBSD__ */ + +out: + if (ret == -1) { + if (mounted) + umount2 (mountpoint, 2); /* lazy umount */ + } + FREE (mnt_param_mnt); + if (source != fsname) + FREE (source); + + return ret; +} + +int +gf_fuse_mount (const char *mountpoint, char *fsname, + unsigned long mountflags, char *mnt_param, + pid_t *mnt_pid, int status_fd) +{ + int fd = -1; + pid_t pid = -1; + int ret = -1; + + fd = open ("/dev/fuse", O_RDWR); + if (fd == -1) { + GFFUSE_LOGERR ("cannot open /dev/fuse (%s)", + strerror (errno)); + return -1; + } + + /* start mount agent */ + pid = fork(); + switch (pid) { + case 0: + /* hello it's mount agent */ + if (!mnt_pid) { + /* daemonize mount agent, caller is + * not interested in waiting for it + */ + pid = fork (); + if (pid) + exit (pid == -1 ? 1 : 0); + } + + ret = fuse_mount_sys (mountpoint, fsname, mountflags, mnt_param, fd); + if (ret == -1) { + gf_log ("glusterfs-fuse", GF_LOG_INFO, + "direct mount failed (%s), " + "retry to mount via fusermount", + strerror (errno)); + + ret = fuse_mount_fusermount (mountpoint, fsname, mountflags, + mnt_param, fd); + } + + if (ret == -1) + GFFUSE_LOGERR ("mount of %s to %s (%s) failed", + fsname, mountpoint, mnt_param); + + if (status_fd >= 0) + (void)write (status_fd, &ret, sizeof (ret)); + exit (!!ret); + /* bye mount agent */ + case -1: + close (fd); + fd = -1; + } + + if (mnt_pid) + *mnt_pid = pid; + + return fd; +} |