diff options
author | Sage Weil <sage@newdream.net> | 2009-07-21 16:42:19 -0700 |
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committer | Sage Weil <sage@newdream.net> | 2009-07-21 16:42:19 -0700 |
commit | d9d3d6254bed21c166cc457f832a39bebe807b4c (patch) | |
tree | f22affb7b28873c07952b6d773fa8470282c3700 /src/mount | |
parent | 8c5836153694459aa09528bb73c23503eb97a93e (diff) | |
download | ceph-d9d3d6254bed21c166cc457f832a39bebe807b4c.tar.gz |
mount.ceph: update /etc/mtab
Diffstat (limited to 'src/mount')
-rw-r--r-- | src/mount/mount.ceph.c | 247 | ||||
-rw-r--r-- | src/mount/mtab.c | 277 |
2 files changed, 524 insertions, 0 deletions
diff --git a/src/mount/mount.ceph.c b/src/mount/mount.ceph.c new file mode 100644 index 00000000000..29417124334 --- /dev/null +++ b/src/mount/mount.ceph.c @@ -0,0 +1,247 @@ +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <netdb.h> +#include <errno.h> +#include <sys/mount.h> + +#define BUF_SIZE 128 + +int verboseflag = 0; + +#include "mtab.c" + +static int safe_cat(char **pstr, int *plen, int pos, const char *str2) +{ + int len2 = strlen(str2); + + while (*plen < pos + len2 + 1) { + *plen += BUF_SIZE; + *pstr = realloc(*pstr, (size_t)*plen); + + if (!*pstr) { + printf("Out of memory\n"); + exit(1); + } + } + + strcpy((*pstr)+pos, str2); + + return pos + len2; +} + +char *mount_resolve_dest(char *orig_str) +{ + char *new_str; + char *mount_path; + char *tok, *p, *port_str; + int len, pos; + + mount_path = strrchr(orig_str, ':'); + if (!mount_path) { + printf("source mount path was not specified\n"); + return NULL; + } + if (mount_path == orig_str) { + printf("server address expected\n"); + return NULL; + } + + *mount_path = '\0'; + mount_path++; + + if (!*mount_path) { + printf("incorrect source mount path\n"); + return NULL; + } + + len = BUF_SIZE; + new_str = (char *)malloc(len); + + p = new_str; + pos = 0; + + tok = strtok(orig_str, ","); + + while (tok) { + struct hostent *ent; + char addr[16]; + + port_str = strchr(tok, ':'); + if (port_str) { + *port_str = 0; + port_str++; + if (!*port_str) + port_str = NULL; + } + + ent = gethostbyname(tok); + + if (!ent) { + printf("server name not found: %s\n", tok); + free(new_str); + return 0; + } + + snprintf(addr, sizeof(addr), "%u.%u.%u.%u", + (unsigned char)ent->h_addr[0], + (unsigned char)ent->h_addr[1], + (unsigned char)ent->h_addr[2], + (unsigned char)ent->h_addr[3]); + + pos = safe_cat(&new_str, &len, pos, addr); + + if (port_str) { + pos = safe_cat(&new_str, &len, pos, ":"); + pos = safe_cat(&new_str, &len, pos, port_str); + } + + tok = strtok(NULL, ","); + if (tok) + pos = safe_cat(&new_str, &len, pos, ","); + + } + + pos = safe_cat(&new_str, &len, pos, ":"); + pos = safe_cat(&new_str, &len, pos, mount_path); + + return new_str; +} + +/* + * this one is partialy based on parse_options() from cifs.mount.c + */ +static int parse_options(char ** optionsp, int * filesys_flags) +{ + const char * data; + char * value = NULL; + char * next_keyword = NULL; + char * out = NULL; + int out_len = 0; + int word_len; + int skip; + int pos = 0; + + if (!optionsp || !*optionsp) + return 1; + data = *optionsp; + + if(verboseflag) + printf("parsing options: %s\n", data); + + while(data != NULL) { + /* check if ends with trailing comma */ + if(*data == 0) + break; + + next_keyword = strchr(data,','); + + /* temporarily null terminate end of keyword=value pair */ + if(next_keyword) + *next_keyword++ = 0; + + /* temporarily null terminate keyword to make keyword and value distinct */ + if ((value = strchr(data, '=')) != NULL) { + *value = '\0'; + value++; + } + + skip = 1; + + if (strncmp(data, "nosuid", 6) == 0) { + *filesys_flags |= MS_NOSUID; + } else if (strncmp(data, "suid", 4) == 0) { + *filesys_flags &= ~MS_NOSUID; + } else if (strncmp(data, "nodev", 5) == 0) { + *filesys_flags |= MS_NODEV; + } else if ((strncmp(data, "nobrl", 5) == 0) || + (strncmp(data, "nolock", 6) == 0)) { + *filesys_flags &= ~MS_MANDLOCK; + } else if (strncmp(data, "dev", 3) == 0) { + *filesys_flags &= ~MS_NODEV; + } else if (strncmp(data, "noexec", 6) == 0) { + *filesys_flags |= MS_NOEXEC; + } else if (strncmp(data, "exec", 4) == 0) { + *filesys_flags &= ~MS_NOEXEC; + } else if (strncmp(data, "ro", 2) == 0) { + *filesys_flags |= MS_RDONLY; + } else if (strncmp(data, "rw", 2) == 0) { + *filesys_flags &= ~MS_RDONLY; + } else if (strncmp(data, "remount", 7) == 0) { + *filesys_flags |= MS_REMOUNT; + } else { + skip = 0; + /* printf("ceph: Unknown mount option %s\n",data); */ + } + + /* Copy (possibly modified) option to out */ + if (!skip) { + word_len = strlen(data); + if (value) + word_len += 1 + strlen(value); + + if (pos) + pos = safe_cat(&out, &out_len, pos, ","); + + if (value) { + pos = safe_cat(&out, &out_len, pos, data); + pos = safe_cat(&out, &out_len, pos, "="); + pos = safe_cat(&out, &out_len, pos, value); + } else { + pos = safe_cat(&out, &out_len, pos, data); + } + + } + data = next_keyword; + } + + *optionsp = out; + return 0; +} + + +int main(int argc, char *argv[]) +{ + int i; + char **new_argv; + int flags = 0; + int options_pos = 0; + + if (argc < 5) + exit(1); + + new_argv = (char **)malloc(sizeof(char *)*argc); + + for (i=0; i<argc; i++) { + new_argv[i] = argv[i]; + if (strcmp(new_argv[i], "-o") == 0) { + options_pos = i+1; + if (options_pos >= argc) { + printf("usage error\n"); + exit(1); + } + } else if (strcmp(new_argv[i], "-v") == 0) { + verboseflag = 1; + } + } + + new_argv[1] = mount_resolve_dest(argv[1]); + + parse_options(&new_argv[options_pos], &flags); + + if (mount(new_argv[1], new_argv[2], "ceph", flags, new_argv[options_pos])) { + switch (errno) { + case ENODEV: + printf("mount error: ceph filesystem not supported by the system\n"); + break; + default: + printf("mount error %d = %s\n",errno,strerror(errno)); + } + } else { + update_mtab_entry(new_argv[1], new_argv[2], "ceph", new_argv[options_pos], flags, 0, 0); + } + + free(new_argv); + exit(0); +} + diff --git a/src/mount/mtab.c b/src/mount/mtab.c new file mode 100644 index 00000000000..48c68971a46 --- /dev/null +++ b/src/mount/mtab.c @@ -0,0 +1,277 @@ + +/* + * this code lifted from util-linux-ng, licensed GPLv2+, + * + * git://git.kernel.org/pub/scm/utils/util-linux-ng/util-linux-ng.git + * + * whoever decided that each special mount program is responsible + * for updating /etc/mtab should be spanked. + * + * <sage@newdream.net> + */ +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <time.h> +#include <mntent.h> +#include <stdarg.h> + + +/* Updating mtab ----------------------------------------------*/ + +/* Flag for already existing lock file. */ +static int we_created_lockfile = 0; +static int lockfile_fd = -1; + +/* Flag to indicate that signals have been set up. */ +static int signals_have_been_setup = 0; + +/* Ensure that the lock is released if we are interrupted. */ +extern char *strsignal(int sig); /* not always in <string.h> */ + +static void +setlkw_timeout (int sig) { + /* nothing, fcntl will fail anyway */ +} + +#define _PATH_MOUNTED "/etc/mtab" +#define _PATH_MOUNTED_LOCK "/etc/mtab~" + +/* exit status - bits below are ORed */ +#define EX_USAGE 1 /* incorrect invocation or permission */ +#define EX_SYSERR 2 /* out of memory, cannot fork, ... */ +#define EX_SOFTWARE 4 /* internal mount bug or wrong version */ +#define EX_USER 8 /* user interrupt */ +#define EX_FILEIO 16 /* problems writing, locking, ... mtab/fstab */ +#define EX_FAIL 32 /* mount failure */ +#define EX_SOMEOK 64 /* some mount succeeded */ + +int die(int err, const char *fmt, ...) { + va_list args; + + va_start(args, fmt); + vfprintf(stderr, fmt, args); + fprintf(stderr, "\n"); + va_end(args); + + exit(err); +} + +static void +handler (int sig) { + die(EX_USER, "%s", strsignal(sig)); +} + +/* Remove lock file. */ +void +unlock_mtab (void) { + if (we_created_lockfile) { + close(lockfile_fd); + lockfile_fd = -1; + unlink (_PATH_MOUNTED_LOCK); + we_created_lockfile = 0; + } +} + +/* Create the lock file. + The lock file will be removed if we catch a signal or when we exit. */ +/* The old code here used flock on a lock file /etc/mtab~ and deleted + this lock file afterwards. However, as rgooch remarks, that has a + race: a second mount may be waiting on the lock and proceed as + soon as the lock file is deleted by the first mount, and immediately + afterwards a third mount comes, creates a new /etc/mtab~, applies + flock to that, and also proceeds, so that the second and third mount + now both are scribbling in /etc/mtab. + The new code uses a link() instead of a creat(), where we proceed + only if it was us that created the lock, and hence we always have + to delete the lock afterwards. Now the use of flock() is in principle + superfluous, but avoids an arbitrary sleep(). */ + +/* Where does the link point to? Obvious choices are mtab and mtab~~. + HJLu points out that the latter leads to races. Right now we use + mtab~.<pid> instead. Use 20 as upper bound for the length of %d. */ +#define MOUNTLOCK_LINKTARGET _PATH_MOUNTED_LOCK "%d" +#define MOUNTLOCK_LINKTARGET_LTH (sizeof(_PATH_MOUNTED_LOCK)+20) + +/* + * The original mount locking code has used sleep(1) between attempts and + * maximal number of attemps has been 5. + * + * There was very small number of attempts and extremely long waiting (1s) + * that is useless on machines with large number of concurret mount processes. + * + * Now we wait few thousand microseconds between attempts and we have global + * time limit (30s) rather than limit for number of attempts. The advantage + * is that this method also counts time which we spend in fcntl(F_SETLKW) and + * number of attempts is not so much restricted. + * + * -- kzak@redhat.com [2007-Mar-2007] + */ + +/* maximum seconds between first and last attempt */ +#define MOUNTLOCK_MAXTIME 30 + +/* sleep time (in microseconds, max=999999) between attempts */ +#define MOUNTLOCK_WAITTIME 5000 + +void +lock_mtab (void) { + int i; + struct timespec waittime; + struct timeval maxtime; + char linktargetfile[MOUNTLOCK_LINKTARGET_LTH]; + + if (!signals_have_been_setup) { + int sig = 0; + struct sigaction sa; + + sa.sa_handler = handler; + sa.sa_flags = 0; + sigfillset (&sa.sa_mask); + + while (sigismember (&sa.sa_mask, ++sig) != -1 + && sig != SIGCHLD) { + if (sig == SIGALRM) + sa.sa_handler = setlkw_timeout; + else + sa.sa_handler = handler; + sigaction (sig, &sa, (struct sigaction *) 0); + } + signals_have_been_setup = 1; + } + + sprintf(linktargetfile, MOUNTLOCK_LINKTARGET, getpid ()); + + i = open (linktargetfile, O_WRONLY|O_CREAT, S_IRUSR|S_IWUSR); + if (i < 0) { + int errsv = errno; + /* linktargetfile does not exist (as a file) + and we cannot create it. Read-only filesystem? + Too many files open in the system? + Filesystem full? */ + die (EX_FILEIO, "can't create lock file %s: %s " + "(use -n flag to override)", + linktargetfile, strerror (errsv)); + } + close(i); + + gettimeofday(&maxtime, NULL); + maxtime.tv_sec += MOUNTLOCK_MAXTIME; + + waittime.tv_sec = 0; + waittime.tv_nsec = (1000 * MOUNTLOCK_WAITTIME); + + /* Repeat until it was us who made the link */ + while (!we_created_lockfile) { + struct timeval now; + struct flock flock; + int errsv, j; + + j = link(linktargetfile, _PATH_MOUNTED_LOCK); + errsv = errno; + + if (j == 0) + we_created_lockfile = 1; + + if (j < 0 && errsv != EEXIST) { + (void) unlink(linktargetfile); + die (EX_FILEIO, "can't link lock file %s: %s " + "(use -n flag to override)", + _PATH_MOUNTED_LOCK, strerror (errsv)); + } + + lockfile_fd = open (_PATH_MOUNTED_LOCK, O_WRONLY); + + if (lockfile_fd < 0) { + /* Strange... Maybe the file was just deleted? */ + int errsv = errno; + gettimeofday(&now, NULL); + if (errno == ENOENT && now.tv_sec < maxtime.tv_sec) { + we_created_lockfile = 0; + continue; + } + (void) unlink(linktargetfile); + die (EX_FILEIO, "can't open lock file %s: %s " + "(use -n flag to override)", + _PATH_MOUNTED_LOCK, strerror (errsv)); + } + + flock.l_type = F_WRLCK; + flock.l_whence = SEEK_SET; + flock.l_start = 0; + flock.l_len = 0; + + if (j == 0) { + /* We made the link. Now claim the lock. */ + if (fcntl (lockfile_fd, F_SETLK, &flock) == -1) { + /* proceed, since it was us who created the lockfile anyway */ + } + (void) unlink(linktargetfile); + } else { + /* Someone else made the link. Wait. */ + gettimeofday(&now, NULL); + if (now.tv_sec < maxtime.tv_sec) { + alarm(maxtime.tv_sec - now.tv_sec); + if (fcntl (lockfile_fd, F_SETLKW, &flock) == -1) { + int errsv = errno; + (void) unlink(linktargetfile); + die (EX_FILEIO, "can't lock lock file %s: %s", + _PATH_MOUNTED_LOCK, (errno == EINTR) ? + "timed out" : strerror (errsv)); + } + alarm(0); + + nanosleep(&waittime, NULL); + } else { + (void) unlink(linktargetfile); + die (EX_FILEIO, "Cannot create link %s\n" + "Perhaps there is a stale lock file?\n", + _PATH_MOUNTED_LOCK); + } + close(lockfile_fd); + } + } +} + +static void +update_mtab_entry(const char *spec, const char *node, const char *type, + const char *opts, int flags, int freq, int pass) { + struct mntent mnt; + + if (!opts) + opts = "rw"; + + mnt.mnt_fsname = strdup(spec); + mnt.mnt_dir = strdup(node); + mnt.mnt_type = strdup(type); + mnt.mnt_opts = strdup(opts); + mnt.mnt_freq = freq; + mnt.mnt_passno = pass; + + FILE *fp; + + lock_mtab(); + fp = setmntent(_PATH_MOUNTED, "a+"); + if (fp == NULL) { + int errsv = errno; + printf("mount: can't open %s: %s", _PATH_MOUNTED, + strerror (errsv)); + } else { + if ((addmntent (fp, &mnt)) == 1) { + int errsv = errno; + printf("mount: error writing %s: %s", + _PATH_MOUNTED, strerror (errsv)); + } + } + endmntent(fp); + unlock_mtab(); + + free(mnt.mnt_fsname); + free(mnt.mnt_dir); +} |