diff options
| -rw-r--r-- | daemon/daemon.h | 3 | ||||
| -rw-r--r-- | daemon/guestfsd.c | 5 | ||||
| -rw-r--r-- | daemon/lvm-filter.c | 109 |
3 files changed, 101 insertions, 16 deletions
diff --git a/daemon/daemon.h b/daemon/daemon.h index b4f99a81..6ed68fd8 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -134,6 +134,9 @@ extern int e2prog (char *name); /* Massive hack for RHEL 5. */ /*-- in lvm.c --*/ extern int lv_canonical (const char *device, char **ret); +/*-- in lvm-filter.c --*/ +extern void copy_lvm (void); + /*-- in proto.c --*/ extern void main_loop (int sock) __attribute__((noreturn)); diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c index 51bb0b73..6373f34a 100644 --- a/daemon/guestfsd.c +++ b/daemon/guestfsd.c @@ -239,6 +239,11 @@ main (int argc, char *argv[]) _umask (0); #endif + /* Make a private copy of /etc/lvm so we can change the config (see + * daemon/lvm-filter.c). + */ + copy_lvm (); + /* Connect to virtio-serial channel. */ int sock = open (VIRTIO_SERIAL_CHANNEL, O_RDWR | O_CLOEXEC); if (sock == -1) { diff --git a/daemon/lvm-filter.c b/daemon/lvm-filter.c index a62d40af..21e2fde4 100644 --- a/daemon/lvm-filter.c +++ b/daemon/lvm-filter.c @@ -23,11 +23,79 @@ #include <inttypes.h> #include <string.h> #include <unistd.h> +#include <sys/stat.h> -#include "daemon.h" #include "c-ctype.h" +#include "ignore-value.h" + +#include "daemon.h" #include "actions.h" +/* This runs during daemon start up and creates a complete copy of + * /etc/lvm so that we can modify it as we desire. We set + * LVM_SYSTEM_DIR to point to the copy. + */ +static char lvm_system_dir[] = "/tmp/lvmXXXXXX"; + +static void rm_lvm_system_dir (void); + +void +copy_lvm (void) +{ + struct stat statbuf; + char cmd[64]; + int r; + + /* If /etc/lvm directory doesn't exist (or isn't a directory) assume + * that this system doesn't support LVM and do nothing. + */ + r = stat ("/etc/lvm", &statbuf); + if (r == -1) { + perror ("copy_lvm: stat: /etc/lvm"); + return; + } + if (! S_ISDIR (statbuf.st_mode)) { + fprintf (stderr, "copy_lvm: warning: /etc/lvm is not a directory\n"); + return; + } + + if (mkdtemp (lvm_system_dir) == NULL) { + perror (lvm_system_dir); + exit (EXIT_FAILURE); + } + + /* Hopefully no dotfiles in there ... XXX */ + snprintf (cmd, sizeof cmd, "cp -a /etc/lvm/* %s", lvm_system_dir); + r = system (cmd); + if (r == -1) { + perror (cmd); + rmdir (lvm_system_dir); + exit (EXIT_FAILURE); + } + + if (WEXITSTATUS (r) != 0) { + fprintf (stderr, "cp command failed with return code %d\n", + WEXITSTATUS (r)); + rmdir (lvm_system_dir); + exit (EXIT_FAILURE); + } + + /* Set environment variable so we use the copy. */ + setenv ("LVM_SYSTEM_DIR", lvm_system_dir, 1); + + /* Set a handler to remove the temporary directory at exit. */ + atexit (rm_lvm_system_dir); +} + +static void +rm_lvm_system_dir (void) +{ + char cmd[64]; + + snprintf (cmd, sizeof cmd, "rm -rf %s", lvm_system_dir); + ignore_value (system (cmd)); +} + /* Does the current line match the regexp /^\s*filter\s*=/ */ static int is_filter_line (const char *line) @@ -52,18 +120,24 @@ is_filter_line (const char *line) return 1; } -/* Rewrite the 'filter = [ ... ]' line in /etc/lvm/lvm.conf. */ +/* Rewrite the 'filter = [ ... ]' line in lvm.conf. */ static int set_filter (const char *filter) { - FILE *ifp = fopen ("/etc/lvm/lvm.conf", "r"); + char lvm_conf[64]; + snprintf (lvm_conf, sizeof lvm_conf, "%s/lvm.conf", lvm_system_dir); + + char lvm_conf_new[64]; + snprintf (lvm_conf_new, sizeof lvm_conf, "%s/lvm.conf.new", lvm_system_dir); + + FILE *ifp = fopen (lvm_conf, "r"); if (ifp == NULL) { - reply_with_perror ("open: /etc/lvm/lvm.conf"); + reply_with_perror ("open: %s", lvm_conf); return -1; } - FILE *ofp = fopen ("/etc/lvm/lvm.conf.new", "w"); + FILE *ofp = fopen (lvm_conf_new, "w"); if (ofp == NULL) { - reply_with_perror ("open: /etc/lvm/lvm.conf.new"); + reply_with_perror ("open: %s", lvm_conf_new); fclose (ifp); return -1; } @@ -79,11 +153,11 @@ set_filter (const char *filter) } if (r < 0) { /* NB. fprintf doesn't set errno on error. */ - reply_with_error ("/etc/lvm/lvm.conf.new: write failed"); + reply_with_error ("%s: write failed", lvm_conf_new); fclose (ifp); fclose (ofp); free (line); - unlink ("/etc/lvm/lvm.conf.new"); + unlink (lvm_conf_new); return -1; } } @@ -91,20 +165,20 @@ set_filter (const char *filter) free (line); if (fclose (ifp) == EOF) { - reply_with_perror ("/etc/lvm/lvm.conf.new"); - unlink ("/etc/lvm/lvm.conf.new"); + reply_with_perror ("close: %s", lvm_conf); + unlink (lvm_conf_new); fclose (ofp); return -1; } if (fclose (ofp) == EOF) { - reply_with_perror ("/etc/lvm/lvm.conf.new"); - unlink ("/etc/lvm/lvm.conf.new"); + reply_with_perror ("close: %s", lvm_conf_new); + unlink (lvm_conf_new); return -1; } - if (rename ("/etc/lvm/lvm.conf.new", "/etc/lvm/lvm.conf") == -1) { - reply_with_perror ("rename: /etc/lvm/lvm.conf"); - unlink ("/etc/lvm/lvm.conf.new"); + if (rename (lvm_conf_new, lvm_conf) == -1) { + reply_with_perror ("rename: %s", lvm_conf); + unlink (lvm_conf_new); return -1; } @@ -144,7 +218,10 @@ reactivate (void) static int rescan (void) { - unlink ("/etc/lvm/cache/.cache"); + char lvm_cache[64]; + snprintf (lvm_cache, sizeof lvm_cache, "%s/cache/.cache", lvm_system_dir); + + unlink (lvm_cache); char *err; int r = command (NULL, &err, "lvm", "vgscan", NULL); |