From a29e2f4fe3c6456d801ae12500c077ec7998ae20 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Mon, 4 Oct 2010 12:18:41 +0200 Subject: libmount: cleanup helpers support Signed-off-by: Karel Zak --- shlibs/mount/src/context.c | 231 +++++++++++++++++++++++---------------------- 1 file changed, 117 insertions(+), 114 deletions(-) (limited to 'shlibs/mount/src/context.c') diff --git a/shlibs/mount/src/context.c b/shlibs/mount/src/context.c index ee7079249..2102be539 100644 --- a/shlibs/mount/src/context.c +++ b/shlibs/mount/src/context.c @@ -54,7 +54,7 @@ struct _mnt_context int flags; /* private context flags */ int ambi; /* libblkid returns ambivalent result */ - char *helper_name; /* name of the used /sbin/[u]mount. helper */ + char *helper; /* name of the used /sbin/[u]mount. helper */ int helper_status; /* helper wait(2) status */ char *orig_user; /* original (non-fixed) user= option */ @@ -136,7 +136,7 @@ void mnt_free_context(mnt_context *cxt) free(cxt->fstype_pattern); free(cxt->optstr_pattern); free(cxt->spec); - free(cxt->helper_name); + free(cxt->helper); free(cxt->orig_user); if (!(cxt->flags & MNT_FL_EXTERN_FS)) @@ -192,11 +192,11 @@ int mnt_reset_context(mnt_context *cxt) cxt->mtab = NULL; free(cxt->spec); - free(cxt->helper_name); + free(cxt->helper); free(cxt->orig_user); cxt->spec = NULL; - cxt->helper_name = NULL; + cxt->helper = NULL; cxt->mountflags = 0; cxt->user_mountflags = 0; @@ -1252,11 +1252,72 @@ static int mnt_context_merge_mountflags(mnt_context *cxt) return 0; } +/* + * The default is to use fstype from cxt->fs, this could be overwritten by + * @type. The @act is MNT_ACT_{MOUNT,UMOUNT}. + * + * Returns: 0 on success or negative number in case of error. Note that success + * does not mean that there is any usable helper, you have to check cxt->helper. + */ +static int mnt_context_prepare_helper(mnt_context *cxt, int act, const char *type) +{ + char search_path[] = FS_SEARCH_PATH; /* from config.h */ + char *p = NULL, *path; + const char *name; + + assert(cxt); + assert(cxt->fs); + + name = MNT_ACT_MOUNT ? "mount" : "umount"; + + if (!type) + type = mnt_fs_get_fstype(cxt->fs); + + if ((cxt->flags & MNT_FL_NOHELPERS) || !type || + !strcmp(type, "none") || (cxt->fs->flags & MNT_FS_SWAP)) + return 0; + + path = strtok_r(search_path, ":", &p); + while (path) { + char helper[PATH_MAX]; + struct stat st; + int rc; + + rc = snprintf(helper, sizeof(helper), "%s/%s.%s", + path, name, type); + path = strtok_r(NULL, ":", &p); + + if (rc >= sizeof(helper) || rc < 0) + continue; + + rc = stat(helper, &st); + if (rc == -1 && errno == ENOENT && strchr(type, '.')) { + /* If type ends with ".subtype" try without it */ + *strrchr(helper, '.') = '\0'; + rc = stat(helper, &st); + } + + DBG(CXT, mnt_debug_h(cxt, "%s ... %s", helper, + rc ? "not found" : "found")); + if (rc) + continue; + + if (cxt->helper) + free(cxt->helper); + cxt->helper = strdup(helper); + if (!cxt->helper) + return -ENOMEM; + return 0; + } + + return 0; +} + static int mnt_context_prepare_update(mnt_context *cxt, int act) { int rc; - if (cxt->flags & MNT_FL_NOMTAB) + if ((cxt->flags & MNT_FL_NOMTAB) || cxt->helper) return 0; if (!cxt->update) { @@ -1341,49 +1402,38 @@ int mnt_context_prepare_mount(mnt_context *cxt) return -EINVAL; rc = mnt_context_apply_fstab(cxt); - if (rc) - goto err; - - rc = mnt_context_merge_mountflags(cxt); - if (rc) - return rc; - - rc = mnt_context_evaluate_permissions(cxt); - if (rc) - goto err; - - rc = mnt_context_fix_optstr(cxt); - if (rc) - goto err; - - rc = mnt_context_prepare_srcpath(cxt); - if (rc) - goto err; - - rc = mnt_context_guess_fstype(cxt); - if (rc) - goto err; + if (!rc) + rc = mnt_context_merge_mountflags(cxt); + if (!rc) + rc = mnt_context_evaluate_permissions(cxt); + if (!rc) + rc = mnt_context_fix_optstr(cxt); + if (!rc) + rc = mnt_context_prepare_srcpath(cxt); + if (!rc) + rc = mnt_context_guess_fstype(cxt); + if (!rc) + rc = mnt_context_prepare_helper(cxt, MNT_ACT_MOUNT, NULL); + if (!rc) + rc = mnt_context_prepare_update(cxt, MNT_ACT_MOUNT); - rc = mnt_context_prepare_update(cxt, MNT_ACT_MOUNT); - if (rc) - goto err; + if (!rc) { + DBG(CXT, mnt_debug_h(cxt, "sucessfully prepared")); + return 0; + } - DBG(CXT, mnt_debug_h(cxt, "sucessfully prepared")); - return 0; -err: DBG(CXT, mnt_debug_h(cxt, "prepare failed")); return rc; } -static int exec_mount_helper(mnt_context *cxt, const char *prog, - const char *subtype) +static int exec_mount_helper(mnt_context *cxt) { char *o = NULL; int rc; assert(cxt); assert(cxt->fs); - assert(prog); + assert(cxt->helper); rc = mnt_context_get_helper_optstr(cxt, &o); if (rc) @@ -1394,7 +1444,7 @@ static int exec_mount_helper(mnt_context *cxt, const char *prog, switch (fork()) { case 0: { - const char *args[12]; + const char *args[12], *type; int i = 0; if (setgid(getgid()) < 0) @@ -1403,8 +1453,9 @@ static int exec_mount_helper(mnt_context *cxt, const char *prog, if (setuid(getuid()) < 0) exit(EXIT_FAILURE); + type = mnt_fs_get_fstype(cxt->fs); - args[i++] = prog; /* 1 */ + args[i++] = cxt->helper; /* 1 */ args[i++] = mnt_fs_get_srcpath(cxt->fs); /* 2 */ args[i++] = mnt_fs_get_target(cxt->fs); /* 3 */ @@ -1420,9 +1471,9 @@ static int exec_mount_helper(mnt_context *cxt, const char *prog, args[i++] = "-o"; /* 8 */ args[i++] = o; /* 9 */ } - if (subtype) { + if (type && !endswith(cxt->helper, type)) { args[i++] = "-t"; /* 10 */ - args[i++] = subtype; /* 11 */ + args[i++] = type; /* 11 */ } args[i] = NULL; /* 12 */ #ifdef CONFIG_LIBMOUNT_DEBUG @@ -1432,7 +1483,7 @@ static int exec_mount_helper(mnt_context *cxt, const char *prog, i, args[i])); #endif DBG_FLUSH; - execv(prog, (char * const *) args); + execv(cxt->helper, (char * const *) args); exit(EXIT_FAILURE); } default: @@ -1440,10 +1491,9 @@ static int exec_mount_helper(mnt_context *cxt, const char *prog, int st; wait(&st); cxt->helper_status = WIFEXITED(st) ? WEXITSTATUS(st) : -1; - cxt->helper_name = strdup(prog); DBG(CXT, mnt_debug_h(cxt, "%s executed [status=%d]", - prog, cxt->helper_status)); + cxt->helper, cxt->helper_status)); rc = 0; break; } @@ -1460,91 +1510,43 @@ done: } /* - * Returns: 0 on success, 1 if helper not found and negative number in case of - * error. + * The default is to use fstype from cxt->fs, this could be overwritten by + * @try_type argument. */ -static int mnt_context_call_helper(mnt_context *cxt, - const char *name, const char *type) -{ - char search_path[] = FS_SEARCH_PATH; /* from config.h */ - char *p = NULL, *path; - - assert(cxt); - - if ((cxt->flags & MNT_FL_NOHELPERS) || - !type || !strcmp(type, "none")) - return 1; - - path = strtok_r(search_path, ":", &p); - while (path) { - char helper[PATH_MAX]; - struct stat st; - const char *subtype = NULL; - int rc; - - rc = snprintf(helper, sizeof(helper), "%s/%s.%s", - path, name, type); - path = strtok_r(NULL, ":", &p); - - if (rc >= sizeof(helper) || rc < 0) - continue; - - rc = stat(helper, &st); - if (rc == -1 && errno == ENOENT && strchr(type, '.')) { - /* If type ends with ".subtype" try without it */ - *strrchr(helper, '.') = '\0'; - subtype = type; - rc = stat(helper, &st); - } - - DBG(CXT, mnt_debug_h(cxt, "%s ... %s", helper, - rc ? "not found" : "found")); - if (rc) - continue; - - return exec_mount_helper(cxt, helper, subtype); - } - - DBG(CXT, mnt_debug_h(cxt, "%s.%s helper not found", name, type)); - return 1; -} - -static int mnt_context_do_mount(mnt_context *cxt, const char *type) +static int mnt_context_do_mount(mnt_context *cxt, const char *try_type) { int rc; - const char *src, *target; + const char *src, *target, *type; unsigned long flags; assert(cxt); - assert(type); assert(cxt->fs); + if (try_type && !cxt->helper) { + rc = mnt_context_prepare_helper(cxt, MNT_ACT_MOUNT, try_type); + if (!rc) + return rc; + } + if (cxt->helper) + return exec_mount_helper(cxt); + + type = try_type ? : mnt_fs_get_fstype(cxt->fs); + flags = cxt->mountflags; src = mnt_fs_get_srcpath(cxt->fs); target = mnt_fs_get_target(cxt->fs); - DBG(CXT, mnt_debug_h(cxt, - "mounting [fstype=%s, source=%s, target=%s, " - "fs_optstr='%s', vfs_optstr='%s', " - "mountflags=%08lx, mountdata=%s", - - type, src, target, - mnt_fs_get_fs_optstr(cxt->fs), - mnt_fs_get_vfs_optstr(cxt->fs), - flags, - cxt->mountdata ? "yes" : "")); - - rc = mnt_context_call_helper(cxt, "mount", type); - if (rc <= 0) - return rc; - if (!src || !target) return -EINVAL; if (!(flags & MS_MGC_MSK)) flags |= MS_MGC_VAL; - DBG(CXT, mnt_debug_h(cxt, "calling mount(2)")); + DBG(CXT, mnt_debug_h(cxt, "calling mount(2) " + "[source=%s, target=%s, type=%s, " + " mountflags=%08lx, mountdata=%s]", + src, target, type, + flags, cxt->mountdata ? "yes" : "")); if (mount(src, target, type, flags, cxt->mountdata)) { cxt->syscall_errno = errno; @@ -1575,16 +1577,17 @@ int mnt_context_mount_fs(mnt_context *cxt) if (!cxt || !cxt->fs || (cxt->fs->flags & MNT_FS_SWAP)) return -EINVAL; - type = mnt_fs_get_fstype(cxt->fs); - if (!(cxt->flags & MNT_FL_MOUNTDATA)) cxt->mountdata = (char *) mnt_fs_get_fs_optstr(cxt->fs); + type = mnt_fs_get_fstype(cxt->fs); + if (type && !strchr(type, ',')) { - rc = mnt_context_do_mount(cxt, type); + rc = mnt_context_do_mount(cxt, NULL); if (rc) return rc; } + /* TODO: try all filesystems from comma separated list of types */ /* TODO: try all filesystems from /proc/filesystems and /etc/filesystems */ @@ -1610,7 +1613,7 @@ int mnt_context_post_mount(mnt_context *cxt) /* * Update /etc/mtab or /var/run/mount/mountinfo */ - if (!cxt->syscall_errno && !cxt->helper_name && + if (!cxt->syscall_errno && !cxt->helper && !(cxt->flags & MNT_FL_NOMTAB) && cxt->update && !mnt_update_is_pointless(cxt->update)) { -- cgit v1.2.3-55-g7522