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tmpfiles: introduce create_directory() and create_subvolume() and mak…

…e them safe
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fbuihuu committed Apr 27, 2018
1 parent a12e4ad commit 4c39d899ff00e90b7290e4985696f321d7f2726f
Showing with 65 additions and 22 deletions.
  1. +65 −22 src/tmpfiles/tmpfiles.c
@@ -1527,17 +1527,18 @@ static const char *creation_mode_verb_table[_CREATION_MODE_MAX] = {

DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(creation_mode_verb, CreationMode);

static int create_directory_or_subvolume(Item *i, const char *path) {
static int create_directory_or_subvolume(const char *path, mode_t mode, bool subvol) {
_cleanup_close_ int pfd = -1;
CreationMode creation;
int r, q = 0;
int r;

assert(i);
assert(IN_SET(i->type,
CREATE_DIRECTORY, TRUNCATE_DIRECTORY,
CREATE_SUBVOLUME, CREATE_SUBVOLUME_NEW_QUOTA, CREATE_SUBVOLUME_INHERIT_QUOTA));
assert(path);

if (IN_SET(i->type, CREATE_SUBVOLUME, CREATE_SUBVOLUME_INHERIT_QUOTA, CREATE_SUBVOLUME_NEW_QUOTA)) {
pfd = path_open_parent_safe(path);
if (pfd < 0)
return pfd;

if (subvol) {
if (btrfs_is_subvol(empty_to_root(arg_root)) <= 0)

/* Don't create a subvolume unless the root directory is
@@ -1550,42 +1551,76 @@ static int create_directory_or_subvolume(Item *i, const char *path) {
* specifically set up a btrfs subvolume for the root
* dir too. */

r = -ENOTTY;
subvol = false;
else {
RUN_WITH_UMASK((~i->mode) & 0777)
r = btrfs_subvol_make(i->path);
RUN_WITH_UMASK((~mode) & 0777)
r = btrfs_subvol_make_fd(pfd, basename(path));
}
} else
r = 0;

if (IN_SET(i->type, CREATE_DIRECTORY, TRUNCATE_DIRECTORY) || r == -ENOTTY)
if (!subvol || r == -ENOTTY)
RUN_WITH_UMASK(0000)
r = mkdir_label(i->path, i->mode);
r = mkdirat_label(pfd, basename(path), mode);

if (r < 0) {
int k;

if (!IN_SET(r, -EEXIST, -EROFS))
return log_error_errno(r, "Failed to create directory or subvolume \"%s\": %m", i->path);
return log_error_errno(r, "Failed to create directory or subvolume \"%s\": %m", path);

k = is_dir(i->path, false);
k = is_dir_fd(pfd);
if (k == -ENOENT && r == -EROFS)
return log_error_errno(r, "%s does not exist and cannot be created as the file system is read-only.", i->path);
return log_error_errno(r, "%s does not exist and cannot be created as the file system is read-only.", path);
if (k < 0)
return log_error_errno(k, "Failed to check if %s exists: %m", i->path);
return log_error_errno(k, "Failed to check if %s exists: %m", path);
if (!k) {
log_warning("\"%s\" already exists and is not a directory.", i->path);
return 0;
log_warning("\"%s\" already exists and is not a directory.", path);
return -EEXIST;
}

creation = CREATION_EXISTING;
} else
creation = CREATION_NORMAL;

log_debug("%s directory \"%s\".", creation_mode_verb_to_string(creation), i->path);
log_debug("%s directory \"%s\".", creation_mode_verb_to_string(creation), path);

r = openat(pfd, basename(path), O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
if (r < 0)
return -errno;
return r;
}

static int create_directory(Item *i, const char *path) {
_cleanup_close_ int fd = -1;

assert(i);
assert(IN_SET(i->type, CREATE_DIRECTORY, TRUNCATE_DIRECTORY));

fd = create_directory_or_subvolume(path, i->mode, false);
if (fd == -EEXIST)
return 0;
if (fd < 0)
return fd;

return fd_set_perms(i, fd, NULL);
}

static int create_subvolume(Item *i, const char *path) {
_cleanup_close_ int fd = -1;
int r, q = 0;

assert(i);
assert(IN_SET(i->type, CREATE_SUBVOLUME, CREATE_SUBVOLUME_NEW_QUOTA, CREATE_SUBVOLUME_INHERIT_QUOTA));

fd = create_directory_or_subvolume(path, i->mode, true);
if (fd == -EEXIST)
return 0;
if (fd < 0)
return fd;

if (IN_SET(i->type, CREATE_SUBVOLUME_NEW_QUOTA, CREATE_SUBVOLUME_INHERIT_QUOTA)) {
r = btrfs_subvol_auto_qgroup(i->path, 0, i->type == CREATE_SUBVOLUME_NEW_QUOTA);
r = btrfs_subvol_auto_qgroup_fd(fd, 0, i->type == CREATE_SUBVOLUME_NEW_QUOTA);
if (r == -ENOTTY)
log_debug_errno(r, "Couldn't adjust quota for subvolume \"%s\" (unsupported fs or dir not a subvolume): %m", i->path);
else if (r == -EROFS)
@@ -1600,7 +1635,7 @@ static int create_directory_or_subvolume(Item *i, const char *path) {
log_debug("Quota for subvolume \"%s\" already in place, no change made.", i->path);
}

r = path_set_perms(i, i->path);
r = fd_set_perms(i, fd, NULL);
if (q < 0)
return q;

@@ -1846,13 +1881,21 @@ static int create_item(Item *i) {

case CREATE_DIRECTORY:
case TRUNCATE_DIRECTORY:
RUN_WITH_UMASK(0000)
(void) mkdir_parents_label(i->path, 0755);

r = create_directory(i, i->path);
if (r < 0)
return r;
break;

case CREATE_SUBVOLUME:
case CREATE_SUBVOLUME_INHERIT_QUOTA:
case CREATE_SUBVOLUME_NEW_QUOTA:
RUN_WITH_UMASK(0000)
(void) mkdir_parents_label(i->path, 0755);

r = create_directory_or_subvolume(i, i->path);
r = create_subvolume(i, i->path);
if (r < 0)
return r;
break;

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