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Unverified Commit 1b7b7923 by Christian Brauner
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cgroups/cgfsng: replace lxc_write_file()

Signed-off-by: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
parent b805280e
Showing with 75 additions and 43 deletions
src/lxc/cgroups/cgfsng.c
......@@ -500,13 +500,11 @@ static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
copy_parent:
if (!am_initialized) {
fpath = must_make_path(path, "cpuset.cpus", NULL);
ret = lxc_write_to_file(fpath, cpulist, strlen(cpulist), false,
0666);
if (ret < 0) {
SYSERROR("Failed to write cpu list to \"%s\"", fpath);
return false;
}
ret = lxc_write_openat(path, "cpuset.cpus", cpulist, strlen(cpulist));
if (ret < 0)
return log_error_errno(false,
errno, "Failed to write cpu list to \"%s/cpuset.cpus\"",
path);
TRACE("Copied cpu settings of parent cgroup");
}
......@@ -517,7 +515,7 @@ copy_parent:
/* Copy contents of parent(@path)/@file to @path/@file */
static bool copy_parent_file(char *path, char *file)
{
__do_free char *child_path = NULL, *parent_path = NULL, *value = NULL;
__do_free char *parent_path = NULL, *value = NULL;
int ret;
char oldv;
int len = 0;
......@@ -545,13 +543,17 @@ static bool copy_parent_file(char *path, char *file)
}
*lastslash = oldv;
child_path = must_make_path(path, file, NULL);
ret = lxc_write_to_file(child_path, value, len, false, 0666);
ret = lxc_write_openat(path, file, value, len);
if (ret < 0)
SYSERROR("Failed to write \"%s\" to file \"%s\"", value, child_path);
SYSERROR("Failed to write \"%s\" to file \"%s/%s\"", value, path, file);
return ret >= 0;
}
static bool is_unified_hierarchy(const struct hierarchy *h)
{
return h->version == CGROUP2_SUPER_MAGIC;
}
/* Initialize the cpuset hierarchy in first directory of @gname and set
* cgroup.clone_children so that children inherit settings. Since the
* h->base_path is populated by init or ourselves, we know it is already
......@@ -559,11 +561,15 @@ static bool copy_parent_file(char *path, char *file)
*/
static bool cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h, char *cgname)
{
__do_free char *cgpath = NULL, *clonechildrenpath = NULL;
__do_free char *cgpath = NULL;
__do_close_prot_errno int cgroup_fd = -EBADF;
int ret;
char v;
char *slash;
if (is_unified_hierarchy(h))
return true;
if (!string_in_list(h->controllers, "cpuset"))
return true;
......@@ -585,14 +591,13 @@ static bool cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h, char *cgname)
}
}
clonechildrenpath = must_make_path(cgpath, "cgroup.clone_children", NULL);
/* unified hierarchy doesn't have clone_children */
if (!file_exists(clonechildrenpath))
return true;
cgroup_fd = lxc_open_dirfd(cgpath);
if (cgroup_fd < 0)
return false;
ret = lxc_read_from_file(clonechildrenpath, &v, 1);
ret = lxc_readat(cgroup_fd, "cgroup.clone_children", &v, 1);
if (ret < 0) {
SYSERROR("Failed to read file \"%s\"", clonechildrenpath);
SYSERROR("Failed to read file \"%s/cgroup.clone_children\"", cgpath);
return false;
}
......@@ -612,10 +617,10 @@ static bool cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h, char *cgname)
return false;
}
ret = lxc_write_to_file(clonechildrenpath, "1", 1, false, 0666);
ret = lxc_writeat(cgroup_fd, "cgroup.clone_children", "1", 1);
if (ret < 0) {
/* Set clone_children so children inherit our settings */
SYSERROR("Failed to write 1 to \"%s\"", clonechildrenpath);
SYSERROR("Failed to write 1 to \"%s/cgroup.clone_children\"", cgpath);
return false;
}
......@@ -2016,15 +2021,14 @@ __cgfsng_ops static bool cgfsng_get_hierarchies(struct cgroup_ops *ops, int n,
static bool cg_legacy_freeze(struct cgroup_ops *ops)
{
__do_free char *path = NULL;
struct hierarchy *h;
h = get_hierarchy(ops, "freezer");
if (!h)
return ret_set_errno(-1, ENOENT);
path = must_make_path(h->container_full_path, "freezer.state", NULL);
return lxc_write_to_file(path, "FROZEN", STRLITERALLEN("FROZEN"), false, 0666);
return lxc_write_openat(h->container_full_path, "freezer.state",
"FROZEN", STRLITERALLEN("FROZEN"));
}
static int freezer_cgroup_events_cb(int fd, uint32_t events, void *cbdata,
......@@ -2064,7 +2068,6 @@ static int freezer_cgroup_events_cb(int fd, uint32_t events, void *cbdata,
static int cg_unified_freeze(struct cgroup_ops *ops, int timeout)
{
__do_close_prot_errno int fd = -EBADF;
__do_free char *path = NULL;
__do_lxc_mainloop_close struct lxc_epoll_descr *descr_ptr = NULL;
int ret;
struct lxc_epoll_descr descr;
......@@ -2097,8 +2100,7 @@ static int cg_unified_freeze(struct cgroup_ops *ops, int timeout)
return log_error_errno(-1, errno, "Failed to add cgroup.events fd handler to mainloop");
}
path = must_make_path(h->container_full_path, "cgroup.freeze", NULL);
ret = lxc_write_to_file(path, "1", 1, false, 0666);
ret = lxc_write_openat(h->container_full_path, "cgroup.freeze", "1", 1);
if (ret < 0)
return log_error_errno(-1, errno, "Failed to open cgroup.freeze file");
......@@ -2121,21 +2123,19 @@ __cgfsng_ops static int cgfsng_freeze(struct cgroup_ops *ops, int timeout)
static int cg_legacy_unfreeze(struct cgroup_ops *ops)
{
__do_free char *path = NULL;
struct hierarchy *h;
h = get_hierarchy(ops, "freezer");
if (!h)
return ret_set_errno(-1, ENOENT);
path = must_make_path(h->container_full_path, "freezer.state", NULL);
return lxc_write_to_file(path, "THAWED", STRLITERALLEN("THAWED"), false, 0666);
return lxc_write_openat(h->container_full_path, "freezer.state",
"THAWED", STRLITERALLEN("THAWED"));
}
static int cg_unified_unfreeze(struct cgroup_ops *ops, int timeout)
{
__do_close_prot_errno int fd = -EBADF;
__do_free char *path = NULL;
__do_lxc_mainloop_close struct lxc_epoll_descr *descr_ptr = NULL;
int ret;
struct lxc_epoll_descr descr;
......@@ -2168,8 +2168,7 @@ static int cg_unified_unfreeze(struct cgroup_ops *ops, int timeout)
return log_error_errno(-1, errno, "Failed to add cgroup.events fd handler to mainloop");
}
path = must_make_path(h->container_full_path, "cgroup.freeze", NULL);
ret = lxc_write_to_file(path, "0", 1, false, 0666);
ret = lxc_write_openat(h->container_full_path, "cgroup.freeze", "0", 1);
if (ret < 0)
return log_error_errno(-1, errno, "Failed to open cgroup.freeze file");
......@@ -2638,12 +2637,10 @@ static int cg_legacy_set_data(struct cgroup_ops *ops, const char *filename,
const char *value)
{
__do_free char *controller = NULL;
__do_free char *fullpath = NULL;
char *p;
/* "b|c <2^64-1>:<2^64-1> r|w|m" = 47 chars max */
char converted_value[50];
struct hierarchy *h;
int ret = 0;
controller = must_copy_string(filename);
p = strchr(controller, '.');
......@@ -2651,6 +2648,8 @@ static int cg_legacy_set_data(struct cgroup_ops *ops, const char *filename,
*p = '\0';
if (strcmp("devices.allow", filename) == 0 && value[0] == '/') {
int ret;
ret = convert_devpath(value, converted_value);
if (ret < 0)
return ret;
......@@ -2667,9 +2666,7 @@ static int cg_legacy_set_data(struct cgroup_ops *ops, const char *filename,
return -ENOENT;
}
fullpath = must_make_path(h->container_full_path, filename, NULL);
ret = lxc_write_to_file(fullpath, value, strlen(value), false, 0666);
return ret;
return lxc_write_openat(h->container_full_path, filename, value, strlen(value));
}
__cgfsng_ops static bool cgfsng_setup_limits_legacy(struct cgroup_ops *ops,
......@@ -2782,18 +2779,16 @@ __cgfsng_ops static bool cgfsng_setup_limits(struct cgroup_ops *ops,
h = ops->unified;
lxc_list_for_each (iterator, cgroup_settings) {
__do_free char *fullpath = NULL;
int ret;
struct lxc_cgroup *cg = iterator->elem;
int ret;
if (strncmp("devices", cg->subsystem, 7) == 0) {
ret = bpf_device_cgroup_prepare(ops, conf, cg->subsystem,
cg->value);
} else {
fullpath = must_make_path(h->container_full_path,
cg->subsystem, NULL);
ret = lxc_write_to_file(fullpath, cg->value,
strlen(cg->value), false, 0666);
ret = lxc_write_openat(h->container_full_path,
cg->subsystem, cg->value,
strlen(cg->value));
if (ret < 0)
return log_error_errno(false,
errno, "Failed to set \"%s\" to \"%s\"",
......
src/lxc/file_utils.c
......@@ -18,6 +18,27 @@
#include "string_utils.h"
#include "utils.h"
int lxc_open_dirfd(const char *dir)
{
return open(dir, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
}
int lxc_readat(int dirfd, const char *filename, void *buf, size_t count)
{
__do_close_prot_errno int fd = -EBADF;
ssize_t ret;
fd = openat(dirfd, filename, O_RDONLY | O_CLOEXEC);
if (fd < 0)
return -1;
ret = lxc_read_nointr(fd, buf, count);
if (ret < 0 || (size_t)ret != count)
return -1;
return 0;
}
int lxc_writeat(int dirfd, const char *filename, const void *buf, size_t count)
{
__do_close_prot_errno int fd = -EBADF;
......@@ -34,6 +55,18 @@ int lxc_writeat(int dirfd, const char *filename, const void *buf, size_t count)
return 0;
}
int lxc_write_openat(const char *dir, const char *filename, const void *buf,
size_t count)
{
__do_close_prot_errno int dirfd = -EBADF;
dirfd = open(dir, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
if (dirfd < 0)
return -1;
return lxc_writeat(dirfd, filename, buf, count);
}
int lxc_write_to_file(const char *filename, const void *buf, size_t count,
bool add_newline, mode_t mode)
{
......
src/lxc/file_utils.h
......@@ -14,8 +14,11 @@
/* read and write whole files */
extern int lxc_write_to_file(const char *filename, const void *buf,
size_t count, bool add_newline, mode_t mode);
extern int lxc_readat(int dirfd, const char *filename, void *buf, size_t count);
extern int lxc_writeat(int dirfd, const char *filename, const void *buf,
size_t count);
extern int lxc_write_openat(const char *dir, const char *filename,
const void *buf, size_t count);
extern int lxc_read_from_file(const char *filename, void *buf, size_t count);
/* send and receive buffers completely */
......@@ -42,5 +45,6 @@ extern ssize_t lxc_sendfile_nointr(int out_fd, int in_fd, off_t *offset,
size_t count);
extern char *file_to_buf(char *path, size_t *length);
extern int fd_to_fd(int from, int to);
extern int lxc_open_dirfd(const char *dir);
#endif /* __LXC_FILE_UTILS_H */
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