[lxc-devel] [lxc/master] cgroups/cgfsng: rework legacy cpuset handling
brauner on Github
lxc-bot at linuxcontainers.org
Tue Dec 10 18:20:59 UTC 2019
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From f990d3bfde5cf50c393f4c4220e0a7a0e22dc2e6 Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner at ubuntu.com>
Date: Tue, 10 Dec 2019 18:07:47 +0100
Subject: [PATCH 1/2] cgroupfs/cgfsng: pass cgroup to
cg_legacy_handle_cpuset_hierarchy() as const char *
Signed-off-by: Christian Brauner <christian.brauner at ubuntu.com>
---
src/lxc/cgroups/cgfsng.c | 42 ++++++++++++++++++++++++----------------
1 file changed, 25 insertions(+), 17 deletions(-)
diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index 0469a101b6..fa00dbf44e 100644
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -553,7 +553,8 @@ 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
+/*
+ * Initialize the cpuset hierarchy in first directory of @cgroup_leaf 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
* initialized.
@@ -561,14 +562,16 @@ static bool is_unified_hierarchy(const struct hierarchy *h)
* returns -1 on error, 0 when we didn't created a cgroup, 1 if we created a
* cgroup.
*/
-static int cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h, char *cgname)
+static int cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h,
+ const char *cgroup_leaf)
{
int fret = -1;
- __do_free char *cgpath = NULL;
+ __do_free char *parent_or_self = NULL, *dup = NULL;
__do_close_prot_errno int cgroup_fd = -EBADF;
+ size_t len;
int ret;
char v;
- char *slash;
+ char *leaf, *slash;
if (is_unified_hierarchy(h))
return 0;
@@ -576,35 +579,40 @@ static int cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h, char *cgname)
if (!string_in_list(h->controllers, "cpuset"))
return 0;
- if (*cgname == '/')
- cgname++;
- slash = strchr(cgname, '/');
+ if (!cgroup_leaf)
+ return ret_set_errno(-1, EINVAL);
+
+ dup = strdup(cgroup_leaf);
+ if (!dup)
+ return ret_set_errno(-1, ENOMEM);
+
+ leaf += strspn(leaf, "/");
+ slash = strchr(leaf, '/');
if (slash)
*slash = '\0';
-
- cgpath = must_make_path(h->mountpoint, h->container_base_path, cgname, NULL);
+ parent_or_self = must_make_path(h->mountpoint, h->container_base_path, leaf, NULL);
if (slash)
*slash = '/';
fret = 1;
- ret = mkdir(cgpath, 0755);
+ ret = mkdir(parent_or_self, 0755);
if (ret < 0) {
if (errno != EEXIST)
- return log_error_errno(-1, errno, "Failed to create directory \"%s\"", cgpath);
+ return log_error_errno(-1, errno, "Failed to create directory \"%s\"", parent_or_self);
fret = 0;
}
- cgroup_fd = lxc_open_dirfd(cgpath);
+ cgroup_fd = lxc_open_dirfd(parent_or_self);
if (cgroup_fd < 0)
return -1;
ret = lxc_readat(cgroup_fd, "cgroup.clone_children", &v, 1);
if (ret < 0)
- return log_error_errno(-1, errno, "Failed to read file \"%s/cgroup.clone_children\"", cgpath);
+ return log_error_errno(-1, errno, "Failed to read file \"%s/cgroup.clone_children\"", parent_or_self);
/* Make sure any isolated cpus are removed from cpuset.cpus. */
- if (!cg_legacy_filter_and_set_cpus(cgpath, v == '1'))
+ if (!cg_legacy_filter_and_set_cpus(parent_or_self, v == '1'))
return log_error_errno(-1, errno, "Failed to remove isolated cpus");
/* Already set for us by someone else. */
@@ -612,13 +620,13 @@ static int cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h, char *cgname)
TRACE("\"cgroup.clone_children\" was already set to \"1\"");
/* copy parent's settings */
- if (!copy_parent_file(cgpath, "cpuset.mems"))
+ if (!copy_parent_file(parent_or_self, "cpuset.mems"))
return log_error_errno(-1, errno, "Failed to copy \"cpuset.mems\" settings");
/* Set clone_children so children inherit our settings */
ret = lxc_writeat(cgroup_fd, "cgroup.clone_children", "1", 1);
if (ret < 0)
- return log_error_errno(-1, errno, "Failed to write 1 to \"%s/cgroup.clone_children\"", cgpath);
+ return log_error_errno(-1, errno, "Failed to write 1 to \"%s/cgroup.clone_children\"", parent_or_self);
return fret;
}
@@ -1228,7 +1236,7 @@ static int mkdir_eexist_on_last(const char *dir, mode_t mode)
}
static bool create_cgroup_tree(struct hierarchy *h, const char *cgroup_tree,
- char *cgroup_leaf, bool payload)
+ const char *cgroup_leaf, bool payload)
{
__do_free char *path = NULL;
int ret, ret_cpuset;
From 55b560980d3771aa7c99282e98f7508fcf3c1169 Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner at ubuntu.com>
Date: Tue, 10 Dec 2019 18:15:30 +0100
Subject: [PATCH 2/2] cgroups/cgfsng: rework legacy cpuset handling
Signed-off-by: Christian Brauner <christian.brauner at ubuntu.com>
---
src/lxc/cgroups/cgfsng.c | 131 +++++++++++++++------------------------
1 file changed, 51 insertions(+), 80 deletions(-)
diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index fa00dbf44e..e7e3ec3995 100644
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -271,12 +271,12 @@ static uint32_t *lxc_cpumask(char *buf, size_t nbits)
{
char *token;
size_t arrlen;
- uint32_t *bitarr;
+ __do_free uint32_t *bitarr = NULL;
arrlen = BITS_TO_LONGS(nbits);
bitarr = calloc(arrlen, sizeof(uint32_t));
if (!bitarr)
- return NULL;
+ return ret_set_errno(NULL, ENOMEM);
lxc_iterate_parts(token, buf, ",") {
errno = 0;
@@ -289,21 +289,17 @@ static uint32_t *lxc_cpumask(char *buf, size_t nbits)
if (range)
end = strtoul(range + 1, NULL, 0);
- if (!(start <= end)) {
- free(bitarr);
- return NULL;
- }
+ if (!(start <= end))
+ return ret_set_errno(NULL, EINVAL);
- if (end >= nbits) {
- free(bitarr);
- return NULL;
- }
+ if (end >= nbits)
+ return ret_set_errno(NULL, EINVAL);
while (start <= end)
set_bit(start++, bitarr);
}
- return bitarr;
+ return move_ptr(bitarr);
}
/* Turn cpumask into simple, comma-separated cpulist. */
@@ -328,12 +324,12 @@ static char *lxc_cpumask_to_cpulist(uint32_t *bitarr, size_t nbits)
ret = lxc_append_string(&cpulist, numstr);
if (ret < 0) {
lxc_free_array((void **)cpulist, free);
- return NULL;
+ return ret_set_errno(NULL, ENOMEM);
}
}
if (!cpulist)
- return NULL;
+ return ret_set_errno(NULL, ENOMEM);
tmp = lxc_string_join(",", (const char **)cpulist, false);
lxc_free_array((void **)cpulist, free);
@@ -374,7 +370,8 @@ static ssize_t get_max_cpus(char *cpulist)
#define __ISOL_CPUS "/sys/devices/system/cpu/isolated"
#define __OFFLINE_CPUS "/sys/devices/system/cpu/offline"
-static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
+static bool cg_legacy_filter_and_set_cpus(const char *parent_cgroup,
+ char *child_cgroup, bool am_initialized)
{
__do_free char *cpulist = NULL, *fpath = NULL, *isolcpus = NULL,
*offlinecpus = NULL, *posscpus = NULL;
@@ -382,23 +379,14 @@ static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
*possmask = NULL;
int ret;
ssize_t i;
- char *lastslash;
ssize_t maxisol = 0, maxoffline = 0, maxposs = 0;
bool bret = false, flipped_bit = false;
- lastslash = strrchr(path, '/');
- if (!lastslash) {
- ERROR("Failed to detect \"/\" in \"%s\"", path);
- return bret;
- }
- *lastslash = '\0';
- fpath = must_make_path(path, "cpuset.cpus", NULL);
- *lastslash = '/';
+ SYSERROR("AAAA: %s | %s", parent_cgroup, child_cgroup);
+ fpath = must_make_path(parent_cgroup, "cpuset.cpus", NULL);
posscpus = read_file(fpath);
- if (!posscpus) {
- SYSERROR("Failed to read file \"%s\"", fpath);
- return false;
- }
+ if (!posscpus)
+ return log_error_errno(false, errno, "Failed to read file \"%s\"", fpath);
/* Get maximum number of cpus found in possible cpuset. */
maxposs = get_max_cpus(posscpus);
@@ -407,10 +395,8 @@ static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
if (file_exists(__ISOL_CPUS)) {
isolcpus = read_file(__ISOL_CPUS);
- if (!isolcpus) {
- SYSERROR("Failed to read file \"%s\"", __ISOL_CPUS);
- return false;
- }
+ if (!isolcpus)
+ return log_error_errno(false, errno, "Failed to read file \"%s\"", __ISOL_CPUS);
if (isdigit(isolcpus[0])) {
/* Get maximum number of cpus found in isolated cpuset. */
@@ -428,10 +414,8 @@ static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
if (file_exists(__OFFLINE_CPUS)) {
offlinecpus = read_file(__OFFLINE_CPUS);
- if (!offlinecpus) {
- SYSERROR("Failed to read file \"%s\"", __OFFLINE_CPUS);
- return false;
- }
+ if (!offlinecpus)
+ return log_error_errno(false, errno, "Failed to read file \"%s\"", __OFFLINE_CPUS);
if (isdigit(offlinecpus[0])) {
/* Get maximum number of cpus found in offline cpuset. */
@@ -453,25 +437,19 @@ static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
}
possmask = lxc_cpumask(posscpus, maxposs);
- if (!possmask) {
- ERROR("Failed to create cpumask for possible cpus");
- return false;
- }
+ if (!possmask)
+ return log_error_errno(false, errno, "Failed to create cpumask for possible cpus");
if (maxisol > 0) {
isolmask = lxc_cpumask(isolcpus, maxposs);
- if (!isolmask) {
- ERROR("Failed to create cpumask for isolated cpus");
- return false;
- }
+ if (!isolmask)
+ return log_error_errno(false, errno, "Failed to create cpumask for isolated cpus");
}
if (maxoffline > 0) {
offlinemask = lxc_cpumask(offlinecpus, maxposs);
- if (!offlinemask) {
- ERROR("Failed to create cpumask for offline cpus");
- return false;
- }
+ if (!offlinemask)
+ return log_error_errno(false, errno, "Failed to create cpumask for offline cpus");
}
for (i = 0; i <= maxposs; i++) {
@@ -491,18 +469,16 @@ static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
cpulist = move_ptr(posscpus);
TRACE("Removed isolated or offline cpus from cpuset");
}
- if (!cpulist) {
- ERROR("Failed to create cpu list");
- return false;
- }
+ if (!cpulist)
+ return log_error_errno(false, errno, "Failed to create cpu list");
copy_parent:
if (!am_initialized) {
- ret = lxc_write_openat(path, "cpuset.cpus", cpulist, strlen(cpulist));
+ ret = lxc_write_openat(child_cgroup, "cpuset.cpus", cpulist, strlen(cpulist));
if (ret < 0)
return log_error_errno(false,
errno, "Failed to write cpu list to \"%s/cpuset.cpus\"",
- path);
+ child_cgroup);
TRACE("Copied cpu settings of parent cgroup");
}
@@ -511,40 +487,32 @@ static bool cg_legacy_filter_and_set_cpus(char *path, bool am_initialized)
}
/* Copy contents of parent(@path)/@file to @path/@file */
-static bool copy_parent_file(char *path, char *file)
+static bool copy_parent_file(const char *parent_cgroup,
+ const char *child_cgroup, const char *file)
{
- __do_free char *parent_path = NULL, *value = NULL;
+ __do_free char *parent_file = NULL, *value = NULL;
int len = 0;
- char *lastslash = NULL;
int ret;
- lastslash = strrchr(path, '/');
- if (!lastslash)
- return log_error_errno(false, ENOENT,
- "Failed to detect \"/\" in \"%s\"", path);
-
- *lastslash = '\0';
- parent_path = must_make_path(path, file, NULL);
- *lastslash = '/';
-
- len = lxc_read_from_file(parent_path, NULL, 0);
+ parent_file = must_make_path(parent_cgroup, file, NULL);
+ len = lxc_read_from_file(parent_file, NULL, 0);
if (len <= 0)
return log_error_errno(false, errno,
"Failed to determine buffer size");
value = must_realloc(NULL, len + 1);
value[len] = '\0';
- ret = lxc_read_from_file(parent_path, value, len);
+ ret = lxc_read_from_file(parent_file, value, len);
if (ret != len)
return log_error_errno(false, errno,
"Failed to read from parent file \"%s\"",
- parent_path);
+ parent_file);
- ret = lxc_write_openat(path, file, value, len);
+ ret = lxc_write_openat(child_cgroup, file, value, len);
if (ret < 0 && errno != EACCES)
return log_error_errno(false,
errno, "Failed to write \"%s\" to file \"%s/%s\"",
- value, path, file);
+ value, child_cgroup, file);
return true;
}
@@ -565,9 +533,9 @@ static bool is_unified_hierarchy(const struct hierarchy *h)
static int cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h,
const char *cgroup_leaf)
{
- int fret = -1;
- __do_free char *parent_or_self = NULL, *dup = NULL;
+ __do_free char *parent_cgroup = NULL, *child_cgroup = NULL, *dup = NULL;
__do_close_prot_errno int cgroup_fd = -EBADF;
+ int fret = -1;
size_t len;
int ret;
char v;
@@ -586,33 +554,36 @@ static int cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h,
if (!dup)
return ret_set_errno(-1, ENOMEM);
+ parent_cgroup = must_make_path(h->mountpoint, h->container_base_path, NULL);
+
+ leaf = dup;
leaf += strspn(leaf, "/");
slash = strchr(leaf, '/');
if (slash)
*slash = '\0';
- parent_or_self = must_make_path(h->mountpoint, h->container_base_path, leaf, NULL);
+ child_cgroup = must_make_path(parent_cgroup, leaf, NULL);
if (slash)
*slash = '/';
fret = 1;
- ret = mkdir(parent_or_self, 0755);
+ ret = mkdir(child_cgroup, 0755);
if (ret < 0) {
if (errno != EEXIST)
- return log_error_errno(-1, errno, "Failed to create directory \"%s\"", parent_or_self);
+ return log_error_errno(-1, errno, "Failed to create directory \"%s\"", child_cgroup);
fret = 0;
}
- cgroup_fd = lxc_open_dirfd(parent_or_self);
+ cgroup_fd = lxc_open_dirfd(child_cgroup);
if (cgroup_fd < 0)
return -1;
ret = lxc_readat(cgroup_fd, "cgroup.clone_children", &v, 1);
if (ret < 0)
- return log_error_errno(-1, errno, "Failed to read file \"%s/cgroup.clone_children\"", parent_or_self);
+ return log_error_errno(-1, errno, "Failed to read file \"%s/cgroup.clone_children\"", child_cgroup);
/* Make sure any isolated cpus are removed from cpuset.cpus. */
- if (!cg_legacy_filter_and_set_cpus(parent_or_self, v == '1'))
+ if (!cg_legacy_filter_and_set_cpus(parent_cgroup, child_cgroup, v == '1'))
return log_error_errno(-1, errno, "Failed to remove isolated cpus");
/* Already set for us by someone else. */
@@ -620,13 +591,13 @@ static int cg_legacy_handle_cpuset_hierarchy(struct hierarchy *h,
TRACE("\"cgroup.clone_children\" was already set to \"1\"");
/* copy parent's settings */
- if (!copy_parent_file(parent_or_self, "cpuset.mems"))
+ if (!copy_parent_file(parent_cgroup, child_cgroup, "cpuset.mems"))
return log_error_errno(-1, errno, "Failed to copy \"cpuset.mems\" settings");
/* Set clone_children so children inherit our settings */
ret = lxc_writeat(cgroup_fd, "cgroup.clone_children", "1", 1);
if (ret < 0)
- return log_error_errno(-1, errno, "Failed to write 1 to \"%s/cgroup.clone_children\"", parent_or_self);
+ return log_error_errno(-1, errno, "Failed to write 1 to \"%s/cgroup.clone_children\"", child_cgroup);
return fret;
}
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