[Devel] [PATCH RHEL7 COMMIT] ve/devmnt: Introduce ve::devmnt list
Konstantin Khorenko
khorenko at odin.com
Mon May 18 01:52:09 PDT 2015
The commit is pushed to "branch-rh7-3.10.0-123.1.2-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-123.1.2.vz7.5.1
------>
commit 16a628a25414e4cca83d7aa8574fbe22f3e8f500
Author: Kirill Tkhai <ktkhai at odin.com>
Date: Mon May 18 12:52:09 2015 +0400
ve/devmnt: Introduce ve::devmnt list
1)Porting patch "ve: mount option list" by Maxim Patlasov:
The patch adds new fields to ve_struct: devmnt_list and devmnt_mutex.
devmnt_list is the head of list of ve_devmnt structs. Each host block device
visible from CT can have no more than one struct ve_devmnt linked in
ve->devmnt_list. If ve_devmnt is present, it can be found by 'dev' field.
Each ve_devmnt struct may bear two strings: hidden and allowed options.
hidden_options will be automatically added to CT-user-supplied mount options
after checking allowed_options. Only options listed in allowed_options are
allowed.
devmnt_mutex is to protect operations on the list of ve_devmnt structs.
2)Porting patch "vecalls: VE_CONFIGURE_MOUNT_OPTIONS" by Maxim Patlasov.
Reworking the interface using cgroups. Each CT now has a file:
[ve_cgroup_mnt_pnt]/[CTID]/ve.mount_opts
for configuring permittions for a block device. Below is permittions line
example:
"0 major:minor;1 balloon_ino=12,pfcache_csum,pfcache=/vz/pfcache;2 barrier=1"
Here, major:minor is a device, '1' starts comma-separated list of
hidden options, and '2' is allowed ones.
https://jira.sw.ru/browse/PSBM-32273
Signed-off-by: Kirill Tkhai <ktkhai at odin.com>
Acked-by: Maxim Patlasov <mpatlasov at openvz.org>
---
include/linux/ve.h | 11 ++++
kernel/ve/ve.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 162 insertions(+)
diff --git a/include/linux/ve.h b/include/linux/ve.h
index 03e90e4..8b70dbe 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -123,12 +123,23 @@ struct ve_struct {
struct net *ve_netns;
struct mutex sync_mutex;
+ struct list_head devmnt_list;
+ struct mutex devmnt_mutex;
+
struct kmapset_key ve_sysfs_perms;
#if IS_ENABLED(CONFIG_DEVTMPFS)
struct path devtmpfs_root;
#endif
};
+struct ve_devmnt {
+ struct list_head link;
+
+ dev_t dev;
+ char *allowed_options;
+ char *hidden_options; /* balloon_ino, etc. */
+};
+
#define VE_MEMINFO_DEFAULT 1 /* default behaviour */
#define VE_MEMINFO_SYSTEM 0 /* disable meminfo virtualization */
diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
index 609ea75..6ab409f 100644
--- a/kernel/ve/ve.c
+++ b/kernel/ve/ve.c
@@ -40,6 +40,7 @@
#include <linux/task_work.h>
#include <linux/tty.h>
#include <linux/console.h>
+#include <linux/ctype.h>
#include <uapi/linux/vzcalluser.h>
#include <linux/venet.h>
@@ -710,6 +711,8 @@ do_init:
mutex_init(&ve->sync_mutex);
INIT_LIST_HEAD(&ve->devices);
INIT_LIST_HEAD(&ve->ve_list);
+ INIT_LIST_HEAD(&ve->devmnt_list);
+ mutex_init(&ve->devmnt_mutex);
kmapset_init_key(&ve->ve_sysfs_perms);
return &ve->css;
@@ -734,11 +737,33 @@ static void ve_offline(struct cgroup *cg)
veid_free(ve->veid);
}
+static void ve_devmnt_free(struct ve_devmnt *devmnt)
+{
+ if (!devmnt)
+ return;
+
+ kfree(devmnt->allowed_options);
+ kfree(devmnt->hidden_options);
+ kfree(devmnt);
+}
+
+static void free_ve_devmnts(struct ve_struct *ve)
+{
+ while (!list_empty(&ve->devmnt_list)) {
+ struct ve_devmnt *devmnt;
+
+ devmnt = list_first_entry(&ve->devmnt_list, struct ve_devmnt, link);
+ list_del(&devmnt->link);
+ ve_devmnt_free(devmnt);
+ }
+}
+
static void ve_destroy(struct cgroup *cg)
{
struct ve_struct *ve = cgroup_ve(cg);
kmapset_unlink(&ve->ve_sysfs_perms, &ve_sysfs_perms);
+ free_ve_devmnts(ve);
ve_log_destroy(ve);
kfree(ve->binfmt_misc);
@@ -886,6 +911,127 @@ static int ve_legacy_veid_read(struct cgroup *cg, struct cftype *cft,
return seq_printf(m, "%u\n", cgroup_ve(cg)->veid);
}
+/*
+ * 'data' for VE_CONFIGURE_MOUNT_OPTIONS is a zero-terminated string
+ * consisting of substrings separated by MNTOPT_DELIM.
+ */
+#define MNTOPT_DELIM ';'
+
+/*
+ * Each substring has the form of "<type> <comma-separated-list-of-options>"
+ * where types are:
+ */
+enum {
+ MNTOPT_DEVICE = 0,
+ MNTOPT_HIDDEN = 1,
+ MNTOPT_ALLOWED = 2,
+};
+
+/*
+ * 'ptr' points to the first character of buffer to parse
+ * 'endp' points to the last character of buffer to parse
+ */
+static int ve_parse_mount_options(const char *ptr, const char *endp,
+ struct ve_devmnt *devmnt)
+{
+ while (*ptr) {
+ const char *delim = strchr(ptr, MNTOPT_DELIM) ? : endp;
+ char *space = strchr(ptr, ' ');
+ int type;
+ char *options, c, s;
+ int options_size = delim - space;
+ char **opts_pp = NULL; /* where to store 'options' */
+
+ if (delim == ptr || !space || options_size <= 1 ||
+ !isdigit(*ptr) || space > delim)
+ return -EINVAL;
+
+ if (sscanf(ptr, "%d%c", &type, &c) != 2 || c != ' ')
+ return -EINVAL;
+
+ if (type == MNTOPT_DEVICE) {
+ unsigned major, minor;
+ if (devmnt->dev)
+ return -EINVAL; /* Already set */
+ if (sscanf(space + 1, "%u%c%u%c", &major, &c,
+ &minor, &s) != 4 ||
+ c != ':' || s != MNTOPT_DELIM)
+ return -EINVAL;
+ devmnt->dev = MKDEV(major, minor);
+ goto next;
+ }
+
+ options = kmalloc(options_size, GFP_KERNEL);
+ if (!options)
+ return -ENOMEM;
+
+ strncpy(options, space + 1, options_size - 1);
+ options[options_size - 1] = 0;
+
+ switch (type) {
+ case MNTOPT_ALLOWED:
+ opts_pp = &devmnt->allowed_options;
+ break;
+ case MNTOPT_HIDDEN:
+ opts_pp = &devmnt->hidden_options;
+ break;
+ };
+
+ /* wrong type or already set */
+ if (!opts_pp || *opts_pp) {
+ kfree(options);
+ return -EINVAL;
+ }
+
+ *opts_pp = options;
+next:
+ if (!*delim)
+ break;
+
+ ptr = delim + 1;
+ }
+
+ if (!devmnt->dev)
+ return -EINVAL;
+ return 0;
+}
+
+static int ve_mount_opts_write(struct cgroup *cg, struct cftype *cft,
+ const char *buffer)
+{
+ struct ve_struct *ve = cgroup_ve(cg);
+ struct ve_devmnt *devmnt, *old;
+ int size, err;
+
+ size = strlen(buffer);
+ if (size <= 1)
+ return -EINVAL;
+
+ devmnt = kzalloc(sizeof(*devmnt), GFP_KERNEL);
+ if (!devmnt)
+ return -ENOMEM;
+
+ err = ve_parse_mount_options(buffer, buffer + size, devmnt);
+ if (err) {
+ ve_devmnt_free(devmnt);
+ return err;
+ }
+
+ mutex_lock(&ve->devmnt_mutex);
+ list_for_each_entry(old, &ve->devmnt_list, link) {
+ /* Delete old devmnt */
+ if (old->dev == devmnt->dev) {
+ list_del(&old->link);
+ ve_devmnt_free(old);
+ break;
+ }
+ }
+ list_add(&devmnt->link, &ve->devmnt_list);
+ mutex_unlock(&ve->devmnt_mutex);
+
+ return 0;
+}
+
static struct cftype ve_cftypes[] = {
{
.name = "state",
@@ -898,6 +1044,11 @@ static struct cftype ve_cftypes[] = {
.flags = CFTYPE_NOT_ON_ROOT,
.read_seq_string = ve_legacy_veid_read,
},
+ {
+ .name = "mount_opts",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .write_string = ve_mount_opts_write,
+ },
{ }
};
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