Revision b1dd693e5b9348bd68a80e679e03cf9c0973b01b authored by Daisuke Nishimura on 24 November 2010, 20:57:06 UTC, committed by Linus Torvalds on 24 November 2010, 21:50:44 UTC
__mem_cgroup_try_charge() can be called under down_write(&mmap_sem)(e.g. mlock does it). This means it can cause deadlock if it races with move charge: Ex.1) move charge | try charge --------------------------------------+------------------------------ mem_cgroup_can_attach() | down_write(&mmap_sem) mc.moving_task = current | .. mem_cgroup_precharge_mc() | __mem_cgroup_try_charge() mem_cgroup_count_precharge() | prepare_to_wait() down_read(&mmap_sem) | if (mc.moving_task) -> cannot aquire the lock | -> true | schedule() Ex.2) move charge | try charge --------------------------------------+------------------------------ mem_cgroup_can_attach() | mc.moving_task = current | mem_cgroup_precharge_mc() | mem_cgroup_count_precharge() | down_read(&mmap_sem) | .. | up_read(&mmap_sem) | | down_write(&mmap_sem) mem_cgroup_move_task() | .. mem_cgroup_move_charge() | __mem_cgroup_try_charge() down_read(&mmap_sem) | prepare_to_wait() -> cannot aquire the lock | if (mc.moving_task) | -> true | schedule() To avoid this deadlock, we do all the move charge works (both can_attach() and attach()) under one mmap_sem section. And after this patch, we set/clear mc.moving_task outside mc.lock, because we use the lock only to check mc.from/to. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 11e7946
ceph_common.c
#include <linux/ceph/ceph_debug.h>
#include <linux/backing-dev.h>
#include <linux/ctype.h>
#include <linux/fs.h>
#include <linux/inet.h>
#include <linux/in6.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/parser.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/statfs.h>
#include <linux/string.h>
#include <linux/ceph/libceph.h>
#include <linux/ceph/debugfs.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/mon_client.h>
#include <linux/ceph/auth.h>
/*
* find filename portion of a path (/foo/bar/baz -> baz)
*/
const char *ceph_file_part(const char *s, int len)
{
const char *e = s + len;
while (e != s && *(e-1) != '/')
e--;
return e;
}
EXPORT_SYMBOL(ceph_file_part);
const char *ceph_msg_type_name(int type)
{
switch (type) {
case CEPH_MSG_SHUTDOWN: return "shutdown";
case CEPH_MSG_PING: return "ping";
case CEPH_MSG_AUTH: return "auth";
case CEPH_MSG_AUTH_REPLY: return "auth_reply";
case CEPH_MSG_MON_MAP: return "mon_map";
case CEPH_MSG_MON_GET_MAP: return "mon_get_map";
case CEPH_MSG_MON_SUBSCRIBE: return "mon_subscribe";
case CEPH_MSG_MON_SUBSCRIBE_ACK: return "mon_subscribe_ack";
case CEPH_MSG_STATFS: return "statfs";
case CEPH_MSG_STATFS_REPLY: return "statfs_reply";
case CEPH_MSG_MDS_MAP: return "mds_map";
case CEPH_MSG_CLIENT_SESSION: return "client_session";
case CEPH_MSG_CLIENT_RECONNECT: return "client_reconnect";
case CEPH_MSG_CLIENT_REQUEST: return "client_request";
case CEPH_MSG_CLIENT_REQUEST_FORWARD: return "client_request_forward";
case CEPH_MSG_CLIENT_REPLY: return "client_reply";
case CEPH_MSG_CLIENT_CAPS: return "client_caps";
case CEPH_MSG_CLIENT_CAPRELEASE: return "client_cap_release";
case CEPH_MSG_CLIENT_SNAP: return "client_snap";
case CEPH_MSG_CLIENT_LEASE: return "client_lease";
case CEPH_MSG_OSD_MAP: return "osd_map";
case CEPH_MSG_OSD_OP: return "osd_op";
case CEPH_MSG_OSD_OPREPLY: return "osd_opreply";
default: return "unknown";
}
}
EXPORT_SYMBOL(ceph_msg_type_name);
/*
* Initially learn our fsid, or verify an fsid matches.
*/
int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid)
{
if (client->have_fsid) {
if (ceph_fsid_compare(&client->fsid, fsid)) {
pr_err("bad fsid, had %pU got %pU",
&client->fsid, fsid);
return -1;
}
} else {
pr_info("client%lld fsid %pU\n", ceph_client_id(client), fsid);
memcpy(&client->fsid, fsid, sizeof(*fsid));
ceph_debugfs_client_init(client);
client->have_fsid = true;
}
return 0;
}
EXPORT_SYMBOL(ceph_check_fsid);
static int strcmp_null(const char *s1, const char *s2)
{
if (!s1 && !s2)
return 0;
if (s1 && !s2)
return -1;
if (!s1 && s2)
return 1;
return strcmp(s1, s2);
}
int ceph_compare_options(struct ceph_options *new_opt,
struct ceph_client *client)
{
struct ceph_options *opt1 = new_opt;
struct ceph_options *opt2 = client->options;
int ofs = offsetof(struct ceph_options, mon_addr);
int i;
int ret;
ret = memcmp(opt1, opt2, ofs);
if (ret)
return ret;
ret = strcmp_null(opt1->name, opt2->name);
if (ret)
return ret;
ret = strcmp_null(opt1->secret, opt2->secret);
if (ret)
return ret;
/* any matching mon ip implies a match */
for (i = 0; i < opt1->num_mon; i++) {
if (ceph_monmap_contains(client->monc.monmap,
&opt1->mon_addr[i]))
return 0;
}
return -1;
}
EXPORT_SYMBOL(ceph_compare_options);
static int parse_fsid(const char *str, struct ceph_fsid *fsid)
{
int i = 0;
char tmp[3];
int err = -EINVAL;
int d;
dout("parse_fsid '%s'\n", str);
tmp[2] = 0;
while (*str && i < 16) {
if (ispunct(*str)) {
str++;
continue;
}
if (!isxdigit(str[0]) || !isxdigit(str[1]))
break;
tmp[0] = str[0];
tmp[1] = str[1];
if (sscanf(tmp, "%x", &d) < 1)
break;
fsid->fsid[i] = d & 0xff;
i++;
str += 2;
}
if (i == 16)
err = 0;
dout("parse_fsid ret %d got fsid %pU", err, fsid);
return err;
}
/*
* ceph options
*/
enum {
Opt_osdtimeout,
Opt_osdkeepalivetimeout,
Opt_mount_timeout,
Opt_osd_idle_ttl,
Opt_last_int,
/* int args above */
Opt_fsid,
Opt_name,
Opt_secret,
Opt_ip,
Opt_last_string,
/* string args above */
Opt_noshare,
Opt_nocrc,
};
static match_table_t opt_tokens = {
{Opt_osdtimeout, "osdtimeout=%d"},
{Opt_osdkeepalivetimeout, "osdkeepalive=%d"},
{Opt_mount_timeout, "mount_timeout=%d"},
{Opt_osd_idle_ttl, "osd_idle_ttl=%d"},
/* int args above */
{Opt_fsid, "fsid=%s"},
{Opt_name, "name=%s"},
{Opt_secret, "secret=%s"},
{Opt_ip, "ip=%s"},
/* string args above */
{Opt_noshare, "noshare"},
{Opt_nocrc, "nocrc"},
{-1, NULL}
};
void ceph_destroy_options(struct ceph_options *opt)
{
dout("destroy_options %p\n", opt);
kfree(opt->name);
kfree(opt->secret);
kfree(opt);
}
EXPORT_SYMBOL(ceph_destroy_options);
int ceph_parse_options(struct ceph_options **popt, char *options,
const char *dev_name, const char *dev_name_end,
int (*parse_extra_token)(char *c, void *private),
void *private)
{
struct ceph_options *opt;
const char *c;
int err = -ENOMEM;
substring_t argstr[MAX_OPT_ARGS];
opt = kzalloc(sizeof(*opt), GFP_KERNEL);
if (!opt)
return err;
opt->mon_addr = kcalloc(CEPH_MAX_MON, sizeof(*opt->mon_addr),
GFP_KERNEL);
if (!opt->mon_addr)
goto out;
dout("parse_options %p options '%s' dev_name '%s'\n", opt, options,
dev_name);
/* start with defaults */
opt->flags = CEPH_OPT_DEFAULT;
opt->osd_timeout = CEPH_OSD_TIMEOUT_DEFAULT;
opt->osd_keepalive_timeout = CEPH_OSD_KEEPALIVE_DEFAULT;
opt->mount_timeout = CEPH_MOUNT_TIMEOUT_DEFAULT; /* seconds */
opt->osd_idle_ttl = CEPH_OSD_IDLE_TTL_DEFAULT; /* seconds */
/* get mon ip(s) */
/* ip1[:port1][,ip2[:port2]...] */
err = ceph_parse_ips(dev_name, dev_name_end, opt->mon_addr,
CEPH_MAX_MON, &opt->num_mon);
if (err < 0)
goto out;
/* parse mount options */
while ((c = strsep(&options, ",")) != NULL) {
int token, intval, ret;
if (!*c)
continue;
err = -EINVAL;
token = match_token((char *)c, opt_tokens, argstr);
if (token < 0 && parse_extra_token) {
/* extra? */
err = parse_extra_token((char *)c, private);
if (err < 0) {
pr_err("bad option at '%s'\n", c);
goto out;
}
continue;
}
if (token < Opt_last_int) {
ret = match_int(&argstr[0], &intval);
if (ret < 0) {
pr_err("bad mount option arg (not int) "
"at '%s'\n", c);
continue;
}
dout("got int token %d val %d\n", token, intval);
} else if (token > Opt_last_int && token < Opt_last_string) {
dout("got string token %d val %s\n", token,
argstr[0].from);
} else {
dout("got token %d\n", token);
}
switch (token) {
case Opt_ip:
err = ceph_parse_ips(argstr[0].from,
argstr[0].to,
&opt->my_addr,
1, NULL);
if (err < 0)
goto out;
opt->flags |= CEPH_OPT_MYIP;
break;
case Opt_fsid:
err = parse_fsid(argstr[0].from, &opt->fsid);
if (err == 0)
opt->flags |= CEPH_OPT_FSID;
break;
case Opt_name:
opt->name = kstrndup(argstr[0].from,
argstr[0].to-argstr[0].from,
GFP_KERNEL);
break;
case Opt_secret:
opt->secret = kstrndup(argstr[0].from,
argstr[0].to-argstr[0].from,
GFP_KERNEL);
break;
/* misc */
case Opt_osdtimeout:
opt->osd_timeout = intval;
break;
case Opt_osdkeepalivetimeout:
opt->osd_keepalive_timeout = intval;
break;
case Opt_osd_idle_ttl:
opt->osd_idle_ttl = intval;
break;
case Opt_mount_timeout:
opt->mount_timeout = intval;
break;
case Opt_noshare:
opt->flags |= CEPH_OPT_NOSHARE;
break;
case Opt_nocrc:
opt->flags |= CEPH_OPT_NOCRC;
break;
default:
BUG_ON(token);
}
}
/* success */
*popt = opt;
return 0;
out:
ceph_destroy_options(opt);
return err;
}
EXPORT_SYMBOL(ceph_parse_options);
u64 ceph_client_id(struct ceph_client *client)
{
return client->monc.auth->global_id;
}
EXPORT_SYMBOL(ceph_client_id);
/*
* create a fresh client instance
*/
struct ceph_client *ceph_create_client(struct ceph_options *opt, void *private)
{
struct ceph_client *client;
int err = -ENOMEM;
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (client == NULL)
return ERR_PTR(-ENOMEM);
client->private = private;
client->options = opt;
mutex_init(&client->mount_mutex);
init_waitqueue_head(&client->auth_wq);
client->auth_err = 0;
client->extra_mon_dispatch = NULL;
client->supported_features = CEPH_FEATURE_SUPPORTED_DEFAULT;
client->required_features = CEPH_FEATURE_REQUIRED_DEFAULT;
client->msgr = NULL;
/* subsystems */
err = ceph_monc_init(&client->monc, client);
if (err < 0)
goto fail;
err = ceph_osdc_init(&client->osdc, client);
if (err < 0)
goto fail_monc;
return client;
fail_monc:
ceph_monc_stop(&client->monc);
fail:
kfree(client);
return ERR_PTR(err);
}
EXPORT_SYMBOL(ceph_create_client);
void ceph_destroy_client(struct ceph_client *client)
{
dout("destroy_client %p\n", client);
/* unmount */
ceph_osdc_stop(&client->osdc);
/*
* make sure mds and osd connections close out before destroying
* the auth module, which is needed to free those connections'
* ceph_authorizers.
*/
ceph_msgr_flush();
ceph_monc_stop(&client->monc);
ceph_debugfs_client_cleanup(client);
if (client->msgr)
ceph_messenger_destroy(client->msgr);
ceph_destroy_options(client->options);
kfree(client);
dout("destroy_client %p done\n", client);
}
EXPORT_SYMBOL(ceph_destroy_client);
/*
* true if we have the mon map (and have thus joined the cluster)
*/
static int have_mon_and_osd_map(struct ceph_client *client)
{
return client->monc.monmap && client->monc.monmap->epoch &&
client->osdc.osdmap && client->osdc.osdmap->epoch;
}
/*
* mount: join the ceph cluster, and open root directory.
*/
int __ceph_open_session(struct ceph_client *client, unsigned long started)
{
struct ceph_entity_addr *myaddr = NULL;
int err;
unsigned long timeout = client->options->mount_timeout * HZ;
/* initialize the messenger */
if (client->msgr == NULL) {
if (ceph_test_opt(client, MYIP))
myaddr = &client->options->my_addr;
client->msgr = ceph_messenger_create(myaddr,
client->supported_features,
client->required_features);
if (IS_ERR(client->msgr)) {
client->msgr = NULL;
return PTR_ERR(client->msgr);
}
client->msgr->nocrc = ceph_test_opt(client, NOCRC);
}
/* open session, and wait for mon and osd maps */
err = ceph_monc_open_session(&client->monc);
if (err < 0)
return err;
while (!have_mon_and_osd_map(client)) {
err = -EIO;
if (timeout && time_after_eq(jiffies, started + timeout))
return err;
/* wait */
dout("mount waiting for mon_map\n");
err = wait_event_interruptible_timeout(client->auth_wq,
have_mon_and_osd_map(client) || (client->auth_err < 0),
timeout);
if (err == -EINTR || err == -ERESTARTSYS)
return err;
if (client->auth_err < 0)
return client->auth_err;
}
return 0;
}
EXPORT_SYMBOL(__ceph_open_session);
int ceph_open_session(struct ceph_client *client)
{
int ret;
unsigned long started = jiffies; /* note the start time */
dout("open_session start\n");
mutex_lock(&client->mount_mutex);
ret = __ceph_open_session(client, started);
mutex_unlock(&client->mount_mutex);
return ret;
}
EXPORT_SYMBOL(ceph_open_session);
static int __init init_ceph_lib(void)
{
int ret = 0;
ret = ceph_debugfs_init();
if (ret < 0)
goto out;
ret = ceph_msgr_init();
if (ret < 0)
goto out_debugfs;
pr_info("loaded (mon/osd proto %d/%d, osdmap %d/%d %d/%d)\n",
CEPH_MONC_PROTOCOL, CEPH_OSDC_PROTOCOL,
CEPH_OSDMAP_VERSION, CEPH_OSDMAP_VERSION_EXT,
CEPH_OSDMAP_INC_VERSION, CEPH_OSDMAP_INC_VERSION_EXT);
return 0;
out_debugfs:
ceph_debugfs_cleanup();
out:
return ret;
}
static void __exit exit_ceph_lib(void)
{
dout("exit_ceph_lib\n");
ceph_msgr_exit();
ceph_debugfs_cleanup();
}
module_init(init_ceph_lib);
module_exit(exit_ceph_lib);
MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
MODULE_DESCRIPTION("Ceph filesystem for Linux");
MODULE_LICENSE("GPL");
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