linux/fs/ceph/debugfs.c
Alex Markuze 15f519e9f8 ceph: fix race condition validating r_parent before applying state
Add validation to ensure the cached parent directory inode matches the
directory info in MDS replies. This prevents client-side race conditions
where concurrent operations (e.g. rename) cause r_parent to become stale
between request initiation and reply processing, which could lead to
applying state changes to incorrect directory inodes.

[ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to
  move CEPH_CAP_PIN reference when r_parent is updated:

  When the parent directory lock is not held, req->r_parent can become
  stale and is updated to point to the correct inode.  However, the
  associated CEPH_CAP_PIN reference was not being adjusted.  The
  CEPH_CAP_PIN is a reference on an inode that is tracked for
  accounting purposes.  Moving this pin is important to keep the
  accounting balanced. When the pin was not moved from the old parent
  to the new one, it created two problems: The reference on the old,
  stale parent was never released, causing a reference leak.
  A reference for the new parent was never acquired, creating the risk
  of a reference underflow later in ceph_mdsc_release_request().  This
  patch corrects the logic by releasing the pin from the old parent and
  acquiring it for the new parent when r_parent is switched.  This
  ensures reference accounting stays balanced. ]

Cc: stable@vger.kernel.org
Signed-off-by: Alex Markuze <amarkuze@redhat.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2025-09-09 12:57:02 +02:00

485 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/math64.h>
#include <linux/ktime.h>
#include <linux/ceph/libceph.h>
#include <linux/ceph/mon_client.h>
#include <linux/ceph/auth.h>
#include <linux/ceph/debugfs.h>
#include "super.h"
#ifdef CONFIG_DEBUG_FS
#include "mds_client.h"
#include "metric.h"
static int mdsmap_show(struct seq_file *s, void *p)
{
int i;
struct ceph_fs_client *fsc = s->private;
struct ceph_mdsmap *mdsmap;
if (!fsc->mdsc || !fsc->mdsc->mdsmap)
return 0;
mdsmap = fsc->mdsc->mdsmap;
seq_printf(s, "epoch %d\n", mdsmap->m_epoch);
seq_printf(s, "root %d\n", mdsmap->m_root);
seq_printf(s, "max_mds %d\n", mdsmap->m_max_mds);
seq_printf(s, "session_timeout %d\n", mdsmap->m_session_timeout);
seq_printf(s, "session_autoclose %d\n", mdsmap->m_session_autoclose);
for (i = 0; i < mdsmap->possible_max_rank; i++) {
struct ceph_entity_addr *addr = &mdsmap->m_info[i].addr;
int state = mdsmap->m_info[i].state;
seq_printf(s, "\tmds%d\t%s\t(%s)\n", i,
ceph_pr_addr(addr),
ceph_mds_state_name(state));
}
return 0;
}
/*
* mdsc debugfs
*/
static int mdsc_show(struct seq_file *s, void *p)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct rb_node *rp;
char *path;
mutex_lock(&mdsc->mutex);
for (rp = rb_first(&mdsc->request_tree); rp; rp = rb_next(rp)) {
req = rb_entry(rp, struct ceph_mds_request, r_node);
if (req->r_request && req->r_session)
seq_printf(s, "%lld\tmds%d\t", req->r_tid,
req->r_session->s_mds);
else if (!req->r_request)
seq_printf(s, "%lld\t(no request)\t", req->r_tid);
else
seq_printf(s, "%lld\t(no session)\t", req->r_tid);
seq_printf(s, "%s", ceph_mds_op_name(req->r_op));
if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
seq_puts(s, "\t(unsafe)");
else
seq_puts(s, "\t");
if (req->r_inode) {
seq_printf(s, " #%llx", ceph_ino(req->r_inode));
} else if (req->r_dentry) {
struct ceph_path_info path_info;
path = ceph_mdsc_build_path(mdsc, req->r_dentry, &path_info, 0);
if (IS_ERR(path))
path = NULL;
spin_lock(&req->r_dentry->d_lock);
seq_printf(s, " #%llx/%pd (%s)",
ceph_ino(d_inode(req->r_dentry->d_parent)),
req->r_dentry,
path ? path : "");
spin_unlock(&req->r_dentry->d_lock);
ceph_mdsc_free_path_info(&path_info);
} else if (req->r_path1) {
seq_printf(s, " #%llx/%s", req->r_ino1.ino,
req->r_path1);
} else {
seq_printf(s, " #%llx", req->r_ino1.ino);
}
if (req->r_old_dentry) {
struct ceph_path_info path_info;
path = ceph_mdsc_build_path(mdsc, req->r_old_dentry, &path_info, 0);
if (IS_ERR(path))
path = NULL;
spin_lock(&req->r_old_dentry->d_lock);
seq_printf(s, " #%llx/%pd (%s)",
req->r_old_dentry_dir ?
ceph_ino(req->r_old_dentry_dir) : 0,
req->r_old_dentry,
path ? path : "");
spin_unlock(&req->r_old_dentry->d_lock);
ceph_mdsc_free_path_info(&path_info);
} else if (req->r_path2 && req->r_op != CEPH_MDS_OP_SYMLINK) {
if (req->r_ino2.ino)
seq_printf(s, " #%llx/%s", req->r_ino2.ino,
req->r_path2);
else
seq_printf(s, " %s", req->r_path2);
}
seq_puts(s, "\n");
}
mutex_unlock(&mdsc->mutex);
return 0;
}
#define CEPH_LAT_METRIC_SHOW(name, total, avg, min, max, sq) { \
s64 _total, _avg, _min, _max, _sq, _st; \
_avg = ktime_to_us(avg); \
_min = ktime_to_us(min == KTIME_MAX ? 0 : min); \
_max = ktime_to_us(max); \
_total = total - 1; \
_sq = _total > 0 ? DIV64_U64_ROUND_CLOSEST(sq, _total) : 0; \
_st = int_sqrt64(_sq); \
_st = ktime_to_us(_st); \
seq_printf(s, "%-14s%-12lld%-16lld%-16lld%-16lld%lld\n", \
name, total, _avg, _min, _max, _st); \
}
#define CEPH_SZ_METRIC_SHOW(name, total, avg, min, max, sum) { \
u64 _min = min == U64_MAX ? 0 : min; \
seq_printf(s, "%-14s%-12lld%-16llu%-16llu%-16llu%llu\n", \
name, total, avg, _min, max, sum); \
}
static int metrics_file_show(struct seq_file *s, void *p)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_client_metric *m = &fsc->mdsc->metric;
seq_printf(s, "item total\n");
seq_printf(s, "------------------------------------------\n");
seq_printf(s, "%-35s%lld\n", "total inodes",
percpu_counter_sum(&m->total_inodes));
seq_printf(s, "%-35s%lld\n", "opened files",
atomic64_read(&m->opened_files));
seq_printf(s, "%-35s%lld\n", "pinned i_caps",
atomic64_read(&m->total_caps));
seq_printf(s, "%-35s%lld\n", "opened inodes",
percpu_counter_sum(&m->opened_inodes));
return 0;
}
static const char * const metric_str[] = {
"read",
"write",
"metadata",
"copyfrom"
};
static int metrics_latency_show(struct seq_file *s, void *p)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_client_metric *cm = &fsc->mdsc->metric;
struct ceph_metric *m;
s64 total, avg, min, max, sq;
int i;
seq_printf(s, "item total avg_lat(us) min_lat(us) max_lat(us) stdev(us)\n");
seq_printf(s, "-----------------------------------------------------------------------------------\n");
for (i = 0; i < METRIC_MAX; i++) {
m = &cm->metric[i];
spin_lock(&m->lock);
total = m->total;
avg = m->latency_avg;
min = m->latency_min;
max = m->latency_max;
sq = m->latency_sq_sum;
spin_unlock(&m->lock);
CEPH_LAT_METRIC_SHOW(metric_str[i], total, avg, min, max, sq);
}
return 0;
}
static int metrics_size_show(struct seq_file *s, void *p)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_client_metric *cm = &fsc->mdsc->metric;
struct ceph_metric *m;
s64 total;
u64 sum, avg, min, max;
int i;
seq_printf(s, "item total avg_sz(bytes) min_sz(bytes) max_sz(bytes) total_sz(bytes)\n");
seq_printf(s, "----------------------------------------------------------------------------------------\n");
for (i = 0; i < METRIC_MAX; i++) {
/* skip 'metadata' as it doesn't use the size metric */
if (i == METRIC_METADATA)
continue;
m = &cm->metric[i];
spin_lock(&m->lock);
total = m->total;
sum = m->size_sum;
avg = total > 0 ? DIV64_U64_ROUND_CLOSEST(sum, total) : 0;
min = m->size_min;
max = m->size_max;
spin_unlock(&m->lock);
CEPH_SZ_METRIC_SHOW(metric_str[i], total, avg, min, max, sum);
}
return 0;
}
static int metrics_caps_show(struct seq_file *s, void *p)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_client_metric *m = &fsc->mdsc->metric;
int nr_caps = 0;
seq_printf(s, "item total miss hit\n");
seq_printf(s, "-------------------------------------------------\n");
seq_printf(s, "%-14s%-16lld%-16lld%lld\n", "d_lease",
atomic64_read(&m->total_dentries),
percpu_counter_sum(&m->d_lease_mis),
percpu_counter_sum(&m->d_lease_hit));
nr_caps = atomic64_read(&m->total_caps);
seq_printf(s, "%-14s%-16d%-16lld%lld\n", "caps", nr_caps,
percpu_counter_sum(&m->i_caps_mis),
percpu_counter_sum(&m->i_caps_hit));
return 0;
}
static int caps_show_cb(struct inode *inode, int mds, void *p)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct seq_file *s = p;
struct ceph_cap *cap;
spin_lock(&ci->i_ceph_lock);
cap = __get_cap_for_mds(ci, mds);
if (cap)
seq_printf(s, "0x%-17llx%-3d%-17s%-17s\n", ceph_ino(inode),
cap->session->s_mds,
ceph_cap_string(cap->issued),
ceph_cap_string(cap->implemented));
spin_unlock(&ci->i_ceph_lock);
return 0;
}
static int caps_show(struct seq_file *s, void *p)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_mds_client *mdsc = fsc->mdsc;
int total, avail, used, reserved, min, i;
struct cap_wait *cw;
ceph_reservation_status(fsc, &total, &avail, &used, &reserved, &min);
seq_printf(s, "total\t\t%d\n"
"avail\t\t%d\n"
"used\t\t%d\n"
"reserved\t%d\n"
"min\t\t%d\n\n",
total, avail, used, reserved, min);
seq_printf(s, "ino mds issued implemented\n");
seq_printf(s, "--------------------------------------------------\n");
mutex_lock(&mdsc->mutex);
for (i = 0; i < mdsc->max_sessions; i++) {
struct ceph_mds_session *session;
session = __ceph_lookup_mds_session(mdsc, i);
if (!session)
continue;
mutex_unlock(&mdsc->mutex);
mutex_lock(&session->s_mutex);
ceph_iterate_session_caps(session, caps_show_cb, s);
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
mutex_lock(&mdsc->mutex);
}
mutex_unlock(&mdsc->mutex);
seq_printf(s, "\n\nWaiters:\n--------\n");
seq_printf(s, "tgid ino need want\n");
seq_printf(s, "-----------------------------------------------------\n");
spin_lock(&mdsc->caps_list_lock);
list_for_each_entry(cw, &mdsc->cap_wait_list, list) {
seq_printf(s, "%-13d0x%-17llx%-17s%-17s\n", cw->tgid, cw->ino,
ceph_cap_string(cw->need),
ceph_cap_string(cw->want));
}
spin_unlock(&mdsc->caps_list_lock);
return 0;
}
static int mds_sessions_show(struct seq_file *s, void *ptr)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_auth_client *ac = fsc->client->monc.auth;
struct ceph_options *opt = fsc->client->options;
int mds;
mutex_lock(&mdsc->mutex);
/* The 'num' portion of an 'entity name' */
seq_printf(s, "global_id %llu\n", ac->global_id);
/* The -o name mount argument */
seq_printf(s, "name \"%s\"\n", opt->name ? opt->name : "");
/* The list of MDS session rank+state */
for (mds = 0; mds < mdsc->max_sessions; mds++) {
struct ceph_mds_session *session =
__ceph_lookup_mds_session(mdsc, mds);
if (!session) {
continue;
}
mutex_unlock(&mdsc->mutex);
seq_printf(s, "mds.%d %s\n",
session->s_mds,
ceph_session_state_name(session->s_state));
ceph_put_mds_session(session);
mutex_lock(&mdsc->mutex);
}
mutex_unlock(&mdsc->mutex);
return 0;
}
static int status_show(struct seq_file *s, void *p)
{
struct ceph_fs_client *fsc = s->private;
struct ceph_entity_inst *inst = &fsc->client->msgr.inst;
struct ceph_entity_addr *client_addr = ceph_client_addr(fsc->client);
seq_printf(s, "instance: %s.%lld %s/%u\n", ENTITY_NAME(inst->name),
ceph_pr_addr(client_addr), le32_to_cpu(client_addr->nonce));
seq_printf(s, "blocklisted: %s\n", str_true_false(fsc->blocklisted));
return 0;
}
DEFINE_SHOW_ATTRIBUTE(mdsmap);
DEFINE_SHOW_ATTRIBUTE(mdsc);
DEFINE_SHOW_ATTRIBUTE(caps);
DEFINE_SHOW_ATTRIBUTE(mds_sessions);
DEFINE_SHOW_ATTRIBUTE(status);
DEFINE_SHOW_ATTRIBUTE(metrics_file);
DEFINE_SHOW_ATTRIBUTE(metrics_latency);
DEFINE_SHOW_ATTRIBUTE(metrics_size);
DEFINE_SHOW_ATTRIBUTE(metrics_caps);
/*
* debugfs
*/
static int congestion_kb_set(void *data, u64 val)
{
struct ceph_fs_client *fsc = (struct ceph_fs_client *)data;
fsc->mount_options->congestion_kb = (int)val;
return 0;
}
static int congestion_kb_get(void *data, u64 *val)
{
struct ceph_fs_client *fsc = (struct ceph_fs_client *)data;
*val = (u64)fsc->mount_options->congestion_kb;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(congestion_kb_fops, congestion_kb_get,
congestion_kb_set, "%llu\n");
void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc)
{
doutc(fsc->client, "begin\n");
debugfs_remove(fsc->debugfs_bdi);
debugfs_remove(fsc->debugfs_congestion_kb);
debugfs_remove(fsc->debugfs_mdsmap);
debugfs_remove(fsc->debugfs_mds_sessions);
debugfs_remove(fsc->debugfs_caps);
debugfs_remove(fsc->debugfs_status);
debugfs_remove(fsc->debugfs_mdsc);
debugfs_remove_recursive(fsc->debugfs_metrics_dir);
doutc(fsc->client, "done\n");
}
void ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
{
char name[NAME_MAX];
doutc(fsc->client, "begin\n");
fsc->debugfs_congestion_kb =
debugfs_create_file("writeback_congestion_kb",
0600,
fsc->client->debugfs_dir,
fsc,
&congestion_kb_fops);
snprintf(name, sizeof(name), "../../bdi/%s",
bdi_dev_name(fsc->sb->s_bdi));
fsc->debugfs_bdi =
debugfs_create_symlink("bdi",
fsc->client->debugfs_dir,
name);
fsc->debugfs_mdsmap = debugfs_create_file("mdsmap",
0400,
fsc->client->debugfs_dir,
fsc,
&mdsmap_fops);
fsc->debugfs_mds_sessions = debugfs_create_file("mds_sessions",
0400,
fsc->client->debugfs_dir,
fsc,
&mds_sessions_fops);
fsc->debugfs_mdsc = debugfs_create_file("mdsc",
0400,
fsc->client->debugfs_dir,
fsc,
&mdsc_fops);
fsc->debugfs_caps = debugfs_create_file("caps",
0400,
fsc->client->debugfs_dir,
fsc,
&caps_fops);
fsc->debugfs_status = debugfs_create_file("status",
0400,
fsc->client->debugfs_dir,
fsc,
&status_fops);
fsc->debugfs_metrics_dir = debugfs_create_dir("metrics",
fsc->client->debugfs_dir);
debugfs_create_file("file", 0400, fsc->debugfs_metrics_dir, fsc,
&metrics_file_fops);
debugfs_create_file("latency", 0400, fsc->debugfs_metrics_dir, fsc,
&metrics_latency_fops);
debugfs_create_file("size", 0400, fsc->debugfs_metrics_dir, fsc,
&metrics_size_fops);
debugfs_create_file("caps", 0400, fsc->debugfs_metrics_dir, fsc,
&metrics_caps_fops);
doutc(fsc->client, "done\n");
}
#else /* CONFIG_DEBUG_FS */
void ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
{
}
void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc)
{
}
#endif /* CONFIG_DEBUG_FS */