perf-eh_elf/util/comm.c
Linus Torvalds 16c00db4bb Merge tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS fixes from David Howells:
 "Here's a set of patches that fix a number of bugs in the in-kernel AFS
  client, including:

   - Fix directory locking to not use individual page locks for
     directory reading/scanning but rather to use a semaphore on the
     afs_vnode struct as the directory contents must be read in a single
     blob and data from different reads must not be mixed as the entire
     contents may be shuffled about between reads.

   - Fix address list parsing to handle port specifiers correctly.

   - Only give up callback records on a server if we actually talked to
     that server (we might not be able to access a server).

   - Fix some callback handling bugs, including refcounting,
     whole-volume callbacks and when callbacks actually get broken in
     response to a CB.CallBack op.

   - Fix some server/address rotation bugs, including giving up if we
     can't probe a server; giving up if a server says it doesn't have a
     volume, but there are more servers to try.

   - Fix the decoding of fetched statuses to be OpenAFS compatible.

   - Fix the handling of server lookups in Cache Manager ops (such as
     CB.InitCallBackState3) to use a UUID if possible and to handle no
     server being found.

   - Fix a bug in server lookup where not all addresses are compared.

   - Fix the non-encryption of calls that prevents some servers from
     being accessed (this also requires an AF_RXRPC patch that has
     already gone in through the net tree).

  There's also a patch that adds tracepoints to log Cache Manager ops
  that don't find a matching server, either by UUID or by address"

* tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Fix the non-encryption of calls
  afs: Fix CB.CallBack handling
  afs: Fix whole-volume callback handling
  afs: Fix afs_find_server search loop
  afs: Fix the handling of an unfound server in CM operations
  afs: Add a tracepoint to record callbacks from unlisted servers
  afs: Fix the handling of CB.InitCallBackState3 to find the server by UUID
  afs: Fix VNOVOL handling in address rotation
  afs: Fix AFSFetchStatus decoder to provide OpenAFS compatibility
  afs: Fix server rotation's handling of fileserver probe failure
  afs: Fix refcounting in callback registration
  afs: Fix giving up callbacks on server destruction
  afs: Fix address list parsing
  afs: Fix directory page locking
2018-05-15 10:48:36 -07:00

146 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "comm.h"
#include "util.h"
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <linux/refcount.h>
#include "rwsem.h"
struct comm_str {
char *str;
struct rb_node rb_node;
refcount_t refcnt;
};
/* Should perhaps be moved to struct machine */
static struct rb_root comm_str_root;
static struct rw_semaphore comm_str_lock = {.lock = PTHREAD_RWLOCK_INITIALIZER,};
static struct comm_str *comm_str__get(struct comm_str *cs)
{
if (cs)
refcount_inc(&cs->refcnt);
return cs;
}
static void comm_str__put(struct comm_str *cs)
{
if (cs && refcount_dec_and_test(&cs->refcnt)) {
down_write(&comm_str_lock);
rb_erase(&cs->rb_node, &comm_str_root);
up_write(&comm_str_lock);
zfree(&cs->str);
free(cs);
}
}
static struct comm_str *comm_str__alloc(const char *str)
{
struct comm_str *cs;
cs = zalloc(sizeof(*cs));
if (!cs)
return NULL;
cs->str = strdup(str);
if (!cs->str) {
free(cs);
return NULL;
}
refcount_set(&cs->refcnt, 1);
return cs;
}
static
struct comm_str *__comm_str__findnew(const char *str, struct rb_root *root)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct comm_str *iter, *new;
int cmp;
while (*p != NULL) {
parent = *p;
iter = rb_entry(parent, struct comm_str, rb_node);
cmp = strcmp(str, iter->str);
if (!cmp)
return comm_str__get(iter);
if (cmp < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
new = comm_str__alloc(str);
if (!new)
return NULL;
rb_link_node(&new->rb_node, parent, p);
rb_insert_color(&new->rb_node, root);
return new;
}
static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root)
{
struct comm_str *cs;
down_write(&comm_str_lock);
cs = __comm_str__findnew(str, root);
up_write(&comm_str_lock);
return cs;
}
struct comm *comm__new(const char *str, u64 timestamp, bool exec)
{
struct comm *comm = zalloc(sizeof(*comm));
if (!comm)
return NULL;
comm->start = timestamp;
comm->exec = exec;
comm->comm_str = comm_str__findnew(str, &comm_str_root);
if (!comm->comm_str) {
free(comm);
return NULL;
}
return comm;
}
int comm__override(struct comm *comm, const char *str, u64 timestamp, bool exec)
{
struct comm_str *new, *old = comm->comm_str;
new = comm_str__findnew(str, &comm_str_root);
if (!new)
return -ENOMEM;
comm_str__put(old);
comm->comm_str = new;
comm->start = timestamp;
if (exec)
comm->exec = true;
return 0;
}
void comm__free(struct comm *comm)
{
comm_str__put(comm->comm_str);
free(comm);
}
const char *comm__str(const struct comm *comm)
{
return comm->comm_str->str;
}