16c00db4bb
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
104 lines
2 KiB
C
104 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <errno.h>
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#include <sched.h>
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#include "util.h"
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#include "../perf.h"
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#include "cloexec.h"
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#include "asm/bug.h"
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#include "debug.h"
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#include <unistd.h>
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#include <asm/unistd.h>
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#include <sys/syscall.h>
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static unsigned long flag = PERF_FLAG_FD_CLOEXEC;
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int __weak sched_getcpu(void)
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{
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#ifdef __NR_getcpu
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unsigned cpu;
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int err = syscall(__NR_getcpu, &cpu, NULL, NULL);
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if (!err)
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return cpu;
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#else
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errno = ENOSYS;
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#endif
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return -1;
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}
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static int perf_flag_probe(void)
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{
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/* use 'safest' configuration as used in perf_evsel__fallback() */
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struct perf_event_attr attr = {
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.type = PERF_TYPE_SOFTWARE,
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.config = PERF_COUNT_SW_CPU_CLOCK,
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.exclude_kernel = 1,
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};
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int fd;
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int err;
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int cpu;
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pid_t pid = -1;
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char sbuf[STRERR_BUFSIZE];
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cpu = sched_getcpu();
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if (cpu < 0)
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cpu = 0;
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/*
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* Using -1 for the pid is a workaround to avoid gratuitous jump label
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* changes.
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*/
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while (1) {
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/* check cloexec flag */
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fd = sys_perf_event_open(&attr, pid, cpu, -1,
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PERF_FLAG_FD_CLOEXEC);
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if (fd < 0 && pid == -1 && errno == EACCES) {
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pid = 0;
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continue;
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}
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break;
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}
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err = errno;
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if (fd >= 0) {
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close(fd);
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return 1;
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}
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WARN_ONCE(err != EINVAL && err != EBUSY,
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"perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n",
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err, str_error_r(err, sbuf, sizeof(sbuf)));
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/* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */
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while (1) {
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fd = sys_perf_event_open(&attr, pid, cpu, -1, 0);
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if (fd < 0 && pid == -1 && errno == EACCES) {
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pid = 0;
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continue;
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}
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break;
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}
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err = errno;
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if (fd >= 0)
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close(fd);
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if (WARN_ONCE(fd < 0 && err != EBUSY,
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"perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n",
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err, str_error_r(err, sbuf, sizeof(sbuf))))
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return -1;
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return 0;
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}
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unsigned long perf_event_open_cloexec_flag(void)
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{
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static bool probed;
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if (!probed) {
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if (perf_flag_probe() <= 0)
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flag = 0;
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probed = true;
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}
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return flag;
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}
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