Commit 3579650e authored by Ramon Nou's avatar Ramon Nou
Browse files

fix(client): revalidate dentry cache misses against metadata servers

parent 9a87740e

include/client/gkfs_libc.hpp

+4 −4
Changes for include/client/gkfs_libc.hpp: 4 added lines, 4 removed lines.
Original line number Diff line number Diff line
@@ -356,14 +356,14 @@ flistxattr(int fd, char* list, size_t size); 
int

posix_spawn(pid_t* __restrict pid, const char* __restrict path,

            const posix_spawn_file_actions_t* __restrict file_actions,

            const posix_spawnattr_t* __restrict attrp,

            char* const argv[], char* const envp[]);

            const posix_spawnattr_t* __restrict attrp, char* const argv[],

            char* const envp[]);



int

posix_spawnp(pid_t* __restrict pid, const char* __restrict file,

             const posix_spawn_file_actions_t* __restrict file_actions,

             const posix_spawnattr_t* __restrict attrp,

             char* const argv[], char* const envp[]);

             const posix_spawnattr_t* __restrict attrp, char* const argv[],

             char* const envp[]);



//========================= C++ ABI Interceptions

//==============================//

src/client/gkfs_libc.cpp

+2 −1
Changes for src/client/gkfs_libc.cpp: 2 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -2463,7 +2463,8 @@ chdir(const char* path) throw() { 
    if(path != nullptr && CTX && !CTX->mountdir().empty()) {

        std::string p(path);

        if(p.rfind(CTX->mountdir(), 0) == 0 && !GKFS_INTERCEPTION_ENABLED()) {

            long cres = syscall_no_intercept(SYS_chdir, CTX->mountdir().c_str());

            long cres =

                    syscall_no_intercept(SYS_chdir, CTX->mountdir().c_str());

            if(cres < 0) {

                syscall_no_intercept(SYS_chdir, "/");

            }

src/client/intercept.cpp

+3 −2
Changes for src/client/intercept.cpp: 3 added lines, 2 removed lines.
Original line number Diff line number Diff line
@@ -1553,8 +1553,9 @@ void 
stop_interception() {

    LOG(DEBUG, "Disabling syscall interception for client process");



    // Reset callback function pointer to passthrough so that subsequent syscalls

    // (during exit/shutdown/atexit) are forwarded to kernel instead of triggering SIGTRAP.

    // Reset callback function pointer to passthrough so that subsequent

    // syscalls (during exit/shutdown/atexit) are forwarded to kernel instead of

    // triggering SIGTRAP.

    intercept_hook_point = passthrough_hook_wrapper;

    intercept_hook_point_post_kernel = nullptr;

    intercept_hook_point_clone_child = nullptr;

src/client/preload_util.cpp

+5 −6
Changes for src/client/preload_util.cpp: 5 added lines, 6 removed lines.
Original line number Diff line number Diff line
@@ -327,12 +327,11 @@ get_metadata(const string& path, bool follow_links, bool include_inline) { 
            md.size(cache_entry->size);

            return md;

        }

        if(CTX->dentry_cache()->has_dir(parent)) {

            LOG(DEBUG, "{}(): Negative dentry cache hit for file '{}'", __func__,

                path);

            errno = ENOENT;

            return {};

        }

        // A directory listing is not an authoritative negative lookup:

        // another client can create entries, and the cached directory may

        // contain only a subset of a paginated listing. In particular, '/'

        // has itself as parent but is not an entry in its own listing.

        // Always ask the metadata server on a cache miss.

    }

    if(gkfs::config::proxy::fwd_stat && CTX->use_proxy()) {

        err = gkfs::rpc::forward_stat_proxy(path, attr);

tests/integration/operations/test_client_cache.py

+28 −0
Changes for tests/integration/operations/test_client_cache.py: 28 added lines, 0 removed lines.
Original line number Diff line number Diff line 
import pytest

import os

import sys



from harness.gkfs import Client as GKFSClient





def test_dentry_cache_misses_revalidate(gkfs_daemon, gkfs_shell):

    """Cached listings must not hide the root or another client's creates."""

    code = f"""

import os

import subprocess

import sys

root = {str(gkfs_daemon.mountdir)!r}

assert os.listdir(root) == []

os.mkdir(root + '/seed')

assert 'seed' in os.listdir(root)

# Root is not an entry in its own cached listing.

assert os.stat(root).st_mode

assert 'seed' in os.listdir(root)

path = root + '/created-by-peer'

subprocess.run([sys.executable, '-c',

                'import os; os.mkdir(' + repr(path) + ')'], check=True)

assert os.stat(path).st_mode

os.rmdir(path)

os.rmdir(root + '/seed')

"""

    result = gkfs_shell.run(

        sys.executable, "-c", code,

        env={"LIBGKFS_DENTRY_CACHE": "ON",

             "LIBGKFS_DENTRY_CACHE_CLEAR_ON_CLOSE": "OFF"})

    assert result.exit_code == 0, result.stderr.decode()





@pytest.fixture

def gkfs_client_cache(test_workspace, gkfs_daemon, monkeypatch):

    """

src/client/path.cpp

+2 −2

File changed.

Contains only whitespace changes.

include/client/logging.hpp

+2 −2

File changed.

Contains only whitespace changes.