@@ -62,6 +62,7 @@ libsupport-routines = \
support_format_herrno \
support_format_hostent \
support_format_netent \
+ support_fuse \
support_isolate_in_subprocess \
support_mutex_pi_monotonic \
support_need_proc \
new file mode 100644
@@ -0,0 +1,169 @@
+/* Facilities for FUSE-backed file system tests.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* Before using this functionality, use support_enter_mount_namespace
+ to ensure that mounts do not impact the overall system. */
+
+#ifndef SUPPORT_FUSE_H
+#define SUPPORT_FUSE_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/* Defined in <linux/fuse.h>. */
+struct fuse_attr_out;
+struct fuse_entry_out;
+struct fuse_in_header;
+struct fuse_open_out;
+
+/* Opaque type for tracking FUSE mount state. */
+struct support_fuse;
+
+/* This function disables a mount point created using
+ support_fuse_mount. */
+void support_fuse_unmount (struct support_fuse *) __nonnull ((1));
+
+/* This function is called on a separate thread after calling
+ support_fuse_mount. F is the mount state, and CLOSURE the argument
+ that was passed to support_fuse_mount. The callback function is
+ expected to call support_fuse_read to read packets from the kernel
+ and handle them according to the test's need. */
+typedef void (*support_fuse_callback) (struct support_fuse *f, void *closure);
+
+/* This function creates a new mount point, implemented by CALLBACK.
+ CLOSURE is passed to CALLBACK as the second argument. */
+struct support_fuse *support_fuse_mount (support_fuse_callback callback,
+ void *closure)
+ __nonnull ((1)) __attr_dealloc (support_fuse_unmount, 1);
+
+/* This function returns the path to the mount point for F. The
+ returned string is valid until support_fuse_unmount (F) is called. */
+const char * support_fuse_mountpoint (struct support_fuse *f) __nonnull ((1));
+
+
+/* Renders the OPCODE as a string (FUSE_* constant. The caller must
+ free the returned string. */
+char * support_fuse_opcode (uint32_t opcode) __attr_dealloc_free;
+
+/* Use to provide a checked cast facility. Use the
+ support_fuse_in_cast macro below. */
+void *support_fuse_cast_internal (struct fuse_in_header *, uint32_t)
+ __nonnull ((1));
+
+/* The macro expansion support_fuse_in_cast (P, TYPE) casts the
+ pointer INH to the appropriate type corresponding to the FUSE_TYPE
+ opcode. It fails (terminates the process) if INH->opcode does not
+ match FUSE_TYPE. The type of the returned pointer matches that of
+ the FUSE_* constant. */
+#define support_fuse_in_payload_type_CREATE struct fuse_create_in
+#define support_fuse_in_payload_type_INIT struct fuse_init_in
+#define support_fuse_in_payload_type_LOOKUP char
+#define support_fuse_in_payload_type_OPEN struct fuse_open_in
+#define support_fuse_in_payload_type_READ struct fuse_read_in
+#define support_fuse_in_payload_type_SETATTR struct fuse_setattr_in
+#define support_fuse_in_payload_type_WRITE struct fuse_write_in
+#define support_fuse_cast(inh, typ) \
+ ((support_fuse_in_payload_type_##typ *) \
+ support_fuse_cast_internal ((inh), FUSE_##typ))
+
+/* This function should be called from the callback function. It
+ returns NULL if the mount point has been unmounted. The result can
+ be cast using support_fuse_in_cast. The pointer is invalidated
+ with the next call to support_fuse_read.
+
+ Typical use involves handling some basics using the
+ support_fuse_handle_* building blocks, following by a switch
+ statement on the result member of the returned struct, to implement
+ what a particular test needs. Casts to payload data should be made
+ using support_fuse_in_cast.
+
+ By default, FUSE_FORGET responses are filtered. See
+ support_fuse_filter_forget for turning that off. */
+struct fuse_in_header *support_fuse_read (struct support_fuse *f)
+ __nonnull ((1));
+
+/* This function can be called from a callback function to handle
+ basic aspects of directories (OPENDIR, GETATTR, RELEASEDIR).
+ inh->nodeid is used as the inode number for the directory. This
+ function must be called after support_fuse_read. */
+bool support_fuse_handle_directory (struct support_fuse *f) __nonnull ((1));
+
+/* This function can be called from a callback function to handle
+ access to the mount point itself, after call support_fuse_read. */
+bool support_fuse_handle_mountpoint (struct support_fuse *f) __nonnull ((1));
+
+/* If FILTER_ENABLED, future support_fuse_read calls will not return
+ FUSE_FORGET events (and simply discared them, as they require no
+ reply). If !FILTER_ENABLED, the callback needs to handled
+ FUSE_FORGET events and call support_fuse_no_reply. */
+void support_fuse_filter_forget (struct support_fuse *f, bool filter_enabled)
+ __nonnull ((1));
+
+/* This function should be called from the callback function after
+ support_fuse_read returned a non-null pointer. It sends out a
+ response packet on the FUSE device with the supplied payload data. */
+void support_fuse_reply (struct support_fuse *f,
+ const void *payload, size_t payload_size)
+ __nonnull ((1)) __attr_access ((__read_only__, 2, 3));
+
+/* This function should be called from the callback function. It
+ replies to a request with an error indicator. ERROR must be positive. */
+void support_fuse_reply_error (struct support_fuse *f, uint32_t error)
+ __nonnull ((1));
+
+/* This function should be called from the callback function. It
+ sends out an empty (but success-indicating) reply packet. */
+void support_fuse_reply_empty (struct support_fuse *f) __nonnull ((1));
+
+/* Do not send a reply. Only to be used after a support_fuse_read
+ call that returned a FUSE_FORGET event. */
+void support_fuse_no_reply (struct support_fuse *f) __nonnull ((1));
+
+/* Specific reponse preparation functions. The returned object can be
+ updated as needed. If a NODEID argument is present, it will be
+ used to set the inode and FUSE nodeid fields. Without such an
+ argument, it is initialized from the current request (if the reply
+ requires this field). This function must be called after
+ support_fuse_read. The actual response must be sent using
+ support_fuse_reply_prepared (or a support_fuse_reply_error call can
+ be used to cancel the response). */
+struct fuse_entry_out *support_fuse_prepare_entry (struct support_fuse *f,
+ uint64_t nodeid)
+ __nonnull ((1));
+struct fuse_attr_out *support_fuse_prepare_attr (struct support_fuse *f)
+ __nonnull ((1));
+
+/* Similar to the other support_fuse_prepare_* functions, but it
+ prepares for two response packets. They can be updated through the
+ pointers written to *OUT_ENTRY and *OUT_OPEN prior to calling
+ support_fuse_reply_prepared. */
+void support_fuse_prepare_create (struct support_fuse *f,
+ uint64_t nodeid,
+ struct fuse_entry_out **out_entry,
+ struct fuse_open_out **out_open)
+ __nonnull ((1, 3, 4));
+
+
+/* Send a prepared response. Must be called after one of the
+ support_fuse_prepare_* functions and before the next
+ support_fuse_read call. */
+void support_fuse_reply_prepared (struct support_fuse *f) __nonnull ((1));
+
+#endif /* SUPPORT_FUSE_H */
new file mode 100644
@@ -0,0 +1,21 @@
+/* Facilities for FUSE-backed file system tests. Stub version.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <support/fuse.h>
+
+/* Not supported. */
@@ -662,3 +662,9 @@ tests-internal += \
tst-rseq-nptl \
# tests-internal
endif
+
+ifeq ($(subdir),support)
+tests += \
+ tst-support_fuse \
+ # tests
+endif # ($(subdir),support)
new file mode 100644
@@ -0,0 +1,589 @@
+/* Facilities for FUSE-backed file system tests.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <support/fuse.h>
+#include <linux/fuse.h>
+
+#include <dirent.h>
+#include <errno.h>
+#include <sys/mount.h>
+#include <sys/sysmacros.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#include <array_length.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+
+struct support_fuse
+{
+ char *mountpoint;
+ void *buffer_start; /* Allocation begin. */
+ void *buffer_next; /* Next read position. */
+ void *buffer_limit; /* End of buffered data. */
+ void *buffer_end; /* End of allocation. */
+ struct fuse_in_header *inh; /* Most recent request (support_fuse_read). */
+ union /* Space for prepared responses. */
+ {
+ struct fuse_attr_out attr;
+ struct fuse_entry_out entry;
+ struct
+ {
+ struct fuse_entry_out entry;
+ struct fuse_open_out open;
+ } create;
+ } prepared;
+ size_t prepared_size; /* 0 if inactive. */
+ pthread_t handler; /* Thread handling requests. */
+ uid_t uid; /* Cached value for the current process. */
+ uid_t gid; /* Cached value for the current process. */
+ int fd; /* FUSE file descriptor. */
+ int connection; /* Entry under /sys/fs/fuse/connections. */
+ bool filter_forget; /* Controls FUSE_FORGET event dropping. */
+};
+
+struct fuse_thread_wrapper_args
+{
+ struct support_fuse *f;
+ support_fuse_callback callback;
+ void *closure;
+};
+
+/* Allocate the read buffer in F with SIZE bytes capacity. Does not
+ free the previously allocated buffer. */
+static void support_fuse_allocate (struct support_fuse *f, size_t size)
+ __nonnull ((1));
+
+/* Internal mkdtemp replacement */
+static char * support_fuse_mkdir (const char *prefix) __nonnull ((1));
+
+/* Low-level allocation function for support_fuse_mount. Does not
+ perform the mount. */
+static struct support_fuse *support_fuse_open (void);
+
+/* Thread wrapper function for use with pthread_create. Uses struct
+ fuse_thread_wrapper_args. */
+static void *support_fuse_thread_wrapper (void *closure) __nonnull ((1));
+
+/* Initial step before preparing a reply. SIZE must be the size of
+ the F->prepared member that is going to be used. */
+static void support_fuse_prepare_1 (struct support_fuse *f, size_t size);
+
+/* Similar to support_fuse_reply_error, but not check that ERROR is
+ not zero. */
+static void support_fuse_reply_error_1 (struct support_fuse *f,
+ uint32_t error) __nonnull ((1));
+
+/* Path to the directory containing mount points. Initialized by an
+ ELF constructor. All mountpoints are collected there so that the
+ test wrapper can clean them up without keeping track of them
+ individually. */
+static char *support_fuse_mountpoints;
+
+/* PID of the process that should clean up the mount points in the ELF
+ destructor. */
+static pid_t support_fuse_cleanup_pid;
+
+static void
+support_fuse_allocate (struct support_fuse *f, size_t size)
+{
+ f->buffer_start = xmalloc (size);
+ f->buffer_end = f->buffer_start + size;
+ f->buffer_limit = f->buffer_start;
+ f->buffer_next = f->buffer_limit;
+}
+
+void
+support_fuse_filter_forget (struct support_fuse *f, bool filter)
+{
+ f->filter_forget = filter;
+}
+
+void *
+support_fuse_cast_internal (struct fuse_in_header *p, uint32_t expected)
+{
+ if (expected != p->opcode
+ && !(expected == FUSE_READ && p->opcode == FUSE_READDIR))
+ {
+ char *expected1 = support_fuse_opcode (expected);
+ char *actual = support_fuse_opcode (p->opcode);
+ FAIL_EXIT1 ("attempt to cast %s to %s", actual, expected1);
+ }
+ return p + 1;
+}
+
+bool
+support_fuse_handle_directory (struct support_fuse *f)
+{
+ TEST_VERIFY (f->inh != NULL);
+ switch (f->inh->opcode)
+ {
+ case FUSE_OPENDIR:
+ {
+ struct fuse_open_out out =
+ {
+ };
+ support_fuse_reply (f, &out, sizeof (out));
+ }
+ return true;
+ case FUSE_RELEASEDIR:
+ support_fuse_reply_empty (f);
+ return true;
+ case FUSE_GETATTR:
+ {
+ struct fuse_attr_out *out = support_fuse_prepare_attr (f);
+ out->attr.mode = S_IFDIR | 0700;
+ support_fuse_reply_prepared (f);
+ }
+ return true;
+ default:
+ return false;
+ }
+}
+
+bool
+support_fuse_handle_mountpoint (struct support_fuse *f)
+{
+ TEST_VERIFY (f->inh != NULL);
+ /* 1 is the root node. */
+ if (f->inh->opcode == FUSE_GETATTR && f->inh->nodeid == 1)
+ return support_fuse_handle_directory (f);
+ return false;
+}
+
+static char *
+support_fuse_mkdir (const char *prefix)
+{
+ /* Do not use mkdtemp to avoid interfering with its tests. */
+ unsigned int counter = 1;
+ unsigned int pid = getpid ();
+ while (true)
+ {
+ char *path = xasprintf ("%s%u.%u/", prefix, pid, counter);
+ if (mkdir (path, 0700) == 0)
+ return path;
+ if (errno != EEXIST)
+ FAIL_EXIT1 ("mkdir (\"%s\"): %m", path);
+ free (path);
+ ++counter;
+ }
+}
+
+struct support_fuse *
+support_fuse_mount (support_fuse_callback callback, void *closure)
+{
+ /* Request at least minor version 12 because it changed struct sizes. */
+ enum { min_version = 12 };
+
+ struct support_fuse *f = support_fuse_open ();
+ char *mount_options
+ = xasprintf ("fd=%d,rootmode=040700,user_id=%u,group_id=%u",
+ f->fd, (unsigned int) getuid(), (unsigned int) getgid ());
+ if (mount ("fuse", f->mountpoint, "fuse.glibc",
+ MS_NOSUID|MS_NODEV, mount_options)
+ != 0)
+ FAIL_EXIT1 ("FUSE mount on %s: %m", f->mountpoint);
+ free (mount_options);
+
+ /* Retry with an older FUSE version. */
+ while (true)
+ {
+ struct fuse_in_header *inh = support_fuse_read (f);
+ struct fuse_init_in *init_in = support_fuse_cast (inh, INIT);
+ if (init_in->major < 7
+ || (init_in->major == 7 && init_in->minor < min_version))
+ FAIL_UNSUPPORTED ("kernel FUSE version is %u.%u, too old",
+ init_in->major, init_in->minor);
+ if (init_in->major > 7)
+ {
+ uint32_t major = 7;
+ support_fuse_reply (f, &major, sizeof (major));
+ continue;
+ }
+ struct fuse_init_out out =
+ {
+ .major = 7,
+ .minor = min_version,
+ };
+ support_fuse_reply (f, &out, sizeof (out));
+
+ {
+ struct fuse_thread_wrapper_args args =
+ {
+ .f = f,
+ .callback = callback,
+ .closure = closure,
+ };
+ f->handler = xpthread_create (NULL,
+ support_fuse_thread_wrapper, &args);
+ struct stat64 st;
+ xstat64 (f->mountpoint, &st);
+ f->connection = minor (st.st_dev);
+ /* Got a reply from the thread, safe to deallocate args. */
+ }
+
+ return f;
+ }
+}
+
+const char *
+support_fuse_mountpoint (struct support_fuse *f)
+{
+ return f->mountpoint;
+}
+
+void
+support_fuse_no_reply (struct support_fuse *f)
+{
+ TEST_VERIFY (f->inh != NULL);
+ TEST_COMPARE (f->inh->opcode, FUSE_FORGET);
+ f->inh = NULL;
+}
+
+char *
+support_fuse_opcode (uint32_t op)
+{
+ const char *result;
+ switch (op)
+ {
+#define X(n) case n: result = #n; break
+ X(FUSE_LOOKUP);
+ X(FUSE_FORGET);
+ X(FUSE_GETATTR);
+ X(FUSE_SETATTR);
+ X(FUSE_READLINK);
+ X(FUSE_SYMLINK);
+ X(FUSE_MKNOD);
+ X(FUSE_MKDIR);
+ X(FUSE_UNLINK);
+ X(FUSE_RMDIR);
+ X(FUSE_RENAME);
+ X(FUSE_LINK);
+ X(FUSE_OPEN);
+ X(FUSE_READ);
+ X(FUSE_WRITE);
+ X(FUSE_STATFS);
+ X(FUSE_RELEASE);
+ X(FUSE_FSYNC);
+ X(FUSE_SETXATTR);
+ X(FUSE_GETXATTR);
+ X(FUSE_LISTXATTR);
+ X(FUSE_REMOVEXATTR);
+ X(FUSE_FLUSH);
+ X(FUSE_INIT);
+ X(FUSE_OPENDIR);
+ X(FUSE_READDIR);
+ X(FUSE_RELEASEDIR);
+ X(FUSE_FSYNCDIR);
+ X(FUSE_GETLK);
+ X(FUSE_SETLK);
+ X(FUSE_SETLKW);
+ X(FUSE_ACCESS);
+ X(FUSE_CREATE);
+ X(FUSE_INTERRUPT);
+ X(FUSE_BMAP);
+ X(FUSE_DESTROY);
+ X(FUSE_IOCTL);
+ X(FUSE_POLL);
+/* These are not present in Linux 3.2.
+ X(FUSE_NOTIFY_REPLY);
+ X(FUSE_BATCH_FORGET);
+ X(FUSE_FALLOCATE);
+ X(FUSE_READDIRPLUS);
+ X(FUSE_RENAME2);
+ X(FUSE_LSEEK);
+ X(FUSE_COPY_FILE_RANGE);
+ X(FUSE_SETUPMAPPING);
+ X(FUSE_REMOVEMAPPING);
+ X(FUSE_SYNCFS);
+ X(FUSE_TMPFILE);
+ X(FUSE_STATX); */
+#undef X
+ default:
+ return xasprintf ("FUSE_unknown_%u", op);
+ }
+ return xstrdup (result);
+}
+
+static struct support_fuse *
+support_fuse_open (void)
+{
+ struct support_fuse *result = xmalloc (sizeof (*result));
+ result->mountpoint = support_fuse_mkdir (support_fuse_mountpoints);
+ result->inh = NULL;
+ result->prepared_size = 0;
+ result->uid = getuid ();
+ result->gid = getgid ();
+ result->fd = open ("/dev/fuse", O_RDWR, 0);
+ if (result->fd < 0)
+ {
+ if (errno == ENOENT || errno == ENODEV || errno == EPERM
+ || errno == EACCES)
+ FAIL_UNSUPPORTED ("cannot open /dev/fuse: %m");
+ else
+ FAIL_EXIT1 ("cannot open /dev/fuse: %m");
+ }
+ result->connection = -1;
+ result->filter_forget = true;
+ support_fuse_allocate (result, FUSE_MIN_READ_BUFFER);
+ return result;
+}
+
+static void
+support_fuse_prepare_1 (struct support_fuse *f, size_t size)
+{
+ TEST_VERIFY (f->prepared_size == 0);
+ f->prepared_size = size;
+ memset (&f->prepared, 0, size);
+}
+
+struct fuse_attr_out *
+support_fuse_prepare_attr (struct support_fuse *f)
+{
+ support_fuse_prepare_1 (f, sizeof (f->prepared.attr));
+ f->prepared.attr.attr.uid = f->uid;
+ f->prepared.attr.attr.gid = f->gid;
+ f->prepared.attr.attr.ino = f->inh->nodeid;
+ return &f->prepared.attr;
+}
+
+void
+support_fuse_prepare_create (struct support_fuse *f,
+ uint64_t nodeid,
+ struct fuse_entry_out **out_entry,
+ struct fuse_open_out **out_open)
+{
+ support_fuse_prepare_1 (f, sizeof (f->prepared.create));
+ f->prepared.create.entry.nodeid = nodeid;
+ f->prepared.create.entry.attr.uid = f->uid;
+ f->prepared.create.entry.attr.gid = f->gid;
+ f->prepared.create.entry.attr.ino = nodeid;
+ *out_entry = &f->prepared.create.entry;
+ *out_open = &f->prepared.create.open;
+}
+
+struct fuse_entry_out *
+support_fuse_prepare_entry (struct support_fuse *f, uint64_t nodeid)
+{
+ support_fuse_prepare_1 (f, sizeof (f->prepared.entry));
+ f->prepared.entry.nodeid = nodeid;
+ f->prepared.entry.attr.uid = f->uid;
+ f->prepared.entry.attr.gid = f->gid;
+ f->prepared.entry.attr.ino = nodeid;
+ return &f->prepared.entry;
+}
+
+struct fuse_in_header *
+support_fuse_read (struct support_fuse *f)
+{
+ TEST_VERIFY (f->inh == NULL);
+ while (true)
+ {
+ if (f->buffer_next < f->buffer_limit)
+ {
+ f->inh = f->buffer_next;
+ f->buffer_next = (void *) f->buffer_next + f->inh->len;
+ /* Suppress FUSE_FORGET responses if requested. */
+ if (f->filter_forget && f->inh->opcode == FUSE_FORGET)
+ {
+ f->inh = NULL;
+ continue;
+ }
+ return f->inh;
+ }
+ ssize_t ret = read (f->fd, f->buffer_start,
+ f->buffer_end - f->buffer_start);
+ if (ret == 0)
+ FAIL_EXIT (1, "unexpected EOF on FUSE device");
+ if (ret < 0 && errno == EINVAL)
+ {
+ /* Increase buffer size. */
+ size_t new_size = 2 * (size_t) (f->buffer_end - f->buffer_start);
+ free (f->buffer_start);
+ support_fuse_allocate (f, new_size);
+ continue;
+ }
+ if (ret < 0)
+ {
+ if (errno == ENODEV)
+ /* Unmount detected. */
+ return NULL;
+ FAIL_EXIT1 ("read error on FUSE device: %m");
+ }
+ /* Read was successful, make [next, limit) the active buffer area. */
+ f->buffer_next = f->buffer_start;
+ f->buffer_limit = (void *) f->buffer_start + ret;
+ }
+}
+
+void
+support_fuse_reply (struct support_fuse *f,
+ const void *payload, size_t payload_size)
+{
+ TEST_VERIFY_EXIT (f->inh != NULL);
+ TEST_VERIFY (f->prepared_size == 0);
+ struct fuse_out_header outh =
+ {
+ .len = sizeof (outh) + payload_size,
+ .unique = f->inh->unique,
+ };
+ struct iovec iov[] =
+ {
+ { &outh, sizeof (outh) },
+ { (void *) payload, payload_size },
+ };
+ ssize_t ret = writev (f->fd, iov, array_length (iov));
+ if (ret < 0)
+ FAIL_EXIT1 ("FUSE write failed for %s response (%zu bytes payload): %m",
+ support_fuse_opcode (f->inh->opcode), payload_size);
+ if (ret != sizeof (outh) + payload_size)
+ FAIL_EXIT1 ("FUSE write short for %s response (%zu bytes payload):"
+ " %zd bytes",
+ support_fuse_opcode (f->inh->opcode), payload_size, ret);
+ f->inh = NULL;
+}
+
+void
+support_fuse_reply_empty (struct support_fuse *f)
+{
+ support_fuse_reply_error_1 (f, 0);
+}
+
+static void
+support_fuse_reply_error_1 (struct support_fuse *f, uint32_t error)
+{
+ TEST_VERIFY_EXIT (f->inh != NULL);
+ struct fuse_out_header outh =
+ {
+ .len = sizeof (outh),
+ .error = -error,
+ .unique = f->inh->unique,
+ };
+ ssize_t ret = write (f->fd, &outh, sizeof (outh));
+ if (ret < 0)
+ FAIL_EXIT1 ("FUSE write failed for %s error response: %m",
+ support_fuse_opcode (f->inh->opcode));
+ if (ret != sizeof (outh))
+ FAIL_EXIT1 ("FUSE write short for %s error response: %zd bytes",
+ support_fuse_opcode (f->inh->opcode), ret);
+ f->inh = NULL;
+ f->prepared_size = 0;
+}
+
+void
+support_fuse_reply_error (struct support_fuse *f, uint32_t error)
+{
+ TEST_VERIFY (error > 0);
+ support_fuse_reply_error_1 (f, error);
+}
+
+void
+support_fuse_reply_prepared (struct support_fuse *f)
+{
+ TEST_VERIFY_EXIT (f->prepared_size != 0);
+ /* Re-use the non-prepared reply function. It requires
+ f->prepared_size to be zero, so reset the field before the call. */
+ size_t prepared_size = f->prepared_size;
+ f->prepared_size = 0;
+ support_fuse_reply (f, &f->prepared, prepared_size);
+}
+
+static void *
+support_fuse_thread_wrapper (void *closure)
+{
+ struct fuse_thread_wrapper_args args
+ = *(struct fuse_thread_wrapper_args *) closure;
+
+ /* Handle the initial stat call. */
+ struct fuse_in_header *inh = support_fuse_read (args.f);
+ if (inh == NULL || !support_fuse_handle_mountpoint (args.f))
+ {
+ support_fuse_reply_error (args.f, EIO);
+ return NULL;
+ }
+
+ args.callback (args.f, args.closure);
+ return NULL;
+}
+
+void
+support_fuse_unmount (struct support_fuse *f)
+{
+ {
+ char *path = xasprintf ("/sys/fs/fuse/connections/%d/abort",
+ f->connection);
+ /* Some kernels do not support these files under /sys. */
+ int fd = open (path, O_RDWR | O_TRUNC);
+ if (fd >= 0)
+ {
+ write (fd, "1", 1);
+ xclose (fd);
+ }
+ free (path);
+ }
+ if (umount (f->mountpoint) != 0)
+ FAIL ("FUSE: umount (\"%s\"): %m", f->mountpoint);
+ xpthread_join (f->handler);
+ if (rmdir (f->mountpoint) != 0)
+ FAIL ("FUSE: rmdir (\"%s\"): %m", f->mountpoint);
+ xclose (f->fd);
+ free (f->mountpoint);
+ free (f);
+}
+
+static void __attribute__ ((constructor))
+init (void)
+{
+ /* The test_dir test driver variable is not yet set at this point. */
+ const char *tmpdir = getenv ("TMPDIR");
+ if (tmpdir == NULL || tmpdir[0] == '\0')
+ tmpdir = "/tmp";
+
+ char *prefix = xasprintf ("%s/glibc-tst-fuse.", tmpdir);
+ support_fuse_mountpoints = support_fuse_mkdir (prefix);
+ free (prefix);
+ support_fuse_cleanup_pid = getpid ();
+}
+
+static void __attribute__ ((destructor))
+fini (void)
+{
+ if (support_fuse_cleanup_pid != getpid ()
+ || support_fuse_mountpoints == NULL)
+ return;
+ DIR *dir = opendir (support_fuse_mountpoints);
+ while (true)
+ {
+ struct dirent64 *e = readdir64 (dir);
+ if (e == NULL)
+ /* Ignore errors. */
+ break;
+ if (*e->d_name == '.')
+ /* Skip "." and "..". No hidden files expected. */
+ continue;
+ if (unlinkat (dirfd (dir), e->d_name, AT_REMOVEDIR) != 0)
+ break;
+ rewinddir (dir);
+ }
+ rmdir (support_fuse_mountpoints);
+ free (support_fuse_mountpoints);
+ support_fuse_mountpoints = NULL;
+}
new file mode 100644
@@ -0,0 +1,291 @@
+/* Facilities for FUSE-backed file system tests.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <support/fuse.h>
+#include <linux/fuse.h>
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+
+static void
+fuse_thread (struct support_fuse *f, void *closure)
+{
+ /* Turn on returning FUSE_FORGET responses. */
+ support_fuse_filter_forget (f, false);
+
+ /* Inode and nodeid for "file" and "new". */
+ enum { NODE_FILE = 2, NODE_NEW };
+ struct fuse_in_header *inh;
+ while ((inh = support_fuse_read (f)) != NULL)
+ {
+ {
+ char *opcode = support_fuse_opcode (inh->opcode);
+ printf ("info: (T) event %s(%llu) len=%u nodeid=%llu\n",
+ opcode, (unsigned long long int) inh->unique, inh->len,
+ (unsigned long long int) inh->nodeid);
+ free (opcode);
+ }
+
+ /* Handle mountpoint and basic directory operation for the root (1). */
+ if (support_fuse_handle_mountpoint (f)
+ || (inh->nodeid == 1 && support_fuse_handle_directory (f)))
+ continue;
+
+ switch (inh->opcode)
+ {
+ case FUSE_READDIR:
+ /* Implementation of getdents64. */
+ if (inh->nodeid == 1)
+ {
+ struct fuse_read_in *p = support_fuse_cast (inh, READ);
+ if (p->offset == 0)
+ {
+ /* Pad the name to a multiple of 8, as required by
+ the kernel interface. */
+ size_t name_size = 8;
+ size_t e_size = (offsetof (struct fuse_dirent, name)
+ + name_size);
+ struct fuse_dirent *e = xmalloc (e_size);
+ e->ino = NODE_FILE;
+ e->off = 2;
+ e->namelen = name_size;
+ e->type = DT_REG;
+ memcpy (e->name, "file\0\0\0", 8);
+ support_fuse_reply (f, e, e_size);
+ free (e);
+ }
+ else
+ support_fuse_reply_empty (f);
+ }
+ else
+ support_fuse_reply_error (f, EIO);
+ break;
+ case FUSE_LOOKUP:
+ /* Part of the implementation of open. */
+ {
+ char *name = support_fuse_cast (inh, LOOKUP);
+ printf (" name: %s\n", name);
+ if (inh->nodeid == 1 && strcmp (name, "file") == 0)
+ {
+ struct fuse_entry_out *out
+ = support_fuse_prepare_entry (f, NODE_FILE);
+ out->attr.mode = S_IFREG | 0600;
+ support_fuse_reply_prepared (f);
+ }
+ else
+ support_fuse_reply_error (f, ENOENT);
+ }
+ break;
+ case FUSE_OPEN:
+ /* Implementation of open. */
+ {
+ struct fuse_open_in *p = support_fuse_cast (inh, OPEN);
+ if (inh->nodeid == NODE_FILE)
+ {
+ TEST_VERIFY (!(p->flags & O_EXCL));
+ struct fuse_open_out out = { 0, };
+ support_fuse_reply (f, &out, sizeof (out));
+ }
+ else
+ support_fuse_reply_error (f, ENOENT);
+ }
+ break;
+ case FUSE_GETATTR:
+ /* Happens after open. */
+ if (inh->nodeid == NODE_FILE)
+ {
+ struct fuse_attr_out *out = support_fuse_prepare_attr (f);
+ out->attr.mode = S_IFREG | 0600;
+ out->attr.size = strlen ("Hello, world!");
+ support_fuse_reply_prepared (f);
+ }
+ else
+ support_fuse_reply_error (f, ENOENT);
+ break;
+ case FUSE_READ:
+ /* Implementation of read. */
+ if (inh->nodeid == NODE_FILE)
+ {
+ struct fuse_read_in *p = support_fuse_cast (inh, READ);
+ TEST_COMPARE (p->offset, 0);
+ TEST_VERIFY (p->size >= strlen ("Hello, world!"));
+ support_fuse_reply (f,
+ "Hello, world!", strlen ("Hello, world!"));
+ }
+ else
+ support_fuse_reply_error (f, EIO);
+ break;
+ case FUSE_FLUSH:
+ /* Sent in response to close. */
+ support_fuse_reply_empty (f);
+ break;
+ case FUSE_GETXATTR:
+ /* This happens as part of a open-for-write operation.
+ Signal no support for extended attributes. */
+ support_fuse_reply_error (f, ENOSYS);
+ break;
+ case FUSE_SETATTR:
+ /* This happens as part of a open-for-write operation to
+ implement O_TRUNC. */
+ if (inh->nodeid == NODE_FILE)
+ {
+ struct fuse_setattr_in *p = support_fuse_cast (inh, SETATTR);
+ /* FATTR_LOCKOWNER may also be set. */
+ TEST_COMPARE ((p->valid) & ~ FATTR_LOCKOWNER, FATTR_SIZE);
+ TEST_COMPARE (p->size, 0);
+ struct fuse_attr_out *out = support_fuse_prepare_attr (f);
+ out->attr.mode = S_IFREG | 0600;
+ support_fuse_reply_prepared (f);
+ }
+ else
+ support_fuse_reply_error (f, EIO);
+ break;
+ case FUSE_WRITE:
+ /* Implementation of write. */
+ if (inh->nodeid == NODE_FILE)
+ {
+ struct fuse_write_in *p = support_fuse_cast (inh, WRITE);
+ TEST_COMPARE (p->offset, 0);
+ /* Write payload follows after struct fuse_write_in. */
+ TEST_COMPARE_BLOB (p + 1, p->size,
+ "Good day to you too.",
+ strlen ("Good day to you too."));
+ struct fuse_write_out out =
+ {
+ .size = p->size,
+ };
+ support_fuse_reply (f, &out, sizeof (out));
+ }
+ else
+ support_fuse_reply_error (f, EIO);
+ break;
+ case FUSE_CREATE:
+ /* Implementation of O_CREAT. */
+ if (inh->nodeid == 1)
+ {
+ struct fuse_create_in *p = support_fuse_cast (inh, CREATE);
+ /* Name follows after struct fuse_create_in. */
+ char *name = (char *) (p + 1);
+ TEST_VERIFY (S_ISREG (p->mode));
+ TEST_COMPARE (p->mode & 0700, 0600);
+ TEST_COMPARE_STRING (name, "new");
+ struct fuse_entry_out *out_entry;
+ struct fuse_open_out *out_open;
+ support_fuse_prepare_create (f, NODE_NEW, &out_entry, &out_open);
+ out_entry->attr.mode = S_IFREG | 0600;
+ support_fuse_reply_prepared (f);
+ }
+ else
+ support_fuse_reply_error (f, EIO);
+ break;
+ case FUSE_FORGET:
+ support_fuse_no_reply (f);
+ break;
+ default:
+ support_fuse_reply_error (f, EIO);
+ }
+ }
+}
+
+static int
+do_test (void)
+{
+ support_become_root ();
+ if (!support_enter_mount_namespace ())
+ FAIL_UNSUPPORTED ("mount namespaces not supported");
+ struct support_fuse *f = support_fuse_mount (fuse_thread, NULL);
+
+ printf ("info: Attributes of mountpoint/root directory %s\n",
+ support_fuse_mountpoint (f));
+ {
+ struct statx st;
+ xstatx (AT_FDCWD, support_fuse_mountpoint (f), 0, STATX_BASIC_STATS, &st);
+ TEST_COMPARE (st.stx_uid, getuid ());
+ TEST_COMPARE (st.stx_gid, getgid ());
+ TEST_VERIFY (S_ISDIR (st.stx_mode));
+ TEST_COMPARE (st.stx_mode & 0777, 0700);
+ }
+
+ printf ("info: List directory %s\n", support_fuse_mountpoint (f));
+ {
+ DIR *dir = opendir (support_fuse_mountpoint (f));
+ TEST_VERIFY_EXIT (dir != NULL);
+ struct dirent *e = readdir (dir);
+ TEST_VERIFY (e != NULL);
+ TEST_COMPARE (closedir (dir), 0);
+ }
+
+ char *file_path = xasprintf ("%s/file", support_fuse_mountpoint (f));
+
+ printf ("info: Attributes of FILE %s\n", file_path);
+ {
+ struct statx st;
+ xstatx (AT_FDCWD, file_path, 0, STATX_BASIC_STATS, &st);
+ TEST_COMPARE (st.stx_uid, getuid ());
+ TEST_COMPARE (st.stx_gid, getgid ());
+ TEST_VERIFY (S_ISREG (st.stx_mode));
+ TEST_COMPARE (st.stx_mode & 0777, 0600);
+ TEST_COMPARE (st.stx_size, strlen ("Hello, world!"));
+ }
+
+ printf ("info: Read from %s\n", file_path);
+ {
+ int fd = xopen (file_path, O_RDONLY, 0);
+ char buf[64];
+ ssize_t len = read (fd, buf, sizeof (buf));
+ if (len < 0)
+ FAIL_EXIT1 ("read: %m");
+ TEST_COMPARE_BLOB (buf, len, "Hello, world!", strlen ("Hello, world!"));
+ xclose (fd);
+ }
+
+ printf ("info: Write to %s\n", file_path);
+ {
+ int fd = xopen (file_path, O_WRONLY | O_TRUNC, 0);
+ xwrite (fd, "Good day to you too.", strlen ("Good day to you too."));
+ xclose (fd);
+ }
+
+ printf ("info: Attempt O_EXCL creation of existing %s\n", file_path);
+ /* O_EXCL creation shall fail. */
+ errno = 0;
+ TEST_COMPARE (open64 (file_path, O_RDWR | O_EXCL | O_CREAT, 0600), -1);
+ TEST_COMPARE (errno, EEXIST);
+
+ free (file_path);
+
+ {
+ char *new_path = xasprintf ("%s/new", support_fuse_mountpoint (f));
+ printf ("info: Test successful O_EXCL creation at %s\n", new_path);
+ int fd = xopen (new_path, O_RDWR | O_EXCL | O_CREAT, 0600);
+ xclose (fd);
+ free (new_path);
+ }
+
+ support_fuse_unmount (f);
+ return 0;
+}
+
+#include <support/test-driver.c>