Added compiling target Android support

Makefile

@@ -215,6 +215,8 @@ objects = \
 	kernel-shared/uuid-tree.o	\
 	kernel-shared/volumes.o	\
 	kernel-shared/zoned.o	\
+	android-compat/pthread.o	\
+	android-compat/qsort.o	\
 	common/array.o		\
 	common/cpu-utils.o	\
 	common/device-scan.o	\
@@ -292,8 +294,8 @@ tune_objects = tune/main.o tune/seeding.o tune/change-uuid.o tune/change-metadat
 all_objects = $(objects) $(cmds_objects) $(libbtrfs_objects) $(convert_objects) \
 	      $(mkfs_objects) $(image_objects) $(tune_objects) $(libbtrfsutil_objects)
 
-tags_files = $(addsuffix /*.[ch], . check cmds common convert crypto image include mkfs tune \
-	       kernel-lib kernel-shared kernel-shared/uapi \
+tags_files = $(addsuffix /*.[ch], . android-compat check cmds common convert crypto \
+	       image include mkfs tune kernel-lib kernel-shared kernel-shared/uapi \
 	       libbtrfs libbtrfsutil libbtrfsutil/python tests)
 
 udev_rules = 64-btrfs-dm.rules 64-btrfs-zoned.rules
@@ -917,6 +919,7 @@ clean: $(CLEANDIRS)
 		libbtrfs.a libbtrfsutil.a $(libs_shared) $(lib_links)
 	@echo "Cleaning object files and dependencies"
 	$(Q)$(RM) -f -- *.o .deps/*.o.d  \
+		android-compat/*.o android-compat/.deps/*.o.d \
 		check/*.o check/.deps/*.o.d \
 		cmds/*.o cmds/.deps/*.o.d \
 		common/*.o common/.deps/*.o.d \

android-compat/pthread.c

@@ -0,0 +1,57 @@
+
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "include/config.h"
+
+#ifdef __ANDROID__
+
+/* Workaround for `pthread_cancel()` in Android, using `pthread_kill()` instead,
+ * as Android NDK does not support `pthread_cancel()`.
+ */
+
+#include <string.h>
+#include <signal.h>
+#include "android-compat/pthread.h"
+
+int pthread_setcanceltype(int type, int *oldtype) { return 0; }
+int pthread_setcancelstate(int state, int *oldstate) { return 0; }
+int pthread_cancel(pthread_t thread_id) {
+	int status;
+	if ((status = btrfs_set_thread_exit_handler()) == 0) {
+		status = pthread_kill(thread_id, SIGUSR1);
+	}
+	return status;
+}
+
+void btrfs_thread_exit_handler(int sig) {
+	pthread_exit(0);
+}
+
+int btrfs_set_thread_exit_handler() {
+	int rc;
+	struct sigaction actions;
+
+	memset(&actions, 0, sizeof(actions));
+	sigemptyset(&actions.sa_mask);
+	actions.sa_flags = 0;
+	actions.sa_handler = btrfs_thread_exit_handler;
+
+	rc = sigaction(SIGUSR1, &actions, NULL);
+	return rc;
+}
+
+#endif

android-compat/pthread.h

@@ -0,0 +1,45 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __ANDROID_COMPAT_PTHREAD_H__
+#define __ANDROID_COMPAT_PTHREAD_H__
+
+#include "include/config.h"
+
+#include <pthread.h>
+
+#ifdef __ANDROID__
+
+/* Adding missing `pthread` related definitions in Android.
+ */
+
+#define PTHREAD_CANCELED ((void *) -1)
+
+#define PTHREAD_CANCEL_DEFERRED 0
+#define PTHREAD_CANCEL_ASYNCHRONOUS 0
+#define PTHREAD_CANCEL_ENABLE 0
+#define PTHREAD_CANCEL_DISABLE 0
+
+int pthread_setcanceltype(int type, int *oldtype);
+int pthread_setcancelstate(int state, int *oldstate);
+int pthread_cancel(pthread_t thread_id);
+
+int btrfs_set_thread_exit_handler();
+void btrfs_thread_exit_handler(int sig);
+
+#endif
+
+#endif

android-compat/qsort.c

@@ -0,0 +1,50 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "android-compat/qsort.h"
+#include <stdlib.h>
+
+struct qsort_r_context {
+	int (*compar)(const void *, const void *, void *);
+	void *arg;
+};
+
+#if __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_THREADS__)
+static _Thread_local struct qsort_r_context *qsort_r_ctx = NULL;
+#else
+static __thread struct qsort_r_context *qsort_r_ctx = NULL;
+#endif
+
+static int qsort_r_stub_compare(const void *a, const void *b)
+{
+	return qsort_r_ctx->compar(a, b, qsort_r_ctx->arg);
+}
+
+void qsort_r(void *base, size_t nel, size_t width,
+		 int (*compar)(const void *, const void *, void *), void *arg)
+{
+	if (nel == 0) return;
+
+	struct qsort_r_context ctx;
+	ctx.compar = compar;
+	ctx.arg = arg;
+	struct qsort_r_context *old_ctx = qsort_r_ctx;
+	qsort_r_ctx = &ctx;
+	qsort(base, nel, width, qsort_r_stub_compare);
+
+	// Restore the old context after qsort is finished.
+	qsort_r_ctx = old_ctx;
+}

android-compat/qsort.h

@@ -0,0 +1,50 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __ANDROID_COMPAT_QSORT_H__
+#define __ANDROID_COMPAT_QSORT_H__
+
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief A compatible implementation of the GNU C Library (Glibc) qsort_r.
+ *
+ * Sorts an array using the quicksort algorithm. This function is thread-safe
+ * by allowing a custom context pointer (arg) to be passed to the comparison
+ * function.
+ *
+ * @param base   A pointer to the first element of the array to be sorted.
+ * @param nel    The number of elements in the array.
+ * @param width  The size in bytes of each element in the array.
+ * @param compar The comparison function, which takes two elements and a context
+ * pointer. The function must return:
+ * - A negative integer if the first element is less than the second.
+ * - Zero if the elements are equal.
+ * - A positive integer if the first element is greater than the second.
+ * @param arg    The custom pointer passed to the comparison function.
+ */
+void qsort_r(void *base, size_t nel, size_t width,
+	     int (*compar)(const void *, const void *, void *), void *arg);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

cmds/inspect.c

@@ -14,6 +14,7 @@
  * Boston, MA 021110-1307, USA.
  */
 
+#include "android-compat/qsort.h"
 #include "kerncompat.h"
 #include <sys/ioctl.h>
 #include <sys/stat.h>
@@ -878,9 +879,10 @@ static int print_list_chunks(struct list_chunks_ctx *ctx, const char *sortmode,
 	}
 
 	/* Skip additional sort if nothing defined by user. */
-	if (comp.count > 0)
+	if (comp.count > 0) {
 		qsort_r(ctx->stats, ctx->length, sizeof(ctx->stats[0]),
 			(sort_r_cmp_t)compare_cmp_multi, &comp);
+	}
 
 	col_count = 9;
 	/* Two rows for header and separator. */

cmds/rescue-chunk-recover.c

@@ -22,10 +22,13 @@
 #include <stdlib.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <pthread.h>
+#include "android-compat/pthread.h"
 #include <errno.h>
 #include <stddef.h>
 #include <string.h>
+#ifdef __ANDROID__
+#include <stdatomic.h>
+#endif
 #include "kernel-lib/list.h"
 #include "kernel-shared/accessors.h"
 #include "kernel-shared/extent-io-tree.h"
@@ -82,6 +85,9 @@ struct device_scan {
 	struct btrfs_device *dev;
 	int fd;
 	u64 bytenr;
+#ifdef __ANDROID__
+	atomic_flag thread_running;
+#endif
 };
 
 static struct extent_record *btrfs_new_extent_record(struct extent_buffer *eb)
@@ -761,8 +767,12 @@ static int scan_one_device(void *dev_scan_struct)
 		return 1;
 
 	buf = malloc(sizeof(*buf) + rc->nodesize);
-	if (!buf)
+	if (!buf) {
+#ifdef __ANDROID__
+		atomic_flag_clear(&dev_scan->thread_running);
+#endif
 		return -ENOMEM;
+	}
 	buf->len = rc->nodesize;
 
 	bytenr = 0;
@@ -823,6 +833,9 @@ static int scan_one_device(void *dev_scan_struct)
 out:
 	close(fd);
 	free(buf);
+#ifdef __ANDROID__
+	atomic_flag_clear(&dev_scan->thread_running);
+#endif
 	return ret;
 }
 
@@ -869,6 +882,9 @@ static int scan_devices(struct recover_control *rc)
 		dev_scans[devidx].dev = dev;
 		dev_scans[devidx].fd = fd;
 		dev_scans[devidx].bytenr = -1;
+#ifdef __ANDROID__
+		atomic_flag_test_and_set(&dev_scans[devidx].thread_running);
+#endif
 		devidx++;
 	}
 
@@ -887,8 +903,15 @@ static int scan_devices(struct recover_control *rc)
 		for (i = 0; i < devidx; i++) {
 			if (dev_scans[i].bytenr == -1)
 				continue;
+#ifdef __ANDROID__
+			if (atomic_flag_test_and_set(&dev_scans[i].thread_running))
+				ret = EBUSY;
+			else
+				ret = pthread_join(t_scans[i], (void **)&t_rets[i]);
+#else
 			ret = pthread_tryjoin_np(t_scans[i],
 						 (void **)&t_rets[i]);
+#endif
 			if (ret == EBUSY) {
 				all_done = false;
 				continue;

cmds/scrub.c

@@ -27,7 +27,7 @@
 #include <poll.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <pthread.h>
+#include "android-compat/pthread.h"
 #include <ctype.h>
 #include <signal.h>
 #include <stdarg.h>

cmds/send.c

@@ -21,7 +21,7 @@
 #include <stdbool.h>
 #include <unistd.h>
 #include <fcntl.h>
-#include <pthread.h>
+#include "android-compat/pthread.h"
 #include <getopt.h>
 #include <limits.h>
 #include <errno.h>

common/sort-utils.c

@@ -78,6 +78,9 @@ int compare_add_sort_id(struct compare *comp, int id)
 		if (comp->sortdef[i].name == NULL)
 			return -1;
 		if (comp->sortdef[i].id == id) {
+#ifdef __ANDROID__
+			comp->id[comp->count] = id;
+#endif
 			comp->comp[comp->count] = comp->sortdef[i].comp;
 			comp->count++;
 			break;

common/sort-utils.h

@@ -89,6 +89,9 @@ struct compare {
 	unsigned long invert_map;
 	int count;
 	const struct sortdef *sortdef;
+#ifdef __ANDROID__
+	int id[SORT_MAX_KEYS];
+#endif
 };
 
 int compare_init(struct compare *comp, const struct sortdef *sortdef);

common/task-utils.c

@@ -15,7 +15,7 @@
  */
 
 #include <sys/timerfd.h>
-#include <pthread.h>
+#include "android-compat/pthread.h"
 #include <stdlib.h>
 #include <unistd.h>
 #include <time.h>

common/task-utils.h

@@ -19,7 +19,7 @@
 
 #include "kerncompat.h"
 #include <time.h>
-#include <pthread.h>
+#include "android-compat/pthread.h"
 
 struct periodic_info {
 	int timer_fd;

convert/main.c

@@ -88,7 +88,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <getopt.h>
-#include <pthread.h>
+#include "android-compat/pthread.h"
 #include <stdbool.h>
 #include <errno.h>
 #include <limits.h>