fsmonitor: completing a stale patch that Implements fsmonitor for Linux

Makefile

@@ -2088,6 +2088,10 @@ ifdef HAVE_CLOCK_GETTIME
 	BASIC_CFLAGS += -DHAVE_CLOCK_GETTIME
 endif
 
+ifdef HAVE_LINUX_MAGIC_H
+	BASIC_CFLAGS += -DHAVE_LINUX_MAGIC_H
+endif
+
 ifdef HAVE_CLOCK_MONOTONIC
 	BASIC_CFLAGS += -DHAVE_CLOCK_MONOTONIC
 endif

compat/fsmonitor/fsm-health-linux.c

@@ -0,0 +1,24 @@
+#include "cache.h"
+#include "config.h"
+#include "fsmonitor.h"
+#include "fsm-health.h"
+#include "fsmonitor--daemon.h"
+
+int fsm_health__ctor(struct fsmonitor_daemon_state *state)
+{
+	return 0;
+}
+
+void fsm_health__dtor(struct fsmonitor_daemon_state *state)
+{
+	return;
+}
+
+void fsm_health__loop(struct fsmonitor_daemon_state *state)
+{
+	return;
+}
+
+void fsm_health__stop_async(struct fsmonitor_daemon_state *state)
+{
+}

compat/fsmonitor/fsm-ipc-darwin.c

@@ -1,56 +1 @@
-#include "git-compat-util.h"
-#include "config.h"
-#include "gettext.h"
-#include "hex.h"
-#include "path.h"
-#include "repository.h"
-#include "strbuf.h"
-#include "fsmonitor-ll.h"
-#include "fsmonitor-ipc.h"
-#include "fsmonitor-path-utils.h"
-
-static GIT_PATH_FUNC(fsmonitor_ipc__get_default_path, "fsmonitor--daemon.ipc")
-
-const char *fsmonitor_ipc__get_path(struct repository *r)
-{
-	static const char *ipc_path = NULL;
-	git_SHA_CTX sha1ctx;
-	char *sock_dir = NULL;
-	struct strbuf ipc_file = STRBUF_INIT;
-	unsigned char hash[GIT_MAX_RAWSZ];
-
-	if (!r)
-		BUG("No repository passed into fsmonitor_ipc__get_path");
-
-	if (ipc_path)
-		return ipc_path;
-
-
-	/* By default the socket file is created in the .git directory */
-	if (fsmonitor__is_fs_remote(r->gitdir) < 1) {
-		ipc_path = fsmonitor_ipc__get_default_path();
-		return ipc_path;
-	}
-
-	git_SHA1_Init(&sha1ctx);
-	git_SHA1_Update(&sha1ctx, r->worktree, strlen(r->worktree));
-	git_SHA1_Final(hash, &sha1ctx);
-
-	repo_config_get_string(r, "fsmonitor.socketdir", &sock_dir);
-
-	/* Create the socket file in either socketDir or $HOME */
-	if (sock_dir && *sock_dir) {
-		strbuf_addf(&ipc_file, "%s/.git-fsmonitor-%s",
-					sock_dir, hash_to_hex(hash));
-	} else {
-		strbuf_addf(&ipc_file, "~/.git-fsmonitor-%s", hash_to_hex(hash));
-	}
-	free(sock_dir);
-
-	ipc_path = interpolate_path(ipc_file.buf, 1);
-	if (!ipc_path)
-		die(_("Invalid path: %s"), ipc_file.buf);
-
-	strbuf_release(&ipc_file);
-	return ipc_path;
-}
+#include "fsm-ipc-unix.c"

compat/fsmonitor/fsm-ipc-linux.c

@@ -0,0 +1 @@
+#include "fsm-ipc-unix.c"

compat/fsmonitor/fsm-ipc-unix.c

@@ -0,0 +1,53 @@
+#include "cache.h"
+#include "config.h"
+#include "hex.h"
+#include "strbuf.h"
+#include "fsmonitor.h"
+#include "fsmonitor-ipc.h"
+#include "fsmonitor-path-utils.h"
+
+static GIT_PATH_FUNC(fsmonitor_ipc__get_default_path, "fsmonitor--daemon.ipc")
+
+const char *fsmonitor_ipc__get_path(struct repository *r)
+{
+	static const char *ipc_path = NULL;
+	git_SHA_CTX sha1ctx;
+	char *sock_dir = NULL;
+	struct strbuf ipc_file = STRBUF_INIT;
+	unsigned char hash[GIT_MAX_RAWSZ];
+
+	if (!r)
+		BUG("No repository passed into fsmonitor_ipc__get_path");
+
+	if (ipc_path)
+		return ipc_path;
+
+
+	/* By default the socket file is created in the .git directory */
+	if (fsmonitor__is_fs_remote(r->gitdir) < 1) {
+		ipc_path = fsmonitor_ipc__get_default_path();
+		return ipc_path;
+	}
+
+	git_SHA1_Init(&sha1ctx);
+	git_SHA1_Update(&sha1ctx, r->worktree, strlen(r->worktree));
+	git_SHA1_Final(hash, &sha1ctx);
+
+	repo_config_get_string(r, "fsmonitor.socketdir", &sock_dir);
+
+	/* Create the socket file in either socketDir or $HOME */
+	if (sock_dir && *sock_dir) {
+		strbuf_addf(&ipc_file, "%s/.git-fsmonitor-%s",
+					sock_dir, hash_to_hex(hash));
+	} else {
+		strbuf_addf(&ipc_file, "~/.git-fsmonitor-%s", hash_to_hex(hash));
+	}
+	free(sock_dir);
+
+	ipc_path = interpolate_path(ipc_file.buf, 1);
+	if (!ipc_path)
+		die(_("Invalid path: %s"), ipc_file.buf);
+
+	strbuf_release(&ipc_file);
+	return ipc_path;
+}

compat/fsmonitor/fsm-path-utils-linux.c

@@ -0,0 +1,195 @@
+#include "git-compat-util.h"
+#include "abspath.h"
+#include "fsmonitor.h"
+#include "fsmonitor-path-utils.h"
+#include "fsm-path-utils-linux.h"
+#include <errno.h>
+#include <mntent.h>
+#include <sys/mount.h>
+#include <sys/vfs.h>
+#include <sys/statvfs.h>
+
+static int is_remote_fs(const char *path)
+{
+	struct statfs fs;
+
+	if (statfs(path, &fs))
+		return error_errno(_("statfs('%s') failed"), path);
+
+	switch (fs.f_type) {
+	case ACFS_SUPER_MAGIC:
+	case AFS_SUPER_MAGIC:
+	case CEPH_SUPER_MAGIC:
+	case CIFS_SUPER_MAGIC:
+	case CODA_SUPER_MAGIC:
+	case FHGFS_SUPER_MAGIC:
+	case GFS_SUPER_MAGIC:
+	case GPFS_SUPER_MAGIC:
+	case IBRIX_SUPER_MAGIC:
+	case KAFS_SUPER_MAGIC:
+	case LUSTRE_SUPER_MAGIC:
+	case NCP_SUPER_MAGIC:
+	case NFS_SUPER_MAGIC:
+	case NFSD_SUPER_MAGIC:
+	case OCFS2_SUPER_MAGIC:
+	case PANFS_SUPER_MAGIC:
+	case SMB_SUPER_MAGIC:
+	case SMB2_SUPER_MAGIC:
+	case SNFS_SUPER_MAGIC:
+	case VMHGFS_SUPER_MAGIC:
+	case VXFS_SUPER_MAGIC:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static int find_mount(const char *path, const struct statvfs *fs,
+			struct mntent *entry)
+{
+	const char *const mounts = "/proc/mounts";
+	char *rp = real_pathdup(path, 1);
+	struct mntent *ment = NULL;
+	struct statvfs mntfs;
+	FILE *fp;
+	int found = 0;
+	int ret = 0;
+	size_t dlen, plen, flen = 0;
+
+	entry->mnt_fsname = NULL;
+	entry->mnt_dir = NULL;
+	entry->mnt_type = NULL;
+
+	fp = setmntent(mounts, "r");
+	if (!fp) {
+		free(rp);
+		return error_errno(_("setmntent('%s') failed"), mounts);
+	}
+
+	plen = strlen(rp);
+
+	/* read all the mount information and compare to path */
+	while ((ment = getmntent(fp))) {
+		if (statvfs(ment->mnt_dir, &mntfs)) {
+			switch (errno) {
+			case EPERM:
+			case ESRCH:
+			case EACCES:
+				continue;
+			default:
+				error_errno(_("statvfs('%s') failed"), ment->mnt_dir);
+				ret = -1;
+				goto done;
+			}
+		}
+
+		/* is mount on the same filesystem and is a prefix of the path */
+		if ((fs->f_fsid == mntfs.f_fsid) &&
+			!strncmp(ment->mnt_dir, rp, strlen(ment->mnt_dir))) {
+			dlen = strlen(ment->mnt_dir);
+			if (dlen > plen)
+				continue;
+			/*
+			 * look for the longest prefix (including root)
+			 */
+			if (dlen > flen &&
+				((dlen == 1 && ment->mnt_dir[0] == '/') ||
+				 (!rp[dlen] || rp[dlen] == '/'))) {
+				flen = dlen;
+				found = 1;
+
+				/*
+				 * https://man7.org/linux/man-pages/man3/getmntent.3.html
+				 *
+				 * The pointer points to a static area of memory which is
+				 * overwritten by subsequent calls to getmntent().
+				 */
+				free(entry->mnt_fsname);
+				free(entry->mnt_dir);
+				free(entry->mnt_type);
+				entry->mnt_fsname = xstrdup(ment->mnt_fsname);
+				entry->mnt_dir = xstrdup(ment->mnt_dir);
+				entry->mnt_type = xstrdup(ment->mnt_type);
+			}
+		}
+	}
+
+done:
+	free(rp);
+	endmntent(fp);
+
+	if (!found)
+		return -1;
+
+	return ret;
+}
+
+int fsmonitor__get_fs_info(const char *path, struct fs_info *fs_info)
+{
+	int ret = 0;
+	struct mntent entry;
+	struct statvfs fs;
+
+	fs_info->is_remote = -1;
+	fs_info->typename = NULL;
+
+	if (statvfs(path, &fs))
+		return error_errno(_("statvfs('%s') failed"), path);
+
+	if (find_mount(path, &fs, &entry) < 0) {
+		ret = -1;
+		goto done;
+	}
+
+	trace_printf_key(&trace_fsmonitor,
+			 "statvfs('%s') [flags 0x%08lx] '%s' '%s'",
+			 path, fs.f_flag, entry.mnt_type, entry.mnt_fsname);
+
+	fs_info->is_remote = is_remote_fs(entry.mnt_dir);
+	fs_info->typename = xstrdup(entry.mnt_fsname);
+
+	if (fs_info->is_remote < 0)
+		ret = -1;
+
+	trace_printf_key(&trace_fsmonitor,
+				"'%s' is_remote: %d",
+				path, fs_info->is_remote);
+
+done:
+	free(entry.mnt_fsname);
+	free(entry.mnt_dir);
+	free(entry.mnt_type);
+	return ret;
+}
+
+int fsmonitor__is_fs_remote(const char *path)
+{
+	int ret = 0;
+	struct fs_info fs;
+
+	if (fsmonitor__get_fs_info(path, &fs))
+		ret = -1;
+	else
+		ret = fs.is_remote;
+
+	free(fs.typename);
+
+	return ret;
+}
+
+/*
+ * No-op for now.
+ */
+int fsmonitor__get_alias(const char *path, struct alias_info *info)
+{
+	return 0;
+}
+
+/*
+ * No-op for now.
+ */
+char *fsmonitor__resolve_alias(const char *path,
+		const struct alias_info *info)
+{
+	return NULL;
+}