1 files changed, 128 insertions, 5 deletions

diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index ec37d0b2e0d..065368a2208 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -15,6 +15,7 @@
 #include "postgres_fe.h"
 
 #include <sys/stat.h>
+#include <dirent.h>
 #include <fcntl.h>
 #include <unistd.h>
 
@@ -35,6 +36,9 @@ static void remove_target_dir(const char *path);
 static void create_target_symlink(const char *path, const char *link);
 static void remove_target_symlink(const char *path);
 
+static void recurse_dir(const char *datadir, const char *parentpath,
+						process_file_callback_t callback);
+
 /*
  * Open a target file for writing. If 'trunc' is true and the file already
  * exists, it will be truncated.
@@ -83,7 +87,7 @@ close_target_file(void)
 void
 write_target_range(char *buf, off_t begin, size_t size)
 {
-	int			writeleft;
+	size_t		writeleft;
 	char	   *p;
 
 	/* update progress report */
@@ -101,7 +105,7 @@ write_target_range(char *buf, off_t begin, size_t size)
 	p = buf;
 	while (writeleft > 0)
 	{
-		int			writelen;
+		ssize_t		writelen;
 
 		errno = 0;
 		writelen = write(dstfd, p, writeleft);
@@ -305,9 +309,6 @@ sync_target_dir(void)
  * buffer is actually *filesize + 1. That's handy when reading a text file.
  * This function can be used to read binary files as well, you can just
  * ignore the zero-terminator in that case.
- *
- * This function is used to implement the fetchFile function in the "fetch"
- * interface (see fetch.c), but is also called directly.
  */
 char *
 slurpFile(const char *datadir, const char *path, size_t *filesize)
@@ -352,3 +353,125 @@ slurpFile(const char *datadir, const char *path, size_t *filesize)
 		*filesize = len;
 	return buffer;
 }
+
+/*
+ * Traverse through all files in a data directory, calling 'callback'
+ * for each file.
+ */
+void
+traverse_datadir(const char *datadir, process_file_callback_t callback)
+{
+	recurse_dir(datadir, NULL, callback);
+}
+
+/*
+ * recursive part of traverse_datadir
+ *
+ * parentpath is the current subdirectory's path relative to datadir,
+ * or NULL at the top level.
+ */
+static void
+recurse_dir(const char *datadir, const char *parentpath,
+			process_file_callback_t callback)
+{
+	DIR		   *xldir;
+	struct dirent *xlde;
+	char		fullparentpath[MAXPGPATH];
+
+	if (parentpath)
+		snprintf(fullparentpath, MAXPGPATH, "%s/%s", datadir, parentpath);
+	else
+		snprintf(fullparentpath, MAXPGPATH, "%s", datadir);
+
+	xldir = opendir(fullparentpath);
+	if (xldir == NULL)
+		pg_fatal("could not open directory \"%s\": %m",
+				 fullparentpath);
+
+	while (errno = 0, (xlde = readdir(xldir)) != NULL)
+	{
+		struct stat fst;
+		char		fullpath[MAXPGPATH * 2];
+		char		path[MAXPGPATH * 2];
+
+		if (strcmp(xlde->d_name, ".") == 0 ||
+			strcmp(xlde->d_name, "..") == 0)
+			continue;
+
+		snprintf(fullpath, sizeof(fullpath), "%s/%s", fullparentpath, xlde->d_name);
+
+		if (lstat(fullpath, &fst) < 0)
+		{
+			if (errno == ENOENT)
+			{
+				/*
+				 * File doesn't exist anymore. This is ok, if the new primary
+				 * is running and the file was just removed. If it was a data
+				 * file, there should be a WAL record of the removal. If it
+				 * was something else, it couldn't have been anyway.
+				 *
+				 * TODO: But complain if we're processing the target dir!
+				 */
+			}
+			else
+				pg_fatal("could not stat file \"%s\": %m",
+						 fullpath);
+		}
+
+		if (parentpath)
+			snprintf(path, sizeof(path), "%s/%s", parentpath, xlde->d_name);
+		else
+			snprintf(path, sizeof(path), "%s", xlde->d_name);
+
+		if (S_ISREG(fst.st_mode))
+			callback(path, FILE_TYPE_REGULAR, fst.st_size, NULL);
+		else if (S_ISDIR(fst.st_mode))
+		{
+			callback(path, FILE_TYPE_DIRECTORY, 0, NULL);
+			/* recurse to handle subdirectories */
+			recurse_dir(datadir, path, callback);
+		}
+#ifndef WIN32
+		else if (S_ISLNK(fst.st_mode))
+#else
+		else if (pgwin32_is_junction(fullpath))
+#endif
+		{
+#if defined(HAVE_READLINK) || defined(WIN32)
+			char		link_target[MAXPGPATH];
+			int			len;
+
+			len = readlink(fullpath, link_target, sizeof(link_target));
+			if (len < 0)
+				pg_fatal("could not read symbolic link \"%s\": %m",
+						 fullpath);
+			if (len >= sizeof(link_target))
+				pg_fatal("symbolic link \"%s\" target is too long",
+						 fullpath);
+			link_target[len] = '\0';
+
+			callback(path, FILE_TYPE_SYMLINK, 0, link_target);
+
+			/*
+			 * If it's a symlink within pg_tblspc, we need to recurse into it,
+			 * to process all the tablespaces.  We also follow a symlink if
+			 * it's for pg_wal.  Symlinks elsewhere are ignored.
+			 */
+			if ((parentpath && strcmp(parentpath, "pg_tblspc") == 0) ||
+				strcmp(path, "pg_wal") == 0)
+				recurse_dir(datadir, path, callback);
+#else
+			pg_fatal("\"%s\" is a symbolic link, but symbolic links are not supported on this platform",
+					 fullpath);
+#endif							/* HAVE_READLINK */
+		}
+	}
+
+	if (errno)
+		pg_fatal("could not read directory \"%s\": %m",
+				 fullparentpath);
+
+	if (closedir(xldir))
+		pg_fatal("could not close directory \"%s\": %m",
+				 fullparentpath);
+}