1 /*-------------------------------------------------------------------------
2  *
3  * rmtree.c
4  *
5  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
6  * Portions Copyright (c) 1994, Regents of the University of California
7  *
8  * IDENTIFICATION
9  *	  src/common/rmtree.c
10  *
11  *-------------------------------------------------------------------------
12  */
13 
14 #ifndef FRONTEND
15 #include "postgres.h"
16 #else
17 #include "postgres_fe.h"
18 #endif
19 
20 #include <unistd.h>
21 #include <sys/stat.h>
22 
23 #ifndef FRONTEND
24 #define pg_log_warning(...) elog(WARNING, __VA_ARGS__)
25 #else
26 #include "common/logging.h"
27 #endif
28 
29 
30 /*
31  *	rmtree
32  *
33  *	Delete a directory tree recursively.
34  *	Assumes path points to a valid directory.
35  *	Deletes everything under path.
36  *	If rmtopdir is true deletes the directory too.
37  *	Returns true if successful, false if there was any problem.
38  *	(The details of the problem are reported already, so caller
39  *	doesn't really have to say anything more, but most do.)
40  */
41 bool
42 rmtree(const char *path, bool rmtopdir)
43 {
44 	bool		result = true;
45 	char		pathbuf[MAXPGPATH];
46 	char	  **filenames;
47 	char	  **filename;
48 	struct stat statbuf;
49 
50 	/*
51 	 * we copy all the names out of the directory before we start modifying
52 	 * it.
53 	 */
54 	filenames = pgfnames(path);
55 
56 	if (filenames == NULL)
57 		return false;
58 
59 	/* now we have the names we can start removing things */
60 	for (filename = filenames; *filename; filename++)
61 	{
62 		snprintf(pathbuf, MAXPGPATH, "%s/%s", path, *filename);
63 
64 		/*
65 		 * It's ok if the file is not there anymore; we were just about to
66 		 * delete it anyway.
67 		 *
68 		 * This is not an academic possibility. One scenario where this
69 		 * happens is when bgwriter has a pending unlink request for a file in
70 		 * a database that's being dropped. In dropdb(), we call
71 		 * ForgetDatabaseSyncRequests() to flush out any such pending unlink
72 		 * requests, but because that's asynchronous, it's not guaranteed that
73 		 * the bgwriter receives the message in time.
74 		 */
75 		if (lstat(pathbuf, &statbuf) != 0)
76 		{
77 			if (errno != ENOENT)
78 			{
79 				pg_log_warning("could not stat file or directory \"%s\": %m",
80 							   pathbuf);
81 				result = false;
82 			}
83 			continue;
84 		}
85 
86 		if (S_ISDIR(statbuf.st_mode))
87 		{
88 			/* call ourselves recursively for a directory */
89 			if (!rmtree(pathbuf, true))
90 			{
91 				/* we already reported the error */
92 				result = false;
93 			}
94 		}
95 		else
96 		{
97 			if (unlink(pathbuf) != 0)
98 			{
99 				if (errno != ENOENT)
100 				{
101 					pg_log_warning("could not remove file or directory \"%s\": %m",
102 								   pathbuf);
103 					result = false;
104 				}
105 			}
106 		}
107 	}
108 
109 	if (rmtopdir)
110 	{
111 		if (rmdir(path) != 0)
112 		{
113 			pg_log_warning("could not remove file or directory \"%s\": %m",
114 						   path);
115 			result = false;
116 		}
117 	}
118 
119 	pgfnames_cleanup(filenames);
120 
121 	return result;
122 }
123