granicus.if.org Git - postgresql/blob - src/common/rmtree.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * rmtree.c
   4  *
   5  * Portions Copyright (c) 1996-2019, 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 "fe_utils/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 }