rmtree.c

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/*-------------------------------------------------------------------------
 *
 * rmtree.c
 *
 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *    src/common/rmtree.c
 *
 *-------------------------------------------------------------------------
 */
 
#ifndef FRONTEND
#include "postgres.h"
#else
#include "postgres_fe.h"
#endif
 
#include <unistd.h>
#include <sys/stat.h>
 
#include "common/file_utils.h"
 
#ifndef FRONTEND
#include "storage/fd.h"
#define pg_log_warning(...) elog(WARNING, __VA_ARGS__)
#define LOG_LEVEL WARNING
#define OPENDIR(x) AllocateDir(x)
#define CLOSEDIR(x) FreeDir(x)
#else
#include "common/logging.h"
#define LOG_LEVEL PG_LOG_WARNING
#define OPENDIR(x) opendir(x)
#define CLOSEDIR(x) closedir(x)
#endif
 
/*
 *  rmtree
 *
 *  Delete a directory tree recursively.
 *  Assumes path points to a valid directory.
 *  Deletes everything under path.
 *  If rmtopdir is true deletes the directory too.
 *  Returns true if successful, false if there was any problem.
 *  (The details of the problem are reported already, so caller
 *  doesn't really have to say anything more, but most do.)
 */
bool
rmtree(const char *path, bool rmtopdir)
{
    char        pathbuf[MAXPGPATH];
    DIR        *dir;
    struct dirent *de;
    bool        result = true;
    size_t      dirnames_size = 0;
    size_t      dirnames_capacity = 8;
    char      **dirnames = palloc(sizeof(char *) * dirnames_capacity);
 
    dir = OPENDIR(path);
    if (dir == NULL)
    {
        pg_log_warning("could not open directory \"%s\": %m", path);
        return false;
    }
 
    while (errno = 0, (de = readdir(dir)))
    {
        if (strcmp(de->d_name, ".") == 0 ||
            strcmp(de->d_name, "..") == 0)
            continue;
        snprintf(pathbuf, sizeof(pathbuf), "%s/%s", path, de->d_name);
        switch (get_dirent_type(pathbuf, de, false, LOG_LEVEL))
        {
            case PGFILETYPE_ERROR:
                /* already logged, press on */
                break;
            case PGFILETYPE_DIR:
 
                /*
                 * Defer recursion until after we've closed this directory, to
                 * avoid using more than one file descriptor at a time.
                 */
                if (dirnames_size == dirnames_capacity)
                {
                    dirnames = repalloc(dirnames,
                                        sizeof(char *) * dirnames_capacity * 2);
                    dirnames_capacity *= 2;
                }
                dirnames[dirnames_size++] = pstrdup(pathbuf);
                break;
            default:
                if (unlink(pathbuf) != 0 && errno != ENOENT)
                {
                    pg_log_warning("could not unlink file \"%s\": %m", pathbuf);
                    result = false;
                }
                break;
        }
    }
 
    if (errno != 0)
    {
        pg_log_warning("could not read directory \"%s\": %m", path);
        result = false;
    }
 
    CLOSEDIR(dir);
 
    /* Now recurse into the subdirectories we found. */
    for (size_t i = 0; i < dirnames_size; ++i)
    {
        if (!rmtree(dirnames[i], true))
            result = false;
        pfree(dirnames[i]);
    }
 
    if (rmtopdir)
    {
        if (rmdir(path) != 0)
        {
            pg_log_warning("could not remove directory \"%s\": %m", path);
            result = false;
        }
    }
 
    pfree(dirnames);
 
    return result;
}