pgmkdirp.c File Reference

#include "c.h"
#include <sys/stat.h>

Include dependency graph for pgmkdirp.c:

Go to the source code of this file.

Functions
int	pg_mkdir_p (char *path, int omode)

Function Documentation

pg_mkdir_p()

int pg_mkdir_p	(	char *	path,
		int	omode
	)

Definition at line 57 of file pgmkdirp.c.

{
    mode_t      numask,
                oumask;
    int         last,
                retval;
    char       *p;
 
    retval = 0;
    p = path;
 
#ifdef WIN32
    /* skip network and drive specifiers for win32 */
    if (strlen(p) >= 2)
    {
        if (p[0] == '/' && p[1] == '/')
        {
            /* network drive */
            p = strchr(p + 2, '/');
            if (p == NULL)
            {
                errno = EINVAL;
                return -1;
            }
        }
        else if (p[1] == ':' &&
                 ((p[0] >= 'a' && p[0] <= 'z') ||
                  (p[0] >= 'A' && p[0] <= 'Z')))
        {
            /* local drive */
            p += 2;
        }
    }
#endif
 
    /*
     * POSIX 1003.2: For each dir operand that does not name an existing
     * directory, effects equivalent to those caused by the following command
     * shall occur:
     *
     * mkdir -p -m $(umask -S),u+wx $(dirname dir) && mkdir [-m mode] dir
     *
     * We change the user's umask and then restore it, instead of doing
     * chmod's.  Note we assume umask() can't change errno.
     */
    oumask = umask(0);
    numask = oumask & ~(S_IWUSR | S_IXUSR);
    (void) umask(numask);
 
    if (p[0] == '/')            /* Skip leading '/'. */
        ++p;
    for (last = 0; !last; ++p)
    {
        if (p[0] == '\0')
            last = 1;
        else if (p[0] != '/')
            continue;
        *p = '\0';
        if (!last && p[1] == '\0')
            last = 1;
 
        if (last)
            (void) umask(oumask);
 
        if (mkdir(path, last ? omode : S_IRWXU | S_IRWXG | S_IRWXO) < 0)
        {
            /*
             * If we got EEXIST because there's already a directory there,
             * don't complain.
             */
#ifndef WIN32
            int         save_errno = errno;
            struct stat sb;
 
            if (save_errno != EEXIST ||
                stat(path, &sb) != 0 ||
                !S_ISDIR(sb.st_mode))
            {
                /* Don't let stat replace mkdir's errno */
                errno = save_errno;
                retval = -1;
                break;
            }
#else                           /* WIN32 */
            /*
             * On Windows, stat() opens a handle and can transiently fail on a
             * directory another process is concurrently creating.  Probe with
             * a path-based attribute query instead: it requests only
             * FILE_READ_ATTRIBUTES and is exempt from share-mode denial, so
             * it reliably sees a concurrently-created directory.  We assume
             * GetFileAttributes() won't change errno.
             */
            DWORD       attr = GetFileAttributes(path);
 
            if (errno != EEXIST ||
                attr == INVALID_FILE_ATTRIBUTES ||
                !(attr & FILE_ATTRIBUTE_DIRECTORY))
            {
                retval = -1;
                break;
            }
#endif                          /* WIN32 */
        }
 
        if (!last)
            *p = '/';
    }
 
    /* ensure we restored umask */
    (void) umask(oumask);
 
    return retval;
}

References fb(), mkdir, S_IRWXG, S_IRWXO, S_IRWXU, S_ISDIR, S_IWUSR, S_IXUSR, and stat.

Referenced by create_data_directory(), create_fullpage_directory(), create_output_directory(), create_xlog_or_symlink(), main(), prepare_for_swap(), recovery_create_dbdir(), StartLogStreamer(), TablespaceCreateDbspace(), and verify_dir_is_empty_or_create().