xfs_io: Allow -P and -L to be given to open for O_PATH and O_NOFOLLOW

[thirdparty/xfsprogs-dev.git] / io / open.c

diff --git a/io/open.c b/io/open.c
index 2cce0455263a1da26cc1eaea762c68b67fa0735c..4a92b423e9e0ffabd038b56586a795e485706a1c 100644 (file)
--- a/io/open.c
+++ b/io/open.c
@@ -38,6 +38,18 @@
 #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
 #endif
 
+#ifndef O_PATH
+#if defined __alpha__
+#define O_PATH          040000000
+#elif defined(__hppa__)
+#define O_PATH          020000000
+#elif defined(__sparc__)
+#define O_PATH          0x1000000
+#else
+#define O_PATH          010000000
+#endif
+#endif /* O_PATH */
+
 static cmdinfo_t open_cmd;
 static cmdinfo_t close_cmd;
 static cmdinfo_t chproj_cmd;
@@ -74,6 +86,10 @@ openfile(
                oflags |= O_NONBLOCK;
        if (flags & IO_TMPFILE)
                oflags |= O_TMPFILE;
+       if (flags & IO_PATH)
+               oflags |= O_PATH;
+       if (flags & IO_NOFOLLOW)
+               oflags |= O_NOFOLLOW;
 
        fd = open(path, oflags, mode);
        if (fd < 0) {
@@ -97,13 +113,16 @@ openfile(
        if (!geom || !platform_test_xfs_fd(fd))
                return fd;
 
-       if (xfsctl(path, fd, XFS_IOC_FSGEOMETRY, geom) < 0) {
+       if (flags & IO_PATH) {
+               /* Can't call ioctl() on O_PATH fds */
+               memset(geom, 0, sizeof(*geom));
+       } else if (xfsctl(path, fd, XFS_IOC_FSGEOMETRY, geom) < 0) {
                perror("XFS_IOC_FSGEOMETRY");
                close(fd);
                return -1;
        }
 
-       if (!(flags & IO_READONLY) && (flags & IO_REALTIME)) {
+       if (!(flags & (IO_READONLY | IO_PATH)) && (flags & IO_REALTIME)) {
                struct fsxattr  attr;
 
                if (xfsctl(path, fd, FS_IOC_FSGETXATTR, &attr) < 0) {
@@ -191,6 +210,8 @@ open_help(void)
 " -t -- open with O_TRUNC (truncate the file to zero length if it exists)\n"
 " -R -- mark the file as a realtime XFS file immediately after opening it\n"
 " -T -- open with O_TMPFILE (create a file not visible in the namespace)\n"
+" -P -- open with O_PATH (create an fd that is merely a location reference)\n"
+" -L -- open with O_NOFOLLOW (don't follow symlink)\n"
 " Note1: usually read/write direct IO requests must be blocksize aligned;\n"
 "        some kernels, however, allow sectorsize alignment for direct IO.\n"
 " Note2: the bmap for non-regular files can be obtained provided the file\n"
@@ -216,7 +237,7 @@ open_f(
                return 0;
        }
 
-       while ((c = getopt(argc, argv, "FRTacdfm:nrstx")) != EOF) {
+       while ((c = getopt(argc, argv, "FLPRTacdfm:nrstx")) != EOF) {
                switch (c) {
                case 'F':
                        /* Ignored / deprecated now, handled automatically */
@@ -257,6 +278,12 @@ open_f(
                case 'T':
                        flags |= IO_TMPFILE;
                        break;
+               case 'P':
+                       flags |= IO_PATH;
+                       break;
+               case 'L':
+                       flags |= IO_NOFOLLOW;
+                       break;
                default:
                        return command_usage(&open_cmd);
                }
@@ -270,6 +297,12 @@ open_f(
                return -1;
        }
 
+       if ((flags & (IO_PATH|IO_NOFOLLOW)) &&
+           (flags & ~(IO_PATH|IO_NOFOLLOW))) {
+               fprintf(stderr, _("-P and -L are incompatible with the other options\n"));
+               return -1;
+       }
+
        fd = openfile(argv[optind], &geometry, flags, mode, &fsp);
        if (fd < 0)
                return 0;
@@ -785,7 +818,7 @@ open_init(void)
        open_cmd.argmax = -1;
        open_cmd.flags = CMD_NOMAP_OK | CMD_NOFILE_OK |
                         CMD_FOREIGN_OK | CMD_FLAG_ONESHOT;
-       open_cmd.args = _("[-acdrstxT] [-m mode] [path]");
+       open_cmd.args = _("[-acdrstxRTPL] [-m mode] [path]");
        open_cmd.oneline = _("open the file specified by path");
        open_cmd.help = open_help;