diff options
Diffstat (limited to 'man2/mount_setattr.2')
| -rw-r--r-- | man2/mount_setattr.2 | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/man2/mount_setattr.2 b/man2/mount_setattr.2 index 8df02641a..efccd5b53 100644 --- a/man2/mount_setattr.2 +++ b/man2/mount_setattr.2 @@ -10,8 +10,6 @@ Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf - -.PP .BR "#include <linux/fcntl.h>" " /* Definition of " AT_* " constants */" .BR "#include <linux/mount.h>" " /* Definition of " MOUNT_ATTR_* " constants */" .BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */" @@ -175,19 +173,19 @@ are equivalent to the following steps: .in +4n .EX unsigned int current_mnt_flags = mnt\->mnt_flags; - +\& /* * Clear all flags set in .attr_clr, * clearing MOUNT_ATTR_NOEXEC and MOUNT_ATTR_NODEV. */ current_mnt_flags &= \(tiattr\->attr_clr; - +\& /* * Now set all flags set in .attr_set, * applying MOUNT_ATTR_RDONLY and MOUNT_ATTR_NOSUID. */ current_mnt_flags |= attr\->attr_set; - +\& mnt\->mnt_flags = current_mnt_flags; .EE .in @@ -912,7 +910,7 @@ with a structure which has every byte nonzero #include <string.h> #include <sys/syscall.h> #include <unistd.h> - +\& static inline int mount_setattr(int dirfd, const char *pathname, unsigned int flags, struct mount_attr *attr, size_t size) @@ -920,13 +918,13 @@ mount_setattr(int dirfd, const char *pathname, unsigned int flags, return syscall(SYS_mount_setattr, dirfd, pathname, flags, attr, size); } - +\& static inline int open_tree(int dirfd, const char *filename, unsigned int flags) { return syscall(SYS_open_tree, dirfd, filename, flags); } - +\& static inline int move_mount(int from_dirfd, const char *from_pathname, int to_dirfd, const char *to_pathname, unsigned int flags) @@ -934,7 +932,7 @@ move_mount(int from_dirfd, const char *from_pathname, return syscall(SYS_move_mount, from_dirfd, from_pathname, to_dirfd, to_pathname, flags); } - +\& static const struct option longopts[] = { {"map\-mount", required_argument, NULL, \[aq]a\[aq]}, {"recursive", no_argument, NULL, \[aq]b\[aq]}, @@ -945,7 +943,7 @@ static const struct option longopts[] = { {"no\-access\-time", no_argument, NULL, \[aq]g\[aq]}, { NULL, 0, NULL, 0 }, }; - +\& int main(int argc, char *argv[]) { @@ -957,7 +955,7 @@ main(int argc, char *argv[]) const char *source; const char *target; struct mount_attr *attr = &(struct mount_attr){}; - +\& while ((ret = getopt_long_only(argc, argv, "", longopts, &index)) != \-1) { switch (ret) { @@ -989,13 +987,13 @@ main(int argc, char *argv[]) errx(EXIT_FAILURE, "Invalid argument specified"); } } - +\& if ((argc \- optind) < 2) errx(EXIT_FAILURE, "Missing source or target mount point"); - +\& source = argv[optind]; target = argv[optind + 1]; - +\& /* In the following, \-1 as the \[aq]dirfd\[aq] argument ensures that open_tree() fails if \[aq]source\[aq] is not an absolute pathname. */ .\" Christian Brauner @@ -1010,36 +1008,36 @@ main(int argc, char *argv[]) .\" resolve-flag space have made this **chef's kiss**. .\" If I can't operate based on a well-known dirfd I use absolute paths .\" with a -EBADF dirfd passed to *at() functions. - +\& fd_tree = open_tree(\-1, source, OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC | AT_EMPTY_PATH | (recursive ? AT_RECURSIVE : 0)); if (fd_tree == \-1) err(EXIT_FAILURE, "open(%s)", source); - +\& if (fd_userns >= 0) { attr\->attr_set |= MOUNT_ATTR_IDMAP; attr\->userns_fd = fd_userns; } - +\& ret = mount_setattr(fd_tree, "", AT_EMPTY_PATH | (recursive ? AT_RECURSIVE : 0), attr, sizeof(struct mount_attr)); if (ret == \-1) err(EXIT_FAILURE, "mount_setattr"); - +\& close(fd_userns); - +\& /* In the following, \-1 as the \[aq]to_dirfd\[aq] argument ensures that open_tree() fails if \[aq]target\[aq] is not an absolute pathname. */ - +\& ret = move_mount(fd_tree, "", \-1, target, MOVE_MOUNT_F_EMPTY_PATH); if (ret == \-1) err(EXIT_FAILURE, "move_mount() to %s", target); - +\& close(fd_tree); - +\& exit(EXIT_SUCCESS); } .EE |