git: dd62980f662c - stable/14 - pw userdel: destroy home dataset if empty
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Date: Wed, 21 Aug 2024 10:31:43 UTC
The branch stable/14 has been updated by des:
URL: https://cgit.FreeBSD.org/src/commit/?id=dd62980f662cd632bf59c6062f48b5021b307afe
commit dd62980f662cd632bf59c6062f48b5021b307afe
Author: Mike Karels <karels@FreeBSD.org>
AuthorDate: 2024-05-29 23:55:14 +0000
Commit: Dag-Erling Smørgrav <des@FreeBSD.org>
CommitDate: 2024-08-21 10:31:10 +0000
pw userdel: destroy home dataset if empty
When removing a user's home directory, if the directory is a ZFS
dataset, it cannot be removed. If the directory has been emptied,
use "zfs destroy" to destroy it. This complements the automatic
dataset creation in adduser. Note that datasets within the directory
and snapshots are not handled, as the complete path is not constructed.
While here, add waitpid() calls to rmat() and pw_user_del().
Reviewed by: des
Differential Revision: https://reviews.freebsd.org/D45348
(cherry picked from commit d2f1f71ec8c62dd26d6169d0d671a5aa5a933c1a)
---
usr.sbin/pw/pw.8 | 6 ++-
usr.sbin/pw/pw_user.c | 15 ++++---
usr.sbin/pw/pwupd.h | 2 +-
usr.sbin/pw/rm_r.c | 113 +++++++++++++++++++++++++++++++++++++++++++++-----
4 files changed, 118 insertions(+), 18 deletions(-)
diff --git a/usr.sbin/pw/pw.8 b/usr.sbin/pw/pw.8
index 5d461fc6464e..5ba35c193811 100644
--- a/usr.sbin/pw/pw.8
+++ b/usr.sbin/pw/pw.8
@@ -741,6 +741,9 @@ Secondly, it will only remove files and directories that are actually owned by
the user, or symbolic links owned by anyone under the user's home directory.
Finally, after deleting all contents owned by the user only empty directories
will be removed.
+If the home directory is a ZFS dataset and has been emptied,
+the dataset will be destroyed.
+ZFS datasets within the home directory and snapshots are not handled.
If any additional cleanup work is required, this is left to the administrator.
.El
.Pp
@@ -1077,7 +1080,8 @@ No base home directory configured.
.Xr passwd 5 ,
.Xr pw.conf 5 ,
.Xr pwd_mkdb 8 ,
-.Xr vipw 8
+.Xr vipw 8 ,
+.Xr zfs 8
.Sh HISTORY
The
.Nm
diff --git a/usr.sbin/pw/pw_user.c b/usr.sbin/pw/pw_user.c
index 89354b249935..d9fd8c77c13e 100644
--- a/usr.sbin/pw/pw_user.c
+++ b/usr.sbin/pw/pw_user.c
@@ -28,7 +28,7 @@
*/
#include <sys/param.h>
-#include <sys/types.h>
+#include <sys/wait.h>
#include <assert.h>
#include <ctype.h>
@@ -669,6 +669,7 @@ rmat(uid_t uid)
while ((e = readdir(d)) != NULL) {
struct stat st;
+ pid_t pid;
if (strncmp(e->d_name, ".lock", 5) != 0 &&
stat(e->d_name, &st) == 0 &&
@@ -679,11 +680,12 @@ rmat(uid_t uid)
e->d_name,
NULL
};
- if (posix_spawn(NULL, argv[0], NULL, NULL,
+ if (posix_spawn(&pid, argv[0], NULL, NULL,
(char *const *) argv, environ)) {
warn("Failed to execute '%s %s'",
argv[0], argv[1]);
- }
+ } else
+ (void) waitpid(pid, NULL, 0);
}
}
closedir(d);
@@ -919,11 +921,14 @@ pw_user_del(int argc, char **argv, char *arg1)
"-r",
NULL
};
- if (posix_spawnp(NULL, argv[0], NULL, NULL,
+ pid_t pid;
+
+ if (posix_spawnp(&pid, argv[0], NULL, NULL,
(char *const *) argv, environ)) {
warn("Failed to execute '%s %s'",
argv[0], argv[1]);
- }
+ } else
+ (void) waitpid(pid, NULL, 0);
}
}
diff --git a/usr.sbin/pw/pwupd.h b/usr.sbin/pw/pwupd.h
index 4eff0be81066..55d359d5cc6f 100644
--- a/usr.sbin/pw/pwupd.h
+++ b/usr.sbin/pw/pwupd.h
@@ -140,7 +140,7 @@ void vendgrent(void);
void copymkdir(int rootfd, char const * dir, int skelfd, mode_t mode, uid_t uid,
gid_t gid, int flags);
-void rm_r(int rootfd, char const * dir, uid_t uid);
+bool rm_r(int rootfd, char const * dir, uid_t uid);
__END_DECLS
#endif /* !_PWUPD_H */
diff --git a/usr.sbin/pw/rm_r.c b/usr.sbin/pw/rm_r.c
index 14218d68215b..f25da8ce6ad3 100644
--- a/usr.sbin/pw/rm_r.c
+++ b/usr.sbin/pw/rm_r.c
@@ -26,35 +26,58 @@
* SUCH DAMAGE.
*/
+#include <sys/param.h>
+#include <sys/mount.h>
#include <sys/stat.h>
+#include <sys/wait.h>
#include <dirent.h>
+#include <err.h>
+#include <errno.h>
#include <fcntl.h>
+#include <libgen.h>
+#include <libutil.h>
+#include <spawn.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "pwupd.h"
-void
+static bool try_dataset_remove(const char *home);
+extern char **environ;
+
+/*
+ * "rm -r" a directory tree. If the top-level directory cannot be removed
+ * due to EBUSY, indicating that it is a ZFS dataset, and we have emptied
+ * it, destroy the dataset. Return true if any files or directories
+ * remain.
+ */
+bool
rm_r(int rootfd, const char *path, uid_t uid)
{
int dirfd;
DIR *d;
struct dirent *e;
struct stat st;
+ const char *fullpath;
+ bool skipped = false;
+ fullpath = path;
if (*path == '/')
path++;
dirfd = openat(rootfd, path, O_DIRECTORY);
if (dirfd == -1) {
- return;
+ return (true);
}
d = fdopendir(dirfd);
if (d == NULL) {
(void)close(dirfd);
- return;
+ return (true);
}
while ((e = readdir(d)) != NULL) {
if (strcmp(e->d_name, ".") == 0 || strcmp(e->d_name, "..") == 0)
@@ -62,16 +85,84 @@ rm_r(int rootfd, const char *path, uid_t uid)
if (fstatat(dirfd, e->d_name, &st, AT_SYMLINK_NOFOLLOW) != 0)
continue;
- if (S_ISDIR(st.st_mode))
- rm_r(dirfd, e->d_name, uid);
- else if (S_ISLNK(st.st_mode) || st.st_uid == uid)
+ if (S_ISDIR(st.st_mode)) {
+ if (rm_r(dirfd, e->d_name, uid) == true)
+ skipped = true;
+ } else if (S_ISLNK(st.st_mode) || st.st_uid == uid)
unlinkat(dirfd, e->d_name, 0);
+ else
+ skipped = true;
}
closedir(d);
if (fstatat(rootfd, path, &st, AT_SYMLINK_NOFOLLOW) != 0)
- return;
- if (S_ISLNK(st.st_mode))
- unlinkat(rootfd, path, 0);
- else if (st.st_uid == uid)
- unlinkat(rootfd, path, AT_REMOVEDIR);
+ return (skipped);
+ if (S_ISLNK(st.st_mode)) {
+ if (unlinkat(rootfd, path, 0) == -1)
+ skipped = true;
+ } else if (st.st_uid == uid) {
+ if (unlinkat(rootfd, path, AT_REMOVEDIR) == -1) {
+ if (errno == EBUSY && skipped == false)
+ skipped = try_dataset_remove(fullpath);
+ else
+ skipped = true;
+ }
+ } else
+ skipped = true;
+
+ return (skipped);
+}
+
+/*
+ * If the home directory is a ZFS dataset, attempt to destroy it.
+ * Return true if the dataset is not destroyed.
+ * This would be more straightforward as a shell script.
+ */
+static bool
+try_dataset_remove(const char *path)
+{
+ bool skipped = true;
+ struct statfs stat;
+ const char *argv[] = {
+ "/sbin/zfs",
+ "destroy",
+ NULL,
+ NULL
+ };
+ int status;
+ pid_t pid;
+
+ /* see if this is an absolute path (top-level directory) */
+ if (*path != '/')
+ return (skipped);
+ /* see if ZFS is loaded */
+ if (kld_isloaded("zfs") == 0)
+ return (skipped);
+ /* This won't work if root dir is not / (-R option) */
+ if (strcmp(conf.rootdir, "/") != 0) {
+ warnx("cannot destroy home dataset when -R was used");
+ return (skipped);
+ }
+ /* if so, find dataset name */
+ if (statfs(path, &stat) != 0) {
+ warn("statfs %s", path);
+ return (skipped);
+ }
+ /*
+ * Check that the path refers to the dataset itself,
+ * not a subdirectory.
+ */
+ if (strcmp(stat.f_mntonname, path) != 0)
+ return (skipped);
+ argv[2] = stat.f_mntfromname;
+ if ((skipped = posix_spawn(&pid, argv[0], NULL, NULL,
+ (char *const *) argv, environ)) != 0) {
+ warn("Failed to execute '%s %s %s'",
+ argv[0], argv[1], argv[2]);
+ } else {
+ if (waitpid(pid, &status, 0) != -1 && status != 0) {
+ warnx("'%s %s %s' exit status %d\n",
+ argv[0], argv[1], argv[2], status);
+ }
+ }
+ return (skipped);
}