From: Christian Brauner <brauner@kernel.org>
To: linux-fsdevel@vger.kernel.org
Cc: Josef Bacik <josef@toxicpanda.com>,
Jeff Layton <jlayton@kernel.org>,
Lennart Poettering <lennart@poettering.net>,
Daan De Meyer <daan.j.demeyer@gmail.com>,
Seth Forshee <sforshee@kernel.org>,
Miklos Szeredi <miklos@szeredi.hu>,
Christian Brauner <brauner@kernel.org>
Subject: [PATCH v2 4/4] samples/vfs: add STATMOUNT_MNT_{G,U}IDMAP
Date: Tue, 04 Feb 2025 12:27:49 +0100 [thread overview]
Message-ID: <20250204-work-mnt_idmap-statmount-v2-4-007720f39f2e@kernel.org> (raw)
In-Reply-To: <20250204-work-mnt_idmap-statmount-v2-0-007720f39f2e@kernel.org>
Illustrate how to use STATMOUNT_MNT_{G,U}IDMAP.
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
samples/vfs/samples-vfs.h | 14 +++++++++++++-
samples/vfs/test-list-all-mounts.c | 26 ++++++++++++++++++++++++--
2 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/samples/vfs/samples-vfs.h b/samples/vfs/samples-vfs.h
index 103e1e7c4cec..a7ff4e79e8e6 100644
--- a/samples/vfs/samples-vfs.h
+++ b/samples/vfs/samples-vfs.h
@@ -42,7 +42,11 @@ struct statmount {
__u32 opt_array; /* [str] Array of nul terminated fs options */
__u32 opt_sec_num; /* Number of security options */
__u32 opt_sec_array; /* [str] Array of nul terminated security options */
- __u64 __spare2[46];
+ __u32 mnt_uidmap_num; /* Number of uid mappings */
+ __u32 mnt_uidmap; /* [str] Array of uid mappings */
+ __u32 mnt_gidmap_num; /* Number of gid mappings */
+ __u32 mnt_gidmap; /* [str] Array of gid mappings */
+ __u64 __spare2[44];
char str[]; /* Variable size part containing strings */
};
@@ -158,6 +162,14 @@ struct mnt_ns_info {
#define STATX_MNT_ID_UNIQUE 0x00004000U /* Want/got extended stx_mount_id */
#endif
+#ifndef STATMOUNT_MNT_UIDMAP
+#define STATMOUNT_MNT_UIDMAP 0x00001000U /* Want/got uidmap... */
+#endif
+
+#ifndef STATMOUNT_MNT_GIDMAP
+#define STATMOUNT_MNT_GIDMAP 0x00002000U /* Want/got gidmap... */
+#endif
+
#ifndef MOUNT_ATTR_RDONLY
#define MOUNT_ATTR_RDONLY 0x00000001 /* Mount read-only */
#endif
diff --git a/samples/vfs/test-list-all-mounts.c b/samples/vfs/test-list-all-mounts.c
index ce272ded8a79..bb3b83d8f1d7 100644
--- a/samples/vfs/test-list-all-mounts.c
+++ b/samples/vfs/test-list-all-mounts.c
@@ -128,14 +128,16 @@ int main(int argc, char *argv[])
STATMOUNT_MNT_POINT |
STATMOUNT_MNT_NS_ID |
STATMOUNT_MNT_OPTS |
- STATMOUNT_FS_TYPE, 0);
+ STATMOUNT_FS_TYPE |
+ STATMOUNT_MNT_UIDMAP |
+ STATMOUNT_MNT_GIDMAP, 0);
if (!stmnt) {
printf("Failed to statmount(%" PRIu64 ") in mount namespace(%" PRIu64 ")\n",
(uint64_t)last_mnt_id, (uint64_t)info.mnt_ns_id);
continue;
}
- printf("mnt_id:\t\t%" PRIu64 "\nmnt_parent_id:\t%" PRIu64 "\nfs_type:\t%s\nmnt_root:\t%s\nmnt_point:\t%s\nmnt_opts:\t%s\n\n",
+ printf("mnt_id:\t\t%" PRIu64 "\nmnt_parent_id:\t%" PRIu64 "\nfs_type:\t%s\nmnt_root:\t%s\nmnt_point:\t%s\nmnt_opts:\t%s\n",
(uint64_t)stmnt->mnt_id,
(uint64_t)stmnt->mnt_parent_id,
(stmnt->mask & STATMOUNT_FS_TYPE) ? stmnt->str + stmnt->fs_type : "",
@@ -143,6 +145,26 @@ int main(int argc, char *argv[])
(stmnt->mask & STATMOUNT_MNT_POINT) ? stmnt->str + stmnt->mnt_point : "",
(stmnt->mask & STATMOUNT_MNT_OPTS) ? stmnt->str + stmnt->mnt_opts : "");
+ if (stmnt->mask & STATMOUNT_MNT_UIDMAP) {
+ const char *idmap = stmnt->str + stmnt->mnt_uidmap;
+
+ for (size_t idx = 0; idx < stmnt->mnt_uidmap_num; idx++) {
+ printf("mnt_uidmap[%lu]:\t%s\n", idx, idmap);
+ idmap += strlen(idmap) + 1;
+ }
+ }
+
+ if (stmnt->mask & STATMOUNT_MNT_GIDMAP) {
+ const char *idmap = stmnt->str + stmnt->mnt_gidmap;
+
+ for (size_t idx = 0; idx < stmnt->mnt_gidmap_num; idx++) {
+ printf("mnt_gidmap[%lu]:\t%s\n", idx, idmap);
+ idmap += strlen(idmap) + 1;
+ }
+ }
+
+ printf("\n");
+
free(stmnt);
}
}
--
2.47.2
next prev parent reply other threads:[~2025-02-04 11:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-04 11:27 [PATCH v2 0/4] statmount: allow to retrieve idmappings Christian Brauner
2025-02-04 11:27 ` [PATCH v2 1/4] uidgid: add map_id_range_up() Christian Brauner
2025-02-04 11:27 ` [PATCH v2 2/4] statmount: allow to retrieve idmappings Christian Brauner
2025-02-04 11:27 ` [PATCH v2 3/4] samples/vfs: check whether flag was raised Christian Brauner
2025-02-04 11:27 ` Christian Brauner [this message]
2025-02-04 12:38 ` [PATCH v2 0/4] statmount: allow to retrieve idmappings Jeff Layton
-- strict thread matches above, loose matches on Subject: below --
2025-02-04 11:28 Christian Brauner
2025-02-04 11:28 ` [PATCH v2 4/4] samples/vfs: add STATMOUNT_MNT_{G,U}IDMAP Christian Brauner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250204-work-mnt_idmap-statmount-v2-4-007720f39f2e@kernel.org \
--to=brauner@kernel.org \
--cc=daan.j.demeyer@gmail.com \
--cc=jlayton@kernel.org \
--cc=josef@toxicpanda.com \
--cc=lennart@poettering.net \
--cc=linux-fsdevel@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=sforshee@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.