* [PATCH 2/3] blkpr: add read-keys command
2025-12-11 16:09 [PATCH 0/3] blkpr: add read-keys and read-reservations commands Stefan Hajnoczi
2025-12-11 16:09 ` [PATCH 1/3] blkpr: prepare for _IOR() ioctls Stefan Hajnoczi
@ 2025-12-11 16:09 ` Stefan Hajnoczi
2025-12-11 16:09 ` [PATCH 3/3] blkpr: add read-reservation command Stefan Hajnoczi
2 siblings, 0 replies; 6+ messages in thread
From: Stefan Hajnoczi @ 2025-12-11 16:09 UTC (permalink / raw)
To: util-linux; +Cc: pizhenwei, hare, kwolf, Stefan Hajnoczi
The new IOC_PR_READ_KEYS ioctl lists registered keys on a device. Add a
command so that users can inspect keys. This is useful both for
troubleshooting and for recovery scenarios.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
meson.build | 3 +++
sys-utils/blkpr.c | 46 ++++++++++++++++++++++++++++++++++++++++++
configure.ac | 4 ++++
sys-utils/blkpr.8.adoc | 3 ++-
4 files changed, 55 insertions(+), 1 deletion(-)
diff --git a/meson.build b/meson.build
index 8b7880e46..47b43c2af 100644
--- a/meson.build
+++ b/meson.build
@@ -765,6 +765,9 @@ conf.set('HAVE_DECL_BLK_ZONE_REP_CAPACITY', have ? 1 : false)
have = cc.has_header_symbol('linux/pr.h', 'PR_REP_CAPACITY')
conf.set('HAVE_DECL_PR_REP_CAPACITY', have ? 1 : false)
+have = cc.has_header_symbol('linux/pr.h', 'IOC_PR_READ_KEYS')
+conf.set('HAVE_DECL_IOC_PR_READ_KEYS', have ? 1 : false)
+
code = '''
#include <time.h>
#if !@0@
diff --git a/sys-utils/blkpr.c b/sys-utils/blkpr.c
index c6b030def..843ef7da1 100644
--- a/sys-utils/blkpr.c
+++ b/sys-utils/blkpr.c
@@ -103,6 +103,12 @@ static const struct type_string pr_command[] = {
{IOC_PR_CLEAR, "clear",
" * clear: This command unregisters both key and any other reservation\n"
" key registered with the device and drops any existing reservation.\n"},
+
+#if HAVE_DECL_IOC_PR_READ_KEYS
+ {IOC_PR_READ_KEYS, "read-keys",
+ " * read-keys: This command lists reservation keys currently registered\n"
+ " with the device.\n"},
+#endif
};
static const struct type_string pr_flag[] = {
@@ -151,6 +157,41 @@ PARSE(pr_type)
PARSE(pr_command)
PARSE(pr_flag)
+#if HAVE_DECL_IOC_PR_READ_KEYS
+static int do_pr_read_keys(int fd)
+{
+ struct pr_read_keys pr_rk;
+ uint32_t num_keys = 8;
+ uint64_t *keys = NULL;
+ int ret;
+
+ /* Loop to grow keys[] until it is large enough */
+ do {
+ num_keys *= 2;
+ keys = xreallocarray(keys, num_keys, sizeof(keys[0]));
+
+ pr_rk.keys_ptr = (uintptr_t)keys;
+ pr_rk.num_keys = num_keys;
+
+ ret = ioctl(fd, IOC_PR_READ_KEYS, &pr_rk);
+ if (ret)
+ goto out;
+ } while (pr_rk.num_keys > num_keys);
+
+ if (pr_rk.num_keys) {
+ for (uint32_t i = 0; i < pr_rk.num_keys; i++) {
+ printf(_("%#" PRIx64 "\n"), (uint64_t)keys[i]);
+ }
+ } else {
+ printf(_("No registered keys\n"));
+ }
+
+out:
+ free(keys);
+ return ret;
+}
+#endif /* HAVE_DECL_IOC_PR_READ_KEYS */
+
static int do_pr(char *path, uint64_t key, uint64_t oldkey, int op, int type, int flag)
{
struct pr_registration pr_reg;
@@ -190,6 +231,11 @@ static int do_pr(char *path, uint64_t key, uint64_t oldkey, int op, int type, in
pr_clr.flags = flag;
ret = ioctl(fd, op, &pr_clr);
break;
+#if HAVE_DECL_IOC_PR_READ_KEYS
+ case IOC_PR_READ_KEYS:
+ ret = do_pr_read_keys(fd);
+ break;
+#endif
default:
errno = EINVAL;
err(EXIT_FAILURE, _("unknown command"));
diff --git a/configure.ac b/configure.ac
index a424e0947..bbd2156d7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -445,6 +445,10 @@ AC_CHECK_DECLS([PR_REP_CAPACITY], [], [], [
#include <linux/pr.h>
])
+AC_CHECK_DECLS([IOC_PR_READ_KEYS], [], [], [
+ #include <linux/pr.h>
+])
+
AC_CHECK_HEADERS([security/openpam.h], [], [], [
#ifdef HAVE_SECURITY_PAM_APPL_H
#include <security/pam_appl.h>
diff --git a/sys-utils/blkpr.8.adoc b/sys-utils/blkpr.8.adoc
index 98983b779..3a157af38 100644
--- a/sys-utils/blkpr.8.adoc
+++ b/sys-utils/blkpr.8.adoc
@@ -25,7 +25,8 @@ The _device_ argument is the pathname of the block device.
*-c*, *--command* _command_::
The command for managing persistent reservations. Supported commands are:
-*register*, *reserve*, *release*, *preempt*, *preempt-abort*, and *clear*.
+*register*, *reserve*, *release*, *preempt*, *preempt-abort*, *clear*, and
+*read-keys*.
*-k*, *--key* _key_::
The key the command should operate on.
--
2.52.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/3] blkpr: add read-reservation command
2025-12-11 16:09 [PATCH 0/3] blkpr: add read-keys and read-reservations commands Stefan Hajnoczi
2025-12-11 16:09 ` [PATCH 1/3] blkpr: prepare for _IOR() ioctls Stefan Hajnoczi
2025-12-11 16:09 ` [PATCH 2/3] blkpr: add read-keys command Stefan Hajnoczi
@ 2025-12-11 16:09 ` Stefan Hajnoczi
2025-12-17 10:53 ` Karel Zak
2 siblings, 1 reply; 6+ messages in thread
From: Stefan Hajnoczi @ 2025-12-11 16:09 UTC (permalink / raw)
To: util-linux; +Cc: pizhenwei, hare, kwolf, Stefan Hajnoczi
The new IOC_PR_READ_RESERVATION ioctl reports the current reservation on
a device. Add a command so that users can inspect the current
reservation. This is useful both for troubleshooting and for recovery
scenarios.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
meson.build | 3 +++
sys-utils/blkpr.c | 60 +++++++++++++++++++++++++++++++++++++-----
configure.ac | 4 +++
sys-utils/blkpr.8.adoc | 4 +--
4 files changed, 62 insertions(+), 9 deletions(-)
diff --git a/meson.build b/meson.build
index 47b43c2af..b759e992f 100644
--- a/meson.build
+++ b/meson.build
@@ -768,6 +768,9 @@ conf.set('HAVE_DECL_PR_REP_CAPACITY', have ? 1 : false)
have = cc.has_header_symbol('linux/pr.h', 'IOC_PR_READ_KEYS')
conf.set('HAVE_DECL_IOC_PR_READ_KEYS', have ? 1 : false)
+have = cc.has_header_symbol('linux/pr.h', 'IOC_PR_READ_RESERVATION')
+conf.set('HAVE_DECL_IOC_PR_READ_RESERVATION', have ? 1 : false)
+
code = '''
#include <time.h>
#if !@0@
diff --git a/sys-utils/blkpr.c b/sys-utils/blkpr.c
index 843ef7da1..0cb73a3bd 100644
--- a/sys-utils/blkpr.c
+++ b/sys-utils/blkpr.c
@@ -73,7 +73,7 @@ static const struct type_string pr_type[] = {
};
static const struct type_string pr_command[] = {
- {IOC_PR_REGISTER, "register",
+ {IOC_PR_REGISTER, "register",
" * register: This command registers a new reservation if the key argument\n"
" is non-null. If no existing reservation exists oldkey must be zero, if\n"
" an existing reservation should be replaced oldkey must contain the old\n"
@@ -81,34 +81,39 @@ static const struct type_string pr_command[] = {
" reservation passed in oldkey.\n"
},
- {IOC_PR_RESERVE, "reserve",
+ {IOC_PR_RESERVE, "reserve",
" * reserve: This command reserves the device and thus restricts access for\n"
" other devices based on the type argument. The key argument must be\n"
" the existing reservation key for the device as acquired by the register,\n"
" preempt, preempt-abort commands.\n"},
- {IOC_PR_RELEASE, "release",
+ {IOC_PR_RELEASE, "release",
" * release: This command releases the reservation specified by key and flags\n"
" and thus removes any access restriction implied by it.\n"},
- {IOC_PR_PREEMPT, "preempt",
+ {IOC_PR_PREEMPT, "preempt",
" * preempt: This command releases the existing reservation referred to by\n"
" old_key and replaces it with a new reservation of type for the\n"
" reservation key key.\n"},
- {IOC_PR_PREEMPT_ABORT, "preempt-abort",
+ {IOC_PR_PREEMPT_ABORT, "preempt-abort",
" * preempt-abort: This command works like preempt except that it also aborts\n"
" any outstanding command sent over a connection identified by oldkey.\n"},
- {IOC_PR_CLEAR, "clear",
+ {IOC_PR_CLEAR, "clear",
" * clear: This command unregisters both key and any other reservation\n"
" key registered with the device and drops any existing reservation.\n"},
#if HAVE_DECL_IOC_PR_READ_KEYS
- {IOC_PR_READ_KEYS, "read-keys",
+ {IOC_PR_READ_KEYS, "read-keys",
" * read-keys: This command lists reservation keys currently registered\n"
" with the device.\n"},
#endif
+
+#if HAVE_DECL_IOC_PR_READ_RESERVATION
+ {IOC_PR_READ_RESERVATION, "read-reservation",
+ " * read-reservation: This command shows the current reservation.\n"},
+#endif
};
static const struct type_string pr_flag[] = {
@@ -140,6 +145,18 @@ static int parse_type_by_str(const struct type_string *ts, int nmem, char *patte
return -1;
}
+static inline const char *type_to_str(const struct type_string *ts, int nmem,
+ int type)
+{
+ int i;
+
+ for (i = 0; i < nmem; i++) {
+ if (ts[i].type == type)
+ return ts[i].str;
+ }
+ return "unknown type";
+}
+
#define PRINT_SUPPORTED(XX) \
static void print_##XX(FILE *out) \
@@ -192,6 +209,30 @@ out:
}
#endif /* HAVE_DECL_IOC_PR_READ_KEYS */
+#if HAVE_DECL_IOC_PR_READ_RESERVATION
+static int do_pr_read_reservation(int fd)
+{
+ struct pr_read_reservation pr_rr;
+ const char *type_str;
+ int ret;
+
+ ret = ioctl(fd, IOC_PR_READ_RESERVATION, &pr_rr);
+ if (ret)
+ return ret;
+
+ type_str = type_to_str(pr_type, ARRAY_SIZE(pr_type), pr_rr.type);
+
+ if (pr_rr.key) {
+ printf(_("Key: %#" PRIx64 "\n"), (uint64_t)pr_rr.key);
+ printf(_("Generation: %#x\n"), pr_rr.generation);
+ printf(_("Type: %s\n"), type_str);
+ } else {
+ printf(_("No reservation\n"));
+ }
+ return 0;
+}
+#endif /* HAVE_DECL_IOC_PR_READ_RESERVATION */
+
static int do_pr(char *path, uint64_t key, uint64_t oldkey, int op, int type, int flag)
{
struct pr_registration pr_reg;
@@ -235,6 +276,11 @@ static int do_pr(char *path, uint64_t key, uint64_t oldkey, int op, int type, in
case IOC_PR_READ_KEYS:
ret = do_pr_read_keys(fd);
break;
+#endif
+#if HAVE_DECL_IOC_PR_READ_RESERVATION
+ case IOC_PR_READ_RESERVATION:
+ ret = do_pr_read_reservation(fd);
+ break;
#endif
default:
errno = EINVAL;
diff --git a/configure.ac b/configure.ac
index bbd2156d7..9dfb12a7a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -449,6 +449,10 @@ AC_CHECK_DECLS([IOC_PR_READ_KEYS], [], [], [
#include <linux/pr.h>
])
+AC_CHECK_DECLS([IOC_PR_READ_RESERVATION], [], [], [
+ #include <linux/pr.h>
+])
+
AC_CHECK_HEADERS([security/openpam.h], [], [], [
#ifdef HAVE_SECURITY_PAM_APPL_H
#include <security/pam_appl.h>
diff --git a/sys-utils/blkpr.8.adoc b/sys-utils/blkpr.8.adoc
index 3a157af38..630bafb92 100644
--- a/sys-utils/blkpr.8.adoc
+++ b/sys-utils/blkpr.8.adoc
@@ -25,8 +25,8 @@ The _device_ argument is the pathname of the block device.
*-c*, *--command* _command_::
The command for managing persistent reservations. Supported commands are:
-*register*, *reserve*, *release*, *preempt*, *preempt-abort*, *clear*, and
-*read-keys*.
+*register*, *reserve*, *release*, *preempt*, *preempt-abort*, *clear*,
+*read-keys*, and *read-reservation*.
*-k*, *--key* _key_::
The key the command should operate on.
--
2.52.0
^ permalink raw reply related [flat|nested] 6+ messages in thread