From a55e7504bb588a910ca5afb652e4c09eaa16375c Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 17 Dec 2025 13:26:06 -0500 Subject: [PATCH] blkpr: add read-keys command 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 --- sys-utils/blkpr.8.adoc | 3 ++- sys-utils/blkpr.c | 46 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+), 1 deletion(-) 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. diff --git a/sys-utils/blkpr.c b/sys-utils/blkpr.c index c6b030def..84e736e9f 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"}, + +#ifdef 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) +#ifdef 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 /* 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; +#ifdef 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")); -- 2.47.3