From fa99d9cd9cbc6aca3245afcfe321b8226985597d Mon Sep 17 00:00:00 2001 From: Rob Norris Date: Fri, 10 May 2024 13:54:08 +1000 Subject: [PATCH] zfs_dbgmsg_print: make FreeBSD and Linux consistent FreeBSD was using fprintf(), which might not be signal-safe. Meanwhile, Linux's locking did not cover the header output. This two quirks are unrelated, but both have the same response: be like the other one. So with this commit, both functions are the same except for the names of their lock and list variables. Sponsored-by: Klara, Inc. Sponsored-by: Wasabi Technology, Inc. Reviewed-by: Brian Behlendorf Signed-off-by: Rob Norris Closes #16181 --- module/os/freebsd/zfs/zfs_debug.c | 24 ++++++++++++++++++++---- module/os/linux/zfs/zfs_debug.c | 3 ++- 2 files changed, 22 insertions(+), 5 deletions(-) diff --git a/module/os/freebsd/zfs/zfs_debug.c b/module/os/freebsd/zfs/zfs_debug.c index 78d50c6fd8b7..3e832a9104f2 100644 --- a/module/os/freebsd/zfs/zfs_debug.c +++ b/module/os/freebsd/zfs/zfs_debug.c @@ -234,13 +234,29 @@ __dprintf(boolean_t dprint, const char *file, const char *func, void zfs_dbgmsg_print(const char *tag) { - zfs_dbgmsg_t *zdm; + ssize_t ret __attribute__((unused)); - (void) printf("ZFS_DBGMSG(%s):\n", tag); mutex_enter(&zfs_dbgmsgs_lock); - for (zdm = list_head(&zfs_dbgmsgs); zdm; + + /* + * We use write() in this function instead of printf() + * so it is safe to call from a signal handler. + */ + ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); + ret = write(STDOUT_FILENO, tag, strlen(tag)); + ret = write(STDOUT_FILENO, ") START:\n", 9); + + for (zfs_dbgmsg_t zdm = list_head(&zfs_dbgmsgs); zdm != NULL; zdm = list_next(&zfs_dbgmsgs, zdm)) - (void) printf("%s\n", zdm->zdm_msg); + ret = write(STDOUT_FILENO, zdm->zdm_msg, + strlen(zdm->zdm_msg)); + ret = write(STDOUT_FILENO, "\n", 1); + } + + ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); + ret = write(STDOUT_FILENO, tag, strlen(tag)); + ret = write(STDOUT_FILENO, ") END\n", 6); + mutex_exit(&zfs_dbgmsgs_lock); } #endif /* _KERNEL */ diff --git a/module/os/linux/zfs/zfs_debug.c b/module/os/linux/zfs/zfs_debug.c index f707959c9445..bc5c028dca09 100644 --- a/module/os/linux/zfs/zfs_debug.c +++ b/module/os/linux/zfs/zfs_debug.c @@ -225,6 +225,8 @@ zfs_dbgmsg_print(const char *tag) { ssize_t ret __attribute__((unused)); + mutex_enter(&zfs_dbgmsgs.pl_lock); + /* * We use write() in this function instead of printf() * so it is safe to call from a signal handler. @@ -233,7 +235,6 @@ zfs_dbgmsg_print(const char *tag) ret = write(STDOUT_FILENO, tag, strlen(tag)); ret = write(STDOUT_FILENO, ") START:\n", 9); - mutex_enter(&zfs_dbgmsgs.pl_lock); for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs.pl_list); zdm != NULL; zdm = list_next(&zfs_dbgmsgs.pl_list, zdm)) { ret = write(STDOUT_FILENO, zdm->zdm_msg,