From 1c33de9e1370bc56e10f3b5306e27c8aa6a18873 Mon Sep 17 00:00:00 2001

From: Michal Sekletar <msekleta@redhat.com>

Date: Mon, 1 Feb 2016 10:44:58 +0100

Subject: [PATCH] journalctl: make "journalctl /dev/sda" work

Currently when journalctl is called with path to block device node we

add following match _KERNEL_DEVICE=b$MAJOR:$MINOR.

That is not sufficient to actually obtain logs about the disk because

dev_printk() kernel helper puts to /dev/kmsg information about the

device in following format, +$SUBSYSTEM:$ADDRESS,

e.g. "+pci:pci:0000:00:14.0".

Now we will walk upward the syspath and add match for every device in

format produced by dev_printk() as well as match for its device node if

it exists.

Cherry-picked from: 795ab08f783e78e85f1493879f13ac44cb113b00

Resolves: #947636

---

 Makefile.am              |   3 +-

 src/journal/journalctl.c | 118 +++++++++++++++++++++++++++++++--------

 2 files changed, 97 insertions(+), 24 deletions(-)

diff --git a/Makefile.am b/Makefile.am

index 2645f66bc1..255937643e 100644

--- a/Makefile.am

+++ b/Makefile.am

@@ -4245,7 +4245,8 @@ journalctl_LDADD = \

 	libsystemd-journal-internal.la \

 	libsystemd-internal.la \

 	libsystemd-logs.la \

-	libsystemd-shared.la

+	libsystemd-shared.la \

+	libudev-core.la

 if HAVE_ACL

 journalctl_LDADD += \

diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c

index 836d7d2141..3db1cd24ef 100644

--- a/src/journal/journalctl.c

+++ b/src/journal/journalctl.c

@@ -63,6 +63,8 @@

 #include "mkdir.h"

 #include "bus-util.h"

 #include "bus-error.h"

+#include "udev.h"

+#include "udev-util.h"

 #define DEFAULT_FSS_INTERVAL_USEC (15*USEC_PER_MINUTE)

@@ -134,6 +136,80 @@ typedef struct boot_id_t {

         LIST_FIELDS(struct boot_id_t, boot_list);

 } boot_id_t;

+static int add_matches_for_device(sd_journal *j, const char *devpath) {

+        int r;

+        _cleanup_udev_unref_ struct udev *udev = NULL;

+        _cleanup_udev_device_unref_ struct udev_device *device = NULL;

+        struct udev_device *d = NULL;

+        struct stat st;

+

+        assert(j);

+        assert(devpath);

+

+        if (!path_startswith(devpath, "/dev/")) {

+                log_error("Devpath does not start with /dev/");

+                return -EINVAL;

+        }

+

+        udev = udev_new();

+        if (!udev)

+                return log_oom();

+

+        r = stat(devpath, &st);

+        if (r < 0)

+                log_error_errno(errno, "Couldn't stat file: %m");

+

+        d = device = udev_device_new_from_devnum(udev, S_ISBLK(st.st_mode) ? 'b' : 'c', st.st_rdev);

+        if (!device)

+                return log_error_errno(errno, "Failed to get udev device from devnum %u:%u: %m", major(st.st_rdev), minor(st.st_rdev));

+

+        while (d) {

+                _cleanup_free_ char *match = NULL;

+                const char *subsys, *sysname, *devnode;

+

+                subsys = udev_device_get_subsystem(d);

+                if (!subsys) {

+                        d = udev_device_get_parent(d);

+                        continue;

+                }

+

+                sysname = udev_device_get_sysname(d);

+                if (!sysname) {

+                        d = udev_device_get_parent(d);

+                        continue;

+                }

+

+                match = strjoin("_KERNEL_DEVICE=+", subsys, ":", sysname, NULL);

+                if (!match)

+                        return log_oom();

+

+                r = sd_journal_add_match(j, match, 0);

+                if (r < 0)

+                        return log_error_errno(r, "Failed to add match: %m");

+

+                devnode = udev_device_get_devnode(d);

+                if (devnode) {

+                        _cleanup_free_ char *match1 = NULL;

+

+                        r = stat(devnode, &st);

+                        if (r < 0)

+                                return log_error_errno(r, "Failed to stat() device node \"%s\": %m", devnode);

+

+                        r = asprintf(&match1, "_KERNEL_DEVICE=%c%u:%u", S_ISBLK(st.st_mode) ? 'b' : 'c', major(st.st_rdev), minor(st.st_rdev));

+                        if (r < 0)

+                                return log_oom();

+

+                        r = sd_journal_add_match(j, match1, 0);

+                        if (r < 0)

+                                return log_error_errno(r, "Failed to add match: %m");

+                }

+

+                d = udev_device_get_parent(d);

+        }

+

+        return 0;

+}

+

 static void pager_open_if_enabled(void) {

         if (arg_no_pager)

@@ -788,13 +864,12 @@ static int add_matches(sd_journal *j, char **args) {

                         have_term = false;

                 } else if (path_is_absolute(*i)) {

-                        _cleanup_free_ char *p, *t = NULL, *t2 = NULL;

+                        _cleanup_free_ char *p, *t = NULL, *t2 = NULL, *interpreter = NULL;

                         const char *path;

-                        _cleanup_free_ char *interpreter = NULL;

                         struct stat st;

                         p = canonicalize_file_name(*i);

-                        path = p ? p : *i;

+                        path = p ?: *i;

                         if (stat(path, &st) < 0)

                                 return log_error_errno(errno, "Couldn't stat file: %m");

@@ -808,40 +883,37 @@ static int add_matches(sd_journal *j, char **args) {

                                                 return log_oom();

                                         t = strappend("_COMM=", comm);

+                                        if (!t)

+                                                return log_oom();

                                         /* Append _EXE only if the interpreter is not a link.

                                            Otherwise, it might be outdated often. */

-                                        if (lstat(interpreter, &st) == 0 &&

-                                            !S_ISLNK(st.st_mode)) {

+                                        if (lstat(interpreter, &st) == 0 && !S_ISLNK(st.st_mode)) {

                                                 t2 = strappend("_EXE=", interpreter);

                                                 if (!t2)

                                                         return log_oom();

                                         }

-                                } else

+                                } else {

                                         t = strappend("_EXE=", path);

-                        } else if (S_ISCHR(st.st_mode)) {

-                                if (asprintf(&t, "_KERNEL_DEVICE=c%u:%u",

-                                             major(st.st_rdev),

-                                             minor(st.st_rdev)) < 0)

-                                        return -ENOMEM;

-                        } else if (S_ISBLK(st.st_mode)) {

-                                if (asprintf(&t, "_KERNEL_DEVICE=b%u:%u",

-                                             major(st.st_rdev),

-                                             minor(st.st_rdev)) < 0)

-                                        return -ENOMEM;

+                                        if (!t)

+                                                return log_oom();

+                                }

+

+                                r = sd_journal_add_match(j, t, 0);

+

+                                if (r >=0 && t2)

+                                        r = sd_journal_add_match(j, t2, 0);

+

+                        } else if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {

+                                r = add_matches_for_device(j, path);

+                                if (r < 0)

+                                        return r;

                         } else {

                                 log_error("File is neither a device node, nor regular file, nor executable: %s", *i);

                                 return -EINVAL;

                         }

-                        if (!t)

-                                return log_oom();

-

-                        r = sd_journal_add_match(j, t, 0);

-                        if (t2)

-                                r = sd_journal_add_match(j, t2, 0);

                         have_term = true;

-

                 } else {

                         r = sd_journal_add_match(j, *i, 0);

                         have_term = true;