[git commit] mdev: add support for $DEVNAME and /dev/mdev.log debug aid
Denys Vlasenko
vda.linux at googlemail.com
Fri May 18 02:45:35 UTC 2012
commit: http://git.busybox.net/busybox/commit/?id=516530c932bd17d87c9eb4347a490be051e495f4
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
make_device 1843 2083 +240
mdev_main 712 804 +92
packed_usage 29236 29251 +15
keywords 288 19 -269
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/1 up/down: 347/-269) Total: 78 bytes
text data bss dec hex filename
887506 497 7584 895587 daa63 busybox_old
887982 497 7584 896063 dac3f busybox_unstripped
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
examples/mdev_fat.conf | 3 -
util-linux/mdev.c | 167 ++++++++++++++++++++++++++++++++++++++++++------
2 files changed, 147 insertions(+), 23 deletions(-)
diff --git a/examples/mdev_fat.conf b/examples/mdev_fat.conf
index da28bc3..df329b4 100644
--- a/examples/mdev_fat.conf
+++ b/examples/mdev_fat.conf
@@ -108,6 +108,3 @@ usbdev[0-9].[0-9]_.* root:root 660
# zaptel devices
zap(.*) root:dialout 660 =zap/%1
dahdi!(.*) root:dialout 660 =dahdi/%1
-
-# If $DEVNAME exists, create device with this name
-$DEVNAME=bus/usb/.* 0:0 660 ! @mkdir -p "`dirname "$DEVNAME"`"; mknod -m 0660 "$DEVNAME" c "$MAJOR" "$MINOR"
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 0a34122..70d1903 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -93,6 +93,8 @@
//usage: "If /dev/mdev.seq file exists, mdev will wait for its value\n"
//usage: "to match $SEQNUM variable. This prevents plug/unplug races.\n"
//usage: "To activate this feature, create empty /dev/mdev.seq at boot."
+//usage: "\n"
+//usage: "If /dev/mdev.log file exists, debug log will be appended to it.\n"
#include "libbb.h"
#include "xregex.h"
@@ -139,6 +141,98 @@
* This happens regardless of /sys/class/.../dev existence.
*/
+/* Kernel's hotplug environment constantly changes.
+ * Here are new cases I observed on 3.1.0:
+ *
+ * Case with $DEVNAME and $DEVICE, not just $DEVPATH:
+ * ACTION=add
+ * BUSNUM=001
+ * DEVICE=/proc/bus/usb/001/003
+ * DEVNAME=bus/usb/001/003
+ * DEVNUM=003
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5
+ * DEVTYPE=usb_device
+ * MAJOR=189
+ * MINOR=2
+ * PRODUCT=18d1/4e12/227
+ * SUBSYSTEM=usb
+ * TYPE=0/0/0
+ *
+ * Case with $DEVICE, but no $DEVNAME - apparenty, usb iface notification?
+ * "Please load me a module" thing?
+ * ACTION=add
+ * DEVICE=/proc/bus/usb/001/003
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0
+ * DEVTYPE=usb_interface
+ * INTERFACE=8/6/80
+ * MODALIAS=usb:v18D1p4E12d0227dc00dsc00dp00ic08isc06ip50
+ * PRODUCT=18d1/4e12/227
+ * SUBSYSTEM=usb
+ * TYPE=0/0/0
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5
+ * DEVTYPE=scsi_host
+ * SUBSYSTEM=scsi
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/scsi_host/host5
+ * SUBSYSTEM=scsi_host
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0
+ * DEVTYPE=scsi_target
+ * SUBSYSTEM=scsi
+ *
+ * Case with strange $MODALIAS:
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0
+ * DEVTYPE=scsi_device
+ * MODALIAS=scsi:t-0x00
+ * SUBSYSTEM=scsi
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0/scsi_disk/5:0:0:0
+ * SUBSYSTEM=scsi_disk
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0/scsi_device/5:0:0:0
+ * SUBSYSTEM=scsi_device
+ *
+ * Case with explicit $MAJOR/$MINOR (no need to read /sys/$DEVPATH/dev?):
+ * ACTION=add
+ * DEVNAME=bsg/5:0:0:0
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0/bsg/5:0:0:0
+ * MAJOR=253
+ * MINOR=1
+ * SUBSYSTEM=bsg
+ *
+ * ACTION=add
+ * DEVPATH=/devices/virtual/bdi/8:16
+ * SUBSYSTEM=bdi
+ *
+ * ACTION=add
+ * DEVNAME=sdb
+ * DEVPATH=/block/sdb
+ * DEVTYPE=disk
+ * MAJOR=8
+ * MINOR=16
+ * SUBSYSTEM=block
+ *
+ * Case with ACTION=change:
+ * ACTION=change
+ * DEVNAME=sdb
+ * DEVPATH=/block/sdb
+ * DEVTYPE=disk
+ * DISK_MEDIA_CHANGE=1
+ * MAJOR=8
+ * MINOR=16
+ * SUBSYSTEM=block
+ */
+
+static const char keywords[] ALIGN1 = "add\0remove\0change\0";
+enum { OP_add, OP_remove };
+
struct rule {
bool keep_matching;
bool regex_compiled;
@@ -154,6 +248,7 @@ struct rule {
struct globals {
int root_major, root_minor;
+ smallint verbose;
char *subsystem;
#if ENABLE_FEATURE_MDEV_CONF
const char *filename;
@@ -366,13 +461,17 @@ static char *build_alias(char *alias, const char *device_name)
* after NUL, but we promise to not mangle (IOW: to restore if needed)
* path string.
* NB2: "mdev -s" may call us many times, do not leak memory/fds!
+ *
+ * device_name = $DEVNAME (may be NULL)
+ * path = /sys/$DEVPATH
*/
-static void make_device(char *path, int delete)
+static void make_device(char *device_name, char *path, int operation)
{
- char *device_name, *subsystem_slash_devname;
+ char *subsystem_slash_devname;
int major, minor, type, len;
- dbg("%s('%s', delete:%d)", __func__, path, delete);
+ if (G.verbose)
+ bb_error_msg("make_device: %s, %s, op:%d", device_name, path, operation);
/* Try to read major/minor string. Note that the kernel puts \n after
* the data, so we don't need to worry about null terminating the string
@@ -380,7 +479,7 @@ static void make_device(char *path, int delete)
* We also depend on path having writeable space after it.
*/
major = -1;
- if (!delete) {
+ if (operation != OP_remove) {
char *dev_maj_min = path + strlen(path);
strcpy(dev_maj_min, "/dev");
@@ -398,7 +497,8 @@ static void make_device(char *path, int delete)
/* else: for delete, -1 still deletes the node, but < -1 suppresses that */
/* Determine device name, type, major and minor */
- device_name = (char*) bb_basename(path);
+ if (!device_name)
+ device_name = (char*) bb_basename(path);
/* http://kernel.org/doc/pending/hotplug.txt says that only
* "/sys/block/..." is for block devices. "/sys/bus" etc is not.
* But since 2.6.25 block devices are also in /sys/class/block.
@@ -434,7 +534,7 @@ static void make_device(char *path, int delete)
char *command;
char *alias;
char aliaslink = aliaslink; /* for compiler */
- const char *node_name;
+ char *node_name;
const struct rule *rule;
str_to_match = "";
@@ -456,6 +556,8 @@ static void make_device(char *path, int delete)
if (!str_to_match)
continue;
} else {
+//TODO: $DEVNAME can have slashes too,
+// we should stop abusing '/' as a special syntax in our regex'es
/* regex to match [subsystem/]device_name */
str_to_match = (rule->regex_has_slash ? path : device_name);
}
@@ -537,7 +639,7 @@ static void make_device(char *path, int delete)
/* Are we running this command now?
* Run $cmd on delete, @cmd on create, *cmd on both
*/
- if (s2 - s != delete) {
+ if (s2 - s != (operation == OP_remove) || *s2 == '*') {
/* We are here if: '*',
* or: '@' and delete = 0,
* or: '$' and delete = 1
@@ -556,8 +658,15 @@ static void make_device(char *path, int delete)
dbg("alias2:'%s'", alias);
}
- if (!delete && major >= 0) {
- dbg("mknod('%s',%o,(%d,%d))", node_name, rule->mode | type, major, minor);
+ if (operation == OP_add && major >= 0) {
+ char *slash = strrchr(node_name, '/');
+ if (slash) {
+ *slash = '\0';
+ bb_make_directory(node_name, 0755, FILEUTILS_RECUR);
+ *slash = '/';
+ }
+ if (G.verbose)
+ bb_error_msg("mknod: %s (%d,%d) %o", node_name, major, minor, rule->mode | type);
if (mknod(node_name, rule->mode | type, makedev(major, minor)) && errno != EEXIST)
bb_perror_msg("can't create '%s'", node_name);
if (major == G.root_major && minor == G.root_minor)
@@ -571,6 +680,8 @@ static void make_device(char *path, int delete)
//TODO: on devtmpfs, device_name already exists and symlink() fails.
//End result is that instead of symlink, we have two nodes.
//What should be done?
+ if (G.verbose)
+ bb_error_msg("symlink: %s", device_name);
symlink(node_name, device_name);
}
}
@@ -582,17 +693,24 @@ static void make_device(char *path, int delete)
char *s1 = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
putenv(s);
putenv(s1);
+ if (G.verbose)
+ bb_error_msg("running: %s", command);
if (system(command) == -1)
bb_perror_msg("can't run '%s'", command);
bb_unsetenv_and_free(s1);
bb_unsetenv_and_free(s);
}
- if (delete && major >= -1) {
+ if (operation == OP_remove && major >= -1) {
if (ENABLE_FEATURE_MDEV_RENAME && alias) {
- if (aliaslink == '>')
+ if (aliaslink == '>') {
+ if (G.verbose)
+ bb_error_msg("unlink: %s", device_name);
unlink(device_name);
+ }
}
+ if (G.verbose)
+ bb_error_msg("unlink: %s", node_name);
unlink(node_name);
}
@@ -624,7 +742,7 @@ static int FAST_FUNC fileAction(const char *fileName,
strcpy(scratch, fileName);
scratch[len] = '\0';
- make_device(scratch, /*delete:*/ 0);
+ make_device(/*DEVNAME:*/ NULL, scratch, OP_add);
return TRUE;
}
@@ -762,9 +880,8 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
char *fw;
char *seq;
char *action;
- char *env_path;
- static const char keywords[] ALIGN1 = "remove\0add\0";
- enum { OP_remove = 0, OP_add };
+ char *env_devname;
+ char *env_devpath;
smalluint op;
/* Hotplug:
@@ -773,9 +890,10 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
* DEVPATH is like "/block/sda" or "/class/input/mice"
*/
action = getenv("ACTION");
- env_path = getenv("DEVPATH");
+ env_devname = getenv("DEVNAME"); /* can be NULL */
+ env_devpath = getenv("DEVPATH");
G.subsystem = getenv("SUBSYSTEM");
- if (!action || !env_path /*|| !G.subsystem*/)
+ if (!action || !env_devpath /*|| !G.subsystem*/)
bb_show_usage();
fw = getenv("FIRMWARE");
op = index_in_strings(keywords, action);
@@ -804,16 +922,25 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
} while (--timeout);
}
- snprintf(temp, PATH_MAX, "/sys%s", env_path);
+ {
+ int logfd = open("/dev/mdev.log", O_WRONLY | O_APPEND);
+ if (logfd >= 0) {
+ xmove_fd(logfd, STDERR_FILENO);
+ G.verbose = 1;
+ bb_error_msg("pid: %u seq: %s action: %s", getpid(), seq, action);
+ }
+ }
+
+ snprintf(temp, PATH_MAX, "/sys%s", env_devpath);
if (op == OP_remove) {
/* Ignoring "remove firmware". It was reported
* to happen and to cause erroneous deletion
* of device nodes. */
if (!fw)
- make_device(temp, /*delete:*/ 1);
+ make_device(env_devname, temp, op);
}
else if (op == OP_add) {
- make_device(temp, /*delete:*/ 0);
+ make_device(env_devname, temp, op);
if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
if (fw)
load_firmware(fw, temp);
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