[PATCH] experimental (very simple) SYMLINK creation

> > here is a experimental symlink creation patch - for discussion,
> > in which direction we should go.
> > It is possible now to define SYMLINK= after the NAME= in udev.rules.
> > The link is relative to the node, but the path is not optimized now
> > if the node and the link are in the same nested directory.
> > Only one link is supported, cause i need to sleep now :)
> >
> > 06-simple-symlink-creation.diff
> >   simple symlink creation
> >   reorganized udev-remove to have access to the symlink field
> >   subdir creation/removal are functions now
> >   udev-test.pl tests for link creation/removal

Here is a new version with relative link target path optimization
an better tests in udev-test.pl:

LABEL, BUS="scsi", vendor="IBM-ESXS", NAME="1/2/a/b/node", SYMLINK="1/2/c/d/symlink"

  Dec  7 06:48:34 pim udev[13789]: create_node: symlink 'udev-root/1/2/c/d/symlink' to node '1/2/a/b/node' requested
  Dec  7 06:48:34 pim udev[13789]: create_path: created 'udev-root/1/2/c'
  Dec  7 06:48:34 pim udev[13789]: create_path: created 'udev-root/1/2/c/d'
  Dec  7 06:48:34 pim udev[13789]: create_node: symlink(../../a/b/node, udev-root/1/2/c/d/symlink)
This commit is contained in:
kay.sievers@vrfy.org 2003-12-07 09:12:07 -08:00 committed by Greg KH
parent eadb1bbc2e
commit 3d150dfb28
7 changed files with 228 additions and 106 deletions

View File

@ -121,6 +121,7 @@ int add_config_dev(struct config_device *new_dev)
copy_string(dev, new_dev, place);
copy_string(dev, new_dev, kernel_name);
copy_string(dev, new_dev, exec_program);
copy_string(dev, new_dev, symlink);
return 0;
}
@ -366,6 +367,7 @@ static int do_callout(struct sysfs_class_device *class_dev, struct udevice *udev
if (strcmp_pattern(dev->id, udev->callout_value) != 0)
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("callout returned matching value '%s', '%s' becomes '%s'",
dev->id, class_dev->name, udev->name);
return 0;
@ -416,6 +418,7 @@ label_found:
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found matching attribute '%s', '%s' becomes '%s' ",
dev->sysfs_file, class_dev->name, udev->name);
@ -461,6 +464,7 @@ static int do_number(struct sysfs_class_device *class_dev, struct udevice *udev,
if (!found)
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found matching id '%s', '%s' becomes '%s'",
dev->id, class_dev->name, udev->name);
return 0;
@ -506,6 +510,7 @@ static int do_topology(struct sysfs_class_device *class_dev, struct udevice *ude
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found matching place '%s', '%s' becomes '%s'",
dev->place, class_dev->name, udev->name);
return 0;
@ -528,6 +533,7 @@ static int do_replace(struct sysfs_class_device *class_dev, struct udevice *udev
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found name, '%s' becomes '%s'", dev->kernel_name, udev->name);
return 0;
@ -618,8 +624,9 @@ int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *ud
goto done;
found:
/* substitute placeholder in NAME */
/* substitute placeholder */
apply_format(udev, udev->name);
apply_format(udev, udev->symlink);
done:
perm = find_perm(udev->name);

View File

@ -63,6 +63,7 @@ struct config_device {
char kernel_name[NAME_SIZE];
char exec_program[FILE_SIZE];
char name[NAME_SIZE];
char symlink[NAME_SIZE];
};
struct perm_device {

View File

@ -213,10 +213,16 @@ int namedev_init_rules(void)
break;
strfieldcpy(dev.name, temp3);
/* SYMLINK="name" */
temp2 = strsep(&temp, ",");
retval = get_value("SYMLINK", &temp, &temp3);
if (retval == 0)
strfieldcpy(dev.symlink, temp3);
dbg_parse("LABEL name='%s', bus='%s', "
"sysfs_file='%s', sysfs_value='%s'",
"sysfs_file='%s', sysfs_value='%s', symlink='%s'",
dev.name, dev.bus, dev.sysfs_file,
dev.sysfs_value);
dev.sysfs_value, dev.symlink);
}
if (strcasecmp(temp2, TYPE_NUMBER) == 0) {
@ -243,8 +249,14 @@ int namedev_init_rules(void)
break;
strfieldcpy(dev.name, temp3);
dbg_parse("NUMBER name='%s', bus='%s', id='%s'",
dev.name, dev.bus, dev.id);
/* SYMLINK="name" */
temp2 = strsep(&temp, ",");
retval = get_value("SYMLINK", &temp, &temp3);
if (retval == 0)
strfieldcpy(dev.symlink, temp3);
dbg_parse("NUMBER name='%s', bus='%s', id='%s', symlink='%s'",
dev.name, dev.bus, dev.id, dev.symlink);
}
if (strcasecmp(temp2, TYPE_TOPOLOGY) == 0) {
@ -271,8 +283,15 @@ int namedev_init_rules(void)
break;
strfieldcpy(dev.name, temp3);
dbg_parse("TOPOLOGY name='%s', bus='%s', place='%s'",
dev.name, dev.bus, dev.place);
/* SYMLINK="name" */
temp2 = strsep(&temp, ",");
retval = get_value("SYMLINK", &temp, &temp3);
if (retval == 0)
strfieldcpy(dev.symlink, temp3);
dbg_parse("TOPOLOGY name='%s', bus='%s', "
"place='%s', symlink='%s'",
dev.name, dev.bus, dev.place, dev.symlink);
}
if (strcasecmp(temp2, TYPE_REPLACE) == 0) {
@ -291,9 +310,17 @@ int namedev_init_rules(void)
if (retval)
break;
strfieldcpy(dev.name, temp3);
dbg_parse("REPLACE name='%s', kernel_name='%s'",
dev.name, dev.kernel_name);
/* SYMLINK="name" */
temp2 = strsep(&temp, ",");
retval = get_value("SYMLINK", &temp, &temp3);
if (retval == 0)
strfieldcpy(dev.symlink, temp3);
dbg_parse("REPLACE name='%s', kernel_name='%s', symlink='%s'",
dev.name, dev.kernel_name, dev.symlink);
}
if (strcasecmp(temp2, TYPE_CALLOUT) == 0) {
/* number type */
dev.type = CALLOUT;
@ -324,8 +351,17 @@ int namedev_init_rules(void)
if (retval)
break;
strfieldcpy(dev.name, temp3);
dbg_parse("CALLOUT name='%s', program='%s'",
dev.name, dev.exec_program);
/* SYMLINK="name" */
temp2 = strsep(&temp, ",");
retval = get_value("SYMLINK", &temp, &temp3);
if (retval == 0)
strfieldcpy(dev.symlink, temp3);
dbg_parse("CALLOUT name='%s', bus='%s', program='%s', "
"id='%s', symlink='%s'",
dev.name, dev.bus, dev.exec_program,
dev.id, dev.symlink);
}
retval = add_config_dev(&dev);
@ -414,7 +450,7 @@ int namedev_init_permissions(void)
dev.mode);
retval = add_perm_dev(&dev);
if (retval) {
dbg("add_config_dev returned with error %d", retval);
dbg("add_perm_dev returned with error %d", retval);
goto exit;
}
}

View File

@ -39,7 +39,7 @@ my @tests = (
expected => "boot_disk" ,
conf => <<EOF
LABEL, BUS="scsi", vendor="IBM-ESXS", NAME="boot_disk%n"
REPLACE, KERNEL="ttyUSB0", NAME="visor""
REPLACE, KERNEL="ttyUSB0", NAME="visor"
EOF
},
{
@ -179,6 +179,42 @@ EOF
CALLOUT, BUS="usb", PROGRAM="/bin/echo -n usb-%b", ID="*", NAME="%c"
CALLOUT, BUS="scsi", PROGRAM="/bin/echo -n scsi-%b", ID="*", NAME="%c"
CALLOUT, BUS="foo", PROGRAM="/bin/echo -n foo-%b", ID="*", NAME="%c"
EOF
},
{
desc => "symlink creation (same directory)",
subsys => "tty",
devpath => "class/tty/ttyUSB0",
expected => "visor0" ,
conf => <<EOF
REPLACE, KERNEL="ttyUSB[0-9]*", NAME="ttyUSB%n", SYMLINK="visor%n"
EOF
},
{
desc => "symlink creation (relative link back)",
subsys => "block",
devpath => "block/sda/sda2",
expected => "1/2/a/b/symlink" ,
conf => <<EOF
LABEL, BUS="scsi", vendor="IBM-ESXS", NAME="1/2/node", SYMLINK="1/2/a/b/symlink"
EOF
},
{
desc => "symlink creation (relative link forward)",
subsys => "block",
devpath => "block/sda/sda2",
expected => "1/2/symlink" ,
conf => <<EOF
LABEL, BUS="scsi", vendor="IBM-ESXS", NAME="1/2/a/b/node", SYMLINK="1/2/symlink"
EOF
},
{
desc => "symlink creation (relative link back and forward)",
subsys => "block",
devpath => "block/sda/sda2",
expected => "1/2/c/d/symlink" ,
conf => <<EOF
LABEL, BUS="scsi", vendor="IBM-ESXS", NAME="1/2/a/b/node", SYMLINK="1/2/c/d/symlink"
EOF
},
);
@ -238,7 +274,8 @@ foreach my $config (@tests) {
}
udev("remove", $config->{subsys}, $config->{devpath}, \$config->{conf});
if (-e "$PWD/$udev_root$config->{expected}") {
if ((-e "$PWD/$udev_root$config->{expected}") ||
(-l "$PWD/$udev_root$config->{expected}")) {
print "remove: error\n\n";
system("tree $udev_root");
$error++;

View File

@ -72,6 +72,34 @@ exit:
return retval;
}
static int create_path(char *file)
{
char p[NAME_SIZE];
char *pos;
int retval;
struct stat stats;
strncpy(p, file, sizeof(p));
pos = strchr(p+1, '/');
while (1) {
pos = strchr(pos+1, '/');
if (pos == NULL)
break;
*pos = 0x00;
if (stat(p, &stats)) {
retval = mkdir(p, 0755);
if (retval) {
dbg("mkdir(%s) failed with error '%s'",
p, strerror(errno));
return retval;
}
dbg("created '%s'", p);
}
*pos = '/';
}
return 0;
}
/*
* we possibly want to add some symlinks here
* only numeric owner/group id's are supported
@ -79,10 +107,14 @@ exit:
static int create_node(struct udevice *dev)
{
char filename[255];
char linktarget[255];
int retval = 0;
uid_t uid = 0;
gid_t gid = 0;
dev_t res;
int i;
int tail;
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, dev->name, sizeof(filename));
@ -109,31 +141,9 @@ static int create_node(struct udevice *dev)
return -EINVAL;
}
/* create subdirectories if requested */
if (strchr(dev->name, '/')) {
char path[255];
char *pos;
struct stat stats;
strncpy(path, filename, sizeof(path));
pos = strchr(path+1, '/');
while (1) {
pos = strchr(pos+1, '/');
if (pos == NULL)
break;
*pos = 0x00;
if (stat(path, &stats)) {
retval = mkdir(path, 0755);
if (retval) {
dbg("mkdir(%s) failed with error '%s'",
path, strerror(errno));
return retval;
}
dbg("created '%s'", path);
}
*pos = '/';
}
}
/* create parent directories if needed */
if (strrchr(dev->name, '/'))
create_path(filename);
dbg("mknod(%s, %#o, %u, %u)", filename, dev->mode, dev->major, dev->minor);
retval = mknod(filename, dev->mode, res);
@ -179,8 +189,43 @@ static int create_node(struct udevice *dev)
dbg("chown(%s, %u, %u)", filename, uid, gid);
retval = chown(filename, uid, gid);
if (retval)
dbg("chown(%s, %u, %u) failed with error '%s'", filename,
uid, gid, strerror(errno));
dbg("chown(%s, %u, %u) failed with error '%s'",
filename, uid, gid, strerror(errno));
}
/* create symlink if requested */
if (*dev->symlink) {
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, dev->symlink, sizeof(filename));
dbg("symlink '%s' to node '%s' requested", filename, dev->name);
if (strrchr(dev->symlink, '/'))
create_path(filename);
/* optimize relative link */
linktarget[0] = '\0';
i = 0;
tail = 0;
while ((dev->name[i] == dev->symlink[i]) && dev->name[i]) {
if (dev->name[i] == '/')
tail = i+1;
i++;
}
while (dev->symlink[i]) {
if (dev->symlink[i] == '/')
strcat(linktarget, "../");
i++;
}
if (*linktarget == '\0')
strcpy(linktarget, "./");
strcat(linktarget, &dev->name[tail]);
dbg("symlink(%s, %s)", linktarget, filename);
retval = symlink(linktarget, filename);
if (retval)
dbg("symlink(%s, %s) failed with error '%s'",
linktarget, filename, strerror(errno));
}
return retval;

View File

@ -34,47 +34,43 @@
#include "udevdb.h"
#include "libsysfs/libsysfs.h"
/*
* Look up the sysfs path in the database to see if we have named this device
* something different from the kernel name. If we have, us it. If not, use
* the default kernel name for lack of anything else to know to do.
*/
static char *get_name(char *path, int major, int minor)
static int delete_path(char *path)
{
static char name[100];
struct udevice *dev;
char *temp;
char *pos;
int retval;
dev = udevdb_get_dev(path);
if (dev != NULL) {
strcpy(name, dev->name);
goto exit;
pos = strrchr(path, '/');
while (1) {
*pos = '\0';
pos = strrchr(path, '/');
/* don't remove the last one */
if ((pos == path) || (pos == NULL))
break;
/* remove if empty */
retval = rmdir(path);
if (retval) {
if (errno == ENOTEMPTY)
return 0;
dbg("rmdir(%s) failed with error '%s'",
path, strerror(errno));
break;
}
dbg("removed '%s'", path);
}
dbg("'%s' not found in database, falling back on default name", path);
temp = strrchr(path, '/');
if (temp == NULL)
return NULL;
strncpy(name, &temp[1], sizeof(name));
exit:
dbg("name is '%s'", name);
return &name[0];
return 0;
}
/*
* We also want to clean up any symlinks that were created in create_node()
*/
static int delete_node(char *name)
static int delete_node(struct udevice *dev)
{
char filename[255];
int retval;
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, name, sizeof(filename));
strncat(filename, dev->name, sizeof(filename));
dbg("unlinking '%s'", filename);
dbg("unlinking node '%s'", filename);
retval = unlink(filename);
if (retval) {
dbg("unlink(%s) failed with error '%s'",
@ -83,49 +79,48 @@ static int delete_node(char *name)
}
/* remove subdirectories */
if (strchr(name, '/')) {
char *pos;
if (strchr(dev->name, '/'))
delete_path(filename);
pos = strrchr(filename, '/');
while (1) {
*pos = 0x00;
pos = strrchr(filename, '/');
/* don't remove the last one */
if ((pos == filename) || (pos == NULL))
break;
/* remove if empty */
retval = rmdir(filename);
if (retval) {
if (errno == ENOTEMPTY)
return 0;
dbg("rmdir(%s) failed with error '%s'",
filename, strerror(errno));
break;
}
dbg("removed '%s'", filename);
if (*dev->symlink) {
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, dev->symlink, sizeof(filename));
dbg("unlinking symlink '%s'", filename);
retval = unlink(filename);
if (retval) {
dbg("unlink(%s) failed with error '%s'",
filename, strerror(errno));
return retval;
}
if (strchr(dev->symlink, '/')) {
delete_path(filename);
}
}
return retval;
}
int udev_remove_device(char *device, char *subsystem)
/*
* Look up the sysfs path in the database to see if we have named this device
* something different from the kernel name. If we have, us it. If not, use
* the default kernel name for lack of anything else to know to do.
*/
int udev_remove_device(char *path, char *subsystem)
{
char *name;
int retval = 0;
char name[100];
struct udevice *dev;
char *temp;
name = get_name(device, 0, 0);
if (name == NULL) {
dbg ("get_name failed");
retval = -ENODEV;
goto exit;
dev = udevdb_get_dev(path);
if (dev == NULL) {
dbg("'%s' not found in database, falling back on default name", path);
temp = strrchr(path, '/');
if (temp == NULL)
return -ENODEV;
strncpy(name, &temp[1], sizeof(name));
}
udevdb_delete_dev(device);
return delete_node(name);
exit:
return retval;
dbg("name is '%s'", dev->name);
udevdb_delete_dev(path);
return delete_node(dev);
}

1
udev.h
View File

@ -64,6 +64,7 @@ struct udevice {
int major;
int minor;
mode_t mode;
char symlink[NAME_SIZE];
/* fields that help us in building strings */
unsigned char bus_id[SYSFS_NAME_LEN];