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db: store devpath - node relationship for all devices

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If we don't have any interesting values to store, we just use
a symlink (doesn't occupy a whole page on tmpfs like a file)
to store the name of the node belonging to a devpath. This will
allow udevinfo to resolve all names, even when we don't have a
full database entry.
This commit is contained in:
Kay Sievers 2006-08-18 02:27:16 +02:00
parent 878b47da74
commit 554dde8e9a
1 changed files with 85 additions and 32 deletions
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117
udev_db.c
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@ -70,49 +70,55 @@ static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
int udev_db_add_device(struct udevice *udev)
{
char filename[PATH_SIZE];
struct name_entry *name_loop;
FILE *f;
if (udev->test_run)
return 0;
/* don't write anything if udev created only the node with the
* kernel name without any interesting data to remember
devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
create_path(filename);
/*
* create only a symlink with the name as the target
* if we don't have any interesting data to remember
*/
if (strcmp(udev->name, udev->dev->kernel_name) == 0 &&
list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
!udev->partitions && !udev->ignore_remove) {
dbg("nothing interesting to store in udevdb, skip");
goto exit;
dbg("nothing interesting to store, create symlink");
unlink(filename);
if (symlink(udev->name, filename) != 0) {
err("unable to create db link '%s': %s", filename, strerror(errno));
return -1;
}
} else {
struct name_entry *name_loop;
FILE *f;
f = fopen(filename, "w");
if (f == NULL) {
err("unable to create db file '%s': %s", filename, strerror(errno));
return -1;
}
dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
fprintf(f, "N:%s\n", udev->name);
list_for_each_entry(name_loop, &udev->symlink_list, node)
fprintf(f, "S:%s\n", name_loop->name);
fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
if (udev->partitions)
fprintf(f, "A:%u\n", udev->partitions);
if (udev->ignore_remove)
fprintf(f, "R:%u\n", udev->ignore_remove);
list_for_each_entry(name_loop, &udev->env_list, node)
fprintf(f, "E:%s\n", name_loop->name);
fclose(f);
}
devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
create_path(filename);
f = fopen(filename, "w");
if (f == NULL) {
err("unable to create db file '%s': %s", filename, strerror(errno));
return -1;
}
dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
fprintf(f, "N:%s\n", udev->name);
list_for_each_entry(name_loop, &udev->symlink_list, node)
fprintf(f, "S:%s\n", name_loop->name);
fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
if (udev->partitions)
fprintf(f, "A:%u\n", udev->partitions);
if (udev->ignore_remove)
fprintf(f, "R:%u\n", udev->ignore_remove);
list_for_each_entry(name_loop, &udev->env_list, node)
fprintf(f, "E:%s\n", name_loop->name);
fclose(f);
exit:
return 0;
}
int udev_db_get_device(struct udevice *udev, const char *devpath)
{
struct stat stats;
char filename[PATH_SIZE];
char line[PATH_SIZE];
unsigned int major, minor;
@ -122,13 +128,35 @@ int udev_db_get_device(struct udevice *udev, const char *devpath)
size_t cur;
size_t count;
strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
devpath_to_db_path(devpath, filename, sizeof(filename));
if (file_map(filename, &buf, &bufsize) != 0) {
if (lstat(filename, &stats) != 0) {
info("no db file to read %s: %s", filename, strerror(errno));
return -1;
}
if ((stats.st_mode & S_IFMT) == S_IFLNK) {
char target[NAME_SIZE];
int target_len;
info("found a symlink as db file");
target_len = readlink(filename, target, sizeof(target));
if (target_len > 0)
target[target_len] = '\0';
else {
info("error reading db link %s: %s", filename, strerror(errno));
return -1;
}
dbg("db link points to '%s'", target);
strlcpy(udev->name, target, sizeof(udev->name));
return 0;
}
if (file_map(filename, &buf, &bufsize) != 0) {
info("error reading db file %s: %s", filename, strerror(errno));
return -1;
}
strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
cur = 0;
while (cur < bufsize) {
count = buf_get_line(buf, bufsize, cur);
@ -216,6 +244,7 @@ int udev_db_lookup_name(const char *name, char *devpath, size_t len)
struct dirent *ent;
char filename[PATH_SIZE];
char nodename[PATH_SIZE];
struct stat stats;
char *bufline;
char *buf;
size_t bufsize;
@ -232,8 +261,32 @@ int udev_db_lookup_name(const char *name, char *devpath, size_t len)
filename[sizeof(filename)-1] = '\0';
dbg("looking at '%s'", filename);
if (lstat(filename, &stats) != 0) {
info("unable to read %s: %s", filename, strerror(errno));
continue;
}
if ((stats.st_mode & S_IFMT) == S_IFLNK) {
char target[NAME_SIZE];
int target_len;
info("found a symlink as db file");
target_len = readlink(filename, target, sizeof(target));
if (target_len > 0)
target[target_len] = '\0';
else {
info("error reading db link %s: %s", filename, strerror(errno));
return -1;
}
dbg("db link points to '%s'", target);
if (strcmp(name, target) == 0) {
db_file_to_devpath(ent->d_name, devpath, len);
found =1;
}
continue;
}
if (file_map(filename, &buf, &bufsize) != 0) {
err("unable to read db file '%s': %s", filename, strerror(errno));
info("unable to read db file '%s': %s", filename, strerror(errno));
continue;
}