diff options
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 78 |
1 files changed, 62 insertions, 16 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index b12c1b0d3e1d..3b48640f89d5 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -155,6 +155,7 @@ struct ubd { /* name (and fd, below) of the file opened for writing, either the * backing or the cow file. */ char *file; + char *serial; int count; int fd; __u64 size; @@ -180,6 +181,7 @@ struct ubd { #define DEFAULT_UBD { \ .file = NULL, \ + .serial = NULL, \ .count = 0, \ .fd = -1, \ .size = -1, \ @@ -272,7 +274,7 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out) { struct ubd *ubd_dev; struct openflags flags = global_openflags; - char *backing_file; + char *file, *backing_file, *serial; int n, err = 0, i; if(index_out) *index_out = -1; @@ -368,24 +370,27 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out) goto out; break_loop: - backing_file = strchr(str, ','); + file = strsep(&str, ",:"); + if (*file == '\0') + file = NULL; - if (backing_file == NULL) - backing_file = strchr(str, ':'); + backing_file = strsep(&str, ",:"); + if (*backing_file == '\0') + backing_file = NULL; - if(backing_file != NULL){ - if(ubd_dev->no_cow){ - *error_out = "Can't specify both 'd' and a cow file"; - goto out; - } - else { - *backing_file = '\0'; - backing_file++; - } + serial = strsep(&str, ",:"); + if (*serial == '\0') + serial = NULL; + + if (backing_file && ubd_dev->no_cow) { + *error_out = "Can't specify both 'd' and a cow file"; + goto out; } + err = 0; - ubd_dev->file = str; + ubd_dev->file = file; ubd_dev->cow.file = backing_file; + ubd_dev->serial = serial; ubd_dev->boot_openflags = flags; out: mutex_unlock(&ubd_lock); @@ -406,7 +411,7 @@ static int ubd_setup(char *str) __setup("ubd", ubd_setup); __uml_help(ubd_setup, -"ubd<n><flags>=<filename>[(:|,)<filename2>]\n" +"ubd<n><flags>=<filename>[(:|,)<filename2>][(:|,)<serial>]\n" " This is used to associate a device with a file in the underlying\n" " filesystem. When specifying two filenames, the first one is the\n" " COW name and the second is the backing file name. As separator you can\n" @@ -429,6 +434,12 @@ __uml_help(ubd_setup, " UMLs and file locking will be turned off - this is appropriate for a\n" " cluster filesystem and inappropriate at almost all other times.\n\n" " 't' will disable trim/discard support on the device (enabled by default).\n\n" +" An optional device serial number can be exposed using the serial parameter\n" +" on the cmdline which is exposed as a sysfs entry. This is particularly\n" +" useful when a unique number should be given to the device. Note when\n" +" specifying a label, the filename2 must be also presented. It can be\n" +" an empty string, in which case the backing file is not used:\n" +" ubd0=File,,Serial\n" ); static int udb_setup(char *str) @@ -868,6 +879,41 @@ static void ubd_device_release(struct device *dev) *ubd_dev = ((struct ubd) DEFAULT_UBD); } +static ssize_t serial_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + struct ubd *ubd_dev = disk->private_data; + + if (!ubd_dev) + return 0; + + return sprintf(buf, "%s", ubd_dev->serial); +} + +static DEVICE_ATTR_RO(serial); + +static struct attribute *ubd_attrs[] = { + &dev_attr_serial.attr, + NULL, +}; + +static umode_t ubd_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + return a->mode; +} + +static const struct attribute_group ubd_attr_group = { + .attrs = ubd_attrs, + .is_visible = ubd_attrs_are_visible, +}; + +static const struct attribute_group *ubd_attr_groups[] = { + &ubd_attr_group, + NULL, +}; + static int ubd_disk_register(int major, u64 size, int unit, struct gendisk **disk_out) { @@ -899,7 +945,7 @@ static int ubd_disk_register(int major, u64 size, int unit, disk->private_data = &ubd_devs[unit]; disk->queue = ubd_devs[unit].queue; - device_add_disk(parent, disk, NULL); + device_add_disk(parent, disk, ubd_attr_groups); *disk_out = disk; return 0; |