[SCSI] modalias for scsi devices

The following patch adds support for sysfs/uevent modalias
attribute for scsi devices (like disks, tapes, cdroms etc),
based on whatever current sd.c, sr.c, st.c and osst.c drivers
supports.

The modalias format is like this:

 scsi:type-0x04

(for TYPE_WORM, handled by sr.c now).

Several comments.

o This hexadecimal type value is because all TYPE_XXX constants
  in include/scsi/scsi.h are given in hex, but __stringify() will
  not convert them to decimal (so it will NOT be scsi:type-4).
  Since it does not really matter in which format it is, while
  both modalias in module and modalias attribute match each other,
  I descided to go for that 0x%02x format (and added a comment in
  include/scsi/scsi.h to keep them that way), instead of changing
  them all to decimal.

o There was no .uevent routine for SCSI bus.  It might be a good
  idea to add some more ueven environment variables in there.

o osst.c driver handles tapes too, like st.c, but only SOME tapes.
  With this setup, hotplug scripts (or whatever is used by the
  user) will try to load both st and osst modules for all SCSI
  tapes found, because both modules have scsi:type-0x01 alias).
  It is not harmful, but one extra module is no good either.
  It is possible to solve this, by exporting more info in
  modalias attribute, including vendor and device identification
  strings, so that modalias becomes something like
    scsi:type-0x12:vendor-Adaptec LTD:device-OnStream Tape Drive
  and having that, match for all 3 attributes, not only device
  type.  But oh well, vendor and device strings may be large,
  and they do contain spaces and whatnot.
  So I left them for now, awaiting for comments first.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index a967fadb7439a90be85775551c2ce4fea93bbc54..08060fb478b621e453bae3e46e7ca8611d185b93 100644 (file)
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -87,6 +87,7 @@ MODULE_AUTHOR("Willem Riede");
 MODULE_DESCRIPTION("OnStream {DI-|FW-|SC-|USB}{30|50} Tape Driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_CHARDEV_MAJOR(OSST_MAJOR);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
 
 module_param(max_dev, int, 0444);
 MODULE_PARM_DESC(max_dev, "Maximum number of OnStream Tape Drives to attach (4)");

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 96db51c40ef327cb715e32741e8cfd712f9a7735..5326f5cbeae9a21a1128ff4c88d1a197961adc9a 100644 (file)
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -276,6 +276,19 @@ static int scsi_bus_match(struct device *dev, struct device_driver *gendrv)
        return (sdp->inq_periph_qual == SCSI_INQ_PQ_CON)? 1: 0;
 }
 
+static int scsi_bus_uevent(struct device *dev, char **envp, int num_envp,
+                          char *buffer, int buffer_size)
+{
+       struct scsi_device *sdev = to_scsi_device(dev);
+       int i = 0;
+       int length = 0;
+
+       add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
+                      "MODALIAS=" SCSI_DEVICE_MODALIAS_FMT, sdev->type);
+       envp[i] = NULL;
+       return 0;
+}
+
 static int scsi_bus_suspend(struct device * dev, pm_message_t state)
 {
        struct device_driver *drv = dev->driver;
@@ -331,6 +344,7 @@ static int scsi_bus_resume(struct device * dev)
 struct bus_type scsi_bus_type = {
         .name          = "scsi",
         .match         = scsi_bus_match,
+       .uevent         = scsi_bus_uevent,
        .suspend        = scsi_bus_suspend,
        .resume         = scsi_bus_resume,
 };
@@ -558,6 +572,14 @@ show_sdev_iostat(iorequest_cnt);
 show_sdev_iostat(iodone_cnt);
 show_sdev_iostat(ioerr_cnt);
 
+static ssize_t
+sdev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
+{
+       struct scsi_device *sdev;
+       sdev = to_scsi_device(dev);
+       return snprintf (buf, 20, SCSI_DEVICE_MODALIAS_FMT "\n", sdev->type);
+}
+static DEVICE_ATTR(modalias, S_IRUGO, sdev_show_modalias, NULL);
 
 /* Default template for device attributes.  May NOT be modified */
 static struct device_attribute *scsi_sysfs_sdev_attrs[] = {
@@ -577,6 +599,7 @@ static struct device_attribute *scsi_sysfs_sdev_attrs[] = {
        &dev_attr_iorequest_cnt,
        &dev_attr_iodone_cnt,
        &dev_attr_ioerr_cnt,
+       &dev_attr_modalias,
        NULL
 };
 

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index b044dcf73427bf26d5f011aedf98954b8f0a5aad..00e46662296f89ebdfe1def87804f10fcd5e390c 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -82,6 +82,9 @@ MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
 
 static DEFINE_IDR(sd_index_idr);
 static DEFINE_SPINLOCK(sd_index_lock);

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 1857d68e7195e5b9c19a20afa3fd1ed6af08e790..f9a52af7f5b468a3fce49719b43606668f75d264 100644 (file)
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -62,6 +62,8 @@
 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
 
 #define SR_DISKS       256
 

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 98d8411bbccc1108fe09aa018f7dae17032387f7..55bfeccf68a27ff3ff4f92dffdd89282d0c4bc6a 100644 (file)
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -89,6 +89,7 @@ MODULE_AUTHOR("Kai Makisara");
 MODULE_DESCRIPTION("SCSI tape (st) driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
 
 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
  * of sysfs parameters (which module_param doesn't yet support).

diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 5c0e9791441c91ab712608b078ba420f0852e1d9..9f8f80ab0c8b4690e2e31d2cba984508007717a0 100644 (file)
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -203,6 +203,7 @@ static inline int scsi_status_is_good(int status)
 
 /*
  *  DEVICE TYPES
+ *  Please keep them in 0x%02x format for $MODALIAS to work
  */
 
 #define TYPE_DISK           0x00

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index b05cd3b09e6e957976054c03ba7a014d7355209c..2f3c5b8b1d6a89e406fc5de0724e381a8300d135 100644 (file)
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -358,4 +358,9 @@ static inline int scsi_device_qas(struct scsi_device *sdev)
                return 0;
        return sdev->inquiry[56] & 0x02;
 }
+
+#define MODULE_ALIAS_SCSI_DEVICE(type) \
+       MODULE_ALIAS("scsi:t-" __stringify(type) "*")
+#define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"
+
 #endif /* _SCSI_SCSI_DEVICE_H */