[PATCH v3 1/5] st: Use static class attributes

From: Lee Duncan
Date: Mon May 21 2012 - 19:14:21 EST


From: Jeff Mahoney <jeffm@xxxxxxxx>

st currently sets up and tears down class attributes manually for
every tape drive in the system. This patch uses a statically defined
class with class attributes to let the device core do it for us.

Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
Signed-off-by: Lee Duncan <lduncan@xxxxxxxx>
---
drivers/scsi/st.c | 74 ++++++++++++++++++++++++-----------------------------
1 file changed, 33 insertions(+), 41 deletions(-)

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index e41998c..662f9a0 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -84,7 +84,8 @@ static int try_wdio = 1;
static int st_dev_max;
static int st_nr_dev;

-static struct class *st_sysfs_class;
+static struct class st_sysfs_class;
+static struct device_attribute st_dev_attrs[];

MODULE_AUTHOR("Kai Makisara");
MODULE_DESCRIPTION("SCSI tape (st) driver");
@@ -4195,7 +4196,7 @@ out_free_tape:
if (STm->cdevs[j]) {
if (cdev == STm->cdevs[j])
cdev = NULL;
- device_destroy(st_sysfs_class,
+ device_destroy(&st_sysfs_class,
MKDEV(SCSI_TAPE_MAJOR,
TAPE_MINOR(i, mode, j)));
cdev_del(STm->cdevs[j]);
@@ -4236,7 +4237,7 @@ static int st_remove(struct device *dev)
"tape");
for (mode = 0; mode < ST_NBR_MODES; ++mode) {
for (j=0; j < 2; j++) {
- device_destroy(st_sysfs_class,
+ device_destroy(&st_sysfs_class,
MKDEV(SCSI_TAPE_MAJOR,
TAPE_MINOR(i, mode, j)));
cdev_del(tpnt->modes[mode].cdevs[j]);
@@ -4283,6 +4284,11 @@ static void scsi_tape_release(struct kref *kref)
return;
}

+static struct class st_sysfs_class = {
+ .name = "scsi_tape",
+ .dev_attrs = st_dev_attrs,
+};
+
static int __init init_st(void)
{
int err;
@@ -4292,10 +4298,10 @@ static int __init init_st(void)
printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
verstr, st_fixed_buffer_size, st_max_sg_segs);

- st_sysfs_class = class_create(THIS_MODULE, "scsi_tape");
- if (IS_ERR(st_sysfs_class)) {
- printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n");
- return PTR_ERR(st_sysfs_class);
+ err = class_register(&st_sysfs_class);
+ if (err) {
+ printk(KERN_ERR "Unable register sysfs class for SCSI tapes\n");
+ return err;
}

err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
@@ -4322,7 +4328,7 @@ err_chrdev:
unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
ST_MAX_TAPE_ENTRIES);
err_class:
- class_destroy(st_sysfs_class);
+ class_unregister(&st_sysfs_class);
return err;
}

@@ -4332,7 +4338,7 @@ static void __exit exit_st(void)
scsi_unregister_driver(&st_template.gendrv);
unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
ST_MAX_TAPE_ENTRIES);
- class_destroy(st_sysfs_class);
+ class_unregister(&st_sysfs_class);
kfree(scsi_tapes);
printk(KERN_INFO "st: Unloaded.\n");
}
@@ -4405,10 +4411,9 @@ static void do_remove_sysfs_files(void)
driver_remove_file(sysfs, &driver_attr_try_direct_io);
}

-
/* The sysfs simple class interface */
static ssize_t
-st_defined_show(struct device *dev, struct device_attribute *attr, char *buf)
+defined_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct st_modedef *STm = dev_get_drvdata(dev);
ssize_t l = 0;
@@ -4417,10 +4422,9 @@ st_defined_show(struct device *dev, struct device_attribute *attr, char *buf)
return l;
}

-DEVICE_ATTR(defined, S_IRUGO, st_defined_show, NULL);
-
static ssize_t
-st_defblk_show(struct device *dev, struct device_attribute *attr, char *buf)
+default_blksize_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
struct st_modedef *STm = dev_get_drvdata(dev);
ssize_t l = 0;
@@ -4429,10 +4433,10 @@ st_defblk_show(struct device *dev, struct device_attribute *attr, char *buf)
return l;
}

-DEVICE_ATTR(default_blksize, S_IRUGO, st_defblk_show, NULL);

static ssize_t
-st_defdensity_show(struct device *dev, struct device_attribute *attr, char *buf)
+default_density_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
struct st_modedef *STm = dev_get_drvdata(dev);
ssize_t l = 0;
@@ -4443,11 +4447,9 @@ st_defdensity_show(struct device *dev, struct device_attribute *attr, char *buf)
return l;
}

-DEVICE_ATTR(default_density, S_IRUGO, st_defdensity_show, NULL);
-
static ssize_t
-st_defcompression_show(struct device *dev, struct device_attribute *attr,
- char *buf)
+default_compression_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
struct st_modedef *STm = dev_get_drvdata(dev);
ssize_t l = 0;
@@ -4456,10 +4458,8 @@ st_defcompression_show(struct device *dev, struct device_attribute *attr,
return l;
}

-DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
-
static ssize_t
-st_options_show(struct device *dev, struct device_attribute *attr, char *buf)
+options_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct st_modedef *STm = dev_get_drvdata(dev);
struct scsi_tape *STp;
@@ -4498,7 +4498,14 @@ st_options_show(struct device *dev, struct device_attribute *attr, char *buf)
return l;
}

-DEVICE_ATTR(options, S_IRUGO, st_options_show, NULL);
+static struct device_attribute st_dev_attrs[] = {
+ __ATTR_RO(defined),
+ __ATTR_RO(default_blksize),
+ __ATTR_RO(default_density),
+ __ATTR_RO(default_compression),
+ __ATTR_RO(options),
+ __ATTR_NULL,
+};

static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
{
@@ -4513,7 +4520,8 @@ static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
snprintf(name, 10, "%s%s%s", rew ? "n" : "",
STp->disk->disk_name, st_formats[i]);
st_class_member =
- device_create(st_sysfs_class, &STp->device->sdev_gendev,
+ device_create(&st_sysfs_class,
+ &STp->device->sdev_gendev,
MKDEV(SCSI_TAPE_MAJOR,
TAPE_MINOR(dev_num, mode, rew)),
&STp->modes[mode], "%s", name);
@@ -4524,22 +4532,6 @@ static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
goto out;
}

- error = device_create_file(st_class_member,
- &dev_attr_defined);
- if (error) goto out;
- error = device_create_file(st_class_member,
- &dev_attr_default_blksize);
- if (error) goto out;
- error = device_create_file(st_class_member,
- &dev_attr_default_density);
- if (error) goto out;
- error = device_create_file(st_class_member,
- &dev_attr_default_compression);
- if (error) goto out;
- error = device_create_file(st_class_member,
- &dev_attr_options);
- if (error) goto out;
-
if (mode == 0 && rew == 0) {
error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
&st_class_member->kobj,
--
1.7.9.2

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