[PATCH] s390: convert /proc/cio_ignore

Convert /proc/cio_ignore to a sequential file.  This makes multiple subchannel
sets support easier.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/s390/cio/blacklist.c b/drivers/s390/cio/blacklist.c
index 25e98483d4e4d46b0065cfcd3af29965d64f674c..daea41c63329f8a33a88adc0bded5db9b052828d 100644 (file)
--- a/drivers/s390/cio/blacklist.c
+++ b/drivers/s390/cio/blacklist.c
@@ -15,6 +15,7 @@
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/ctype.h>
 #include <linux/device.h>
 
@@ -279,41 +280,82 @@ blacklist_parse_proc_parameters (char *buf)
        s390_redo_validation ();
 }
 
-/* FIXME: These should be real bus ids and not home-grown ones! */
-static int cio_ignore_read (char *page, char **start, off_t off,
-                           int count, int *eof, void *data)
+/* Iterator struct for all devices. */
+struct ccwdev_iter {
+       int devno;
+       int in_range;
+};
+
+static void *
+cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
 {
-       const unsigned int entry_size = 18; /* "0.0.ABCD-0.0.EFGH\n" */
-       long devno;
-       int len;
-
-       len = 0;
-       for (devno = off; /* abuse the page variable
-                          * as counter, see fs/proc/generic.c */
-            devno < __MAX_SUBCHANNEL && len + entry_size < count; devno++) {
-               if (!test_bit(devno, bl_dev))
-                       continue;
-               len += sprintf(page + len, "0.0.%04lx", devno);
-               if (test_bit(devno + 1, bl_dev)) { /* print range */
-                       while (++devno < __MAX_SUBCHANNEL)
-                               if (!test_bit(devno, bl_dev))
-                                       break;
-                       len += sprintf(page + len, "-0.0.%04lx", --devno);
-               }
-               len += sprintf(page + len, "\n");
-       }
+       struct ccwdev_iter *iter;
+
+       if (*offset > __MAX_SUBCHANNEL)
+               return NULL;
+       iter = kmalloc(sizeof(struct ccwdev_iter), GFP_KERNEL);
+       if (!iter)
+               return ERR_PTR(-ENOMEM);
+       memset(iter, 0, sizeof(struct ccwdev_iter));
+       iter->devno = *offset;
+       return iter;
+}
+
+static void
+cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
+{
+       if (!IS_ERR(it))
+               kfree(it);
+}
 
-       if (devno < __MAX_SUBCHANNEL)
-               *eof = 1;
-       *start = (char *) (devno - off); /* number of checked entries */
-       return len;
+static void *
+cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
+{
+       struct ccwdev_iter *iter;
+
+       if (*offset > __MAX_SUBCHANNEL)
+               return NULL;
+       iter = (struct ccwdev_iter *)it;
+       iter->devno++;
+       (*offset)++;
+       return iter;
 }
 
-static int cio_ignore_write(struct file *file, const char __user *user_buf,
-                            unsigned long user_len, void *data)
+static int
+cio_ignore_proc_seq_show(struct seq_file *s, void *it)
+{
+       struct ccwdev_iter *iter;
+
+       iter = (struct ccwdev_iter *)it;
+       if (!is_blacklisted(iter->devno))
+               /* Not blacklisted, nothing to output. */
+               return 0;
+       if (!iter->in_range) {
+               /* First device in range. */
+               if ((iter->devno == __MAX_SUBCHANNEL) ||
+                   !is_blacklisted(iter->devno + 1))
+                       /* Singular device. */
+                       return seq_printf(s, "0.0.%04x\n", iter->devno);
+               iter->in_range = 1;
+               return seq_printf(s, "0.0.%04x-", iter->devno);
+       }
+       if ((iter->devno == __MAX_SUBCHANNEL) ||
+           !is_blacklisted(iter->devno + 1)) {
+               /* Last device in range. */
+               iter->in_range = 0;
+               return seq_printf(s, "0.0.%04x\n", iter->devno);
+       }
+       return 0;
+}
+
+static ssize_t
+cio_ignore_write(struct file *file, const char __user *user_buf,
+                size_t user_len, loff_t *offset)
 {
        char *buf;
 
+       if (*offset)
+               return -EINVAL;
        if (user_len > 65536)
                user_len = 65536;
        buf = vmalloc (user_len + 1); /* maybe better use the stack? */
@@ -331,6 +373,27 @@ static int cio_ignore_write(struct file *file, const char __user *user_buf,
        return user_len;
 }
 
+static struct seq_operations cio_ignore_proc_seq_ops = {
+       .start = cio_ignore_proc_seq_start,
+       .stop  = cio_ignore_proc_seq_stop,
+       .next  = cio_ignore_proc_seq_next,
+       .show  = cio_ignore_proc_seq_show,
+};
+
+static int
+cio_ignore_proc_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &cio_ignore_proc_seq_ops);
+}
+
+static struct file_operations cio_ignore_proc_fops = {
+       .open    = cio_ignore_proc_open,
+       .read    = seq_read,
+       .llseek  = seq_lseek,
+       .release = seq_release,
+       .write   = cio_ignore_write,
+};
+
 static int
 cio_ignore_proc_init (void)
 {
@@ -341,8 +404,7 @@ cio_ignore_proc_init (void)
        if (!entry)
                return 0;
 
-       entry->read_proc  = cio_ignore_read;
-       entry->write_proc = cio_ignore_write;
+       entry->proc_fops = &cio_ignore_proc_fops;
 
        return 1;
 }