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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/block/aoe/aoechr.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/block/aoe/aoechr.c')
-rw-r--r--drivers/block/aoe/aoechr.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
new file mode 100644
index 000000000000..14aeca3e2e8c
--- /dev/null
+++ b/drivers/block/aoe/aoechr.c
@@ -0,0 +1,244 @@
+/* Copyright (c) 2004 Coraid, Inc. See COPYING for GPL terms. */
+/*
+ * aoechr.c
+ * AoE character device driver
+ */
+
+#include <linux/hdreg.h>
+#include <linux/blkdev.h>
+#include "aoe.h"
+
+enum {
+ //MINOR_STAT = 1, (moved to sysfs)
+ MINOR_ERR = 2,
+ MINOR_DISCOVER,
+ MINOR_INTERFACES,
+ MSGSZ = 2048,
+ NARGS = 10,
+ NMSG = 100, /* message backlog to retain */
+};
+
+struct aoe_chardev {
+ ulong minor;
+ char name[32];
+};
+
+enum { EMFL_VALID = 1 };
+
+struct ErrMsg {
+ short flags;
+ short len;
+ char *msg;
+};
+
+static struct ErrMsg emsgs[NMSG];
+static int emsgs_head_idx, emsgs_tail_idx;
+static struct semaphore emsgs_sema;
+static spinlock_t emsgs_lock;
+static int nblocked_emsgs_readers;
+static struct class_simple *aoe_class;
+static struct aoe_chardev chardevs[] = {
+ { MINOR_ERR, "err" },
+ { MINOR_DISCOVER, "discover" },
+ { MINOR_INTERFACES, "interfaces" },
+};
+
+static int
+discover(void)
+{
+ aoecmd_cfg(0xffff, 0xff);
+ return 0;
+}
+
+static int
+interfaces(const char __user *str, size_t size)
+{
+ if (set_aoe_iflist(str, size)) {
+ printk(KERN_CRIT
+ "%s: could not set interface list: %s\n",
+ __FUNCTION__, "too many interfaces");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+void
+aoechr_error(char *msg)
+{
+ struct ErrMsg *em;
+ char *mp;
+ ulong flags, n;
+
+ n = strlen(msg);
+
+ spin_lock_irqsave(&emsgs_lock, flags);
+
+ em = emsgs + emsgs_tail_idx;
+ if ((em->flags & EMFL_VALID)) {
+bail: spin_unlock_irqrestore(&emsgs_lock, flags);
+ return;
+ }
+
+ mp = kmalloc(n, GFP_ATOMIC);
+ if (mp == NULL) {
+ printk(KERN_CRIT "aoe: aoechr_error: allocation failure, len=%ld\n", n);
+ goto bail;
+ }
+
+ memcpy(mp, msg, n);
+ em->msg = mp;
+ em->flags |= EMFL_VALID;
+ em->len = n;
+
+ emsgs_tail_idx++;
+ emsgs_tail_idx %= ARRAY_SIZE(emsgs);
+
+ spin_unlock_irqrestore(&emsgs_lock, flags);
+
+ if (nblocked_emsgs_readers)
+ up(&emsgs_sema);
+}
+
+static ssize_t
+aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp)
+{
+ int ret = -EINVAL;
+
+ switch ((unsigned long) filp->private_data) {
+ default:
+ printk(KERN_INFO "aoe: aoechr_write: can't write to that file.\n");
+ break;
+ case MINOR_DISCOVER:
+ ret = discover();
+ break;
+ case MINOR_INTERFACES:
+ ret = interfaces(buf, cnt);
+ break;
+ }
+ if (ret == 0)
+ ret = cnt;
+ return ret;
+}
+
+static int
+aoechr_open(struct inode *inode, struct file *filp)
+{
+ int n, i;
+
+ n = MINOR(inode->i_rdev);
+ filp->private_data = (void *) (unsigned long) n;
+
+ for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
+ if (chardevs[i].minor == n)
+ return 0;
+ return -EINVAL;
+}
+
+static int
+aoechr_rel(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+static ssize_t
+aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
+{
+ unsigned long n;
+ char *mp;
+ struct ErrMsg *em;
+ ssize_t len;
+ ulong flags;
+
+ n = (unsigned long) filp->private_data;
+ switch (n) {
+ case MINOR_ERR:
+ spin_lock_irqsave(&emsgs_lock, flags);
+loop:
+ em = emsgs + emsgs_head_idx;
+ if ((em->flags & EMFL_VALID) == 0) {
+ if (filp->f_flags & O_NDELAY) {
+ spin_unlock_irqrestore(&emsgs_lock, flags);
+ return -EAGAIN;
+ }
+ nblocked_emsgs_readers++;
+
+ spin_unlock_irqrestore(&emsgs_lock, flags);
+
+ n = down_interruptible(&emsgs_sema);
+
+ spin_lock_irqsave(&emsgs_lock, flags);
+
+ nblocked_emsgs_readers--;
+
+ if (n) {
+ spin_unlock_irqrestore(&emsgs_lock, flags);
+ return -ERESTARTSYS;
+ }
+ goto loop;
+ }
+ if (em->len > cnt) {
+ spin_unlock_irqrestore(&emsgs_lock, flags);
+ return -EAGAIN;
+ }
+ mp = em->msg;
+ len = em->len;
+ em->msg = NULL;
+ em->flags &= ~EMFL_VALID;
+
+ emsgs_head_idx++;
+ emsgs_head_idx %= ARRAY_SIZE(emsgs);
+
+ spin_unlock_irqrestore(&emsgs_lock, flags);
+
+ n = copy_to_user(buf, mp, len);
+ kfree(mp);
+ return n == 0 ? len : -EFAULT;
+ default:
+ return -EFAULT;
+ }
+}
+
+static struct file_operations aoe_fops = {
+ .write = aoechr_write,
+ .read = aoechr_read,
+ .open = aoechr_open,
+ .release = aoechr_rel,
+ .owner = THIS_MODULE,
+};
+
+int __init
+aoechr_init(void)
+{
+ int n, i;
+
+ n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops);
+ if (n < 0) {
+ printk(KERN_ERR "aoe: aoechr_init: can't register char device\n");
+ return n;
+ }
+ sema_init(&emsgs_sema, 0);
+ spin_lock_init(&emsgs_lock);
+ aoe_class = class_simple_create(THIS_MODULE, "aoe");
+ if (IS_ERR(aoe_class)) {
+ unregister_chrdev(AOE_MAJOR, "aoechr");
+ return PTR_ERR(aoe_class);
+ }
+ for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
+ class_simple_device_add(aoe_class,
+ MKDEV(AOE_MAJOR, chardevs[i].minor),
+ NULL, chardevs[i].name);
+
+ return 0;
+}
+
+void
+aoechr_exit(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
+ class_simple_device_remove(MKDEV(AOE_MAJOR, chardevs[i].minor));
+ class_simple_destroy(aoe_class);
+ unregister_chrdev(AOE_MAJOR, "aoechr");
+}
+