md: do not count blocked devices as spares

[pandora-kernel.git] / fs / libfs.c

diff --git a/fs/libfs.c b/fs/libfs.c
index 5523bde..baeb71e 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -512,6 +512,20 @@ void simple_release_fs(struct vfsmount **mount, int *count)
        mntput(mnt);
 }
 
+/**
+ * simple_read_from_buffer - copy data from the buffer to user space
+ * @to: the user space buffer to read to
+ * @count: the maximum number of bytes to read
+ * @ppos: the current position in the buffer
+ * @from: the buffer to read from
+ * @available: the size of the buffer
+ *
+ * The simple_read_from_buffer() function reads up to @count bytes from the
+ * buffer @from at offset @ppos into the user space address starting at @to.
+ *
+ * On success, the number of bytes read is returned and the offset @ppos is
+ * advanced by this number, or negative value is returned on error.
+ **/
 ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
                                const void *from, size_t available)
 {
@@ -528,6 +542,37 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
        return count;
 }
 
+/**
+ * memory_read_from_buffer - copy data from the buffer
+ * @to: the kernel space buffer to read to
+ * @count: the maximum number of bytes to read
+ * @ppos: the current position in the buffer
+ * @from: the buffer to read from
+ * @available: the size of the buffer
+ *
+ * The memory_read_from_buffer() function reads up to @count bytes from the
+ * buffer @from at offset @ppos into the kernel space address starting at @to.
+ *
+ * On success, the number of bytes read is returned and the offset @ppos is
+ * advanced by this number, or negative value is returned on error.
+ **/
+ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
+                               const void *from, size_t available)
+{
+       loff_t pos = *ppos;
+
+       if (pos < 0)
+               return -EINVAL;
+       if (pos >= available)
+               return 0;
+       if (count > available - pos)
+               count = available - pos;
+       memcpy(to, from + pos, count);
+       *ppos = pos + count;
+
+       return count;
+}
+
 /*
  * Transaction based IO.
  * The file expects a single write which triggers the transaction, and then
@@ -583,8 +628,8 @@ int simple_transaction_release(struct inode *inode, struct file *file)
 /* Simple attribute files */
 
 struct simple_attr {
-       u64 (*get)(void *);
-       void (*set)(void *, u64);
+       int (*get)(void *, u64 *);
+       int (*set)(void *, u64);
        char get_buf[24];       /* enough to store a u64 and "\n\0" */
        char set_buf[24];
        void *data;
@@ -595,7 +640,7 @@ struct simple_attr {
 /* simple_attr_open is called by an actual attribute open file operation
  * to set the attribute specific access operations. */
 int simple_attr_open(struct inode *inode, struct file *file,
-                    u64 (*get)(void *), void (*set)(void *, u64),
+                    int (*get)(void *, u64 *), int (*set)(void *, u64),
                     const char *fmt)
 {
        struct simple_attr *attr;
@@ -615,7 +660,7 @@ int simple_attr_open(struct inode *inode, struct file *file,
        return nonseekable_open(inode, file);
 }
 
-int simple_attr_close(struct inode *inode, struct file *file)
+int simple_attr_release(struct inode *inode, struct file *file)
 {
        kfree(file->private_data);
        return 0;
@@ -634,15 +679,24 @@ ssize_t simple_attr_read(struct file *file, char __user *buf,
        if (!attr->get)
                return -EACCES;
 
-       mutex_lock(&attr->mutex);
-       if (*ppos) /* continued read */
+       ret = mutex_lock_interruptible(&attr->mutex);
+       if (ret)
+               return ret;
+
+       if (*ppos) {            /* continued read */
                size = strlen(attr->get_buf);
-       else      /* first read */
+       } else {                /* first read */
+               u64 val;
+               ret = attr->get(attr->data, &val);
+               if (ret)
+                       goto out;
+
                size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
-                                attr->fmt,
-                                (unsigned long long)attr->get(attr->data));
+                                attr->fmt, (unsigned long long)val);
+       }
 
        ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
+out:
        mutex_unlock(&attr->mutex);
        return ret;
 }
@@ -657,11 +711,13 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf,
        ssize_t ret;
 
        attr = file->private_data;
-
        if (!attr->set)
                return -EACCES;
 
-       mutex_lock(&attr->mutex);
+       ret = mutex_lock_interruptible(&attr->mutex);
+       if (ret)
+               return ret;
+
        ret = -EFAULT;
        size = min(sizeof(attr->set_buf) - 1, len);
        if (copy_from_user(attr->set_buf, buf, size))
@@ -789,10 +845,11 @@ EXPORT_SYMBOL(simple_statfs);
 EXPORT_SYMBOL(simple_sync_file);
 EXPORT_SYMBOL(simple_unlink);
 EXPORT_SYMBOL(simple_read_from_buffer);
+EXPORT_SYMBOL(memory_read_from_buffer);
 EXPORT_SYMBOL(simple_transaction_get);
 EXPORT_SYMBOL(simple_transaction_read);
 EXPORT_SYMBOL(simple_transaction_release);
 EXPORT_SYMBOL_GPL(simple_attr_open);
-EXPORT_SYMBOL_GPL(simple_attr_close);
+EXPORT_SYMBOL_GPL(simple_attr_release);
 EXPORT_SYMBOL_GPL(simple_attr_read);
 EXPORT_SYMBOL_GPL(simple_attr_write);