drop unused dentry argument to ->fsync

[linux-2.6-block.git] / fs / libfs.c

diff --git a/fs/libfs.c b/fs/libfs.c
index ea9a6cc9b35c6b08ef1517837d1c05a4d2da47e1..e57ea58bda68cd5adc82d75864d1ead23ad28dc0 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -58,7 +58,7 @@ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct na
        return NULL;
 }
 
-int simple_sync_file(struct file * file, struct dentry *dentry, int datasync)
+int simple_sync_file(struct file *file, int datasync)
 {
        return 0;
 }
@@ -546,6 +546,40 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
        return count;
 }
 
+/**
+ * simple_write_to_buffer - copy data from user space to the buffer
+ * @to: the buffer to write to
+ * @available: the size of the buffer
+ * @ppos: the current position in the buffer
+ * @from: the user space buffer to read from
+ * @count: the maximum number of bytes to read
+ *
+ * The simple_write_to_buffer() function reads up to @count bytes from the user
+ * space address starting at @from into the buffer @to at offset @ppos.
+ *
+ * On success, the number of bytes written is returned and the offset @ppos is
+ * advanced by this number, or negative value is returned on error.
+ **/
+ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
+               const void __user *from, size_t count)
+{
+       loff_t pos = *ppos;
+       size_t res;
+
+       if (pos < 0)
+               return -EINVAL;
+       if (pos >= available || !count)
+               return 0;
+       if (count > available - pos)
+               count = available - pos;
+       res = copy_from_user(to + pos, from, count);
+       if (res == count)
+               return -EFAULT;
+       count -= res;
+       *ppos = pos + count;
+       return count;
+}
+
 /**
  * memory_read_from_buffer - copy data from the buffer
  * @to: the kernel space buffer to read to
@@ -817,13 +851,13 @@ struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid,
 }
 EXPORT_SYMBOL_GPL(generic_fh_to_parent);
 
-int simple_fsync(struct file *file, struct dentry *dentry, int datasync)
+int simple_fsync(struct file *file, int datasync)
 {
        struct writeback_control wbc = {
                .sync_mode = WB_SYNC_ALL,
                .nr_to_write = 0, /* metadata-only; caller takes care of data */
        };
-       struct inode *inode = dentry->d_inode;
+       struct inode *inode = file->f_mapping->host;
        int err;
        int ret;
 
@@ -864,6 +898,7 @@ EXPORT_SYMBOL(simple_statfs);
 EXPORT_SYMBOL(simple_sync_file);
 EXPORT_SYMBOL(simple_unlink);
 EXPORT_SYMBOL(simple_read_from_buffer);
+EXPORT_SYMBOL(simple_write_to_buffer);
 EXPORT_SYMBOL(memory_read_from_buffer);
 EXPORT_SYMBOL(simple_transaction_set);
 EXPORT_SYMBOL(simple_transaction_get);