* direct blocks
*/
static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
- ext4_fsblk_t goal, int indirect_blks, int blks,
- ext4_fsblk_t new_blocks[4], int *err)
+ ext4_lblk_t iblock, ext4_fsblk_t goal,
+ int indirect_blks, int blks,
+ ext4_fsblk_t new_blocks[4], int *err)
{
int target, i;
- unsigned long count = 0;
+ unsigned long count = 0, blk_allocated = 0;
int index = 0;
ext4_fsblk_t current_block = 0;
int ret = 0;
* the first direct block of this branch. That's the
* minimum number of blocks need to allocate(required)
*/
- target = blks + indirect_blks;
-
- while (1) {
+ /* first we try to allocate the indirect blocks */
+ target = indirect_blks;
+ while (target > 0) {
count = target;
/* allocating blocks for indirect blocks and direct blocks */
- current_block = ext4_new_blocks(handle,inode,goal,&count,err);
+ current_block = ext4_new_meta_blocks(handle, inode,
+ goal, &count, err);
if (*err)
goto failed_out;
new_blocks[index++] = current_block++;
count--;
}
-
- if (count > 0)
+ if (count > 0) {
+ /*
+ * save the new block number
+ * for the first direct block
+ */
+ new_blocks[index] = current_block;
+ printk(KERN_INFO "%s returned more blocks than "
+ "requested\n", __func__);
+ WARN_ON(1);
break;
+ }
}
- /* save the new block number for the first direct block */
- new_blocks[index] = current_block;
-
+ target = blks - count ;
+ blk_allocated = count;
+ if (!target)
+ goto allocated;
+ /* Now allocate data blocks */
+ count = target;
+ /* allocating blocks for data blocks */
+ current_block = ext4_new_blocks(handle, inode, iblock,
+ goal, &count, err);
+ if (*err && (target == blks)) {
+ /*
+ * if the allocation failed and we didn't allocate
+ * any blocks before
+ */
+ goto failed_out;
+ }
+ if (!*err) {
+ if (target == blks) {
+ /*
+ * save the new block number
+ * for the first direct block
+ */
+ new_blocks[index] = current_block;
+ }
+ blk_allocated += count;
+ }
+allocated:
/* total number of blocks allocated for direct blocks */
- ret = count;
+ ret = blk_allocated;
*err = 0;
return ret;
failed_out:
* as described above and return 0.
*/
static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
- int indirect_blks, int *blks, ext4_fsblk_t goal,
- ext4_lblk_t *offsets, Indirect *branch)
+ ext4_lblk_t iblock, int indirect_blks,
+ int *blks, ext4_fsblk_t goal,
+ ext4_lblk_t *offsets, Indirect *branch)
{
int blocksize = inode->i_sb->s_blocksize;
int i, n = 0;
ext4_fsblk_t new_blocks[4];
ext4_fsblk_t current_block;
- num = ext4_alloc_blocks(handle, inode, goal, indirect_blks,
+ num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
*blks, new_blocks, &err);
if (err)
return err;
/*
* Block out ext4_truncate while we alter the tree
*/
- err = ext4_alloc_branch(handle, inode, indirect_blks, &count, goal,
- offsets + (partial - chain), partial);
+ err = ext4_alloc_branch(handle, inode, iblock, indirect_blks,
+ &count, goal,
+ offsets + (partial - chain), partial);
/*
* The ext4_splice_branch call will free and forget any buffers
return err;
}
+
+static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
+{
+ return !buffer_mapped(bh);
+}
+
+int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+ loff_t size;
+ unsigned long len;
+ int ret = -EINVAL;
+ struct file *file = vma->vm_file;
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct address_space *mapping = inode->i_mapping;
+
+ /*
+ * Get i_alloc_sem to stop truncates messing with the inode. We cannot
+ * get i_mutex because we are already holding mmap_sem.
+ */
+ down_read(&inode->i_alloc_sem);
+ size = i_size_read(inode);
+ if (page->mapping != mapping || size <= page_offset(page)
+ || !PageUptodate(page)) {
+ /* page got truncated from under us? */
+ goto out_unlock;
+ }
+ ret = 0;
+ if (PageMappedToDisk(page))
+ goto out_unlock;
+
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+
+ if (page_has_buffers(page)) {
+ /* return if we have all the buffers mapped */
+ if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+ ext4_bh_unmapped))
+ goto out_unlock;
+ }
+ /*
+ * OK, we need to fill the hole... Do write_begin write_end
+ * to do block allocation/reservation.We are not holding
+ * inode.i__mutex here. That allow * parallel write_begin,
+ * write_end call. lock_page prevent this from happening
+ * on the same page though
+ */
+ ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
+ len, AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+ if (ret < 0)
+ goto out_unlock;
+ ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
+ len, len, page, NULL);
+ if (ret < 0)
+ goto out_unlock;
+ ret = 0;
+out_unlock:
+ up_read(&inode->i_alloc_sem);
+ return ret;
+}
projects / linux-2.6-omap-h63xx.git / blobdiff