int nilfs_bmap_get_new_block(const struct nilfs_bmap *bmap, __u64 ptr,
struct buffer_head **bhp)
{
int ret;
ret = nilfs_btnode_get(&NILFS_BMAP_I(bmap)->i_btnode_cache,
ptr, 0, bhp, 1);
if (ret < 0)
return ret;
set_buffer_nilfs_volatile(*bhp);
return 0;
}
/**
* nilfs_btnode_prepare_change_key
* prepare to move contents of the block for old key to one of new key.
* the old buffer will not be removed, but might be reused for new buffer.
* it might return -ENOMEM because of memory allocation errors,
* and might return -EIO because of disk read errors.
*/
int nilfs_btnode_prepare_change_key(struct address_space *btnc,
struct nilfs_btnode_chkey_ctxt *ctxt)
{
struct buffer_head *obh, *nbh;
struct inode *inode = NILFS_BTNC_I(btnc);
__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey;
int err;
if (oldkey == newkey)
return 0;
obh = ctxt->bh;
ctxt->newbh = NULL;
if (inode->i_blkbits == PAGE_CACHE_SHIFT) {
lock_page(obh->b_page);
#if HAVE_EXPORTED_RADIX_TREE_PRELOAD
/*
* We cannot call radix_tree_preload for the kernels older
* than 2.6.23, because it is not exported for modules.
*/
err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
if (err)
goto failed_unlock;
#endif
/* BUG_ON(oldkey != obh->b_page->index); */
if (unlikely(oldkey != obh->b_page->index))
NILFS_PAGE_BUG(obh->b_page,
"invalid oldkey %lld (newkey=%lld)",
(unsigned long long)oldkey,
(unsigned long long)newkey);
retry:
WRITE_LOCK_IRQ(&btnc->tree_lock);
err = radix_tree_insert(&btnc->page_tree, newkey, obh->b_page);
WRITE_UNLOCK_IRQ(&btnc->tree_lock);
/*
* Note: page->index will not change to newkey until
* nilfs_btnode_commit_change_key() will be called.
* To protect the page in intermediate state, the page lock
* is held.
*/
#if HAVE_EXPORTED_RADIX_TREE_PRELOAD
radix_tree_preload_end();
#endif
if (!err)
return 0;
else if (err != -EEXIST)
goto failed_unlock;
err = invalidate_inode_pages2_range(btnc, newkey, newkey);
if (!err)
goto retry;
/* fallback to copy mode */
unlock_page(obh->b_page);
}
err = nilfs_btnode_get(btnc, newkey, 0, &nbh, 1);
if (likely(!err)) {
BUG_ON(nbh == obh);
ctxt->newbh = nbh;
}
return err;
failed_unlock:
unlock_page(obh->b_page);
return err;
}
int nilfs_bmap_get_block(const struct nilfs_bmap *bmap, __u64 ptr,
struct buffer_head **bhp)
{
return nilfs_btnode_get(&NILFS_BMAP_I(bmap)->i_btnode_cache,
ptr, 0, bhp, 0);
}
