int nilfs_copy_dirty_pages(struct address_space *dmap,
struct address_space *smap)
{
struct pagevec pvec;
unsigned int i;
pgoff_t index = 0;
int err = 0;
pagevec_init(&pvec, 0);
repeat:
if (!pagevec_lookup_tag(&pvec, smap, &index, PAGECACHE_TAG_DIRTY,
PAGEVEC_SIZE))
return 0;
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *page = pvec.pages[i], *dpage;
lock_page(page);
if (unlikely(!PageDirty(page)))
NILFS_PAGE_BUG(page, "inconsistent dirty state");
dpage = grab_cache_page(dmap, page->index);
if (unlikely(!dpage)) {
/* No empty page is added to the page cache */
err = -ENOMEM;
unlock_page(page);
break;
}
if (unlikely(!page_has_buffers(page)))
NILFS_PAGE_BUG(page,
"found empty page in dat page cache");
nilfs_copy_page(dpage, page, 1);
__set_page_dirty_nobuffers(dpage);
unlock_page(dpage);
page_cache_release(dpage);
unlock_page(page);
}
pagevec_release(&pvec);
cond_resched();
if (likely(!err))
goto repeat;
return err;
}
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);
retry:
err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
if (err)
goto failed_unlock;
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);
spin_lock_irq(&btnc->tree_lock);
err = radix_tree_insert(&btnc->page_tree, newkey, obh->b_page);
spin_unlock_irq(&btnc->tree_lock);
radix_tree_preload_end();
if (!err)
return 0;
else if (err != -EEXIST)
goto failed_unlock;
err = invalidate_inode_pages2_range(btnc, newkey, newkey);
if (!err)
goto retry;
unlock_page(obh->b_page);
}
nbh = nilfs_btnode_create_block(btnc, newkey);
if (!nbh)
return -ENOMEM;
BUG_ON(nbh == obh);
ctxt->newbh = nbh;
return 0;
failed_unlock:
unlock_page(obh->b_page);
return err;
}
void nilfs_free_private_page(struct page *page)
{
BUG_ON(!PageLocked(page));
BUG_ON(page->mapping);
if (page_has_buffers(page) && !try_to_free_buffers(page))
NILFS_PAGE_BUG(page, "failed to free page");
unlock_page(page);
__free_page(page);
}
/*
* For inode and page debug
*/
int nilfs_releasepage(struct page *page, gfp_t gfp_mask)
{
struct address_space *mapping = page->mapping;
struct inode *inode;
int verbose = (nilfs_debug_info.verbose[NILFS_VERBOSE_PAGE] > 1);
int ret;
if (!verbose && mapping) {
inode = NILFS_AS_I(mapping);
if (inode->i_sb && !(inode->i_sb->s_flags & MS_ACTIVE))
verbose = 1;
}
if (unlikely(!PagePrivate(page)))
NILFS_PAGE_BUG(page, "no buffers");
if (buffer_nilfs_allocated(page_buffers(page)))
NILFS_PAGE_BUG(page, "nilfs allocated page");
/*
* Note that non-busy buffer heads may be discarded though the
* try_to_free_buffers() call. This may happen when the page is not
* dirty, not in writeback, not locked, and belongs to a mapping.
* Before changing the state of buffer heads to busy, the page lock
* must be held to protect them.
*/
ret = try_to_free_buffers(page);
if (verbose && ret && mapping && mapping->host) {
if (page_count(page) > 2 + !PageLRU(page))
/*
* This may happen when the other task just happen to
* find and get the page during this invalidation.
*/
PAGE_DEBUG(page, "too many page count");
}
return ret;
}
/**
* nilfs_btnode_commit_change_key
* commit the change_key operation prepared by prepare_change_key().
*/
void nilfs_btnode_commit_change_key(struct address_space *btnc,
struct nilfs_btnode_chkey_ctxt *ctxt)
{
struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh;
__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey;
struct page *opage;
if (oldkey == newkey)
return;
if (nbh == NULL) { /* blocksize == pagesize */
opage = obh->b_page;
if (unlikely(oldkey != opage->index))
NILFS_PAGE_BUG(opage,
"invalid oldkey %lld (newkey=%lld)",
(unsigned long long)oldkey,
(unsigned long long)newkey);
if (!test_set_buffer_dirty(obh) && TestSetPageDirty(opage))
BUG();
WRITE_LOCK_IRQ(&btnc->tree_lock);
radix_tree_delete(&btnc->page_tree, oldkey);
radix_tree_tag_set(&btnc->page_tree, newkey,
PAGECACHE_TAG_DIRTY);
WRITE_UNLOCK_IRQ(&btnc->tree_lock);
opage->index = obh->b_blocknr = newkey;
unlock_page(opage);
} else {
nilfs_copy_buffer(nbh, obh);
nilfs_btnode_mark_dirty(nbh);
nbh->b_blocknr = newkey;
ctxt->bh = nbh;
nilfs_btnode_delete(obh); /* will decrement bh->b_count */
}
}
void nilfs_btnode_commit_change_key(struct address_space *btnc,
struct nilfs_btnode_chkey_ctxt *ctxt)
{
struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh;
__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey;
struct page *opage;
if (oldkey == newkey)
return;
if (nbh == NULL) {
opage = obh->b_page;
if (unlikely(oldkey != opage->index))
NILFS_PAGE_BUG(opage,
"invalid oldkey %lld (newkey=%lld)",
(unsigned long long)oldkey,
(unsigned long long)newkey);
mark_buffer_dirty(obh);
spin_lock_irq(&btnc->tree_lock);
radix_tree_delete(&btnc->page_tree, oldkey);
radix_tree_tag_set(&btnc->page_tree, newkey,
PAGECACHE_TAG_DIRTY);
spin_unlock_irq(&btnc->tree_lock);
opage->index = obh->b_blocknr = newkey;
unlock_page(opage);
} else {
nilfs_copy_buffer(nbh, obh);
mark_buffer_dirty(nbh);
nbh->b_blocknr = newkey;
ctxt->bh = nbh;
nilfs_btnode_delete(obh);
}
}
/**
* 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);
/*
* We cannot call radix_tree_preload for the kernels older
* than 2.6.23, because it is not exported for modules.
*/
retry:
err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
if (err)
goto failed_unlock;
/* 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);
spin_lock_irq(&btnc->tree_lock);
err = radix_tree_insert(&btnc->page_tree, newkey, obh->b_page);
spin_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.
*/
radix_tree_preload_end();
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);
}
nbh = nilfs_btnode_create_block(btnc, newkey);
if (!nbh)
return -ENOMEM;
BUG_ON(nbh == obh);
ctxt->newbh = nbh;
return 0;
failed_unlock:
unlock_page(obh->b_page);
return err;
}