void jbd2_journal_invalidatepage(journal_t *journal, struct page *page, unsigned long offset) { struct buffer_head *head, *bh, *next; unsigned int curr_off = 0; int may_free = 1; if (!PageLocked(page)) BUG(); if (!page_has_buffers(page)) return; head = bh = page_buffers(page); do { unsigned int next_off = curr_off + bh->b_size; next = bh->b_this_page; if (offset <= curr_off) { lock_buffer(bh); may_free &= journal_unmap_buffer(journal, bh); unlock_buffer(bh); } curr_off = next_off; bh = next; } while (bh != head); if (!offset) { if (may_free && try_to_free_buffers(page)) J_ASSERT(!page_has_buffers(page)); } }
void journal_invalidatepage(journal_t *journal, struct page *page, unsigned long offset) { struct buffer_head *head, *bh, *next; unsigned int curr_off = 0; int may_free = 1; if (!PageLocked(page)) BUG(); if (!page_has_buffers(page)) return; /* We will potentially be playing with lists other than just the * data lists (especially for journaled data mode), so be * cautious in our locking. */ head = bh = page_buffers(page); do { unsigned int next_off = curr_off + bh->b_size; next = bh->b_this_page; if (offset <= curr_off) { /* This block is wholly outside the truncation point */ lock_buffer(bh); may_free &= journal_unmap_buffer(journal, bh); unlock_buffer(bh); } curr_off = next_off; bh = next; } while (bh != head); if (!offset) { if (may_free && try_to_free_buffers(page)) J_ASSERT(!page_has_buffers(page)); } }