From 96150606e2fb82d242c9e4a414e4e922849f7bf7 Mon Sep 17 00:00:00 2001 From: Prasad Joshi Date: Sat, 26 Nov 2011 11:00:47 +0530 Subject: logfs: update page reference count for pined pages LogFS sets PG_private flag to indicate a pined page. We assumed that marking a page as private is enough to ensure its existence. But instead it is necessary to hold a reference count to the page. The change resolves the following BUG BUG: Bad page state in process flush-253:16 pfn:6a6d0 page flags: 0x100000000000808(uptodate|private) Suggested-and-Acked-by: Joern Engel Signed-off-by: Prasad Joshi --- fs/logfs/segment.c | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) (limited to 'fs/logfs/segment.c') diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c index 9d518735325..6aee6092860 100644 --- a/fs/logfs/segment.c +++ b/fs/logfs/segment.c @@ -86,7 +86,11 @@ int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len, BUG_ON(!page); /* FIXME: reserve a pool */ SetPageUptodate(page); memcpy(page_address(page) + offset, buf, copylen); - SetPagePrivate(page); + + if (!PagePrivate(page)) { + SetPagePrivate(page); + page_cache_get(page); + } page_cache_release(page); buf += copylen; @@ -110,7 +114,10 @@ static void pad_partial_page(struct logfs_area *area) page = get_mapping_page(sb, index, 0); BUG_ON(!page); /* FIXME: reserve a pool */ memset(page_address(page) + offset, 0xff, len); - SetPagePrivate(page); + if (!PagePrivate(page)) { + SetPagePrivate(page); + page_cache_get(page); + } page_cache_release(page); } } @@ -130,7 +137,10 @@ static void pad_full_pages(struct logfs_area *area) BUG_ON(!page); /* FIXME: reserve a pool */ SetPageUptodate(page); memset(page_address(page), 0xff, PAGE_CACHE_SIZE); - SetPagePrivate(page); + if (!PagePrivate(page)) { + SetPagePrivate(page); + page_cache_get(page); + } page_cache_release(page); index++; no_indizes--; @@ -485,8 +495,12 @@ static void move_btree_to_page(struct inode *inode, struct page *page, mempool_free(item, super->s_alias_pool); } block->page = page; - SetPagePrivate(page); - page->private = (unsigned long)block; + + if (!PagePrivate(page)) { + SetPagePrivate(page); + page_cache_get(page); + set_page_private(page, (unsigned long) block); + } block->ops = &indirect_block_ops; initialize_block_counters(page, block, data, 0); } @@ -536,8 +550,12 @@ void move_page_to_btree(struct page *page) list_add(&item->list, &block->item_list); } block->page = NULL; - ClearPagePrivate(page); - page->private = 0; + + if (PagePrivate(page)) { + ClearPagePrivate(page); + page_cache_release(page); + set_page_private(page, 0); + } block->ops = &btree_block_ops; err = alias_tree_insert(block->sb, block->ino, block->bix, block->level, block); @@ -702,7 +720,10 @@ void freeseg(struct super_block *sb, u32 segno) page = find_get_page(mapping, ofs >> PAGE_SHIFT); if (!page) continue; - ClearPagePrivate(page); + if (PagePrivate(page)) { + ClearPagePrivate(page); + page_cache_release(page); + } page_cache_release(page); } } -- cgit v1.2.3