From fc0e01974ccccc7530b7634a63ee3fcc57b845ea Mon Sep 17 00:00:00 2001 From: Jason Lunz Date: Sat, 1 Sep 2007 12:06:03 -0700 Subject: [JFFS2] fix write deadlock regression I've bisected the deadlock when many small appends are done on jffs2 down to this commit: commit 6fe6900e1e5b6fa9e5c59aa5061f244fe3f467e2 Author: Nick Piggin Date: Sun May 6 14:49:04 2007 -0700 mm: make read_cache_page synchronous Ensure pages are uptodate after returning from read_cache_page, which allows us to cut out most of the filesystem-internal PageUptodate calls. I didn't have a great look down the call chains, but this appears to fixes 7 possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in block2mtd. All depending on whether the filler is async and/or can return with a !uptodate page. It introduced a wait to read_cache_page, as well as a read_cache_page_async function equivalent to the old read_cache_page without any callers. Switching jffs2_gc_fetch_page to read_cache_page_async for the old behavior makes the deadlocks go away, but maybe reintroduces the use-before-uptodate problem? I don't understand the mm/fs interaction well enough to say. [It's fine. dwmw2.] Signed-off-by: Jason Lunz Signed-off-by: David Woodhouse --- fs/jffs2/fs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 1d3b7a9fc828..8bc727b71696 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -627,7 +627,7 @@ unsigned char *jffs2_gc_fetch_page(struct jffs2_sb_info *c, struct inode *inode = OFNI_EDONI_2SFFJ(f); struct page *pg; - pg = read_cache_page(inode->i_mapping, offset >> PAGE_CACHE_SHIFT, + pg = read_cache_page_async(inode->i_mapping, offset >> PAGE_CACHE_SHIFT, (void *)jffs2_do_readpage_unlock, inode); if (IS_ERR(pg)) return (void *)pg; -- cgit v1.2.3