From c63c7b051395368573779c8309aa5c990dcf2f96 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 2 Apr 2007 19:29:52 -0400 Subject: NFS: Fix a race when doing NFS write coalescing Currently we do write coalescing in a very inefficient manner: one pass in generic_writepages() in order to lock the pages for writing, then one pass in nfs_flush_mapping() and/or nfs_sync_mapping_wait() in order to gather the locked pages for coalescing into RPC requests of size "wsize". In fact, it turns out there is actually a deadlock possible here since we only start I/O on the second pass. If the user signals the process while we're in nfs_sync_mapping_wait(), for instance, then we may exit before starting I/O on all the requests that have been queued up. Signed-off-by: Trond Myklebust --- include/linux/writeback.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 0c78f7f4a976..daa6c125f66e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -59,6 +59,8 @@ struct writeback_control { unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned for_writepages:1; /* This is a writepages() call */ unsigned range_cyclic:1; /* range_start is cyclic */ + + void *fs_private; /* For use by ->writepages() */ }; /* -- cgit v1.2.3 From 0ea971801625184a91a6d80ea85e53875caa0bf5 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 10 May 2007 22:22:51 -0700 Subject: consolidate generic_writepages and mpage_writepages Clean up massive code duplication between mpage_writepages() and generic_writepages(). The new generic function, write_cache_pages() takes a function pointer argument, which will be called for each page to be written. Maybe cifs_writepages() too can use this infrastructure, but I'm not touching that with a ten-foot pole. The upcoming page writeback support in fuse will also want this. Signed-off-by: Miklos Szeredi Acked-by: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/writeback.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index daa6c125f66e..050915b59576 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -111,9 +111,15 @@ balance_dirty_pages_ratelimited(struct address_space *mapping) balance_dirty_pages_ratelimited_nr(mapping, 1); } +typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, + void *data); + int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0); -extern int generic_writepages(struct address_space *mapping, - struct writeback_control *wbc); +int generic_writepages(struct address_space *mapping, + struct writeback_control *wbc); +int write_cache_pages(struct address_space *mapping, + struct writeback_control *wbc, writepage_t writepage, + void *data); int do_writepages(struct address_space *mapping, struct writeback_control *wbc); int sync_page_range(struct inode *inode, struct address_space *mapping, loff_t pos, loff_t count); -- cgit v1.2.3