2.6.28-stable review patch. If anyone has any objections, please let us know. ------------------ From: Wu Fengguang commit 136221fc3219b3805c48db5da065e8e3467175d4 upstream. aops->readpages() and its NFS helper readpage_async_filler() will only be called to do readahead I/O for newly allocated pages. So it's not necessary to test for the always 0 dirty/uptodate page flags. The removal of nfs_wb_page() call also fixes a readahead bug: the NFS readahead has been synchronous since 2.6.23, because that call will clear PG_readahead, which is the reminder for asynchronous readahead. More background: the PG_readahead page flag is shared with PG_reclaim, one for read path and the other for write path. clear_page_dirty_for_io() unconditionally clears PG_readahead to prevent possible readahead residuals, assuming itself to be always called in the write path. However, NFS is one and the only exception in that it _always_ calls clear_page_dirty_for_io() in the read path, i.e. for readpages()/readpage(). Cc: Trond Myklebust Signed-off-by: Wu Fengguang Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/read.c | 6 ------ 1 file changed, 6 deletions(-) --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -533,12 +533,6 @@ readpage_async_filler(void *data, struct unsigned int len; int error; - error = nfs_wb_page(inode, page); - if (error) - goto out_unlock; - if (PageUptodate(page)) - goto out_unlock; - len = nfs_page_length(page); if (len == 0) return nfs_return_empty_page(page); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/