Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759453AbZFAV5f (ORCPT ); Mon, 1 Jun 2009 17:57:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756900AbZFAVwi (ORCPT ); Mon, 1 Jun 2009 17:52:38 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:43476 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755402AbZFAVvC (ORCPT ); Mon, 1 Jun 2009 17:51:02 -0400 From: "Eric W. Biederman" To: Al Viro Cc: , , , , Hugh Dickins , Tejun Heo , Alexey Dobriyan , Linus Torvalds , Alan Cox , Greg Kroah-Hartman , Nick Piggin , Andrew Morton , Christoph Hellwig , "Eric W. Biederman" , "Eric W. Biederman" Date: Mon, 1 Jun 2009 14:50:48 -0700 Message-Id: <1243893048-17031-23-git-send-email-ebiederm@xmission.com> X-Mailer: git-send-email 1.6.3.1.54.g99dd.dirty In-Reply-To: References: X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: viro@ZenIV.linux.org.uk, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, hugh@veritas.com, tj@kernel.org, adobriyan@gmail.com, torvalds@linux-foundation.org, alan@lxorguk.ukuu.org.uk, gregkh@suse.de, npiggin@suse.de, akpm@linux-foundation.org, hch@infradead.org, ebiederm@maxwell.aristanetworks.com, ebiederm@aristanetworks.com X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Al Viro X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 XM_SPF_Neutral SPF-Neutral * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: [PATCH 23/23] vfs: Teach readahead to use the file_hotplug_lock X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1555 Lines: 52 From: Eric W. Biederman Signed-off-by: Eric W. Biederman --- mm/filemap.c | 25 ++++++++++++++++--------- 1 files changed, 16 insertions(+), 9 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 379ff0b..5016aa5 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1402,16 +1402,23 @@ SYSCALL_DEFINE(readahead)(int fd, loff_t offset, size_t count) ret = -EBADF; file = fget(fd); - if (file) { - if (file->f_mode & FMODE_READ) { - struct address_space *mapping = file->f_mapping; - pgoff_t start = offset >> PAGE_CACHE_SHIFT; - pgoff_t end = (offset + count - 1) >> PAGE_CACHE_SHIFT; - unsigned long len = end - start + 1; - ret = do_readahead(mapping, file, start, len); - } - fput(file); + if (!file) + goto out; + + if (!(file->f_mode & FMODE_READ)) + goto out_fput; + + if (file_hotplug_read_trylock(file)) { + struct address_space *mapping = file->f_mapping; + pgoff_t start = offset >> PAGE_CACHE_SHIFT; + pgoff_t end = (offset + count - 1) >> PAGE_CACHE_SHIFT; + unsigned long len = end - start + 1; + ret = do_readahead(mapping, file, start, len); + file_hotplug_read_unlock(file); } +out_fput: + fput(file); +out: return ret; } #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS -- 1.6.3.1.54.g99dd.dirty -- 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/