From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELv2gWmU4M7G1F8wAdSnn3oKUPOEcnUY3pBAZXigKu8/pDedC0tQxcwmpirPfBypqoYFhV6c ARC-Seal: i=1; a=rsa-sha256; t=1521214365; cv=none; d=google.com; s=arc-20160816; b=dTwx2JUBFNOQ6LZlR69+CZboUj8dkGp+2HSuZpYbdxwfMTNv7GncGnFzngTsUec/5q AkFuQD97J150hdEyxmakpK48OhwykLJgeXgmFZlo7QUrzoy4GqAUX6Y3fKngvQR8+KZQ Z/tA3sX9Ux2Fw59P52BxQTzgMJCRe0JKKSAKxwUSa4V0DIcF2liYlmeOZdlIBMsoseiO hJ+KRJtYKfbgGcBW26ytiEcu5UyzTYSURhaRZOBKRle7xoa8t+kz8x1hVSB3Gp/N/el9 crvfvvKeoCfoNSAdy3hHFmOp2GGeUpQwKqWuLUINl9GAoHONt/WWfoXfuvN81nA54Id/ oZ0A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=BE1GAs4Kg1vWrTuosrQoQ3Qn3a4T5FwAxZmbbu16G2Y=; b=vdqRd8gc5uils6TJ3mBpX3XmftfCukFlPd9ottbrZCbngZNrXtqriuQ2ldaMshH+87 yj8bv4l1Nwjo1um6asmW1RPrfiB60eq/QkggJY8Xw0fg3K0EloR+EDshYRDG4oNllt32 MN0hIX1N5zfH78ekaLGnaileJYKO0a1IZC2Rfmyti8X39ZpMkgUqKPp3W5MreORCfJxf yS+su/LoNfw+TKPt9MVBpm2L2OaqGkeKDvXl7f+bQiob9FrCpS4KPpDknJZ9guEBP3Os h0RtxuZ7o/Y41RfQrbcTTca6sQVFGvbtyRrPlbkPAav6DKN4F0TE3NquIkYuqN1deGKi i5Jg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Scott Mayhew , Trond Myklebust Subject: [PATCH 4.9 68/86] NFS: Fix unstable write completion Date: Fri, 16 Mar 2018 16:23:31 +0100 Message-Id: <20180316152321.959682435@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180316152317.167709497@linuxfoundation.org> References: <20180316152317.167709497@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595108875088099694?= X-GMAIL-MSGID: =?utf-8?q?1595108875088099694?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust commit c4f24df942a181699c5bab01b8e5e82b925f77f3 upstream. We do want to respect the FLUSH_SYNC argument to nfs_commit_inode() to ensure that all outstanding COMMIT requests to the inode in question are complete. Currently we may exit early from both nfs_commit_inode() and nfs_write_inode() even if there are COMMIT requests in flight, or unstable writes on the commit list. In order to get the right semantics w.r.t. sync_inode(), we don't need to have nfs_commit_inode() reset the inode dirty flags when called from nfs_wb_page() and/or nfs_wb_all(). We just need to ensure that nfs_write_inode() leaves them in the right state if there are outstanding commits, or stable pages. Reported-by: Scott Mayhew Fixes: dc4fd9ab01ab ("nfs: don't wait on commit in nfs_commit_inode()...") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/write.c | 83 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 43 insertions(+), 40 deletions(-) --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1847,40 +1847,43 @@ int nfs_generic_commit_list(struct inode return status; } -int nfs_commit_inode(struct inode *inode, int how) +static int __nfs_commit_inode(struct inode *inode, int how, + struct writeback_control *wbc) { LIST_HEAD(head); struct nfs_commit_info cinfo; int may_wait = how & FLUSH_SYNC; - int error = 0; - int res; + int ret, nscan; nfs_init_cinfo_from_inode(&cinfo, inode); nfs_commit_begin(cinfo.mds); - res = nfs_scan_commit(inode, &head, &cinfo); - if (res) - error = nfs_generic_commit_list(inode, &head, how, &cinfo); + for (;;) { + ret = nscan = nfs_scan_commit(inode, &head, &cinfo); + if (ret <= 0) + break; + ret = nfs_generic_commit_list(inode, &head, how, &cinfo); + if (ret < 0) + break; + ret = 0; + if (wbc && wbc->sync_mode == WB_SYNC_NONE) { + if (nscan < wbc->nr_to_write) + wbc->nr_to_write -= nscan; + else + wbc->nr_to_write = 0; + } + if (nscan < INT_MAX) + break; + cond_resched(); + } nfs_commit_end(cinfo.mds); - if (res == 0) - return res; - if (error < 0) - goto out_error; - if (!may_wait) - goto out_mark_dirty; - error = wait_on_commit(cinfo.mds); - if (error < 0) - return error; - return res; -out_error: - res = error; - /* Note: If we exit without ensuring that the commit is complete, - * we must mark the inode as dirty. Otherwise, future calls to - * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure - * that the data is on the disk. - */ -out_mark_dirty: - __mark_inode_dirty(inode, I_DIRTY_DATASYNC); - return res; + if (ret || !may_wait) + return ret; + return wait_on_commit(cinfo.mds); +} + +int nfs_commit_inode(struct inode *inode, int how) +{ + return __nfs_commit_inode(inode, how, NULL); } EXPORT_SYMBOL_GPL(nfs_commit_inode); @@ -1890,11 +1893,11 @@ int nfs_write_inode(struct inode *inode, int flags = FLUSH_SYNC; int ret = 0; - /* no commits means nothing needs to be done */ - if (!nfsi->commit_info.ncommit) - return ret; - if (wbc->sync_mode == WB_SYNC_NONE) { + /* no commits means nothing needs to be done */ + if (!nfsi->commit_info.ncommit) + goto check_requests_outstanding; + /* Don't commit yet if this is a non-blocking flush and there * are a lot of outstanding writes for this mapping. */ @@ -1905,16 +1908,16 @@ int nfs_write_inode(struct inode *inode, flags = 0; } - ret = nfs_commit_inode(inode, flags); - if (ret >= 0) { - if (wbc->sync_mode == WB_SYNC_NONE) { - if (ret < wbc->nr_to_write) - wbc->nr_to_write -= ret; - else - wbc->nr_to_write = 0; - } - return 0; - } + ret = __nfs_commit_inode(inode, flags, wbc); + if (!ret) { + if (flags & FLUSH_SYNC) + return 0; + } else if (nfsi->commit_info.ncommit) + goto out_mark_dirty; + +check_requests_outstanding: + if (!atomic_read(&nfsi->commit_info.rpcs_out)) + return ret; out_mark_dirty: __mark_inode_dirty(inode, I_DIRTY_DATASYNC); return ret;