From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f50.google.com (mail-wr1-f50.google.com [209.85.221.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B6C1D2DC767 for ; Fri, 10 Apr 2026 05:59:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775800761; cv=none; b=QDACyItzV1ndWdvwYVCmegHYiYEYKcsoGcXW/C1HpDmyTppGWEcZxIH9S2w64Cmqk6yGn1aMCUI/hTw6fr6R9Expn8bNy5a5ikretcMDSAl6re1kIbMghuFYLxbvSS1vqqpLrx4w3uaXOfLVdmVIBSZL2AXsCHx1SRDwsNkX4ag= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775800761; c=relaxed/simple; bh=ys5DkVZJq0GuwqSjzZXEYHSbFOhD+C4s6x/HWZuWJu0=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=oq+ASD+tsFYh1qLCtGFnP9tzNRYCMhlQeUwn1C4c/5zK2+VLH3NLc7DSrX+TyXv4xMmVnlJhtCs2SWv87Afbcsic2r3/BLZqQSm1crfKIy2Y0p/8M4IFOneMRwu5XNwESHRsBY5tjNuTBleOF9RTHP2oMt6751a75+ZPAcAm5xw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=l4sJqkNH; arc=none smtp.client-ip=209.85.221.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="l4sJqkNH" Received: by mail-wr1-f50.google.com with SMTP id ffacd0b85a97d-43b983bb07eso980035f8f.0 for ; Thu, 09 Apr 2026 22:59:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775800758; x=1776405558; darn=lists.linux.dev; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=1ttLDxm0ieSoWUqU7Qsf8QeJ6W3C2avJVf1XkCWa1Pk=; b=l4sJqkNHSatHNGc+G2mQD1Zugz9e4+5hE8Pd17Cl6bsRmQFo+CDs5wfP/o2hYb/0E/ OCDh9PHe/cqQzP1g9N7G1QJCNfHwCanIAlJZus/e4ktleofr+WU3HsKydQ44lpmkOkOk fCJCSBp4+4GFgBvb+e0kjmwzc7RYJU+Nbe1KP2MRtYZ/FYTej185onwm8hB2vSDOy+1H 2scfIC6gNCdYWv+mBcPNgmTziDKgVcO3WvE0b5W3AMwSsovAVBiPlxxRWDgltcaLXGmc gs1/5N5DyuRiRmnqsOfZ8c3DeutahFyIX9O5YOAhNjQvmQX/b/WwpN52f5se/NtfGDz0 7ymg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775800758; x=1776405558; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=1ttLDxm0ieSoWUqU7Qsf8QeJ6W3C2avJVf1XkCWa1Pk=; b=iszBwRQDMphC/2mrfkaNKS0Ea4Is9khVChuxL44Dd3+91jwqraBa9/8A2cCEFs0hOC Tjw1pbYZnbCbmls1R1N/Ja7vF/58ve+VFOpXCP+GFZVdmd8JUJreW8+cpXYhgTSWH1R6 +Rj2YPezmVsrXrVwi7/mWy6stgGpvhxnF4X5hjmh9z3ABOdrfkEJ131mUAmDjg4uYHxR UZ8iYWG5zkeRLRLIJaqQtAFhwEXZar+XBVmLthRWgR5l0yZmen0sCqv56kyGnHNpvC/9 bR+Nm4XYfMPvFibiq3FnCLkpqpdL4uX+FnYKMDW1NQvXxTCfq5QSMk4cb3sk9c5Dx4pt TKtA== X-Gm-Message-State: AOJu0YwdGrp54LNhDIwMUfn71a7AARHvNjZtZY5F492PISEc7ZOtIzBe uEsMKZ+yN5rhAr7/c26uhRJ5O1vHir9E5bsDeJrOsMJX7XEeKXEnkjM9 X-Gm-Gg: AeBDieugU2Qh2lBbekpkkSSQG0ETahCB/0uZQT6FYLz86A2U93o91l1LUuvuxOzUQyu wVwf3Ne3LI/sOL4femxVVRx9BH++M5x1CrLb8l4kEjwpMtflV4QZblC3LZ7Qawk7XFsQ+ibCM9A y3FkyniUGV4wlADUxmB8oN9k5mRzef2wNqnEhKU4ntSoHK1ci1b9TBOEgpb/3eckH8QmnFet0s5 cVTxsTmS8u6oPcB/RRayK23fo/ph04WGSuDrvrTNXO8yI/rzp/HeLFdPm+tAJi5rl9UtTsnuwH2 adG67t/b48w2fLTYlNQnWSWkyqt3T7VHzWl6y48Q2tt4MCYqS7v64YxemNKbQm34ATFzFkgsHJy eebEXkI4GJ+Ru/RyN3uRUUEm1dHICFQ7pL0/LPvLUXxTHKC81itjKC5Wlog+oDR4bKXNxECxpr8 /HQiJDJ/Gh4Wfz2tAG2ks= X-Received: by 2002:a05:6000:288b:b0:439:c040:cc8a with SMTP id ffacd0b85a97d-43d642b6a81mr2345267f8f.32.1775800757998; Thu, 09 Apr 2026 22:59:17 -0700 (PDT) Received: from localhost ([196.207.164.177]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43d63ab84cdsm4849467f8f.0.2026.04.09.22.59.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2026 22:59:17 -0700 (PDT) Date: Fri, 10 Apr 2026 08:59:14 +0300 From: Dan Carpenter To: David Howells Cc: netfs@lists.linux.dev Subject: [bug report] netfs: Fix unbuffered/DIO writes to dispatch subrequests in strict sequence Message-ID: Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hello David Howells, Commit a0b4c7a49137 ("netfs: Fix unbuffered/DIO writes to dispatch subrequests in strict sequence") from Feb 26, 2026 (linux-next), leads to the following Smatch static checker warning: fs/netfs/direct_write.c:203 netfs_unbuffered_write() error: uninitialized symbol 'ret'. fs/netfs/direct_write.c 94 static int netfs_unbuffered_write(struct netfs_io_request *wreq) 95 { 96 struct netfs_io_subrequest *subreq = NULL; 97 struct netfs_io_stream *stream = &wreq->io_streams[0]; 98 int ret; 99 100 _enter("%llx", wreq->len); 101 102 if (wreq->origin == NETFS_DIO_WRITE) 103 inode_dio_begin(wreq->inode); 104 105 stream->collected_to = wreq->start; 106 107 for (;;) { 108 bool retry = false; 109 110 if (!subreq) { 111 netfs_prepare_write(wreq, stream, wreq->start + wreq->transferred); 112 subreq = stream->construct; 113 stream->construct = NULL; 114 } 115 116 /* Check if (re-)preparation failed. */ 117 if (unlikely(test_bit(NETFS_SREQ_FAILED, &subreq->flags))) { 118 netfs_write_subrequest_terminated(subreq, subreq->error); 119 wreq->error = subreq->error; 120 break; If we break on the first iteration 121 } 122 123 iov_iter_truncate(&subreq->io_iter, wreq->len - wreq->transferred); 124 if (!iov_iter_count(&subreq->io_iter)) 125 break; or here 126 127 subreq->len = netfs_limit_iter(&subreq->io_iter, 0, 128 stream->sreq_max_len, 129 stream->sreq_max_segs); 130 iov_iter_truncate(&subreq->io_iter, subreq->len); 131 stream->submit_extendable_to = subreq->len; 132 133 trace_netfs_sreq(subreq, netfs_sreq_trace_submit); 134 stream->issue_write(subreq); 135 136 /* Async, need to wait. */ 137 netfs_wait_for_in_progress_stream(wreq, stream); 138 139 if (test_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) { 140 retry = true; 141 } else if (test_bit(NETFS_SREQ_FAILED, &subreq->flags)) { 142 ret = subreq->error; 143 wreq->error = ret; 144 netfs_see_subrequest(subreq, netfs_sreq_trace_see_failed); 145 subreq = NULL; 146 break; 147 } 148 ret = 0; 149 150 if (!retry) { 151 netfs_unbuffered_write_collect(wreq, stream, subreq); 152 subreq = NULL; 153 if (wreq->transferred >= wreq->len) 154 break; 155 if (!wreq->iocb && signal_pending(current)) { 156 ret = wreq->transferred ? -EINTR : -ERESTARTSYS; 157 trace_netfs_rreq(wreq, netfs_rreq_trace_intr); 158 break; 159 } 160 continue; 161 } 162 163 /* We need to retry the last subrequest, so first reset the 164 * iterator, taking into account what, if anything, we managed 165 * to transfer. 166 */ 167 subreq->error = -EAGAIN; 168 trace_netfs_sreq(subreq, netfs_sreq_trace_retry); 169 if (subreq->transferred > 0) 170 iov_iter_advance(&wreq->buffer.iter, subreq->transferred); 171 172 if (stream->source == NETFS_UPLOAD_TO_SERVER && 173 wreq->netfs_ops->retry_request) 174 wreq->netfs_ops->retry_request(wreq, stream); 175 176 __clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); 177 __clear_bit(NETFS_SREQ_BOUNDARY, &subreq->flags); 178 __clear_bit(NETFS_SREQ_FAILED, &subreq->flags); 179 subreq->io_iter = wreq->buffer.iter; 180 subreq->start = wreq->start + wreq->transferred; 181 subreq->len = wreq->len - wreq->transferred; 182 subreq->transferred = 0; 183 subreq->retry_count += 1; 184 stream->sreq_max_len = UINT_MAX; 185 stream->sreq_max_segs = INT_MAX; 186 187 netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); 188 189 if (stream->prepare_write) { 190 stream->prepare_write(subreq); 191 __set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags); 192 netfs_stat(&netfs_n_wh_retry_write_subreq); 193 } else { 194 struct iov_iter source; 195 196 netfs_reset_iter(subreq); 197 source = subreq->io_iter; 198 netfs_reissue_write(stream, subreq, &source); 199 } 200 } 201 202 netfs_unbuffered_write_done(wreq); --> 203 _leave(" = %d", ret); 204 return ret; Then ret is uninitialized 205 } This email is a free service from the Smatch-CI project [smatch.sf.net]. regards, dan carpenter