From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 183283ACA4C for ; Thu, 24 Sep 2026 11:21:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790248914; cv=none; b=eTKn7KaoGGXUemEunPUR2lnmZg4sjTiNevmhmirjENC2C1eXXv9uRoMLU6PhXxeJBCf3dY+G1JRkwDA2kAvE3vShhH1xT4v1Sxa/57CHpHKlEQWorHS8Fy4L8KuabHzoKlZyOhEphz12aCBF5M3EfvP+xxiA9Tu0+7zb6SHqQYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790248914; c=relaxed/simple; bh=Qwp5psCP+sHIfQhqs8F+rRHFIUI8pMZCG6/N/IoV9a4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LcFvVqxeBOz9epu0zHow56Brg9J1iS/W4FsXxX16EbZ9oXsz6TynoNiug0Y/jhHoveiPhBKwD2VIDBr+D1DxJlUFO1EhlET8qLsz5iraYQLgBVQlx2uEg7CyzB4l+tgYGIv1s5VBsaQWxfjYpJQdT4B5jPTqW7ClAc29m+f4cxA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jMA+dNY0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jMA+dNY0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0239E1F00893; Thu, 24 Sep 2026 11:21:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790248907; bh=8hJf5tpI5x3xoih5jBiT97CUHhhM3pwz5sQYKblXaJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jMA+dNY0ayPvpAC93diOOu6ym2vv4uWu2NXmE55DAFBQ2mhVs1pNg459EAKLJFldr ivcoc72ng2dlIoXC/jAbgnGMWXk6dCmR9V3koc/Zx20M5W6cGz2otUxGJyzDGqLp9j mudYNWuHraijLTJrTm/TpwI1/K0WdAUjCEkpaYIEp+wuqBOx35Gjm5lGuqvR+RYExo 1ySjxbPhwhsYTnnGxOXQa5jSME1HPzAkkbNoVl5Z1mbJtdhS+B99W+6gd19WEsFjaf fZzItIXj9NMpX25U0LQRr+GAaUOh3D+r3RoJaERQGo4jIl1m2kIxEXmc/YZ389Nwfg 3u40urr/It1rQ== From: Niklas Cassel To: "James E.J. Bottomley" , "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, Damien Le Moal , John Garry , Niklas Cassel Subject: [PATCH v6 04/11] scsi: scsi_debug: Evaluate scsi_debug_lbp() only once Date: Thu, 24 Sep 2026 13:21:32 +0200 Message-ID: <20260924112127.3815255-17-cassel@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260924112127.3815255-13-cassel@kernel.org> References: <20260924112127.3815255-13-cassel@kernel.org> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4672; i=cassel@kernel.org; h=from:subject; bh=Qwp5psCP+sHIfQhqs8F+rRHFIUI8pMZCG6/N/IoV9a4=; b=owGbwMvMwCV2MsVw8cxjvkWMp9WSGLK2su9+/exCA7fUu6ZpppaLOlmSrhxewRjmtEKtf9PvV Yc2qb0401HKwiDGxSArpsji+8Nlf3G3+5TjindsYOawMoEMYeDiFICJ1K5lZHih/VWWz34uz9d4 ZoGn5UF+i2Ra/xfIGnqnr/rV0qZ09yAjw8dJ1pu3tjvczM/vfiXWEsbP//XggeuRJ4+/TC6trsp J4AEA X-Developer-Key: i=cassel@kernel.org; a=openpgp; fpr=5ADE635C0E631CBBD5BE065A352FE6582ED9B5DA Content-Transfer-Encoding: 8bit corrupt_lbas(), resp_write_dt0() and resp_write_same() call scsi_debug_lbp() to decide whether to take the zone metadata lock, and call it again to decide whether to touch the provisioning map that the lock protects. The result is not constant: scsi_debug_lbp() is false while fake_rw is set, and fake_rw is writable at runtime, both as a module parameter and through its driver attribute. The second call can therefore touch the map after the first decided not to take the lock. Call it once and use the result throughout. Assisted-by: LLM Reviewed-by: Damien Le Moal Reviewed-by: John Garry Signed-off-by: Niklas Cassel --- Tested with: modprobe scsi_debug sector_size=512 dev_size_mb=128 lbpu=1 lbpws=1 A WRITE(16) completes and GET LBA STATUS then reports the region as mapped, which covers resp_write_dt0(). A WRITE SAME and a WRITE SAME with the UNMAP bit set complete, and GET LBA STATUS reports the first region as mapped and the second as deallocated, which covers all three uses of the result in resp_write_same(). corrupt_lbas() is not covered. It is reached by writing to the corrupt file in debugfs, and that interface rejected the requests that were tried, for a reason that has nothing to do with this patch. The window that the change closes was not reproduced. It needs fake_rw to be written between two calls, and was found by review. Changes since v5: the three conditions that fit on one line are joined. --- drivers/scsi/scsi_debug.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 18aefe83b7b6..b64ae3ad300d 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -4953,12 +4953,11 @@ static int corrupt_lbas(struct sdebug_dev_info *devip, u64 lba, u32 num, { struct sdeb_store_info *sip = devip2sip(devip, false); bool meta_data_locked = false; + bool lbp = scsi_debug_lbp(); u32 block, num_mapped, b, i; int error = 0; - if (sdebug_dev_is_zoned(devip) || - sdebug_dix || - scsi_debug_lbp()) { + if (sdebug_dev_is_zoned(devip) || sdebug_dix || lbp) { sdeb_meta_write_lock(sip); meta_data_locked = true; } @@ -4975,8 +4974,7 @@ static int corrupt_lbas(struct sdebug_dev_info *devip, u64 lba, u32 num, goto out_unlock; } - if (scsi_debug_lbp() && - (!map_state(sip, lba, &num_mapped) || num > num_mapped)) { + if (lbp && (!map_state(sip, lba, &num_mapped) || num > num_mapped)) { pr_err("can't modify unmapped logical blocks: %llu:%u", lba, num); error = -EINVAL; @@ -5035,6 +5033,7 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) struct sdeb_store_info *sip = devip2sip(devip, true); u8 *cmd = scp->cmnd; bool meta_data_locked = false; + bool lbp = scsi_debug_lbp(); if (unlikely(sdebug_opts & SDEBUG_OPT_UNALIGNED_WRITE && atomic_read(&sdeb_inject_pending))) { @@ -5101,8 +5100,7 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) } if (sdebug_dev_is_zoned(devip) || - (sdebug_dix && scsi_prot_sg_count(scp)) || - scsi_debug_lbp()) { + (sdebug_dix && scsi_prot_sg_count(scp)) || lbp) { sdeb_meta_write_lock(sip); meta_data_locked = true; } @@ -5147,7 +5145,7 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) } ret = do_device_access(sip, scp, 0, lba, num, group, true, false); - if (unlikely(scsi_debug_lbp())) + if (unlikely(lbp)) map_region(sip, lba, num); /* If ZBC zone then bump its write pointer */ @@ -5374,8 +5372,9 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num, u8 *fs1p; u8 *fsp; bool meta_data_locked = false; + bool lbp = scsi_debug_lbp(); - if (sdebug_dev_is_zoned(devip) || scsi_debug_lbp()) { + if (sdebug_dev_is_zoned(devip) || lbp) { sdeb_meta_write_lock(sip); meta_data_locked = true; } @@ -5384,7 +5383,7 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num, if (ret) goto out; - if (unmap && scsi_debug_lbp()) { + if (unmap && lbp) { unmap_region(sip, lba, num); goto out; } @@ -5414,7 +5413,7 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num, block = do_div(lbaa, sdebug_store_sectors); memmove(fsp + (block * lb_size), fs1p, lb_size); } - if (scsi_debug_lbp()) + if (lbp) map_region(sip, lba, num); /* If ZBC zone then bump its write pointer */ if (sdebug_dev_is_zoned(devip)) -- 2.55.0