From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 823ABC388F7 for ; Mon, 26 Oct 2020 03:23:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3222220878 for ; Mon, 26 Oct 2020 03:23:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ov15loRb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1418685AbgJZDX0 (ORCPT ); Sun, 25 Oct 2020 23:23:26 -0400 Received: from mail-pj1-f66.google.com ([209.85.216.66]:50381 "EHLO mail-pj1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1418058AbgJZDX0 (ORCPT ); Sun, 25 Oct 2020 23:23:26 -0400 Received: by mail-pj1-f66.google.com with SMTP id p21so2424461pju.0 for ; Sun, 25 Oct 2020 20:23:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4IM5WQPMmjRs/RLJidSlXp2yoXqUgayxvOL56ZoOe1A=; b=ov15loRbtjKZyy9d1DyCf9HK8t6NHhGe5auoaPK/vEjSMv/Z7mGafMsqkt4tq4hPE/ Yd+QUq9sfNKzmhaTrWWH+QbJJbTmztFh9V91xJGJc3zMEsrGwD//04kYP7NXDpLmg0Zo pTVoyW/26ChTQCIm4lS5ZaxnMd07MjjaUyBfNT7garWb/5K0v6Ynms7OHn0zxLYF8Yyg Z+6UURmVnavqxavL9/xpIKmsKb2He6TIM0g2e/LPaz7RRjQRPcQpxa7PvGLmLOY4/QUp lkNUR4vnj2JJIn9Z68aNRSAydxjd40lsLuVBtZT+89LEcwExRAEvV9dpq3cp2GLUuZmx f8Aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4IM5WQPMmjRs/RLJidSlXp2yoXqUgayxvOL56ZoOe1A=; b=C9c7JknA59iIt6Wt6NiKbXRXdsE0xiv+aYpmPUMgvGn4D9byyPnumoZQvffZZ4+AmX 7+r7keHsXwzeq/Adcwu1tyOwxTKgdqCYR8OWsve1M24LF2n6F/2MM8MJlvv96ufbcFpo HrkH3PCktXiPMaK56fSyzXPsy7vrk5WE1UFFOTsfVa6R2SiXneEM02wFTrPeU55x8e1/ 2MfrbTOPjGTzi7STfX8tgQFgOWn+BSn0Vk1xTQzgm55Rh8t37J6PREXaWx9oaIT83DTs JwvrzRDsy+zQtpMJMnG7yyc1b7uex7iJg96sdzwUWZWPBRWA6cEYX9YHqhpKNXoC4uOl fXyg== X-Gm-Message-State: AOAM531ly3l3sohMZMCMbUGCv77wGY1hkzfbBkWjVQJRQHx8X/rtAWT7 PZYm54MEH/b8rtQWQ9PAW6A= X-Google-Smtp-Source: ABdhPJxw2txz9lDRv5742c8tn0YVvFuifsJph/L+7Yxu4WQYrcupBA0LdL9tcCYT0bczoOreLlATHQ== X-Received: by 2002:a17:90a:c1:: with SMTP id v1mr14284260pjd.89.1603682605140; Sun, 25 Oct 2020 20:23:25 -0700 (PDT) Received: from garuda.localnet ([122.167.144.110]) by smtp.gmail.com with ESMTPSA id j11sm10030636pfh.143.2020.10.25.20.23.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 25 Oct 2020 20:23:24 -0700 (PDT) From: Chandan Babu R To: Allison Henderson Cc: linux-xfs@vger.kernel.org, darrick.wong@oracle.com, david@fromorbit.com, hch@infradead.org Subject: Re: [PATCH V7 14/14] xfs: Introduce error injection to allocate only minlen size extents for files Date: Mon, 26 Oct 2020 08:53:21 +0530 Message-ID: <2166998.mU4Sq72Tuv@garuda> In-Reply-To: <8878dee5-c3d4-0bf5-ead9-d4682fafdf6f@oracle.com> References: <20201019064048.6591-1-chandanrlinux@gmail.com> <20201019064048.6591-15-chandanrlinux@gmail.com> <8878dee5-c3d4-0bf5-ead9-d4682fafdf6f@oracle.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sunday 25 October 2020 6:52:53 AM IST Allison Henderson wrote: > > On 10/18/20 11:40 PM, Chandan Babu R wrote: > > This commit adds XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT error tag which > > helps userspace test programs to get xfs_bmap_btalloc() to always > > allocate minlen sized extents. > > > > This is required for test programs which need a guarantee that minlen > > extents allocated for a file do not get merged with their existing > > neighbours in the inode's BMBT. "Inode fork extent overflow check" for > > Directories, Xattrs and extension of realtime inodes need this since the > > file offset at which the extents are being allocated cannot be > > explicitly controlled from userspace. > > > > One way to use this error tag is to, > > 1. Consume all of the free space by sequentially writing to a file. > > 2. Punch alternate blocks of the file. This causes CNTBT to contain > > sufficient number of one block sized extent records. > > 3. Inject XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT error tag. > > After step 3, xfs_bmap_btalloc() will issue space allocation > > requests for minlen sized extents only. > > > > ENOSPC error code is returned to userspace when there aren't any "one > > block sized" extents left in any of the AGs. > > > > Signed-off-by: Chandan Babu R > > --- > > fs/xfs/libxfs/xfs_alloc.c | 50 ++++++++++++++++++ > > fs/xfs/libxfs/xfs_alloc.h | 3 ++ > > fs/xfs/libxfs/xfs_bmap.c | 100 +++++++++++++++++++++++++++++++---- > > fs/xfs/libxfs/xfs_errortag.h | 4 +- > > fs/xfs/xfs_error.c | 3 ++ > > 5 files changed, 150 insertions(+), 10 deletions(-) > > > > diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c > > index 852b536551b5..8e132f8b9cc4 100644 > > --- a/fs/xfs/libxfs/xfs_alloc.c > > +++ b/fs/xfs/libxfs/xfs_alloc.c > > @@ -2473,6 +2473,47 @@ xfs_defer_agfl_block( > > xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_AGFL_FREE, &new->xefi_list); > > } > > > > +#ifdef DEBUG > > +/* > > + * Check if an AGF has a free extent record whose length is equal to > > + * args->minlen. > > + */ > > +STATIC int > > +xfs_exact_minlen_extent_available( > > + struct xfs_alloc_arg *args, > > + struct xfs_buf *agbp, > > + int *stat) > > +{ > > + struct xfs_btree_cur *cnt_cur; > > + xfs_agblock_t fbno; > > + xfs_extlen_t flen; > > + int error = 0; > > + > > + cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, agbp, > > + args->agno, XFS_BTNUM_CNT); > > + error = xfs_alloc_lookup_ge(cnt_cur, 0, args->minlen, stat); > > + if (error) > > + goto out; > > + > > + if (*stat == 0) { > > + error = -EFSCORRUPTED; > > + goto out; > > + } > > + > > + error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, stat); > > + if (error) > > + goto out; > > + > > + if (*stat == 1 && flen != args->minlen) > > + *stat = 0; > > + > > +out: > > + xfs_btree_del_cursor(cnt_cur, error); > > + > > + return error; > > +} > > +#endif > > + > > /* > > * Decide whether to use this allocation group for this allocation. > > * If so, fix up the btree freelist's size. > > @@ -2544,6 +2585,15 @@ xfs_alloc_fix_freelist( > > if (!xfs_alloc_space_available(args, need, flags)) > > goto out_agbp_relse; > > > > +#ifdef DEBUG > > + if (args->alloc_minlen_only) { > > + int i; > Just a nit: I think "i" seems like a bit of an odd name here. I think I > might have called it stat to match its parameter name. Other than that, > I think the rest looks ok. Ok, I will rename "i" with "stat" as you have suggested. Thank you for reviewing the patchset. > > Reviewed-by: Allison Henderson > Allison > > + > > + error = xfs_exact_minlen_extent_available(args, agbp, &i); > > + if (error || !i) > > + goto out_agbp_relse; > > + } > > +#endif > > /* > > * Make the freelist shorter if it's too long. > > * > > diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h > > index 6c22b12176b8..a4427c5775c2 100644 > > --- a/fs/xfs/libxfs/xfs_alloc.h > > +++ b/fs/xfs/libxfs/xfs_alloc.h > > @@ -75,6 +75,9 @@ typedef struct xfs_alloc_arg { > > char wasfromfl; /* set if allocation is from freelist */ > > struct xfs_owner_info oinfo; /* owner of blocks being allocated */ > > enum xfs_ag_resv_type resv; /* block reservation to use */ > > +#ifdef DEBUG > > + bool alloc_minlen_only; /* allocate exact minlen extent */ > > +#endif > > } xfs_alloc_arg_t; > > > > /* > > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c > > index 88db23afc51c..74e148cc41b2 100644 > > --- a/fs/xfs/libxfs/xfs_bmap.c > > +++ b/fs/xfs/libxfs/xfs_bmap.c > > @@ -3474,11 +3474,13 @@ xfs_bmap_compute_alignments( > > int error; > > > > /* stripe alignment for allocation is determined by mount parameters */ > > - *stripe_align = 0; > > - if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC)) > > - *stripe_align = mp->m_swidth; > > - else if (mp->m_dalign) > > - *stripe_align = mp->m_dalign; > > + if (stripe_align) { > > + *stripe_align = 0; > > + if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC)) > > + *stripe_align = mp->m_swidth; > > + else if (mp->m_dalign) > > + *stripe_align = mp->m_dalign; > > + } > > > > if (ap->flags & XFS_BMAPI_COWFORK) > > align = xfs_get_cowextsz_hint(ap->ip); > > @@ -3551,6 +3553,71 @@ xfs_bmap_process_allocated_extent( > > xfs_bmap_btalloc_accounting(ap, args); > > } > > > > +#ifdef DEBUG > > +static int > > +xfs_bmap_exact_minlen_extent_alloc( > > + struct xfs_bmalloca *ap) > > +{ > > + struct xfs_alloc_arg args; > > + struct xfs_mount *mp = ap->ip->i_mount; > > + xfs_fileoff_t orig_offset; > > + xfs_extlen_t orig_length; > > + int error; > > + > > + ASSERT(ap->length); > > + orig_offset = ap->offset; > > + orig_length = ap->length; > > + > > + memset(&args, 0, sizeof(args)); > > + args.alloc_minlen_only = 1; > > + args.tp = ap->tp; > > + args.mp = mp; > > + > > + xfs_bmap_compute_alignments(ap, &args, NULL); > > + > > + if (ap->tp->t_firstblock == NULLFSBLOCK) { > > + /* > > + * Unlike the longest extent available in an AG, we don't track > > + * the length of an AG's shortest extent. > > + * XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT is a debug only knob and > > + * hence we can afford to start traversing from the 0th AG since > > + * we need not be concerned about a drop in performance in > > + * "debug only" code paths. > > + */ > > + ap->blkno = XFS_AGB_TO_FSB(mp, 0, 0); > > + } else { > > + ap->blkno = ap->tp->t_firstblock; > > + } > > + > > + args.fsbno = ap->blkno; > > + args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE; > > + args.type = XFS_ALLOCTYPE_FIRST_AG; > > + args.total = args.minlen = args.maxlen = ap->minlen; > > + > > + args.alignment = 1; > > + args.minalignslop = 0; > > + > > + args.minleft = ap->minleft; > > + args.wasdel = ap->wasdel; > > + args.resv = XFS_AG_RESV_NONE; > > + args.datatype = ap->datatype; > > + > > + error = xfs_alloc_vextent(&args); > > + if (error) > > + return error; > > + > > + if (args.fsbno != NULLFSBLOCK) { > > + xfs_bmap_process_allocated_extent(ap, &args, orig_offset, > > + orig_length); > > + } else { > > + ap->blkno = NULLFSBLOCK; > > + ap->length = 0; > > + } > > + > > + return 0; > > +} > > +#endif > > + > > STATIC int > > xfs_bmap_btalloc( > > struct xfs_bmalloca *ap) /* bmap alloc argument struct */ > > @@ -4112,7 +4179,13 @@ xfs_bmap_alloc_userdata( > > return xfs_bmap_rtalloc(bma); > > } > > > > - return xfs_bmap_btalloc(bma); > > +#ifdef DEBUG > > + if (unlikely(XFS_TEST_ERROR(false, mp, > > + XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT))) > > + return xfs_bmap_exact_minlen_extent_alloc(bma); > > + else > > +#endif > > + return xfs_bmap_btalloc(bma); > > } > > > > static int > > @@ -4148,10 +4221,19 @@ xfs_bmapi_allocate( > > else > > bma->minlen = 1; > > > > - if (bma->flags & XFS_BMAPI_METADATA) > > - error = xfs_bmap_btalloc(bma); > > - else > > + if (bma->flags & XFS_BMAPI_METADATA) { > > +#ifdef DEBUG > > + if (unlikely(XFS_TEST_ERROR(false, mp, > > + XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT))) > > + error = xfs_bmap_exact_minlen_extent_alloc(bma); > > + else > > +#endif > > + error = xfs_bmap_btalloc(bma); > > + > > + > > + } else { > > error = xfs_bmap_alloc_userdata(bma); > > + } > > if (error || bma->blkno == NULLFSBLOCK) > > return error; > > > > diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h > > index 1c56fcceeea6..6ca9084b6934 100644 > > --- a/fs/xfs/libxfs/xfs_errortag.h > > +++ b/fs/xfs/libxfs/xfs_errortag.h > > @@ -57,7 +57,8 @@ > > #define XFS_ERRTAG_IUNLINK_FALLBACK 34 > > #define XFS_ERRTAG_BUF_IOERROR 35 > > #define XFS_ERRTAG_REDUCE_MAX_IEXTENTS 36 > > -#define XFS_ERRTAG_MAX 37 > > +#define XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT 37 > > +#define XFS_ERRTAG_MAX 38 > > > > /* > > * Random factors for above tags, 1 means always, 2 means 1/2 time, etc. > > @@ -99,5 +100,6 @@ > > #define XFS_RANDOM_IUNLINK_FALLBACK (XFS_RANDOM_DEFAULT/10) > > #define XFS_RANDOM_BUF_IOERROR XFS_RANDOM_DEFAULT > > #define XFS_RANDOM_REDUCE_MAX_IEXTENTS 1 > > +#define XFS_RANDOM_BMAP_ALLOC_MINLEN_EXTENT 1 > > > > #endif /* __XFS_ERRORTAG_H_ */ > > diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c > > index 3780b118cc47..185b4915b7bf 100644 > > --- a/fs/xfs/xfs_error.c > > +++ b/fs/xfs/xfs_error.c > > @@ -55,6 +55,7 @@ static unsigned int xfs_errortag_random_default[] = { > > XFS_RANDOM_IUNLINK_FALLBACK, > > XFS_RANDOM_BUF_IOERROR, > > XFS_RANDOM_REDUCE_MAX_IEXTENTS, > > + XFS_RANDOM_BMAP_ALLOC_MINLEN_EXTENT, > > }; > > > > struct xfs_errortag_attr { > > @@ -166,6 +167,7 @@ XFS_ERRORTAG_ATTR_RW(bad_summary, XFS_ERRTAG_FORCE_SUMMARY_RECALC); > > XFS_ERRORTAG_ATTR_RW(iunlink_fallback, XFS_ERRTAG_IUNLINK_FALLBACK); > > XFS_ERRORTAG_ATTR_RW(buf_ioerror, XFS_ERRTAG_BUF_IOERROR); > > XFS_ERRORTAG_ATTR_RW(reduce_max_iextents, XFS_ERRTAG_REDUCE_MAX_IEXTENTS); > > +XFS_ERRORTAG_ATTR_RW(bmap_alloc_minlen_extent, XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT); > > > > static struct attribute *xfs_errortag_attrs[] = { > > XFS_ERRORTAG_ATTR_LIST(noerror), > > @@ -205,6 +207,7 @@ static struct attribute *xfs_errortag_attrs[] = { > > XFS_ERRORTAG_ATTR_LIST(iunlink_fallback), > > XFS_ERRORTAG_ATTR_LIST(buf_ioerror), > > XFS_ERRORTAG_ATTR_LIST(reduce_max_iextents), > > + XFS_ERRORTAG_ATTR_LIST(bmap_alloc_minlen_extent), > > NULL, > > }; > > > > > -- chandan