Whamcloud Community JIRA https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 [LU-14186] fallocate does not extend uninitialized PFL components https://jira.whamcloud.com/browse/LU-14186 Lustre <p>I was testing "<tt>fallocate</tt>" as a fast way to allocate space in the file, but I found that it only allocated space on the first (initialized) component of a PFL file. It does not allocate space for any of the later components <b>if those components are uninitialized</b>.</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre># lfs setstripe -E1M -c1 -E16M -c3 -Eeof -c 4 /mnt/testfs/pflfile # ls -l /mnt/testfs/pflfile 0 -rw-r--r--. 1 root 0 Dec 5 13:24 /mnt/testfs/pflfile # fallocate -l $((1048576 * 1024)) /mnt/testfs/pflfile # ls -l /mnt/testfs/pflfile 1024 -rw-r--r--. 1 root 1048576 Dec 5 13:33 /mnt/testfs/pflfile # lfs getstripe /mnt/testfs/pflfile /mnt/testfs/pflfile lcm_layout_gen: 3 lcm_mirror_count: 1 lcm_entry_count: 3 lcme_id: 1 lcme_mirror_id: 0 lcme_flags: init lcme_extent.e_start: 0 lcme_extent.e_end: 1048576 lmm_stripe_count: 1 lmm_stripe_size: 1048576 lmm_pattern: raid0 lmm_layout_gen: 0 lmm_stripe_offset: 3 lmm_objects: - 0: { l_ost_idx: 3, l_fid: [0x100030000:0x60a:0x0] } lcme_id: 2 lcme_mirror_id: 0 lcme_flags: 0 lcme_extent.e_start: 1048576 lcme_extent.e_end: 16777216 lmm_stripe_count: 3 lmm_stripe_size: 1048576 lmm_pattern: raid0 lmm_layout_gen: 0 lmm_stripe_offset: -1 lcme_id: 3 lcme_mirror_id: 0 lcme_flags: 0 lcme_extent.e_start: 16777216 lcme_extent.e_end: 1073741824 lmm_stripe_count: 4 lmm_stripe_size: 2097152 lmm_pattern: raid0 lmm_layout_gen: 0 lmm_stripe_offset: -1 </pre> </div></div> <p>If the file is truncated, the later components are initialized:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre># truncate -s 1023M /mnt/testfs/pflfile # lfs getstripe /mnt/testfs/pflfile /mnt/testfs/pflfile lcm_layout_gen: 4 lcm_mirror_count: 1 lcm_entry_count: 3 lcme_id: 1 lcme_mirror_id: 0 lcme_flags: init lcme_extent.e_start: 0 lcme_extent.e_end: 1048576 lmm_stripe_count: 1 lmm_stripe_size: 1048576 lmm_pattern: raid0 lmm_layout_gen: 0 lmm_stripe_offset: 3 lmm_objects: - 0: { l_ost_idx: 3, l_fid: [0x100030000:0x60a:0x0] } lcme_id: 2 lcme_mirror_id: 0 lcme_flags: init lcme_extent.e_start: 1048576 lcme_extent.e_end: 16777216 lmm_stripe_count: 3 lmm_stripe_size: 1048576 lmm_pattern: raid0 lmm_layout_gen: 65535 lmm_stripe_offset: 0 lmm_objects: - 0: { l_ost_idx: 0, l_fid: [0x100000000:0x1ca:0x0] } - 1: { l_ost_idx: 1, l_fid: [0x100010000:0x8aa:0x0] } - 2: { l_ost_idx: 2, l_fid: [0x100020000:0x6aa:0x0] } lcme_id: 3 lcme_mirror_id: 0 lcme_flags: init lcme_extent.e_start: 16777216 lcme_extent.e_end: 1073741824 lmm_stripe_count: 4 lmm_stripe_size: 2097152 lmm_pattern: raid0 lmm_layout_gen: 65535 lmm_stripe_offset: 0 lmm_objects: - 0: { l_ost_idx: 0, l_fid: [0x100000000:0x1cb:0x0] } - 1: { l_ost_idx: 1, l_fid: [0x100010000:0x8ab:0x0] } - 2: { l_ost_idx: 2, l_fid: [0x100020000:0x6ab:0x0] } - 3: { l_ost_idx: 3, l_fid: [0x100030000:0x60b:0x0] } # lfs df UUID 1K-blocks Used Available Use% Mounted on testfs-MDT0000_UUID 125368 2596 111536 3% /mnt/testfs[MDT:0] testfs-MDT0001_UUID 125368 3112 111020 3% /mnt/testfs[MDT:1] testfs-OST0000_UUID 325368 13796 284412 5% /mnt/testfs[OST:0] testfs-OST0001_UUID 325368 14304 283904 5% /mnt/testfs[OST:1] testfs-OST0002_UUID 325368 13664 284544 5% /mnt/testfs[OST:2] testfs-OST0003_UUID 325368 14692 283516 5% /mnt/testfs[OST:3] filesystem_summary: 1301472 56456 1136376 5% /mnt/testfs </pre> </div></div> <p>If the <tt>fallocate</tt> is run again, this time the space is allocated:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre># fallocate -l $((1048576 * 1024)) /mnt/testfs/pflfile # ls -l /mnt/testfs/pflfile 1048576 -rw-r--r--. 1 root 1073741824 Dec 5 13:37 /mnt/testfs/pflfile # lfs df UUID 1K-blocks Used Available Use% Mounted on testfs-MDT0000_UUID 125368 2596 111536 3% /mnt/testfs[MDT:0] testfs-MDT0001_UUID 125368 3112 111020 3% /mnt/testfs[MDT:1] testfs-OST0000_UUID 325368 276964 21244 93% /mnt/testfs[OST:0] testfs-OST0001_UUID 325368 277472 20736 94% /mnt/testfs[OST:1] testfs-OST0002_UUID 325368 276832 21376 93% /mnt/testfs[OST:2] testfs-OST0003_UUID 325368 272740 25468 92% /mnt/testfs[OST:3] filesystem_summary: 1301472 1104008 88824 93% /mnt/testfs </pre> </div></div> LU-14186 fallocate does not extend uninitialized PFL components Bug Minor Resolved Fixed Wang Shilong Andreas Dilger Sat, 5 Dec 2020 20:45:12 +0000 Sun, 13 Dec 2020 16:05:32 +0000 Sun, 13 Dec 2020 16:05:32 +0000 Lustre 2.14.0 Lustre 2.14.0 0 3 <p>I suspect what is missing is that <tt>fallocate()</tt> needs to internally get the intent lock with the MDS for the full range of data, like a <tt>write()</tt> or <tt>truncate()</tt> call, which will cause it to initialize those components. Then, the later RPCs to the OSTs will "just work".</p> <p>The initialization of later components is probably <b>not</b> needed for <tt>PUNCH_HOLE|KEEP_SIZE</tt>, but is needed if <tt>PUNCH_HOLE</tt> by itself acts like <tt>truncate()</tt> to extend the size, since the size of the file is determined by the size of the OST objects themselves.</p> <p>Wang Shilong (wshilong@whamcloud.com) uploaded a new patch: <a href="https://review.whamcloud.com/40885" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/40885</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-14186" title="fallocate does not extend uninitialized PFL components" class="issue-link" data-issue-key="LU-14186"><del>LU-14186</del></a> lov: instantiate components layout for fallocate<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: f7714e0cc88a0aa427cebb2677be2a1ec5209bf2</p> <p>Oleg Drokin (green@whamcloud.com) merged in patch <a href="https://review.whamcloud.com/40885/" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/40885/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-14186" title="fallocate does not extend uninitialized PFL components" class="issue-link" data-issue-key="LU-14186"><del>LU-14186</del></a> lov: instantiate components layout for fallocate<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: 7e25e6c7d0a710ea25aa0ca277e61fbd18ab3dd3</p> <p>Landed for 2.14</p> Related Development Rank 1|i01gfz: Rank (Obsolete) 9223372036854775807 Severity