From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.17.24]) by sourceware.org (Postfix) with ESMTPS id D0AD6386181F for ; Tue, 5 Dec 2023 07:01:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org D0AD6386181F Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=towo.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=towo.net ARC-Filter: OpenARC Filter v1.0.0 sourceware.org D0AD6386181F Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=212.227.17.24 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701759693; cv=none; b=qiKJpBxCCkAivONp4D/K76pBy5NXQqvhb1ENUunFvpXm9l641GKa5V68XKerD5XE/K1t4Q1WDupFbTSwTp3dZvbrO44SSc8lDqi1uG3cMG+S1xY0ObJgWRpS6zYSQ5py9vq3gPVmZp9HaAY2pXOcDdIns+G7G6Z2hMUqaU+QF8w= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701759693; c=relaxed/simple; bh=OxWmBF7acXoakPuzj16W7FeTaiklotVIV21siFx47ds=; h=Message-ID:Date:MIME-Version:Subject:To:From; b=v8QAZYqbf4lfJjOy8sKN/nJc+sbkOkYEmrHS41T4gLR9TTBfN6C1LMHgDPJ6zuECNz2KOegOKlY1g3xXzmP+rnij+tEF1Kew7dICvyU9lawp8Wom+lHdkO+LmGZr6+dXifK3SPfeDPvEmxeEX1yvhfZxoxgCffOFst0dX7pq/kE= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from [192.168.178.72] ([91.65.51.86]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.183]) with ESMTPSA (Nemesis) id 1MowSu-1rbGrp2tSg-00qVLQ for ; Tue, 05 Dec 2023 07:36:31 +0100 Content-Type: multipart/alternative; boundary="------------vF6MBTsvVRtnLMqF6bgRYANw" Message-ID: <33d4b0df-7a6a-40cf-85a2-9a4300198672@towo.net> Date: Tue, 5 Dec 2023 07:36:31 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Cygwin api to punch a hole into a file? To: cygwin@cygwin.com References: From: Thomas Wolff Autocrypt: addr=towo@towo.net; keydata= xsDNBGNaf3QBDACVevqudcTSevLThXKQPU1QpaDxtGuYjtwmr7i9wXxVGih4Y4oxOJN4PYlu KBX9IVAI4651dA+xYtXuyIkWOPZWyyzkGKavQOn3Q7dk09oj7bh2IwOndpxXXde337D408EQ bQEGbMHr9lOWhSAideowzgCeFIvGTf2AovbPh97HpexJn1/HCRiRAhTNlrkS1DByUgCAeEMK fEr6aGM/Ou29MT+eTnQwOIZTnl9Z9LxM2FtqqMH3MycC7I2OoW3XXhuL8BPQdyJUjWa0/J11 Oo5jFkRXtWenIns6jGn18oW72jnDmo9jXwwS+iZWAV6Y51nhD7jSC+3xs9ORmPCdtHUSpTr1 zh67UueUJ3DUUNVuA25Hn/9EJMJ2L60BGUEr88NEB6pcZhmcwdkurAQeYT6t+frzBz2ctsoN BoxP/Xc02yd+z7hXWRRMrJWh9WHlQHA3Z4FfmyNhyPhs3MgKTJ1E9QfzGquigAmF3/k/Dc1m 7cSOKhGYhpEJdSpdXccJFKkAEQEAAc0cVGhvbWFzIFdvbGZmIDx0b3dvQHRvd28ubmV0PsLB BwQTAQgAMRYhBHUiRKsHn5d8BpWdP8bz0e72Bp0CBQJjWn93AhsDBAsJCAcFFQgJCgsFFgID AQAACgkQxvPR7vYGnQKSMAv8Di+8MXB2mcfsemRdShfLLKcLOv+d0CXAtPVaY3XKxbKpRvC9 +AAT5wIHYjQft77/b2y87vGIh+nQ5hKLtNtQPSDtqG/Igkb5jAXpLi28fSUzgM96DvARmwve 5wSnAU3prxH+Y63YpOpslEcGMRoEtYCDy1ANMYPcEZT/YvDd4CplyyEai4VYrw3/LsESDYlY GK6uMQzZ1jl2cNOUFu6BwLUeZIcwaqGto8n4R4nbf4jxUEpa21bWBPqE+Jf49uipjPr/iJ72 5HbdWuuCfyTTJEJjfNEBigWP2RXM9iNDcO61V3aEjh76tThfBK2MMlLWfZkQaQziu24x8R4B I0efJYWBX2Sv2qnsH/EWj7FUIZjRqGG7LnWHLShfG6yjSOTOWYi8BbsvoftpaLWgZX28aGX4 uzuSZ5L0caXh/pr/gSgqoH/YbuFIgqtQH4seOBgTybd22Vpe78rnc+8450pN8qwchHAZaJka UxS0SpYxXzXmHUKILA4C43s0U/z2Mez9zsDNBGNaf3cBDADeJ7paMrb6f1+k8wM7tyk0/Ded KX/pOejt/D20Ceerw2iL/4tUmBL+A3ic2yjiSFUSsEfHwgCVwKrn4MwZtkesdiphm2lk6xWc k1ENCQy44QwQT6UZ/mHWYWcj5LS6ua183x1zdn9iF3lv150nm/ssw56D7USz/ap1Vh0lf5te D+CIheGLocVDqxWiu7rHP8jKRWFgq/+OU6HKX8p2Yv1oYsykh9qF2bFzawLDS+S1VbfRicfD G0RtceL/BAf7b6UE5u9TGdfrFEa2TKZeS/FS/ViKUfwsXQIki1sWt2FQENbuDY28vxyR46ZZ 0gixDCFUoBw5pkmOGVQa+1RQYrRqlN4X0CAgp7mFVeEHl5NTgiL1bemkQVmHOUDG+CzNg+Lk UGoedAtT672l3JjrnSs4j8zNshpgV2OfAhAC+V9XvqCjMnxzVfXkVlbuWpPfUWQeFclLGg8P agpQUE0Ux+VV4DoeQCxYEnRCf/n7n+IRfILj5+2l6Zw4M7zSu6ii0tUAEQEAAcLA9gQYAQgA IBYhBHUiRKsHn5d8BpWdP8bz0e72Bp0CBQJjWn97AhsMAAoJEMbz0e72Bp0CQr4L/REdT0SF mbapnZIe92THCdtAUgwEv8VdNiNFBJelz8P/fuXuNPtisYvQQD4e64zpWe2UC4Cxo9DUk/pW 6Qci1xaXRKEiSPjHdSGGVB1PFIcqiS75GCf/ga/Dnfsy0Y4Uh6OGTQnkvZLBCe3vvcVLDQ7F PuV79zA9/eOeOW6aGoO6bq/wH+z96f9LyTITkQDy07fm6JYTGuzAoJE2AEboU1mgbtlx+tAa QFkpAQkp2g1Vhc3A7k4vntlHOrjMC+uVFh7QTGFfIlLRF6izUjSe6EZ06LErzlIiE05RP3yF FSRWidW0wze26peYlxYVgH1+T9wMTW2oiTBybfAMHBAxUP7Gr1WUo/oJEr0srWhatz8AwydP y7NwFbdpYn0NcFBaIlLW/JL11Eovwlivow+oGpzGFuuzSuflp2q9s2JWtn4EhW0kEs93D0LP iuJWvRaCZ6aD3uF3FMW8wyVWZYsLrzune2jH8w/uKMprDEOGOm+BcyhEFedTyY1ygbZKl+0G kQ== In-Reply-To: X-Provags-ID: V03:K1:vpAgygVxrm/56UAwiACLFaK2Y2igdYQLZbcJprY6YHwwBTd84Ci AqwtOrIAPZ6foPMDIVn+2Fa1EFqoaTEur1UGkBdbS2TAfPjf3e5PdgIKj1xl6N/MoDREej4 1QNVMtBr/LJk+IRoS/LP7chu6ypOThbfv3hcOC5H90tbCDso///hUcQM9Bk89ezckuP74CN HGpBxXzwiFCHybf3lzA7g== UI-OutboundReport: notjunk:1;M01:P0:dOH0SkgaSUw=;IIIy9AOly/gIQ6OeUvsEht3HT0N vcPS+/rmAxemq17bBXzHWzmvm89gOP0xB2aQvYIp3perPQpXWhKpPAHdEba+6S+WGrHr4JJLw LXKNZ0g7kRftRR8mjcEfsZcuPcfQMGBT1Wtm0ea28B94DSMSKRWBQSArIEp/K2lxHvPmELR/H PMdWA0vhWGKFHCFXx2t+AGmffD4L7WZv8KtMQjzIJKD9MtWNnrxlKMaTpmBfdBVeLudbg5Ngl Sm/UXVy21p9mKiXpIoVKLYeRAI1lMqi6tkMmrSHYDi6fr006cB+eT2iEBgBGnm77fIGyldqB2 LjAfgLXYxHFkc+Tfc6t+RPHfKPd9O5xpsnuyAx9BHoosyrpYqQLbJPqI7wbEiIh0VVK6f1nld uAIWkwrRA/gQ41WqbM1xtoY8iyM2Vfiv3DZwinCvs9chuGqM3L213cdgU4bQPw0lial8GyTFS DUBYGXwEUGyM+orr6znN1fjn20cjotNeTrCWDqbE4VzOduvfO2VOL2XB4YgdZh/+IuebQyesH T/X6xyKH2QtzZH4FvwvNndbDc3e7hd9ms7p5H/tqJ9QrFQNXp6T1uP9kQfvB3Q9SzK69GxEEu PdRiPrQe3sAMv7f4yk6MVWZhPvoNg5skyoCkysbs6FuiN69Cb+G/tOSay4+viwpKqL+/xw7on efXUWbJRYl6GSli6FUg19ZnxTtrnl3dpJ+pNWZ+3RhykfrheDg5iPlW2uzp/SoZJiV76Bxdr7 bK04oyZeXjJAzRn3B34l+DLTfiqWV4c94rreo33EqVSeIt+eoBKqtcgozNic3y+ARU8mgy5Nl 2DWBWtr+ISKRfAxbmQU2mryDJt5qpLu44B8lPknT3HC1jgus2n7r0qQ9lbiOXVDbBeOAHhrnZ XGye/sAd4x9zaPg== X-Spam-Status: No, score=1.1 required=5.0 tests=BAYES_00,HTML_MESSAGE,KAM_DMARC_STATUS,KAM_LOTSOFHASH,RCVD_IN_BARRACUDACENTRAL,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Level: * X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: This is a multi-part message in MIME format. --------------vF6MBTsvVRtnLMqF6bgRYANw Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Am 01.12.2023 um 12:02 schrieb Corinna Vinschen via Cygwin: > On Dec 1 11:22, Cedric Blancher via Cygwin wrote: >> Not all filesystems have a 128k block/stripe size, and certainly most >> filesystems have smaller minimum hole sizes than 128k (e.g. 512bytes >> is common, ref pathconf _PC_MIN_HOLE_SIZE). > There's no _PC_MIN_HOLE_SIZE in Linux or POSIX. In Windows, a sparse > file uses chunks of 64K. You can see this even with a file of just > a single block. Try this: > > $ touch x > $ chattr +S x > > $ echo 1234567890123456789012345678901234567890123456789012345678901234567890123456789 >> x > $ ls -ls x > 1 -rw-r--r-- 1 corinna vinschen 80 Dec 1 11:56 x > > [repeat echo and ls -ls until...] > > $ echo 1234567890123456789012345678901234567890123456789012345678901234567890123456789 >> x > $ ls -ls x > 1 -rw-r--r-- 1 corinna vinschen 720 Dec 1 11:56 x > $ echo 1234567890123456789012345678901234567890123456789012345678901234567890123456789 >> x > $ ls -ls x > 64 -rw-r--r-- 1 corinna vinschen 800 Dec 1 11:56 x2 > ^^ > This For me, it goes up from 1 to 4, then in steps of 4KB. > I don't know how Windows stores short files, maybe they are part of the > metadata up to a point or some such. However, as soon as you raise the > size over a given point, the *allocation size* will be rounded up to 64K > and from that point on, it will be in 64K chunks. Also sparsifying and > desparsifying of blocks only works in 64K chunks. > > > Corinna > --------------vF6MBTsvVRtnLMqF6bgRYANw--