From: Richard Tobin <firstname.lastname@example.org> To: "Erik E. Fair" <email@example.com>, The Eunuchs Hysterical Society <firstname.lastname@example.org> Subject: Re: [TUHS] Unix filesystem semantics history - files with holes Date: Thu, 11 Apr 2019 16:57:48 +0100 (BST) Message-ID: <20190411155748.8791B255ADDC@macaroni.inf.ed.ac.uk> (raw) > When did the Unix filesystem add the semantics for "files with holes" (large, > sparse files)? It was there in the first edition: https://www.bell-labs.com/usr/dmr/www/pdfs/man51.pdf The FILE SYSTEM (V) man page includes a last paragraph identical to that of FILSYS (V) in seventh edition: If block b in a file exists, it is not necessary that all blocks less than b exist. A zero block number either in the address words of the the i-node or in an indirect block indicates that the corresponding block has never been allocated. Such a missing block reads as if it contained all zero words. The first edition indirect blocks were a bit different though: if the file was bigger than 8 blocks (4kB), all the blocks in the inode were (singly) indirect. -- Richard -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.
next prev reply index Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-04-11 2:37 Erik E. Fair 2019-04-11 5:28 ` Ronald Natalie 2019-04-11 15:57 Richard Tobin [this message] 2019-04-11 19:09 ` William Corcoran 2019-04-11 19:49 ` Bakul Shah
Reply instructions: You may reply publically to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190411155748.8791B255ADDC@macaroni.inf.ed.ac.uk \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
The Unix Heritage Society mailing list Archives are clonable: git clone --mirror http://inbox.vuxu.org/tuhs Newsgroup available over NNTP: nntp://inbox.vuxu.org/vuxu.archive.tuhs AGPL code for this site: git clone https://public-inbox.org/ public-inbox