From: "Theodore Ts'o" <tytso@mit.edu>
To: Noel Chiappa <jnc@mercury.lcs.mit.edu>
Cc: tuhs@minnie.tuhs.org
Subject: Re: [TUHS] moving directories in svr2
Date: Thu, 30 Dec 2021 11:40:31 -0500 [thread overview]
Message-ID: <Yc3g/+i9BQBK/5qO@mit.edu> (raw)
In-Reply-To: <20211230034512.B9B3718C08E@mercury.lcs.mit.edu>
On Wed, Dec 29, 2021 at 10:45:12PM -0500, Noel Chiappa wrote:
> > From: Bakul Shah
>
> > My guess is *not* storing a path instead of a ptr to the inode was done
> > to save on memory.
>
> More probably speed; those old disks were not fast, and on a PDP-11, disk
> caches were so small that converting the path to the current directory to its
> in memory inode could take a bunch of disk reads.
The other problem with storing the path as a string is that if
higher-level directories get renamed, the path would become
invalidated. If you store the cwd as "/foo/bar/baz/quux", and someone
renames "/foo/bar" to "/foo/sadness" the cwd-stored-as-a-string would
become invalidated.
Sure, you could scan the pwd of all the processes running on the
system and do edit all of the strings, but once you go SMP, the
potential locking pitfalls would be numerous.
- Ted
next prev parent reply other threads:[~2021-12-30 16:40 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-30 3:45 Noel Chiappa
2021-12-30 4:02 ` Bakul Shah
2021-12-30 16:40 ` Theodore Ts'o [this message]
2021-12-30 22:31 ` Dan Cross
2021-12-31 0:43 ` Bakul Shah
2021-12-31 1:00 ` Rob Pike
2021-12-31 1:45 ` Bakul Shah
2021-12-31 2:23 ` Adam Thornton
2021-12-31 18:56 ` Chet Ramey
2021-12-31 3:08 ` Theodore Ts'o
2021-12-31 3:23 ` Rob Pike
2021-12-31 5:16 ` Theodore Ts'o
2021-12-31 5:21 ` Dan Cross
2021-12-31 5:55 ` Rob Pike
2021-12-31 13:32 ` Michael Kjörling
2021-12-31 15:53 ` Adam Thornton
2021-12-31 16:13 ` Arthur Krewat
2021-12-31 18:17 ` Dan Cross
2021-12-31 18:23 ` Larry McVoy
2021-12-31 18:37 ` Dan Cross
2021-12-31 18:29 ` Arthur Krewat
2022-01-01 0:09 ` Theodore Ts'o
2022-01-03 13:35 ` Dan Cross
2022-01-03 20:23 ` Theodore Ts'o
2022-01-03 20:45 ` Warner Losh
2022-01-03 21:15 ` Dan Cross
2022-01-03 22:26 ` Theodore Ts'o
2022-01-03 23:10 ` Dan Cross
2022-01-04 15:45 ` Chet Ramey
2022-01-09 19:28 ` Larry McVoy
2022-01-03 23:21 ` Doug McIntyre
2022-01-03 23:37 ` Adam Thornton
2022-01-04 14:49 ` Stuart Remphrey
2022-01-03 23:44 ` Larry McVoy
2022-01-03 23:56 ` [TUHS] SMP: BSD vs System V (once was: moving directories in svr2) Greg 'groggy' Lehey
2022-01-07 19:01 ` Warner Losh
2022-01-09 17:31 ` Stuart Remphrey
2022-01-13 2:35 ` Kevin Bowling
2022-01-03 23:56 ` [TUHS] moving directories in svr2 Warner Losh
2022-01-04 2:28 ` Theodore Ts'o
2022-01-04 2:42 ` Larry McVoy
2022-01-04 9:28 ` [TUHS] Mythical Distress Sale (was Re: moving directories in svr2) Rob Gingell
2022-01-04 15:17 ` Larry McVoy
2022-01-04 15:26 ` arnold
2022-01-04 15:40 ` Larry McVoy
2022-01-04 15:48 ` Richard Salz
2022-01-03 22:57 ` [TUHS] moving directories in svr2 Phil Budne
2022-01-04 15:40 ` [TUHS] VRFs (was Re: moving directories in svr2) Derek Fawcus
2021-12-31 5:12 ` [TUHS] moving directories in svr2 Bakul Shah
-- strict thread matches above, loose matches on Subject: below --
2021-12-29 19:33 Noel Chiappa
2021-12-30 3:40 ` Jay Logue via TUHS
2021-12-29 19:13 Douglas McIlroy
2021-12-29 19:37 ` Dan Cross
2021-12-29 20:15 ` Dan Cross
2021-12-29 20:42 ` Richard Salz
2021-12-29 20:58 ` Dan Cross
2021-12-29 21:20 ` Clem Cole
2021-12-30 3:15 ` Bakul Shah
2021-12-29 17:12 Douglas McIlroy
2021-12-29 16:59 Bakul Shah
2021-12-29 17:04 ` Clem Cole
2021-12-29 17:14 ` arnold
2021-12-29 17:38 ` Clem Cole
2021-12-29 17:49 ` Brantley Coile
2021-12-29 18:27 ` ron minnich
2021-12-29 20:59 ` Rob Pike
2021-12-29 14:33 Will Senn
2021-12-29 15:02 ` arnold
2021-12-29 15:38 ` Will Senn
2021-12-29 15:44 ` Richard Salz
2021-12-29 16:17 ` Clem Cole
2021-12-29 16:58 ` Richard Salz
2021-12-30 5:14 ` Dan Stromberg
2021-12-30 16:22 ` Clem Cole
2021-12-30 18:02 ` John Cowan
2021-12-30 23:04 ` Richard Salz
2021-12-29 15:17 ` Clem Cole
2021-12-29 15:44 ` Will Senn
2021-12-29 16:10 ` Clem Cole
2021-12-29 16:33 ` Warner Losh
2021-12-29 16:01 ` Bakul Shah
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