Re: [SLUG] linked folders show different files
On Thursday 01 July 2010 19:00:34 Daniel Pittman wrote: > On which file system, without causing it serious errors? I can't say > categorically that nothing allows it, but it is considered to be a serious > violation of the semantics of the system by ... well, most things. You certainly used to be able to do it on the historical UNIX filesystems. > Certainly all the common file system drivers in Linux, as well as by the > core VFS; see http://lxr.linux.no/linux+v2.6.34/fs/namei.c#L2423 for > vfs_link: > > 2445if (S_ISDIR(inode->i_mode)) > 2446return -EPERM; I wasn't aware Linux had departed from history in that way. That would certainly prevent such links from being created under Linux. It does not exclude the possibility of some non-linux filesystem being in use that does allow it, with the hard link having been created on some other platform (of course we assume here that things were done under Linux, so that would be out of scope for the question unless the poster mentioned it). > ...while you used to be able to break things as root, on some platforms, it > wasn't ever considered a healthy thing to do — at least, to the best of my > knowledge on the topic. It was always considered a bad idea, although in some limited circumstances useful. Apparently some backup tools on OSX (or whatever it's called this week) do it. The old UNIX philosophy was that the kernel would allow root to hose the entire system if that is what root really wanted to do, rather than adopt a more paternalistic approach. > Nope. That isn't even close to accurate; the way data is cached varies > wildly between different systems, but it isn't especially hierarchical; > file data is usually in the page cache indexed by inode. File data, yes. But directory information under Linux also uses the "dcache" (see include/linux/dcache.h in the kernel source), which is the caching I was refering to. As I said I was speculating. I may be wrong about whether the dcache could be caused to be out of synch by hard links to directories. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] linked folders show different files
Troy Rollo writes: > On Thursday 01 July 2010 19:00:34 Daniel Pittman wrote: > >> On which file system, without causing it serious errors? I can't say >> categorically that nothing allows it, but it is considered to be a serious >> violation of the semantics of the system by ... well, most things. > > You certainly used to be able to do it on the historical UNIX filesystems. Do you mean "you could, but it broke things", or "you could, and it worked fine", though? I agree you could do it, just like you could unlink a directory. The results were not healthy, though, on any (historic) platform I am aware of. [...] >> ...while you used to be able to break things as root, on some platforms, it >> wasn't ever considered a healthy thing to do — at least, to the best of my >> knowledge on the topic. > > It was always considered a bad idea, although in some limited circumstances > useful. Apparently some backup tools on OSX (or whatever it's called this > week) do it. TimeMachine, and apparently it does. Rumor varies about it being possible to do this without being TM under Snow Leopard... Still, a modern system that allows a cyclic graph in the file system. Their VFS cache implementers must love them for putting that into the system. :) Daniel -- ✣ Daniel Pittman✉ dan...@rimspace.net☎ +61 401 155 707 ♽ made with 100 percent post-consumer electrons -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Notification Bubbles
Hey everyone. I was looking around today. and I found that you could modify the bubble that comes on the screen. You can run the little script that I have added if you like. Or the way below. :) I Remember someone was trying to make the bubble stay longer in this configuration file you can change it. http://www.webupd8.org/2010/05/finally-easy-way-to-customize-notify.html "sudo add-apt-repository ppa:leolik/leolik" "sudo apt-get update && sudo apt-get upgrade" "gedit ~/.notify-osd &" # Place this in the configuration file that you just made. "slot-allocation = fixed bubble-expire-timeout = 10sec bubble-vertical-gap = 5px bubble-horizontal-gap = 5px bubble-corner-radius = 37,5% bubble-icon-size = 30px bubble-gauge-size = 6px bubble-width = 240px bubble-background-color = 131313 bubble-background-opacity = 90% text-margin-size = 10px text-title-size = 100% text-title-weight = bold text-title-color = ff text-title-opacity = 100% text-body-size = 90% text-body-weight = normal text-body-color = eaeaea text-body-opacity = 100% text-shadow-opacity = 100%" "notify-send test" to test the bubble" One you're done, restart notify-osd with : "pkill notify-osd" -- Joshua Smith notification-config-install.tar.gz Description: application/compressed-tar -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
