Messages in this thread | | | Date | Sun, 12 Feb 2006 16:54:23 -0800 | From | Linda Walsh <> | Subject | Re: max symlink = 5? ?bug? ?feature deficit? |
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Al Viro wrote: > On Sun, Feb 12, 2006 at 02:54:33PM -0800, Linda Walsh wrote: > >> Al Viro wrote: >> >>> Care to RTFS? I mean, really - at least to the point of seeing what's >>> involved in that recursion. >>> >>> >> Hmmm...that's where I got the original parameter numbers, but >> I see it's not so straightforward. I tried a limit of >> 40, but I quickly get an OS hang when trying to reference a >> 13th link. Twelve works at the limit, but would take more testing >> to find out the bottleneck. >> > > Sigh... 12 works at the limit on your particular config, filesystems > being used and syscall being issued (hint: amount of stuff on stack > before we enter mutual recursion varies; so does the amount of stuff > on stack we get from function that are not part of mutual recursion, > but are called from the damn thing). > --- Yeah, I sorta figured that. Is there any easier way to remove the recursion? I dunno about you, but I was always taught that recursion, while elegant, was not always the most efficient in terms of time and space requirements and one could get similar functionality using iteration and a stack.
The GNU libraries _seem_ to indicate a max of 20 links supported there. Googling around, I see I'm not the first person to be surprised by the low limit. I don't recall running into such a limit on any other Unixes, though I'm sure they had some limit.
It can be useful for creating a shadow file-system where only root needs to point to a "target source", and the "symlink" overlay lies over the top of any real, underlying file.
Why can't things just be easy sometimes...:-/ Linda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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