Messages in this thread | | | Date | Sun, 13 Jan 2002 12:35:42 -0800 | From | Andrew Morton <> | Subject | Re: Hard lock when mounting loopback file |
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Marius Gedminas wrote: > > On Sat, Jan 12, 2002 at 11:49:04PM -0800, Andrew Morton wrote: > > I don't know a thing about fat layout, but it appears that it uses a > > linked list of blocks, and if that list ends up pointing back onto > > itself, the kernel goes into an infinite loop in several places chasing > > its way to the end of the list. > > > > The below patch fixed it for me, and I was able to mount and read > > your filesystem image. > > > > Unless someone has a smarter fix, I'll send this to the kernel > > maintainers in a week or two. > > It seems to me that this patch will find only those infinite loops where > the last link of the chain points to itself. But there could be loops > where the last link points to the middle of the chain.
Agree.
> Additional check on the number of followed links could be useful there. > No chain should be longer than the number of clusters on the fs. > Although on large FAT32 filesystems the number of clusters can be high, > a very long loop is still better than an infinite one. (In cases where > we know the file size, this limit can be reduced to > file_size/cluster_size + 1 links).
hmm.. OK, I'll take a look at that approach.
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