Messages in this thread | | | Date | Thu, 2 Oct 2003 11:35:50 +0100 | From | viro@parcelfa ... | Subject | Re: 2.6.0-test6 crash while reading files in /proc/fs/reiserfs/sda1 |
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On Thu, Oct 02, 2003 at 02:08:26PM +0400, Nikita Danilov wrote: > What about creating fake struct vfsmount for /proc/fs/reiserfs/<devname> > and attaching it to the super block of /<mountpoint>? After all > /proc/fs/reiserfs/<devname> is just a view into /<mountpoint>. This will > automatically guarantee that /<mountpoint> cannot be unmounted while > files in /proc/fs/reiserfs/<devname> are opened. Will this screw up > dcache?
I don't see what it would buy you - you get to revalidate the pointer to vfsmount instead of revalidating pointer to superblock, which is not easier. sget()-based revalidation actually works OK - see previous reply for details. With optimistic sget() (which we should've done a long time ago) it's actually cheaper than your original "search by dev_t" - you are looking only through reiserfs superblocks instead of all superblocks in system.
> Yes, possible. I had similar problem in reiser4 also: for some seq_file, > x_start() allocated some data structure (struct x_struct) that is used > by x_next(), x_show(), and is deallocated in x_stop(). As x_struct is > per read invocation rather than per file it cannot be stored in seq_file > itself. I had to resort to returning x_struct from x_start() and passing > it without change through x_next()'s. Thing actually changed by x_next() > was embedded in x_struct. Last x_next() had to deallocate x_struct and > to return NULL (much like your example above).
Umm... And what's the problem with that? If your context is created by ->start() and is needed by ->next() and ->stop(), the above is obvious solution - you are already passing opaque pointer through that sequence, so that's about as straightforward as it gets... - 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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