Messages in this thread Patch in this message | | | Date | Thu, 5 Jan 2006 10:09:33 +0200 | From | Oleg Drokin <> | Subject | Re: d_instantiate_unique / NFS inode leakage? |
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Hello!
On Thu, Jan 05, 2006 at 02:26:47AM +0100, Trond Myklebust wrote: > > Searching for inode leakage in NFS code (seen in 2.6.14 and 2.6.15 at least, > > have not tried earlier versions), I see suspicious place in > > d_instantiate_unique (the only user happens to be NFS). > > There if we have found aliased dentry that we return, inode reference is > > not dropped and inode is not attached anywhere, so it seems the reference > > to inode is leaked in that case. > Yep, that looks like it ought to be the correct behaviour. Could you > please also add a note to this effect in the DocBook header for > d_instantiate_unique?
Sure.
--- fs/dcache.c.orig 2006-01-05 02:28:57.000000000 +0200 +++ fs/dcache.c 2006-01-05 10:04:02.000000000 +0200 @@ -808,10 +808,14 @@ void d_instantiate(struct dentry *entry, * * Fill in inode information in the entry. On success, it returns NULL. * If an unhashed alias of "entry" already exists, then we return the - * aliased dentry instead. + * aliased dentry instead and drop one reference to inode. * * Note that in order to avoid conflicts with rename() etc, the caller * had better be holding the parent directory semaphore. + * + * This also assumes that the inode count has been incremented + * (or otherwise set) by the caller to indicate that it is now + * in use by the dcache. */ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode) { @@ -838,6 +842,7 @@ struct dentry *d_instantiate_unique(stru dget_locked(alias); spin_unlock(&dcache_lock); BUG_ON(!d_unhashed(alias)); + iput(inode); return alias; } list_add(&entry->d_alias, &inode->i_dentry); Bye, Oleg - 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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