knfsd: exportfs: add find_disconnected_root helper

Break the loop that finds the root of a disconnected subtree into a helper of
its own to make reading easier and document the intent.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Hellwig 2007-07-17 04:04:32 -07:00 committed by Linus Torvalds
parent fb66a1989c
commit dd90b50906

View file

@ -70,6 +70,27 @@ find_acceptable_alias(struct dentry *result,
return NULL;
}
/*
* Find root of a disconnected subtree and return a reference to it.
*/
static struct dentry *
find_disconnected_root(struct dentry *dentry)
{
dget(dentry);
spin_lock(&dentry->d_lock);
while (!IS_ROOT(dentry) &&
(dentry->d_parent->d_flags & DCACHE_DISCONNECTED)) {
struct dentry *parent = dentry->d_parent;
dget(parent);
spin_unlock(&dentry->d_lock);
dput(dentry);
dentry = parent;
spin_lock(&dentry->d_lock);
}
spin_unlock(&dentry->d_lock);
return dentry;
}
/**
* find_exported_dentry - helper routine to implement export_operations->decode_fh
* @sb: The &super_block identifying the filesystem
@ -164,23 +185,9 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
* the noprogress counter. If we go through the loop 10 times (2 is
* probably enough) without getting anywhere, we just give up
*/
noprogress= 0;
noprogress = 0;
while (target_dir->d_flags & DCACHE_DISCONNECTED && noprogress++ < 10) {
struct dentry *pd = target_dir;
dget(pd);
spin_lock(&pd->d_lock);
while (!IS_ROOT(pd) &&
(pd->d_parent->d_flags&DCACHE_DISCONNECTED)) {
struct dentry *parent = pd->d_parent;
dget(parent);
spin_unlock(&pd->d_lock);
dput(pd);
pd = parent;
spin_lock(&pd->d_lock);
}
spin_unlock(&pd->d_lock);
struct dentry *pd = find_disconnected_root(target_dir);
if (!IS_ROOT(pd)) {
/* must have found a connected parent - great */