[PATCH 007 of 8] knfsd: exportfs: add find_disconnected_root helper

NeilBrown
2007-05-15T07:18:32Z

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>

### Diffstat output
./fs/exportfs/expfs.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)

diff .prev/fs/exportfs/expfs.c ./fs/exportfs/expfs.c
--- .prev/fs/exportfs/expfs.c 2007-05-14 11:15:46.000000000 +1000
+++ ./fs/exportfs/expfs.c 2007-05-14 11:15:51.000000000 +1000
@@ -70,6 +70,27 @@ find_acceptable_alias(struct dentry *res
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
* 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 */