From: Christoph Hellwig 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 Signed-off-by: Neil Brown Signed-off-by: Andrew Morton --- fs/exportfs/expfs.c | 39 +++++++++++++++++++++++---------------- 1 files changed, 23 insertions(+), 16 deletions(-) diff -puN fs/exportfs/expfs.c~knfsd-exportfs-add-find_disconnected_root-helper fs/exportfs/expfs.c --- a/fs/exportfs/expfs.c~knfsd-exportfs-add-find_disconnected_root-helper +++ a/fs/exportfs/expfs.c @@ -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 */ _