[PATCH] exportfs: add find_acceptable_alias helper
find_exported_dentry contains two duplicate loops to find an alias that the
acceptable callback likes. Split this out to a new helper and switch from
list_for_each to list_for_each_entry to make it more readable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 5bfe400..b06b54f 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -11,6 +11,33 @@
#define dprintk(fmt, args...) do{}while(0)
+static struct dentry *
+find_acceptable_alias(struct dentry *result,
+ int (*acceptable)(void *context, struct dentry *dentry),
+ void *context)
+{
+ struct dentry *dentry, *toput = NULL;
+
+ spin_lock(&dcache_lock);
+ list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
+ dget_locked(dentry);
+ spin_unlock(&dcache_lock);
+ if (toput)
+ dput(toput);
+ if (dentry != result && acceptable(context, dentry)) {
+ dput(result);
+ return dentry;
+ }
+ spin_lock(&dcache_lock);
+ toput = dentry;
+ }
+ spin_unlock(&dcache_lock);
+
+ if (toput)
+ dput(toput);
+ return NULL;
+}
+
/**
* find_exported_dentry - helper routine to implement export_operations->decode_fh
* @sb: The &super_block identifying the filesystem
@@ -52,8 +79,7 @@
struct dentry *target_dir;
int err;
struct export_operations *nops = sb->s_export_op;
- struct list_head *le, *head;
- struct dentry *toput = NULL;
+ struct dentry *alias;
int noprogress;
char nbuf[NAME_MAX+1];
@@ -79,27 +105,10 @@
/* there is no other dentry, so fail */
goto err_result;
}
- /* try any other aliases */
- spin_lock(&dcache_lock);
- head = &result->d_inode->i_dentry;
- list_for_each(le, head) {
- struct dentry *dentry = list_entry(le, struct dentry, d_alias);
- dget_locked(dentry);
- spin_unlock(&dcache_lock);
- if (toput)
- dput(toput);
- toput = NULL;
- if (dentry != result &&
- acceptable(context, dentry)) {
- dput(result);
- return dentry;
- }
- spin_lock(&dcache_lock);
- toput = dentry;
- }
- spin_unlock(&dcache_lock);
- if (toput)
- dput(toput);
+
+ alias = find_acceptable_alias(result, acceptable, context);
+ if (alias)
+ return alias;
}
/* It's a directory, or we are required to confirm the file's
@@ -258,26 +267,10 @@
/* now result is properly connected, it is our best bet */
if (acceptable(context, result))
return result;
- /* one last try of the aliases.. */
- spin_lock(&dcache_lock);
- toput = NULL;
- head = &result->d_inode->i_dentry;
- list_for_each(le, head) {
- struct dentry *dentry = list_entry(le, struct dentry, d_alias);
- dget_locked(dentry);
- spin_unlock(&dcache_lock);
- if (toput) dput(toput);
- if (dentry != result &&
- acceptable(context, dentry)) {
- dput(result);
- return dentry;
- }
- spin_lock(&dcache_lock);
- toput = dentry;
- }
- spin_unlock(&dcache_lock);
- if (toput)
- dput(toput);
+
+ alias = find_acceptable_alias(result, acceptable, context);
+ if (alias)
+ return alias;
/* drat - I just cannot find anything acceptable */
dput(result);