[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>
This commit is contained in:
Christoph Hellwig 2006-01-18 17:43:52 -08:00 committed by Linus Torvalds
parent 846f2fcd77
commit e2f99018eb

View file

@ -11,6 +11,33 @@ struct export_operations export_op_default;
#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 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
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 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
/* 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 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
/* 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);