diff options
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 58b89c9e9b0c8b..68e843e78337d7 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -3099,6 +3099,34 @@ void d_tmpfile(struct file *file, struct inode *inode) } EXPORT_SYMBOL(d_tmpfile); +/* + * Obtain inode number of the parent dentry. + */ +ino_t d_parent_ino(struct dentry *dentry) +{ + struct dentry *parent; + struct inode *iparent; + unsigned seq; + ino_t ret; + + scoped_guard(rcu) { + seq = raw_seqcount_begin(&dentry->d_seq); + parent = READ_ONCE(dentry->d_parent); + iparent = d_inode_rcu(parent); + if (likely(iparent)) { + ret = iparent->i_ino; + if (!read_seqcount_retry(&dentry->d_seq, seq)) + return ret; + } + } + + spin_lock(&dentry->d_lock); + ret = dentry->d_parent->d_inode->i_ino; + spin_unlock(&dentry->d_lock); + return ret; +} +EXPORT_SYMBOL(d_parent_ino); + static __initdata unsigned long dhash_entries; static int __init set_dhash_entries(char *str) { |