iget5_locked — obtain an inode from a mounted file system
struct inode * iget5_locked
(struct super_block * sb, unsigned long hashval, int (*test)
(struct inode *, void *), int (*set)
(struct inode *, void *), void * data);
super block of file system
hash value (usually inode number) to get
callback used for comparisons between inodes
callback used to initialize a new struct inode
opaque data pointer to pass to test and set
iget5_locked uses ifind to search for the inode specified by hashval and data in the inode cache and if present it is returned with an increased reference count. This is a generalized version of iget_locked for file systems where the inode number is not sufficient for unique identification of an inode.
If the inode is not in cache, get_new_inode is called to allocate a new inode and this is returned locked, hashed, and with the I_NEW flag set. The file system gets to fill it in before unlocking it via unlock_new_inode.
Note both test and set are called with the inode_lock held, so can't sleep.