find_inode_nowait (9) Linux Manual Page
find_inode_nowait – find an inode in the inode cache
Synopsis
struct inode *find_inode_nowait(struct super_block *sb, unsigned long hashval, int (*match)(struct inode *, unsigned long, void *), void *data);Arguments
sb
-
- super block of file system to search
hashval
- hash value (usually inode number) to search for
match
- callback used for comparisons between inodes
data
- opaque data pointer to pass to match
Description
Search for the inode specified by hashval and data in the inode cache, where the helper function match will return 0 if the inode does not match, 1 if the inode does match, and -1 if the search should be stopped. The match function must be responsible for taking the i_lock spin_lock and checking i_state for an inode being freed or being initialized, and incrementing the reference count before returning 1. It also must not sleep, since it is called with the inode_hash_lock spinlock held.
This is a even more generalized version of ilookup5 when the function must never block — find_inode can block in __wait_on_freeing_inode — or when the caller can not increment the reference count because the resulting iput might cause an inode eviction. The tradeoff is that the match funtion must be very carefully implemented.