find_inode_nowait (9) - Linux Manuals

find_inode_nowait: find an inode in the inode cache


find_inode_nowait - find an inode in the inode cache


struct inode * find_inode_nowait(struct super_block sb, unsigned long hashval, int (*match(struct inode *, unsigned long, void *), void data);



super block of file system to search


hash value (usually inode number) to search for


callback used for comparisons between inodes


opaque data pointer to pass to match


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.