diff options
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 897eae8faee1..439818420857 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -403,6 +403,28 @@ int pagecache_write_end(struct file *, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata); +/* + * Two-state lock - can be taken for add or block - both states are shared, + * like read side of rwsem, but conflict with other state: + */ +struct pagecache_lock { + atomic_long_t v; + wait_queue_head_t wait; +}; + +static inline void pagecache_lock_init(struct pagecache_lock *lock) +{ + atomic_long_set(&lock->v, 0); + init_waitqueue_head(&lock->wait); +} + +void pagecache_add_put(struct pagecache_lock *); +void pagecache_add_get(struct pagecache_lock *); +void __pagecache_block_put(struct pagecache_lock *); +void __pagecache_block_get(struct pagecache_lock *); +void pagecache_block_put(struct pagecache_lock *); +void pagecache_block_get(struct pagecache_lock *); + struct address_space { struct inode *host; /* owner: inode, block_device */ struct radix_tree_root i_pages; /* cached pages */ @@ -421,6 +443,8 @@ struct address_space { struct list_head private_list; /* for use by the address_space */ void *private_data; /* ditto */ errseq_t wb_err; + struct pagecache_lock add_lock + ____cacheline_aligned_in_smp; /* protects adding new pages */ } __attribute__((aligned(sizeof(long)))) __randomize_layout; /* * On most architectures that alignment is already the case; but |