diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/netfs.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 99659ed9524e..9062adfa2fb9 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -92,6 +92,18 @@ enum netfs_read_source { NETFS_INVALID_READ, } __mode(byte); +typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error, + bool was_async); + +/* + * Resources required to do operations on a cache. + */ +struct netfs_cache_resources { + const struct netfs_cache_ops *ops; + void *cache_priv; + void *cache_priv2; +}; + /* * Descriptor for a single component subrequest. */ @@ -121,11 +133,13 @@ struct netfs_read_request { struct work_struct work; struct inode *inode; /* The file being accessed */ struct address_space *mapping; /* The mapping being accessed */ + struct netfs_cache_resources cache_resources; struct list_head subrequests; /* Requests to fetch I/O from disk or net */ void *netfs_priv; /* Private data for the netfs */ unsigned int debug_id; unsigned int cookie_debug_id; atomic_t nr_rd_ops; /* Number of read ops in progress */ + atomic_t nr_wr_ops; /* Number of write ops in progress */ size_t submitted; /* Amount submitted for I/O so far */ size_t len; /* Length of the request */ short error; /* 0 or error that occurred */ @@ -149,6 +163,7 @@ struct netfs_read_request { struct netfs_read_request_ops { bool (*is_cache_enabled)(struct inode *inode); void (*init_rreq)(struct netfs_read_request *rreq, struct file *file); + int (*begin_cache_operation)(struct netfs_read_request *rreq); void (*expand_readahead)(struct netfs_read_request *rreq); bool (*clamp_length)(struct netfs_read_subrequest *subreq); void (*issue_op)(struct netfs_read_subrequest *subreq); @@ -159,6 +174,46 @@ struct netfs_read_request_ops { void (*cleanup)(struct address_space *mapping, void *netfs_priv); }; +/* + * Table of operations for access to a cache. This is obtained by + * rreq->ops->begin_cache_operation(). + */ +struct netfs_cache_ops { + /* End an operation */ + void (*end_operation)(struct netfs_cache_resources *cres); + + /* Read data from the cache */ + int (*read)(struct netfs_cache_resources *cres, + loff_t start_pos, + struct iov_iter *iter, + bool seek_data, + netfs_io_terminated_t term_func, + void *term_func_priv); + + /* Write data to the cache */ + int (*write)(struct netfs_cache_resources *cres, + loff_t start_pos, + struct iov_iter *iter, + netfs_io_terminated_t term_func, + void *term_func_priv); + + /* Expand readahead request */ + void (*expand_readahead)(struct netfs_cache_resources *cres, + loff_t *_start, size_t *_len, loff_t i_size); + + /* Prepare a read operation, shortening it to a cached/uncached + * boundary as appropriate. + */ + enum netfs_read_source (*prepare_read)(struct netfs_read_subrequest *subreq, + loff_t i_size); + + /* Prepare a write operation, working out what part of the write we can + * actually do. + */ + int (*prepare_write)(struct netfs_cache_resources *cres, + loff_t *_start, size_t *_len, loff_t i_size); +}; + struct readahead_control; extern void netfs_readahead(struct readahead_control *, const struct netfs_read_request_ops *, |