include/blobfs.h: add comments for public APIs

Change-Id: Ia4635850723591a4d5eea298523f26953bb950c1
Signed-off-by: Yanbo Zhou <yanbo.zhou@intel.com>
Reviewed-on: https://review.gerrithub.io/391512
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: GangCao <gang.cao@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
This commit is contained in:
Yanbo Zhou 2017-12-13 10:26:15 +08:00 committed by Changpeng Liu
parent 8561b30502
commit d076dcfb44

View File

@ -73,71 +73,273 @@ typedef void (*spdk_file_stat_op_complete)(void *ctx, struct spdk_file_stat *sta
typedef void (*fs_request_fn)(void *);
typedef void (*fs_send_request_fn)(fs_request_fn, void *);
/* Initialize an spdk_blobfs_opts structure to the default blobfs option values. */
/**
* Initialize a spdk_blobfs_opts structure to the default option values.
*
* \param opts spdk_blobf_opts struture to intialize.
*/
void spdk_fs_opts_init(struct spdk_blobfs_opts *opts);
/**
* Initialize blobstore filesystem.
*
* Initialize the blobstore filesystem on the blobstore block device which has
* been created by the function spdk_bdev_create_bs_dev() in the blob_bdev.h.
* The obtained blobstore filesystem will be passed to the callback function.
*
* \param dev Blobstore block device used by this blobstore filesystem.
* \param opt Initialization options used for this blobstore filesystem.
* \param send_request_fn The function for sending request. This function will
* be invoked any time when the blobstore filesystem wants to pass a message to
* the main dispatch thread.
* \param cb_fn Called when the initialization is complete.
* \param cb_arg Argument passed to function cb_fn.
*/
void spdk_fs_init(struct spdk_bs_dev *dev, struct spdk_blobfs_opts *opt,
fs_send_request_fn send_request_fn,
spdk_fs_op_with_handle_complete cb_fn, void *cb_arg);
/**
* Load blobstore filesystem from the given blobstore block device.
*
* The obtained blobstore filesystem will be passed to the callback function.
*
* \param dev Blobstore block device used by this blobstore filesystem.
* \param send_request_fn The function for sending request. This function will
* be invoked any time when the blobstore filesystem wants to pass a message to
* the main dispatch thread.
* \param cb_fn Called when the loading is complete.
* \param cb_arg Argument passed to function cb_fn.
*/
void spdk_fs_load(struct spdk_bs_dev *dev, fs_send_request_fn send_request_fn,
spdk_fs_op_with_handle_complete cb_fn, void *cb_arg);
/**
* Unload blobstore filesystem.
*
* \param fs Blobstore filesystem to unload.
* \param cb_fn Called when the unloading is complete.
* \param cb_arg Argument passed to function cb_fn.
*/
void spdk_fs_unload(struct spdk_filesystem *fs, spdk_fs_op_complete cb_fn, void *cb_arg);
/**
* Allocate an I/O channel for asynchronous operations.
*
* \param fs Blobstore filesystem to allocate I/O channel.
*
* \return a pointer to the I/O channel on success or NULL otherwise.
*/
struct spdk_io_channel *spdk_fs_alloc_io_channel(struct spdk_filesystem *fs);
/*
* Allocates an I/O channel suitable for using the synchronous blobfs API. These channels do
* not allocate an I/O channel for the underlying blobstore, but rather allocate synchronizaiton
* primitives used to block until any necessary I/O operations are completed on a separate
* polling thread.
/**
* Allocate an I/O channel for synchronous operations.
*
* \param fs Blobstore filesystem to allocate I/O channel.
*
* \return a pointer to the I/O channel on success or NULL otherwise.
*/
struct spdk_io_channel *spdk_fs_alloc_io_channel_sync(struct spdk_filesystem *fs);
/**
* Free I/O channel.
*
* This function will decrease the references of this I/O channel. If the reference
* is reduced to 0, the I/O channel will be freed.
*
* \param channel I/O channel to free.
*/
void spdk_fs_free_io_channel(struct spdk_io_channel *channel);
/**
* Get statistics about the file including the underlying blob id and the file size.
*
* \param fs Blobstore filesystem.
* \param channel The I/O channel used to allocate file request.
* \param name The file name used to look up the matched file in the blobstore filesystem.
* \param stat Caller allocated structure to store the obtained information about
* this file.
*
* \return 0 on success, negative errno on failure.
*/
int spdk_fs_file_stat(struct spdk_filesystem *fs, struct spdk_io_channel *channel,
const char *name, struct spdk_file_stat *stat);
#define SPDK_BLOBFS_OPEN_CREATE (1ULL << 0)
/**
* Create a new file on the given blobstore filesystem.
*
* \param fs Blobstore filesystem.
* \param channel The I/O channel used to allocate file request.
* \param name The file name for this new file.
*
* \return 0 on success, negative errno on failure.
*/
int spdk_fs_create_file(struct spdk_filesystem *fs, struct spdk_io_channel *channel,
const char *name);
/**
* Open the file.
*
* \param fs Blobstore filesystem.
* \param channel The I/O channel used to allocate file request.
* \param name The file name used to look up the matched file in the blobstore filesystem.
* \param flags This flags will be used to control the open mode.
* \param file It will point to the open file if sccessful or NULL otherwirse.
*
* \return 0 on success, negative errno on failure.
*/
int spdk_fs_open_file(struct spdk_filesystem *fs, struct spdk_io_channel *channel,
const char *name, uint32_t flags, struct spdk_file **file);
/**
* Close the file.
*
* \param file File to close.
* \param channel The I/O channel used to allocate file request.
*
* \return 0 on success, negative errno on failure.
*/
int spdk_file_close(struct spdk_file *file, struct spdk_io_channel *channel);
/**
* Change the file name.
*
* This operation will overwrite an existing file if there is a file with the
* same name.
*
* \param fs Blobstore filesystem.
* \param channel The I/O channel used to allocate file request.
* \param old_name Old name of the file.
* \param new_name New name of the file.
*
* \return 0 on success, negative errno on failure.
*/
int spdk_fs_rename_file(struct spdk_filesystem *fs, struct spdk_io_channel *channel,
const char *old_name, const char *new_name);
/**
* Delete the file.
*
* \param fs Blobstore filesystem.
* \param channel The I/O channel used to allocate file request.
* \param name The name of the file to be deleted.
*
* \return 0 on success, negative errno on failure.
*/
int spdk_fs_delete_file(struct spdk_filesystem *fs, struct spdk_io_channel *channel,
const char *name);
/**
* Get the first file in the blobstore filesystem.
*
* \param fs Blobstore filesystem to traverse.
*
* \return an iterator which points to the first file in the blobstore filesystem.
*/
spdk_fs_iter spdk_fs_iter_first(struct spdk_filesystem *fs);
/**
* Get the next file in the blobstore filesystem by using the input iterator.
*
* \param iter The iterator which points to the current file struct.
*
* \return an iterator which points to the next file in the blobstore filesystem.
*/
spdk_fs_iter spdk_fs_iter_next(spdk_fs_iter iter);
#define spdk_fs_iter_get_file(iter) ((struct spdk_file *)(iter))
/**
* Truncate the file.
*
* \param file File to truncate.
* \param channel The I/O channel used to allocate file request.
* \param length New size in bytes of the file.
*/
void spdk_file_truncate(struct spdk_file *file, struct spdk_io_channel *channel,
uint64_t length);
/**
* Get file name.
*
* \param file File to query.
*
* \return the name of the file.
*/
const char *spdk_file_get_name(struct spdk_file *file);
/**
* Obtain the size of the file.
*
* \param file File to query.
*
* \return the size in bytes of the file.
*/
uint64_t spdk_file_get_length(struct spdk_file *file);
/**
* Write data to the given file.
*
* \param file File to write.
* \param channel The I/O channel used to allocate file request.
* \param payload The specified buffer which should contain the data to be transmitted.
* \param offset The beginning position to write data.
* \param length The size in bytes of data to write.
*
* \return 0 on success, negative errno on failure.
*/
int spdk_file_write(struct spdk_file *file, struct spdk_io_channel *channel,
void *payload, uint64_t offset, uint64_t length);
/**
* Read data to user buffer from the given file.
*
* \param file File to read.
* \param channel The I/O channel used to allocate file request.
* \param payload The specified buffer which will store the obtained data.
* \param offset The beginning position to read.
* \param length The size in bytes of data to read.
*
* \return the end position of this read operation on success, negated errno on failure.
*/
int64_t spdk_file_read(struct spdk_file *file, struct spdk_io_channel *channel,
void *payload, uint64_t offset, uint64_t length);
/**
* Set cache size for the blobstore filesystem.
*
* \param size_in_mb Cache size in megabytes.
*/
void spdk_fs_set_cache_size(uint64_t size_in_mb);
/**
* Obtain the cache size.
*
* \return cache size in megabytes.
*/
uint64_t spdk_fs_get_cache_size(void);
#define SPDK_FILE_PRIORITY_LOW 0 /* default */
#define SPDK_FILE_PRIORITY_HIGH 1
/**
* Set priority for the file.
*
* \param file File to set priority.
* \param priority Priority level (SPDK_FILE_PRIORITY_LOW or SPDK_FILE_PRIORITY_HIGH).
*/
void spdk_file_set_priority(struct spdk_file *file, uint32_t priority);
/**
* Synchronize the data from the cache to the disk.
*
* \param file File to sync.
* \param channel The I/O channel used to allocate file request.
*
* \return 0 on success.
*/
int spdk_file_sync(struct spdk_file *file, struct spdk_io_channel *channel);
#ifdef __cplusplus