ClfsAddLogContainer function (wdm.h)

The ClfsAddLogContainer routine adds a container to a CLFS log.

Syntax

CLFSUSER_API NTSTATUS ClfsAddLogContainer(
  [in] PLOG_FILE_OBJECT plfoLog,
  [in] PULONGLONG       pcbContainer,
  [in] PUNICODE_STRING  puszContainerPath
);

Parameters

[in] plfoLog

A pointer to a LOG_FILE_OBJECT structure that represents the log to which the container will be added. The caller previously obtained this pointer by calling ClfsCreateLogFile.

[in] pcbContainer

A pointer to a ULONGLONG-typed variable. The role of this parameter depends on whether the log currently has at least one container.

• If the log currently has no containers, the caller supplies a positive integer that is the requested size, in bytes, of the new container. CLFS creates a container that is the requested size rounded up to a multiple of 512KB (for a dedicated log) or 1MB (for a multiplexed log).
• If the log currently has at least one container and this parameter is the NULL pointer, CLFS creates a new container that is the same size as the existing containers. (All containers in a log must be the same size.)
• If the log currently has at least one container and this parameter is a valid pointer, the caller supplies a positive integer that is the requested size, in bytes, of the new container. The requested size is rounded up to a multiple of 512KB (for a dedicated log) or 1MB (for a multiplexed log). If the rounded-up size is at least as large as the existing container size, CLFS creates a new container that is the same size as the existing containers. On successful return, this parameter receives the existing container size. If the rounded-up size is less than the existing container size, ClfsAddLogContainer fails.

[in] puszContainerPath

A pointer to a UNICODE_STRING structure that supplies the path name for the new container. The path can be absolute or relative to the ___location of the base log file. Paths that are relative to the base log file must begin with CLFS_CONTAINER_RELATIVE_PREFIX, which is the string literal (L"%BLF%\").

Return value

ClfsAddLogContainer returns STATUS_SUCCESS if it succeeds; otherwise, it returns one of the error codes defined in Ntstatus.h.

Remarks

A container is a contiguous extent on stable storage. For example, a container could be a contiguous file on disk. A log is a set of containers along with a base log file. For more information about containers, see CLFS Stable Storage.

A container specified by a path that is relative to the base log file must be in the same directory as the base log file or a subdirectory of the base log file. The directories "." and ".." are not allowed in a relative path.

A log can have some containers with absolute paths and other containers with relative paths.

Containers are created in a non-compressed mode and are initialized with zeros.

A log must have at least two containers before any I/O can be performed on it.

For an explanation of CLFS concepts and terminology, see Common Log File System.

Requirements

See also

ClfsAddLogContainerSet

ClfsRemoveLogContainer