mirror of
https://github.com/apache/nuttx.git
synced 2025-12-07 18:12:33 +08:00
c3e87dd3d1
To save more space (equivalent to the size of one erase sector of MTD device) and to achieve faster read and write speeds, a method for direct writing was introduced at the FTL layer. This can be accomplished simply by using the following oflags during the open operation: 1. O_DIRECT. when this flag is passed in, ftl internally uses the direct write strategy and no read cache is used in ftl; otherwise, each write will be executed with the minimum granularity of flash erase sector size which means a "sector read back - erase sector - write sector" operation is performed by using a read cache buffer in heap. 2. O_SYNC. When this flag is passed in, we assume that the flash has been erased in advance and no erasure operation will be performed internally within ftl. O_SYNC will take effect only when both O_DIRECT and O_SYNC are passed in simultaneously. 3. For uniformity, we remapped the mount flag in mount.h and unified it with the open flag in fcntl.h. The repetitive parts of their definitions were reused, and the remaining part of the mount flag redefine to the unused bit of open flags. Signed-off-by: jingfei <jingfei@xiaomi.com>
117 lines
4.6 KiB
C
117 lines
4.6 KiB
C
/****************************************************************************
|
|
* include/sys/mount.h
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifndef __INCLUDE_SYS_MOUNT_H
|
|
#define __INCLUDE_SYS_MOUNT_H
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/compiler.h>
|
|
#include <nuttx/fs/ioctl.h>
|
|
#include <fcntl.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define BLKSSZGET BIOC_BLKSSZGET
|
|
#define BLKGETSIZE BIOC_BLKGETSIZE
|
|
|
|
/* Mount flags */
|
|
|
|
#define MS_RDONLY O_RDONLY /* Mount file system read-only */
|
|
#define MS_SYNCHRONOUS O_SYNC /* Writes are synced at once */
|
|
#define MS_NOSYMFOLLOW O_NOFOLLOW /* Do not follow symlinks */
|
|
#define MS_NOATIME O_NOATIME /* Do not update access times. */
|
|
#define MS_NOSUID O_RESERVE14 /* Ignore suid and sgid bits */
|
|
#define MS_NODEV O_RESERVE15 /* Disallow access to device special files */
|
|
#define MS_DIRSYNC O_RESERVE16 /* Directory modifications are synchronous */
|
|
#define MS_REMOUNT O_RESERVE17 /* Alter flags of a mounted FS */
|
|
#define MS_MANDLOCK O_RESERVE19 /* Allow mandatory locks on an FS */
|
|
#define MS_NOEXEC O_RESERVE20 /* Disallow program execution */
|
|
|
|
/* Un-mount flags
|
|
*
|
|
* These flags control the behavior of umount2() when there are open file
|
|
* references through the mountpoint. umount2() with no flag bits set is
|
|
* equivalent to umount(), i.e., the umount() will fail with EBUSY if there
|
|
* are open references on the file.
|
|
*
|
|
* MNT_FORCE - Force unmount even if busy. This can cause data loss.
|
|
* MNT_DETACH - Perform a lazy unmount: make the mount point unavailable
|
|
* for new accesses, and actually perform the unmount when the mount
|
|
* point ceases to be busy.
|
|
* MNT_EXPIRE - Mark the mount point as expired. If a mount point is not
|
|
* currently in use, then an initial call to umount2() with this flag
|
|
* fails with the error EAGAIN, but marks the mount point as expired. The
|
|
* mount point remains expired as long as it isn't accessed by any
|
|
* process. A second umount2() call specifying MNT_EXPIRE unmounts an
|
|
* expired mount point. This flag cannot be specified with either
|
|
* MNT_FORCE or MNT_DETACH.
|
|
* UMOUNT_NOFOLLOW (- Don't dereference target if it is a symbolic link.
|
|
* For Linux, this flag allows security problems to be avoided in
|
|
* set-user-ID-root programs that allow unprivileged users to unmount
|
|
* file systems. For NuttX, it is provided only for compatibility
|
|
*
|
|
* Not all options are supported on all file systems.
|
|
*/
|
|
|
|
#define MNT_FORCE (1 << 0)
|
|
#define MNT_DETACH (1 << 1)
|
|
#define MNT_EXPIRE (1 << 2)
|
|
#define UMOUNT_NOFOLLOW (0)
|
|
|
|
/* umount() is equivalent to umount2() with flags = 0 */
|
|
|
|
#define umount(t) umount2(t,0)
|
|
|
|
/****************************************************************************
|
|
* Public Type Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Function Prototypes
|
|
****************************************************************************/
|
|
|
|
#undef EXTERN
|
|
#if defined(__cplusplus)
|
|
#define EXTERN extern "C"
|
|
extern "C"
|
|
{
|
|
#else
|
|
#define EXTERN extern
|
|
#endif
|
|
|
|
int mount(FAR const char *source, FAR const char *target,
|
|
FAR const char *filesystemtype, unsigned long mountflags,
|
|
FAR const void *data);
|
|
int umount2(FAR const char *target, unsigned int flags);
|
|
|
|
#undef EXTERN
|
|
#if defined(__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif /* __INCLUDE_SYS_MOUNT_H */
|