> For the complete documentation index, see [llms.txt](https://oscourse-tsinghua.gitbook.io/ucore-analysis/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://oscourse-tsinghua.gitbook.io/ucore-analysis/ucore/kern/fs/sfs/sfs_lock_c.md).

# sfs\_lock.c

```c
#include <defs.h>
#include <sem.h>
#include <sfs.h>


/*
 * lock_sfs_fs - lock the process of  SFS Filesystem Rd/Wr Disk Block
 *
 * called by: sfs_load_inode, sfs_sync, sfs_reclaim
 */
void
lock_sfs_fs(struct sfs_fs *sfs) {
    down(&(sfs->fs_sem));
}

/*
 * lock_sfs_io - lock the process of SFS File Rd/Wr Disk Block
 *
 * called by: sfs_rwblock, sfs_clear_block, sfs_sync_super
 */
void
lock_sfs_io(struct sfs_fs *sfs) {
    down(&(sfs->io_sem));
}

/*
 * unlock_sfs_fs - unlock the process of  SFS Filesystem Rd/Wr Disk Block
 *
 * called by: sfs_load_inode, sfs_sync, sfs_reclaim
 */
void
unlock_sfs_fs(struct sfs_fs *sfs) {
    up(&(sfs->fs_sem));
}

/*
 * unlock_sfs_io - unlock the process of sfs Rd/Wr Disk Block
 *
 * called by: sfs_rwblock sfs_clear_block sfs_sync_super
 */
void
unlock_sfs_io(struct sfs_fs *sfs) {
    up(&(sfs->io_sem));
}
```