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#ifndef _PROCFS_CONST_H
#define _PROCFS_CONST_H
/*
* The minimum number of inodes depends on a number of factors:
* - Each statically created inode (e.g., /proc/hz) needs an inode. As of
* writing, this requires about a dozen inodes.
* - Deleted inodes that are still in use by VFS must be retained. For deleted
* directories, all their containing directories up to the root must be
* retained as well (to allow the user to "cd .." out). VTreeFS already
* takes care of this. In the case of ProcFS, only PID-based directories can
* be deleted; no other directories are dynamically created. These
* directories currently do not contain subdirectories, either. Hence, for
* deleted open inodes, we need to reserve at most NR_VNODES inodes in the
* worst case.
* - In order for getdents to be able to return all PID-based directories,
* inodes must not be recycled while generating the list of these PID-based
* directories. In the worst case, this means (NR_TASKS + NR_PROCS) extra
* inodes.
* The sum of these is the bare minimum for correct operation in all possible
* circumstances. In practice, not all open files will be deleted files in
* ProcFS, and not all process slots will be in use either, so the average use
* will be a lot less. However, setting the value too low allows for a
* potential denial-of-service attack by a non-root user.
*
* For the moment, we simply set this value to something reasonable.
*/
#define NR_INODES ((NR_TASKS + NR_PROCS) * 4)
/* Various file modes. */
#define REG_ALL_MODE (S_IFREG | 0444) /* world-readable regular */
#define DIR_ALL_MODE (S_IFDIR | 0555) /* world-accessible directory */
#define LNK_ALL_MODE (S_IFLNK | 0777) /* symbolic link */
/* Size of the I/O buffer. */
#define BUF_SIZE 4097 /* 4KB+1 (see buf.c) */
#endif /* _PROCFS_CONST_H */
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