1 #ifndef _PROCFS_CONST_H 2 #define _PROCFS_CONST_H 3 4 /* The minimum number of inodes depends on a number of factors: 5 * - Each statically created inode (e.g., /proc/hz) needs an inode. As of 6 * writing, this requires about a dozen inodes. 7 * - Deleted inodes that are still in use by VFS must be retained. For deleted 8 * directories, all their containing directories up to the root must be 9 * retained as well (to allow the user to "cd .." out). VTreeFS already takes 10 * care of this. In the case of ProcFS, only PID-based directories can be 11 * deleted; no other directories are dynamically created. These directories 12 * currently do not contain subdirectories, either. Hence, for deleted open 13 * inodes, we need to reserve at most NR_VNODES inodes in the worst case. 14 * - In order for getdents to be able to return all PID-based directories, 15 * inodes must not be recycled while generating the list of these PID-based 16 * directories. In the worst case, this means (NR_TASKS + NR_PROCS) extra 17 * inodes. 18 * The sum of these is the bare minimum for correct operation in all possible 19 * circumstances. In practice, not all open files will be deleted files in 20 * ProcFS, and not all process slots will be in use either, so the average use 21 * will be a lot less. However, setting the value too low allows for a 22 * potential denial-of-service attack by a non-root user. 23 * 24 * For the moment, we simply set this value to something reasonable. 25 */ 26 #define NR_INODES ((NR_TASKS + NR_PROCS) * 4) 27 28 /* Various file modes. */ 29 #define REG_ALL_MODE (S_IFREG | 0444) /* world-readable regular */ 30 #define DIR_ALL_MODE (S_IFDIR | 0555) /* world-accessible directory */ 31 #define LNK_ALL_MODE (S_IFLNK | 0777) /* symbolic link */ 32 33 #endif /* _PROCFS_CONST_H */ 34