servers/vfs/file.h

   1 #ifndef __VFS_FILE_H__
   2 #define __VFS_FILE_H__
   3
   4 /* This is the filp table.  It is an intermediary between file descriptors and
   5  * inodes.  A slot is free if filp_count == 0.
   6  */
   7
   8 EXTERN struct filp {
   9   mode_t filp_mode;             /* RW bits, telling how file is opened */
  10   int filp_flags;               /* flags from open and fcntl */
  11   int filp_count;               /* how many file descriptors share this slot?*/
  12   struct vnode *filp_vno;       /* vnode belonging to this file */
  13   off_t filp_pos;               /* file position */
  14   mutex_t filp_lock;            /* lock to gain exclusive access */
  15   struct fproc *filp_softlock;  /* if not NULL; this filp didn't lock the
  16                                  * vnode. Another filp already holds a lock
  17                                  * for this thread */
  18   struct fproc *filp_ioctl_fp;  /* if not NULL, this filp is locked by the
  19                                  * process for a currently ongoing IOCTL call
  20                                  */
  21
  22   /* the following fields are for select() and are owned by the generic
  23    * select() code (i.e., fd-type-specific select() code can't touch these).
  24    * These fields may be changed without holding the filp lock.
  25    */
  26   int filp_selectors;           /* select()ing processes blocking on this fd */
  27   int filp_select_ops;          /* interested in these SEL_* operations */
  28   int filp_select_flags;        /* Select flags for the filp */
  29
  30   /* following are for fd-type-specific select() */
  31   int filp_pipe_select_ops;
  32 } filp[NR_FILPS];
  33
  34 #define FILP_CLOSED     0       /* filp_mode: associated device closed/gone */
  35
  36 #define FSF_UPDATE      001     /* The driver should be informed about new
  37                                  * state.
  38                                  */
  39 #define FSF_BUSY        002     /* Select operation sent to driver but no
  40                                  * reply yet.
  41                                  */
  42 #define FSF_RD_BLOCK    010     /* Read request is blocking, the driver should
  43                                  * keep state.
  44                                  */
  45 #define FSF_WR_BLOCK    020     /* Write request is blocking */
  46 #define FSF_ERR_BLOCK   040     /* Exception request is blocking */
  47 #define FSF_BLOCKED     070
  48 #endif