27d0ecdb62
The remapping from /dev/tty to the real controlling terminal in the device code was confusing the select code. The latter is now aware of this case and should handle it properly, at the cost of one extra field in the filp structure. There is a nasty, hopefully sufficiently rare case of /dev/tty being kept open while controlling terminals are changing, that we are still not handling. Doing so would require more than just a few changes, but the code should at least detect and cleanly fail on this case. Test77 now has a basic test set for selecting on /dev/tty. Change-Id: Iaedea449cdb728d0e66a9de8faacdfd9638dfe92
50 lines
1.8 KiB
C
50 lines
1.8 KiB
C
#ifndef __VFS_FILE_H__
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#define __VFS_FILE_H__
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/* This is the filp table. It is an intermediary between file descriptors and
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* inodes. A slot is free if filp_count == 0.
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*/
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EXTERN struct filp {
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mode_t filp_mode; /* RW bits, telling how file is opened */
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int filp_flags; /* flags from open and fcntl */
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int filp_count; /* how many file descriptors share this slot?*/
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struct vnode *filp_vno; /* vnode belonging to this file */
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off_t filp_pos; /* file position */
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mutex_t filp_lock; /* lock to gain exclusive access */
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struct fproc *filp_softlock; /* if not NULL; this filp didn't lock the
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* vnode. Another filp already holds a lock
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* for this thread */
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struct fproc *filp_ioctl_fp; /* if not NULL, this filp is locked by the
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* process for a currently ongoing IOCTL call
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*/
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/* the following fields are for select() and are owned by the generic
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* select() code (i.e., fd-type-specific select() code can't touch these).
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* These fields may be changed without holding the filp lock.
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*/
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int filp_selectors; /* select()ing processes blocking on this fd */
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int filp_select_ops; /* interested in these SEL_* operations */
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int filp_select_flags; /* Select flags for the filp */
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/* following are for fd-type-specific select() */
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int filp_pipe_select_ops;
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dev_t filp_char_select_dev;
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} filp[NR_FILPS];
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#define FILP_CLOSED 0 /* filp_mode: associated device closed/gone */
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#define FSF_UPDATE 001 /* The driver should be informed about new
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* state.
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*/
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#define FSF_BUSY 002 /* Select operation sent to driver but no
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* reply yet.
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*/
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#define FSF_RD_BLOCK 010 /* Read request is blocking, the driver should
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* keep state.
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*/
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#define FSF_WR_BLOCK 020 /* Write request is blocking */
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#define FSF_ERR_BLOCK 040 /* Exception request is blocking */
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#define FSF_BLOCKED 070
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#endif
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