View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000834 | 1003.1(2013)/Issue7+TC1 | Base Definitions and Headers | public | 2014-04-21 20:47 | 2019-06-10 08:54 |
| Reporter | jilles | Assigned To | |||
| Priority | normal | Severity | Objection | Type | Clarification Requested |
| Status | Closed | Resolution | Accepted As Marked | ||
| Name | Jilles Tjoelker | ||||
| Organization | FreeBSD | ||||
| User Reference | |||||
| Section | 3.168 File Mode | ||||
| Page Number | 60 | ||||
| Line Number | 1780-1781 | ||||
| Interp Status | --- | ||||
| Final Accepted Text | 0000834:0002234 | ||||
| Summary | 0000834: definition of file mode is too restrictive | ||||
| Description | Some of the newer file types such as shared memory objects have to be tested using macros like S_TYPEISSHM(buf) which take a pointer to the whole struct stat instead of the st_mode field. This seems intended to allow the newer file types to be distinguished from each other using other fields in struct stat (such as st_rdev, st_ino or implementation-specific fields), and is important because a 16-bit mode_t only has 4 bits to encode the file type. However, the definition of file mode in XBD 3.168 defines a file mode as "An object containing the file mode bits and file type of a file." The definitions of mode_t and st_mode appear sufficiently vague that it is permitted to store parts of the file type elsewhere. | ||||
| Desired Action | Change XBD 3.168 from An object containing the file mode bits and file type of a file. to An object containing the file mode bits and some information about the file type of a file. Some rationale addition may be useful here to state that only the file types for which S_ISxxx macros exist need be detectable using the file mode. | ||||
| Tags | tc2-2008 | ||||
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This is related to Bug #732, if not a duplicate... As POSIX systems require at least 18 bits for st_mode, to handle permissions, flags, and the required device types, those systems that just store device type and permissions in 16 bits are obsolete systems. In byte granularity, a st_mode field is at least 24 bits and more likely 32. |
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During the phone call of 04-24-2014 it was pointed out that one bit per file type was not required, so that only 15 bits was needed for current requirements if file type is an enumeration. So, 16 bits is plausible, but still leaves just one bit for expansion. |
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Change XBD 3.168 from An object containing the file mode bits and file type of a file. to An object containing the file mode bits and some information about the file type of a file. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2014-04-21 20:47 | jilles | New Issue | |
| 2014-04-21 20:47 | jilles | Name | => Jilles Tjoelker |
| 2014-04-21 20:47 | jilles | Organization | => FreeBSD |
| 2014-04-21 20:47 | jilles | Section | => 3.168 File Mode |
| 2014-04-21 20:47 | jilles | Page Number | => 60 |
| 2014-04-21 20:47 | jilles | Line Number | => 1780-1781 |
| 2014-04-24 15:10 | shware_systems | Note Added: 0002231 | |
| 2014-04-24 15:25 | eblake | Relationship added | related to 0000732 |
| 2014-04-24 15:34 | shware_systems | Note Added: 0002233 | |
| 2014-04-24 15:35 | shware_systems | Note Edited: 0002233 | |
| 2014-04-24 15:48 | geoffclare | Interp Status | => --- |
| 2014-04-24 15:48 | geoffclare | Note Added: 0002234 | |
| 2014-04-24 15:48 | geoffclare | Status | New => Resolved |
| 2014-04-24 15:48 | geoffclare | Resolution | Open => Accepted As Marked |
| 2014-04-24 15:48 | Don Cragun | Note Edited: 0002233 | |
| 2014-04-24 15:48 | geoffclare | Final Accepted Text | => 0000834:0002234 |
| 2014-04-24 15:49 | geoffclare | Tag Attached: tc2-2008 | |
| 2019-06-10 08:54 | agadmin | Status | Resolved => Closed |
