View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000687 | 1003.1(2013)/Issue7+TC1 | System Interfaces | public | 2013-05-02 17:10 | 2024-06-11 09:02 |
| Reporter | nick | Assigned To | |||
| Priority | normal | Severity | Comment | Type | Enhancement Request |
| Status | Closed | Resolution | Accepted As Marked | ||
| Name | Nick Stoughton | ||||
| Organization | USENIX | ||||
| User Reference | nms-fallocate-1 | ||||
| Section | posix_fallocate | ||||
| Page Number | 893 | ||||
| Line Number | 29910-29931 | ||||
| Interp Status | --- | ||||
| Final Accepted Text | 0000687:0001599 | ||||
| Summary | 0000687: Not all filesystems support posix_fallocate | ||||
| Description | As described in 0000684, not every filesystem can (or can easily) support posix_fallocate(). Applications need to know whether a filesystem supports posix_fallocate(). In addition to an error return from posix_fallocate() itself, it would be useful if an application could determine in advance whether or not a filesystem will support a call to posix_fallocate(). | ||||
| Desired Action | Add the following entry to the table in lines 29910-29931: _POSIX_ADVISORY_INFO _PC_ADVISORY_INFO 3,4 Add to RATIONALE, page 896, after line 30037: The value returned for the variable _POSIX_ADVISORY_INFO indicates whether or not the filesystem supports all of the functionality required by the Advisory Information option. In particular, some systems may not support posix_fallocate() on all filesystems. A return value greater than zero indicates that the filesystem support all the functionality required. See <XREF to XBD 2.1.6 on page 26>. In XBD, unistd.h, page 443, after line 14982, add _PC_ADVISORY_INFO | ||||
| Tags | issue8 | ||||
| related to | 0000684 | Closed | posix_fallocate() should be allowed to return ENOTSUP |
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There's a typo in the link and link text to the report about posix_fallocate(). It's 0000684, not 0000654. -------------------------------- The link has been fixed. |
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Hmm, these pathconf() names seem too generic. Can we have "FALLOC" in them? |
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The _POSIX_ADVISORY_INFO option includes posix_madvise() and posix_memalign() which are not file system related, so _PC_ADVISORY_INFO is definitely not the right way to go. I agree with 0000687:0001565 that the new constant name(s) should be specific to posix_fallocate(). The other alternative would be to have it apply to posix_fadvise() as well, but I don't see any need for that since posix_fadvise() doesn't have to do anything with the information the application gives it. I think that as well as adding the _PC_FALLOC constant, there should be a new _POSIX_FALLOC constant added after _POSIX_ASYNC_IO at page 440 line 14855 (and this should be the name used in the Variable column of the pathconf table). |
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This issue must be resolved together with #684 (where I asked for a pathconf() too). In fact, it strikes me as a dup of #684. If concurrent resolution cannot be achieved then this should be closed as a dup of #684. |
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The intent of splitting this into two reports is that for TC2, we should document current behavior but not impose new requirements (bug:684), but for Issue 8, we should add a pathconf() and possibly impose other new requirements (bug:687). Yes, it's annoying that we can't add a pathconf in TC2, but at the same time, we felt it is an important enough issue that something has to be done at TC2 (even if it is only documenting the problem and that a FUTURE DIRECTIONS will probably make it easier to deal with the problem). |
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At page 1426 line 47096, after this text added by 0000684: Not all file systems are capable of supporting posix_fallocate(), in which case the function will return ENOTSUP. However, if a system supports the option, there must be at least one file system that is capable of supporting this function. add: The pathconf() and fpathconf() functions can be used to determine whether a file in a particular file system supports posix_fallocate(). After page 893 line 29928 section fpathconf add:
_POSIX_FALLOC _PC_FALLOC 8
Cross-volume changes to XBD... After page 440 line 14855 section unistd.h, add:
_POSIX_FALLOC
The posix_fallocate() function is supported by the associated file.
After page 443 line 14985 section unistd.h, add: _PC_FALLOC |
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"However, if a system supports the option, there must be at least one file system that is capable of supporting this function." What exactly does this mean? One mounted filesystem? Or one filesystem type? If the latter, must it be included in the OS, or can it be a third-party filesystem? I think it'd be better to exclude this requirement. There's no way to test it in, say, autoconf tests. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2013-05-02 17:10 | nick | New Issue | |
| 2013-05-02 17:10 | nick | Name | => Nick Stoughton |
| 2013-05-02 17:10 | nick | Organization | => USENIX |
| 2013-05-02 17:10 | nick | User Reference | => nms-fallocate-1 |
| 2013-05-02 17:10 | nick | Section | => posix_fallocate |
| 2013-05-02 17:10 | nick | Page Number | => 893 |
| 2013-05-02 17:10 | nick | Line Number | => 29910-29931 |
| 2013-05-02 17:10 | nick | Interp Status | => --- |
| 2013-05-02 17:10 | nick | Issue generated from: 0000684 | |
| 2013-05-02 17:10 | nick | Relationship added | related to 0000684 |
| 2013-05-02 17:21 | nico | Note Added: 0001563 | |
| 2013-05-02 18:11 | nico | Note Added: 0001565 | |
| 2013-05-02 21:07 | Don Cragun | Description Updated | |
| 2013-05-02 21:07 | Don Cragun | Note Edited: 0001563 | |
| 2013-05-03 09:08 | geoffclare | Note Added: 0001566 | |
| 2013-05-03 21:51 | nico | Note Added: 0001586 | |
| 2013-05-03 23:08 | eblake | Note Added: 0001587 | |
| 2013-05-10 09:44 | geoffclare | Note Added: 0001599 | |
| 2013-05-10 09:45 | geoffclare | Tag Attached: issue8 | |
| 2013-05-16 15:09 | geoffclare | Final Accepted Text | => 0000687:0001599 |
| 2013-05-16 15:09 | geoffclare | Status | New => Resolved |
| 2013-05-16 15:09 | geoffclare | Resolution | Open => Accepted As Marked |
| 2013-05-21 19:00 | nico | Note Added: 0001619 | |
| 2020-03-24 15:51 | geoffclare | Status | Resolved => Applied |
| 2024-06-11 09:02 | agadmin | Status | Applied => Closed |
