Re: [patch 01/22] update ctime and mtime for mmaped write
- From: Miklos Szeredi <miklos@xxxxxxxxxx>
- Date: Wed, 28 Feb 2007 18:06:38 +0100
These change still have the undesirable property that although the
modified pages may be flushed to stable storage, the metadata on
the file will not be updated until the application takes positive
action. This is permissible given the current wording in the
specifications, but it would be much more desirable if sync(2),
fsync(P), or the inode being written out due to normal system
activity would also cause the metadata to be updated.
Perhaps the setting of the flag could be checked in some places
like __sync_single_inode() and do_fsync()?
I don't see the point in updating the timestamp from these functions.
The file isn't _modified_ by sync() or fsync(). Just as it's not
modified by stat().
sync() and fsync() do cache->disk, while the file itself stays the
same.
OTOH msync(MS_ASYNC) does memory->file, which is a conceptually file
modifying operation. OK, msync(MS_ASYNC) is actually a no-op on
2.6.18+, but that's purely an implementation detail and no application
should be relying on it.
Before 2.6.18 sync() or fsync() acually didn't flush data written
through a shared mapping to disk, only msync(MS_SYNC), because the
dirty state was only available in the page tables, not in the page or
the inode.
Miklos
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
- Follow-Ups:
- Re: [patch 01/22] update ctime and mtime for mmaped write
- From: Peter Staubach
- Re: [patch 01/22] update ctime and mtime for mmaped write
- References:
- [patch 00/22] misc VFS/VM patches and fuse writable shared mapping support
- From: Miklos Szeredi
- [patch 01/22] update ctime and mtime for mmaped write
- From: Miklos Szeredi
- Re: [patch 01/22] update ctime and mtime for mmaped write
- From: Peter Staubach
- [patch 00/22] misc VFS/VM patches and fuse writable shared mapping support
- Prev by Date: [PATCH] ecryptfs: check xattr operation support fix
- Next by Date: Re: [GIT PATCH] HID and USB HID update for 2.6.21-rc2
- Previous by thread: Re: [patch 01/22] update ctime and mtime for mmaped write
- Next by thread: Re: [patch 01/22] update ctime and mtime for mmaped write
- Index(es):
Relevant Pages
|
|
