lkml.org 
[lkml]   [2007]   [Feb]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [patch 01/22] update ctime and mtime for mmaped write
    From
    Date
    > 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@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-02-28 18:09    [W:0.025 / U:30.264 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site