On Fri, Sep 17, 2010 at 1:51 AM, JD <jd1...@gmail.com> wrote: > > > On 09/16/2010 09:42 AM, Sameer Naik wrote: >> >> Thanks i will try it out. >> >> On Thu, Sep 16, 2010 at 9:59 PM, JD<jd1...@gmail.com> wrote: >>> >>> On 09/16/2010 03:00 AM, Sameer Naik wrote: >>>> >>>> Please find attached. >>>> P.S. I have added the fflush () call before the fsync () call. >>>> >>>> Regards >>>> ~Sameer >>> >>> Well, as I already communicated with Pierre, the man page for fsync says: >>> >>> Calling fsync() does not necessarily ensure that the entry in the >>> directory containing the file has also reached disk. For that, an >>> explicit fsync() on a file descriptor for the directory is also >>> needed. >>> >>> So, when creating a new file, it is not sufficient to flush and fsync the >>> file descriptor. >>> You also need to have opened the containing directory and fsync'ed the >>> directory >>> file descriptor immediately after creating the file. flushing and >>> sync'ing >>> the file >>> comes later when you are done with writing to it. >>> >>> Cheers, >>> >>> JD >>> > > Remember that a directory can only be opened by > DIR *opendir(const char *name); > DIR *fdopendir(int fd); > > Problem is, how can you fsync a dir if you cannot open it > with the open(2) system call? > fsync(2) needs a file descriptor. > DIR * is not a file descriptor. >
dirfd () call gets the fd associated with an open directory. I have noticed that after a new directory is created, it news to be fsync'd to make sure that it is written out to the disk. Given this, if a new directory is created in a mounted partition and the disk is disconnected without doing an unmount (or sync), the created directory will not show up when it is remounted or from my experience it is sometimes present but cannot be written into, resulting in an IO error when trying to write into the directory. Regards ~Sameer > And yet, the man page for fsync says: > > Calling fsync() does not necessarily ensure that the entry in > the > directory containing the file has also reached disk. For that an > explicit fsync() on a file descriptor for the directory is also > needed. > > Maybe someone can clear this up a bit? > > > ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ ntfs-3g-devel mailing list ntfs-3g-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ntfs-3g-devel
