Now that we have reliably tracking of deleted extents in a
transaction we can easily implement "online" discard support
which calls blkdev_issue_discard once a transaction commits.

The actual discard is a two stage operation as we first have
to mark the busy extent as not available for reuse before we
can start the actual discard.  Note that we don't bother
supporting discard for the non-delaylog mode.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Since Linux 2.6.33 the kernel has support for real O_SYNC, which made
the osyncisosync option a no-op.  Warn the users about this and remove
the mount flag for it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

On Linux all filesystems are supposed to be operating under Posix'
restricted chown. Restricted chown means it restricts chown to the owner
unless you have CAP_FOWNER.

NOTE: that 2 files outside of fs/xfs have been modified too for this
change.
Reviewed-by: NDave Chinner <david@fromorbit.com>

SGI-PV: 988919

SGI-Modid: 2.6.x-xfs-melb:linux:32413b
Signed-off-by: NTim Shimmin <tes@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Mention how DMAPI affects default for noikeep.
Slightly modified since Josef's patch was based on
an old xfs.txt prior to Dave's (dgc) checkin which
missed going to oss.
Signed-off-by: NJosef Sipek <jeffpc@josefsipek.net>
Signed-off-by: NTim Shimmin <tes@sgi.com>

Update xfs docs for:
* In memory inode hashes has been removed.
* noikeep is now the default.

SGI-PV: 969561
SGI-Modid: 2.6.x-xfs-melb:linux:29481b
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTim Shimmin <tes@sgi.com>

Signed-off-by: NNathan Scott <nathans@sgi.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!