truncate down followed by delayed allocation (buffered writes) - worst
case scenario for the notorious NULL files problem.  This reduces the
window where we are exposed to that problem significantly.

SGI-PV: 917976
SGI-Modid: xfs-linux-melb:xfs-kern:26100a
Signed-off-by: NNathan Scott <nathans@sgi.com>

mmap only.

SGI-PV: 952736
SGI-Modid: xfs-linux-melb:xfs-kern:25922a
Signed-off-by: NNathan Scott <nathans@sgi.com>

We need not use ->f_pos as the offset for the file input/output. If the
user passed an offset pointer in through sys_splice(), just use that and
leave ->f_pos alone.
Signed-off-by: NJens Axboe <axboe@suse.de>

separate out the 'internal pipe object' abstraction, and make it
usable to splice. This cleans up and fixes several aspects of the
internal splice APIs and the pipe code:

 - pipes: the allocation and freeing of pipe_inode_info is now more symmetric
   and more streamlined with existing kernel practices.

 - splice: small micro-optimization: less pointer dereferencing in splice
   methods
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Update XFS for the ->splice_read/->splice_write changes.
Signed-off-by: NJens Axboe <axboe@suse.de>

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

This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

SGI-PV: 947038
SGI-Modid: xfs-linux-melb:xfs-kern:25474a
Signed-off-by: NNathan Scott <nathans@sgi.com>

help here and vattr may be small enough.

SGI-PV: 947312
SGI-Modid: xfs-linux-melb:xfs-kern:25423a
Signed-off-by: NNathan Scott <nathans@sgi.com>

naming.

SGI-PV: 950556
SGI-Modid: xfs-linux-melb:xfs-kern:25379a
Signed-off-by: NNathan Scott <nathans@sgi.com>

reduce stack use.  Also re-use vattr in some places so that multiple
copies are not held on-stack.

SGI-PV: 947312
SGI-Modid: xfs-linux-melb:xfs-kern:25369a
Signed-off-by: NNathan Scott <nathans@sgi.com>

to reduce stack footprint.

SGI-PV: 947312
SGI-Modid: xfs-linux-melb:xfs-kern:25358a
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 947206
SGI-Modid: xfs-linux-melb:xfs-kern:203960a
Signed-off-by: NChristoph Hellwig <hch@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

boilerplate.

SGI-PV: 913862
SGI-Modid: xfs-linux:xfs-kern:23903a
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 943122
SGI-Modid: xfs-linux:xfs-kern:23901a
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 935317
SGI-Modid: xfs-linux:xfs-kern:192007a
Signed-off-by: NDean Roehrich <roehrich@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 933551
SGI-Modid: xfs-linux:xfs-kern:190622a
Signed-off-by: NDean Roehrich <roehrich@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI Modid: xfs-linux:xfs-kern:21810a
Signed-off-by: NNathan Scott <nathans@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@sgi.com>

handling for unwritten extents can be moved out of interrupt context.

SGI Modid: xfs-linux:xfs-kern:22343a
Signed-off-by: NNathan Scott <nathans@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@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!