linux-toradex.git/fs/nfs/objlayout/objio_osd.c, branch v3.5.3

pnfs-obj: Fix __r4w_get_page when offset is beyond i_size

2012-07-20T08:50:31+00:00

It is very common for the end of the file to be unaligned on
stripe size. But since we know it's beyond file's end then
the XOR should be preformed with all zeros.

Old code used to just read zeros out of the OSD devices, which is a great
waist. But what scares me more about this situation is that, we now have
pages attached to the file's mapping that are beyond i_size. I don't
like the kind of bugs this calls for.

Fix both birds, by returning a global zero_page, if offset is beyond
i_size.

TODO:
	Change the API to ->__r4w_get_page() so a NULL can be
	returned without being considered as error, since XOR API
	treats NULL entries as zero_pages.

[Bug since 3.2. Should apply the same way to all Kernels since]
CC: Stable Tree 
Signed-off-by: Boaz Harrosh

pnfs-obj: don't leak objio_state if ore_write/read fails

2012-07-20T08:50:30+00:00

[Bug since 3.2 Kernel]
CC: Stable Tree 
Signed-off-by: Boaz Harrosh

NFS: Fix sparse warnings

2012-05-04T18:59:51+00:00

Fix the following sparse warnings:

fs/nfs/direct.c:221:6: warning: symbol 'nfs_direct_readpage_release' was
not declared. Should it be static?
fs/nfs/read.c:38:43: warning: non-ANSI function declaration of function
'nfs_readhdr_alloc'
fs/nfs/objlayout/objio_osd.c:214:5: warning: symbol '__alloc_objio_seg'
was not declared. Should it be static?

Reported-by: Dan Carpenter 
Signed-off-by: Trond Myklebust 
Cc: Fred Isaman 
Cc: Boaz Harrosh

NFS: create common nfs_pgio_header for both read and write

2012-04-27T18:10:37+00:00

In order to avoid duplicating all the data in nfs_read_data whenever we
split it up into multiple RPC calls (either due to a short read result
or due to rsize < PAGE_SIZE), we split out the bits that are the same
per RPC call into a separate "header" structure.

The goal this patch moves towards is to have a single header
refcounted by several rpc_data structures.  Thus, want to always refer
from rpc_data to the header, and not the other way.  This patch comes
close to that ideal, but the directio code currently needs some
special casing, isolated in the nfs_direct_[read_write]hdr_release()
functions.  This will be dealt with in a future patch.

Signed-off-by: Fred Isaman 
Signed-off-by: Trond Myklebust

pnfs-obj: autologin: Add support for protocol autologin

2012-03-21T13:31:47+00:00

The pnfs-objects protocol mandates that we autologin into devices not
present in the system, according to information specified in the
get_device_info returned from the server.

The Protocol specifies two login hints.
1. An IP address:port combination
2. A string URI which is constructed as a URL with a protocol prefix
   followed by :// and a string as address. For each  protocol prefix
   the string-address format might be different.

We only support the second option. The first option is just redundant
to the second one.
NOTE: The Kernel part of autologin does not parse the URI string. It
just channels it to a user-mode script. So any new login protocols should
only update the user-mode script which is a part of the nfs-utils package,
but the Kernel need not change.

We implement the autologin by using the call_usermodehelper() API.
(Thanks to Steve Dickson  for pointing it out)
So there is no running daemon needed, and/or special setup.

We Add the osd_login_prog Kernel module parameters which defaults to:
	/sbin/osd_login

Kernel try's to upcall the program specified in osd_login_prog. If the file is
not found or the execution fails Kernel will disable any farther upcalls, by
zeroing out  osd_login_prog, Until Admin re-enables it by setting the
osd_login_prog parameter to a proper program.

Also add text about the osd_login program command line API to:
	Documentation/filesystems/nfs/pnfs.txt
and documentation of the new  osd_login_prog  module parameter to:
	Documentation/kernel-parameters.txt

TODO: Add timeout option in the case osd_login program gets
              stuck

Signed-off-by: Sachin Bhamare 
Signed-off-by: Boaz Harrosh 
Signed-off-by: Trond Myklebust

pnfs-obj: Uglify objio_segment allocation for the sake of the principle :-(

2012-03-14T03:47:59+00:00

At some past instance Linus Trovalds wrote:
> From: Linus Torvalds 
> commit a84a79e4d369a73c0130b5858199e949432da4c6 upstream.
>
> The size is always valid, but variable-length arrays generate worse code
> for no good reason (unless the function happens to be inlined and the
> compiler sees the length for the simple constant it is).
>
> Also, there seems to be some code generation problem on POWER, where
> Henrik Bakken reports that register r28 can get corrupted under some
> subtle circumstances (interrupt happening at the wrong time?).  That all
> indicates some seriously broken compiler issues, but since variable
> length arrays are bad regardless, there's little point in trying to
> chase it down.
>
> "Just don't do that, then".

Since then any use of "variable length arrays" has become blasphemous.
Even in perfectly good, beautiful, perfectly safe code like the one
below where the variable length arrays are only used as a sizeof()
parameter, for type-safe dynamic structure allocations. GCC is not
executing any stack allocation code.

I have produced a small file which defines two functions main1(unsigned numdevs)
and main2(unsigned numdevs). main1 uses code as before with call to malloc
and main2 uses code as of after this patch. I compiled it as:
	gcc -O2 -S see_asm.c
and here is what I get:


main1:
.LFB7:
	.cfi_startproc
	mov	%edi, %edi
	leaq	4(%rdi,%rdi), %rdi
	salq	$3, %rdi
	jmp	malloc
	.cfi_endproc
.LFE7:
	.size	main1, .-main1
	.p2align 4,,15
	.globl	main2
	.type	main2, @function
main2:
.LFB8:
	.cfi_startproc
	mov	%edi, %edi
	addq	$2, %rdi
	salq	$4, %rdi
	jmp	malloc
	.cfi_endproc
.LFE8:
	.size	main2, .-main2
	.section	.text.startup,"ax",@progbits
	.p2align 4,,15


*Exact* same code !!!

So please seriously consider not accepting this patch and leave the
perfectly good code intact.

CC: Linus Torvalds 
Signed-off-by: Boaz Harrosh 
Signed-off-by: Trond Myklebust

NFS: start printks w/ NFS: even if func shown

2012-02-06T23:48:00+00:00

This patch addresses printks that have some context to show that they are
from fs/nfs/, but for the sake of consistency now start with NFS:

Signed-off-by: Weston Andros Adamson 
Signed-off-by: Trond Myklebust

pnfs-obj: Must return layout on IO error

2012-01-06T13:55:33+00:00

As mandated by the standard. In case of an IO error, a pNFS
objects layout driver must return it's layout. This is because
all device errors are reported to the server as part of the
layout return buffer.

This is implemented the same way PNFS_LAYOUTRET_ON_SETATTR
is done, through a bit flag on the pnfs_layoutdriver_type->flags
member. The flag is set by the layout driver that wants a
layout_return preformed at pnfs_ld_{write,read}_done in case
of an error.
(Though I have not defined a wrapper like pnfs_ld_layoutret_on_setattr
 because this code is never called outside of pnfs.c and pnfs IO
 paths)

Without this patch 3.[0-2] Kernels leak memory and have an annoying
WARN_ON after every IO error utilizing the pnfs-obj driver.

[This patch is for 3.2 Kernel. 3.1/0 Kernels need a different patch]
CC: Stable Tree 
Signed-off-by: Boaz Harrosh 
Signed-off-by: Trond Myklebust

pnfs-obj: Support for RAID5 read-4-write interface.

2011-11-03T03:56:09+00:00

The ore need suplied a r4w_get_page/r4w_put_page API
from Filesystem so it can get cache pages to read-into when
writing parial stripes.

Signed-off-by: Boaz Harrosh 
Signed-off-by: Trond Myklebust

pnfs-obj: move to ore 03: Remove old raid engine

2011-11-03T03:56:08+00:00

Finally remove all the old raid engine, which is by now
dead code.

Signed-off-by: Boaz Harrosh 
Signed-off-by: Trond Myklebust