Upon receiving a stateid error such as BAD_STATEID, the client
should retry the operation against the MDS before deciding to
do stateid recovery.

Previously, the code would initiate state recovery and it could
lead to a race in a state manager that could chose an incorrect
recovery method which would lead to the EIO failure for the
application.
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Commit fabbbee0 "PNFS fix fallback to MDS if got error on
commit to DS" moved the pnfs_set_lo_fail() to unhandled errors
which was not correct and lead to a kernel oops on umount.

Instead, fix the original EACCESS on commit to DS error by
getting the new layout and re-doing the IO.

Fixes: fabbbee0 ("PNFS fix fallback to MDS if got error on commit to DS")
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Cc: stable@vger.kernel.org # v4.12
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Calling pnfs_put_lset on an IS_ERR pointer results in a NULL pointer
dereference like the one below. At the same time the check of retvalue
of filelayout_check_deviceid() sets lseg to error, but does not free it
before that.

[ 3000.636161] BUG: unable to handle kernel NULL pointer dereference at 000000000000003c
[ 3000.636970] IP: pnfs_put_lseg+0x29/0x100 [nfsv4]
[ 3000.637420] PGD 4f23b067
[ 3000.637421] PUD 4a0f4067
[ 3000.637679] PMD 0
[ 3000.637937]
[ 3000.638287] Oops: 0000 [#1] SMP
[ 3000.638591] Modules linked in: nfs_layout_nfsv41_files nfsv3 nfnetlink_queue nfnetlink_log nfnetlink bluetooth rfkill rpcsec_gss_krb5 nfsv4 nfs fscache binfmt_misc arc4 md4 nls_utf8 cifs ccm dns_resolver rpcrdma ib_isert iscsi_target_mod ib_iser rdma_cm iw_cm libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib ib_ucm ib_uverbs ib_umad ib_cm ib_core nls_koi8_u nls_cp932 ts_kmp nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr virtio_balloon ppdev virtio_rng parport_pc i2c_piix4 parport acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc xfs libcrc32c ata_generic pata_acpi virtio_blk virtio_net cirrus drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops crc32c_intel ata_piix ttm libata drm serio_raw
[ 3000.645245]  i2c_core virtio_pci virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: xt_u32]
[ 3000.646360] CPU: 1 PID: 26402 Comm: date Not tainted 4.11.0-rc7.1.el7.test.x86_64 #1
[ 3000.647092] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 3000.647638] task: ffff8800415ada00 task.stack: ffffc90000ff0000
[ 3000.648207] RIP: 0010:pnfs_put_lseg+0x29/0x100 [nfsv4]
[ 3000.648696] RSP: 0018:ffffc90000ff39b8 EFLAGS: 00010246
[ 3000.649193] RAX: 0000000000000000 RBX: fffffffffffffff4 RCX: 00000000000d43be
[ 3000.649859] RDX: 00000000000d43bd RSI: 0000000000000000 RDI: fffffffffffffff4
[ 3000.650530] RBP: ffffc90000ff39d8 R08: 000000000001e320 R09: ffffffffa05c35ce
[ 3000.651203] R10: ffff88007fd1e320 R11: ffffea0001283d80 R12: 0000000001400040
[ 3000.651875] R13: ffff88004f77d9f0 R14: ffffc90000ff3cd8 R15: ffff8800417ade00
[ 3000.652546] FS:  00007fac4d5cd740(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000
[ 3000.653304] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3000.653849] CR2: 000000000000003c CR3: 000000004f080000 CR4: 00000000000406e0
[ 3000.654527] Call Trace:
[ 3000.654771]  fl_pnfs_update_layout.constprop.20+0x10c/0x150 [nfs_layout_nfsv41_files]
[ 3000.655505]  filelayout_pg_init_write+0x21d/0x270 [nfs_layout_nfsv41_files]
[ 3000.656195]  __nfs_pageio_add_request+0x11c/0x490 [nfs]
[ 3000.656698]  nfs_pageio_add_request+0xac/0x260 [nfs]
[ 3000.657180]  nfs_do_writepage+0x109/0x2e0 [nfs]
[ 3000.657616]  nfs_writepages_callback+0x16/0x30 [nfs]
[ 3000.658096]  write_cache_pages+0x26f/0x510
[ 3000.658495]  ? nfs_do_writepage+0x2e0/0x2e0 [nfs]
[ 3000.658946]  ? _raw_spin_unlock_bh+0x1e/0x20
[ 3000.659357]  ? wb_wakeup_delayed+0x5f/0x70
[ 3000.659748]  ? __mark_inode_dirty+0x2eb/0x360
[ 3000.660170]  nfs_writepages+0x84/0xd0 [nfs]
[ 3000.660575]  ? nfs_updatepage+0x571/0xb70 [nfs]
[ 3000.661012]  do_writepages+0x1e/0x30
[ 3000.661358]  __filemap_fdatawrite_range+0xc6/0x100
[ 3000.661819]  filemap_write_and_wait_range+0x41/0x90
[ 3000.662292]  nfs_file_fsync+0x34/0x1f0 [nfs]
[ 3000.662704]  vfs_fsync_range+0x3d/0xb0
[ 3000.663065]  vfs_fsync+0x1c/0x20
[ 3000.663385]  nfs4_file_flush+0x57/0x80 [nfsv4]
[ 3000.663813]  filp_close+0x2f/0x70
[ 3000.664132]  __close_fd+0x9a/0xc0
[ 3000.664453]  SyS_close+0x23/0x50
[ 3000.664785]  do_syscall_64+0x67/0x180
[ 3000.665162]  entry_SYSCALL64_slow_path+0x25/0x25
[ 3000.665600] RIP: 0033:0x7fac4d0e1e90
[ 3000.665946] RSP: 002b:00007ffd54e90c88 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
[ 3000.666679] RAX: ffffffffffffffda RBX: 00007fac4d3b5400 RCX: 00007fac4d0e1e90
[ 3000.667349] RDX: 0000000000000000 RSI: 00007fac4d5d9000 RDI: 0000000000000001
[ 3000.668031] RBP: 0000000000000000 R08: 00007fac4d3b6a00 R09: 00007fac4d5cd740
[ 3000.668709] R10: 00007ffd54e909e0 R11: 0000000000000246 R12: 0000000000000000
[ 3000.669385] R13: 00007fac4d3b5e80 R14: 0000000000000000 R15: 0000000000000000
[ 3000.670061] Code: 00 00 66 66 66 66 90 55 48 85 ff 48 89 e5 41 56 41 55 41 54 53 48 89 fb 0f 84 97 00 00 00 f6 05 16 8f bc ff 10 0f 85 a6 00 00 00 <4c> 8b 63 48 48 8d 7b 38 49 8b 84 24 90 00 00 00 4c 8d a8 88 00
[ 3000.671831] RIP: pnfs_put_lseg+0x29/0x100 [nfsv4] RSP: ffffc90000ff39b8
[ 3000.672462] CR2: 000000000000003c
Signed-off-by: NArtem Savkov <asavkov@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we have a layout segment cached in pgio->pg_lseg, we should check it
for validity before reusing it in a new RPC request. Otherwise, if we
recoalesce, we can end up looping forever.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Upong receiving some errors (EACCES) on commit to the DS the code
doesn't fallback to MDS and intead retrieds to the same DS again.
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Fix a filelayout GETDEVICEINFO call hang triggered from the LAYOUTGET
pnfs_layout_process where the GETDEVICEINFO call is waiting for a
session slot, and the LAYOUGET call is waiting for pnfs_layout_process
to complete before freeing the slot GETDEVICEINFO is waiting for..

This occurs in testing against the pynfs pNFS server where the
the on-wire reply highest_slotid and slot id are zero, and the
target high slot id is 8 (negotiated in CREATE_SESSION).

The internal fore channel slot table max_slotid, the maximum allowed
table slotid value, has been reduced via nfs41_set_max_slotid_locked
 from 8 to 1.  Thus there is one slot (slotid 0) available for use but
it has not been freed by LAYOUTGET  proir to the GETDEVICEINFO request.

In order to ensure that layoutrecall callbacks are processed in the
correct order, nfs4_proc_layoutget processing needs to be finished
e.g. pnfs_layout_process) before giving up the slot that identifies
the layoutget (see referring_call_exists).

Move the filelayout_check_layout nfs4_find_get_device call outside of
the pnfs_layout_process call tree.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

In preparation for moving the filelayout getdeviceinfo call from
filelayout_alloc_lseg called by pnfs_process_layout
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The flexfiles layout should never mark a device unavailable.

Move nfs4_mark_deviceid_unavailable out of nfs4_pnfs_ds_connect and call
directly from files layout where it's still needed.

The flexfiles driver still handles marked devices in error paths, but will
now print a rate limited warning.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The nfs4_pnfs_ds_connect path can call rpc_create which can fail or it
can wait on another context to reach the same failure.

This checks that the rpc_create succeeded and returns the error to the
caller.

When an error is returned, both the files and flexfiles layouts will return
NULL from _prepare_ds(). The flexfiles layout will also return the layout
with the error NFS4ERR_NXIO.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.

Use BUILD_BUG_ON in a couple ATM drivers.

In case anyone didn't notice lib/vsprintf.o is about half of SLUB which
is in my opinion is quite an achievement.  Hopefully this patch inspires
someone else to trim vsprintf.c more.

Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This does the right thing depending on if we have a session, rather than
needing to handle this manually in multiple places.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Various places assume that if nfs4_fl_prepare_ds() turns a non-NULL 'ds',
then ds->ds_clp will also be non-NULL.

This is not necessasrily true in the case when the process received a fatal signal
while nfs4_pnfs_ds_connect is waiting in nfs4_wait_ds_connect().
In that case ->ds_clp may not be set, and the devid may not recently have been marked
unavailable.

So add a test for ds_clp == NULL and return NULL in that case.

Fixes: c23266d5 ("NFS4.1 Fix data server connection race")
Signed-off-by: NNeilBrown <neilb@suse.com>
Acked-by: NOlga Kornievskaia <aglo@umich.edu>
Acked-by: NAdamson, Andy <William.Adamson@netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This parameter hasn't been used since f8407299 (Linux 3.11-rc2), so
let's remove it from this function and callers.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

All write callbacks are required to call nfs_writeback_update_inode() upon
success to ensure that file size changes are recorded, and the attribute
cache is invalidated.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

So ensure that we mark the layout for commit once the write is done,
and then ensure that the commit to ds is finished before sending
layoutcommit.

Note that by doing this, we're able to optimise away the commit
for the case of servers that don't need layoutcommit in order to
return updated attributes.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

According to the errata
https://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
we should always send layout commit after a commit to DS.

Fixes: bc7d4b8f ("nfs/filelayout: set layoutcommit...")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

As flexfiles has FF_FLAGS_NO_READ_IO, there is a need to generically
support enforcing that a IOMODE_RW segment will not allow READ I/O.
Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Commit ea2cf228 created nfs_commit_info and saved &inode->i_lock inside
this NFS specific structure.  This obscures the usage of i_lock.
Instead, save struct inode * so later it's clear the spinlock taken is
i_lock.

Should be no functional change.
Signed-off-by: NDave Wysochanski <dwysocha@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

I noticed that all the callers of this function pass cinfo->mds->list as
an argument in addition to the cinfo structure itself.  Let's get rid of
the extra argument, since it doesn't seem to be adding anything.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

In pNFS/flexfiles, we want to return the layout without necessarily marking
it as having completely failed. We therefore move the call to
pnfs_layout_io_set_failed() out of pnfs_error_mark_layout_for_return(),
and then ensura that pNFS/files layout calls it separately.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

For ERESTARTSYS/EIO/EROFS/ENOSPC/E2BIG in layoutget, we
should just bail out instead of hiding the error and
retrying inband IO.

Change all the call sites to pop the error all the way up.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If filelayout_decode_layout fail, _filelayout_free_lseg will causes
a double freeing of fh_array.

[ 1179.279800] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 1179.280198] IP: [<ffffffffa027222d>] filelayout_free_fh_array.isra.11+0x1d/0x70 [nfs_layout_nfsv41_files]
[ 1179.281010] PGD 0
[ 1179.281443] Oops: 0000 [#1]
[ 1179.281831] Modules linked in: nfs_layout_nfsv41_files(OE) nfsv4(OE) nfs(OE) fscache(E) xfs libcrc32c coretemp nfsd crct10dif_pclmul ppdev crc32_pclmul crc32c_intel auth_rpcgss ghash_clmulni_intel nfs_acl lockd vmw_balloon grace sunrpc parport_pc vmw_vmci parport shpchp i2c_piix4 vmwgfx drm_kms_helper ttm drm serio_raw mptspi scsi_transport_spi mptscsih e1000 mptbase ata_generic pata_acpi [last unloaded: fscache]
[ 1179.283891] CPU: 0 PID: 13336 Comm: cat Tainted: G           OE   4.3.0-rc1-pnfs+ #244
[ 1179.284323] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014
[ 1179.285206] task: ffff8800501d48c0 ti: ffff88003e3c4000 task.ti: ffff88003e3c4000
[ 1179.285668] RIP: 0010:[<ffffffffa027222d>]  [<ffffffffa027222d>] filelayout_free_fh_array.isra.11+0x1d/0x70 [nfs_layout_nfsv41_files]
[ 1179.286612] RSP: 0018:ffff88003e3c77f8  EFLAGS: 00010202
[ 1179.287092] RAX: 0000000000000000 RBX: ffff88001fe78900 RCX: 0000000000000000
[ 1179.287731] RDX: ffffea0000f40760 RSI: ffff88001fe789c8 RDI: ffff88001fe789c0
[ 1179.288383] RBP: ffff88003e3c7810 R08: ffffea0000f40760 R09: 0000000000000000
[ 1179.289170] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88001fe789c8
[ 1179.289959] R13: ffff88001fe789c0 R14: ffff88004ec05a80 R15: ffff88004f935b88
[ 1179.290791] FS:  00007f4e66bb5700(0000) GS:ffffffff81c29000(0000) knlGS:0000000000000000
[ 1179.291580] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1179.292209] CR2: 0000000000000000 CR3: 00000000203f8000 CR4: 00000000001406f0
[ 1179.292731] Stack:
[ 1179.293195]  ffff88001fe78900 00000000000000d0 ffff88001fe78178 ffff88003e3c7868
[ 1179.293676]  ffffffffa0272737 0000000000000001 0000000000000001 ffff88001fe78800
[ 1179.294151]  00000000614fffce ffffffff81727671 ffff88001fe78100 ffff88001fe78100
[ 1179.294623] Call Trace:
[ 1179.295092]  [<ffffffffa0272737>] filelayout_alloc_lseg+0xa7/0x2d0 [nfs_layout_nfsv41_files]
[ 1179.295625]  [<ffffffff81727671>] ? out_of_line_wait_on_bit+0x81/0xb0
[ 1179.296133]  [<ffffffffa040407e>] pnfs_layout_process+0xae/0x320 [nfsv4]
[ 1179.296632]  [<ffffffffa03e0a01>] nfs4_proc_layoutget+0x2b1/0x360 [nfsv4]
[ 1179.297134]  [<ffffffffa0402983>] pnfs_update_layout+0x853/0xb30 [nfsv4]
[ 1179.297632]  [<ffffffffa039db24>] ? nfs_get_lock_context+0x74/0x170 [nfs]
[ 1179.298158]  [<ffffffffa0271807>] filelayout_pg_init_read+0x37/0x50 [nfs_layout_nfsv41_files]
[ 1179.298834]  [<ffffffffa03a72d9>] __nfs_pageio_add_request+0x119/0x460 [nfs]
[ 1179.299385]  [<ffffffffa03a6bd7>] ? nfs_create_request.part.9+0x37/0x2e0 [nfs]
[ 1179.299872]  [<ffffffffa03a7cc3>] nfs_pageio_add_request+0xa3/0x1b0 [nfs]
[ 1179.300362]  [<ffffffffa03a8635>] readpage_async_filler+0x85/0x260 [nfs]
[ 1179.300907]  [<ffffffff81180cb1>] read_cache_pages+0x91/0xd0
[ 1179.301391]  [<ffffffffa03a85b0>] ? nfs_read_completion+0x220/0x220 [nfs]
[ 1179.301867]  [<ffffffffa03a8dc8>] nfs_readpages+0x128/0x200 [nfs]
[ 1179.302330]  [<ffffffff81180ef3>] __do_page_cache_readahead+0x203/0x280
[ 1179.302784]  [<ffffffff81180dc8>] ? __do_page_cache_readahead+0xd8/0x280
[ 1179.303413]  [<ffffffff81181116>] ondemand_readahead+0x1a6/0x2f0
[ 1179.303855]  [<ffffffff81181371>] page_cache_sync_readahead+0x31/0x50
[ 1179.304286]  [<ffffffff811750a6>] generic_file_read_iter+0x4a6/0x5c0
[ 1179.304711]  [<ffffffffa03a0316>] ? __nfs_revalidate_mapping+0x1f6/0x240 [nfs]
[ 1179.305132]  [<ffffffffa039ccf2>] nfs_file_read+0x52/0xa0 [nfs]
[ 1179.305540]  [<ffffffff811e343c>] __vfs_read+0xcc/0x100
[ 1179.305936]  [<ffffffff811e3d15>] vfs_read+0x85/0x130
[ 1179.306326]  [<ffffffff811e4a98>] SyS_read+0x58/0xd0
[ 1179.306708]  [<ffffffff8172caaf>] entry_SYSCALL_64_fastpath+0x12/0x76
[ 1179.307094] Code: c4 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 8b 07 49 89 f4 85 c0 74 47 48 8b 06 49 89 fd <48> 8b 38 48 85 ff 74 22 31 db eb 0c 48 63 d3 48 8b 3c d0 48 85
[ 1179.308357] RIP  [<ffffffffa027222d>] filelayout_free_fh_array.isra.11+0x1d/0x70 [nfs_layout_nfsv41_files]
[ 1179.309177]  RSP <ffff88003e3c77f8>
[ 1179.309582] CR2: 0000000000000000
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it.  c files
which need access to more backing-dev details now include
backing-dev.h directly.  This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NJens Axboe <axboe@fb.com>

The LAYOUTCOMMIT operation means different things to different layout types.
For blocks and objects, it is both a data and metadata consistency operation.
For files and flexfiles, it is only a metadata consistency operation.

This patch separates out the 2 cases, allowing the files/flexfiles layout
drivers to optimise away the data consistency calls to layoutcommit.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

pnfs_set_layoutcommit() and pnfs_commit_set_layoutcommit() are 100% identical
except for the function arguments. Refactor to eliminate the difference.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Make it easier to grep for these functions by name.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Use of synchronize_rcu() when unmounting and potentially freeing a lot
of deviceids is problematic. There really is no reason why we can't just
use kfree_rcu() here.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The File Layout's filelayout_mark_request_commit() is almost the
Flex File Layout's ff_layout_mark_request_commit(). And that can
be reduced by calling into nfs_request_add_commit_list().
Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Pass ds_commit_idx through the nfs commit path. It's used to select
the commit bucket when using pnfs and is ignored when not using pnfs.
Several functions had to be changed: nfs_retry_commit,
nfs_mark_request_commit, pnfs_mark_request_commit and the pnfs layout
driver .mark_request_commit functions.
Signed-off-by: NTom Haynes <loghyr@primarydata.com>

'ds_commit_idx' is a better name - it is used to select the right
commit bucket for pnfs.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>

This is needed to support mirrored writes - the first write can't just
trash the lseg, we need to keep it around until all mirrors have
written.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>

Instead of calling layoutreturn directly, call pnfs_error_mark_layout_for_return
to mark layouts for return and let generic code return layout when
layout segments are freed.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

Conflicts:
	fs/nfs/filelayout/filelayout.c

so that flexfile layout client can pass in DS credential instead of
using user cred, which will be done in the next patch.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

pnfs flexfile layout client may want to use NFSv3 ops rather
than the default MDS v4 ops.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

Signed-off-by: NTom Haynes <loghyr@primarydata.com>

flexfile layout may need to set such when making DS connections.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

They can be reused by flexfile layout as well.

Also add a code such that if read fails on one DS and
there are other DSes available to use, don't resend
through MDS but through pNFS so that client can read
from other DSes.
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

flexfile layout may use different auth flavor as specified by MDS.
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>