Optimise the layout return on close code by ensuring that
1) Add a check for whether we hold a layout before taking any spinlocks
2) Only take the spin lock once
3) Use nfs_state->state to speed up open file checks
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
You cannot call pnfs_put_lseg_async() more than once per lseg, so it
is really an inappropriate way to deal with a refcount issue.
Instead, replace it with a function that decrements the refcount, and
puts the final 'free' operation (which is incompatible with locks) on
the workqueue.
Cc: Weston Andros Adamson <dros@primarydata.com>
Fixes: e6cf82d183: pnfs: add pnfs_put_lseg_async
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If a layout driver keeps per-inode state outside of the layout segments it
needs to be notified of any layout returns or recalls on an inode, and not
just about the freeing of layout segments. Add a method to acomplish this,
which will allow the block layout driver to handle the case of truncated
and re-expanded files properly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Expedite layout recall processing by forcing a layout commit when
we see busy segments. Without it the layout recall might have to wait
until the VM decided to start writeback for the file, which can introduce
long delays.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Currently there is no XDR buffer space allocated for the per-layout driver
layoutcommit payload, which leads to server buffer overflows in the
blocklayout driver even under simple workloads. As we can't do per-layout
sizes for XDR operations we'll have to splice a previously encoded list
of pages into the XDR stream, similar to how we handle ACL buffers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
After we issued a layoutreturn operations the may free the layout stateid
and will thus cause bad stateid error when the client uses it again.
We currently try to avoid this case by chosing the open stateid if not
lsegs are present for this inode. But various places can hold refererence
on lsegs and thus cause the list not to be empty shortly after a layout
return. Add an explicit flag to mark the current layout stateid invalid
and force usage of the openstateid after we did a full file layoutreturn.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
When layoutget returns an entirely new layout stateid it should not
check the generation counter as the new stateid will start with a new
counter entirely unrelated to old one.
The current behavior causes constant layoutget failures against a block
server which allocates a new stateid after an recall that removed all
outstanding layouts.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Ensure the lsegs are initialized early so that we don't pass an unitialized
one back to ->free_lseg during error processing.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Track lwb in nfs_commit_data so that we can use it to setup
layoutcommit in commit_done callback.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Highlights include:
- Stable fix for a bug in nfs3_list_one_acl()
- Speed up NFS path walks by supporting LOOKUP_RCU
- More read/write code cleanups
- pNFS fixes for layout return on close
- Fixes for the RCU handling in the rpcsec_gss code
- More NFS/RDMA fixes
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=KE07
-----END PGP SIGNATURE-----
Merge tag 'nfs-for-3.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
- stable fix for a bug in nfs3_list_one_acl()
- speed up NFS path walks by supporting LOOKUP_RCU
- more read/write code cleanups
- pNFS fixes for layout return on close
- fixes for the RCU handling in the rpcsec_gss code
- more NFS/RDMA fixes"
* tag 'nfs-for-3.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits)
nfs: reject changes to resvport and sharecache during remount
NFS: Avoid infinite loop when RELEASE_LOCKOWNER getting expired error
SUNRPC: remove all refcounting of groupinfo from rpcauth_lookupcred
NFS: fix two problems in lookup_revalidate in RCU-walk
NFS: allow lockless access to access_cache
NFS: teach nfs_lookup_verify_inode to handle LOOKUP_RCU
NFS: teach nfs_neg_need_reval to understand LOOKUP_RCU
NFS: support RCU_WALK in nfs_permission()
sunrpc/auth: allow lockless (rcu) lookup of credential cache.
NFS: prepare for RCU-walk support but pushing tests later in code.
NFS: nfs4_lookup_revalidate: only evaluate parent if it will be used.
NFS: add checks for returned value of try_module_get()
nfs: clear_request_commit while holding i_lock
pnfs: add pnfs_put_lseg_async
pnfs: find swapped pages on pnfs commit lists too
nfs: fix comment and add warn_on for PG_INODE_REF
nfs: check wait_on_bit_lock err in page_group_lock
sunrpc: remove "ec" argument from encrypt_v2 operation
sunrpc: clean up sparse endianness warnings in gss_krb5_wrap.c
sunrpc: clean up sparse endianness warnings in gss_krb5_seal.c
...
This is useful when lsegs need to be released while holding locks.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().
So:
Rename wait_on_bit and wait_on_bit_lock to
wait_on_bit_action and wait_on_bit_lock_action
to make it explicit that they need an action function.
Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
which are *not* given an action function but implicitly use
a standard one.
The decision to error-out if a signal is pending is now made
based on the 'mode' argument rather than being encoded in the action
function.
All instances of the old wait_on_bit and wait_on_bit_lock which
can use the new version have been changed accordingly and their
action functions have been discarded.
wait_on_bit{_lock} does not return any specific error code in the
event of a signal so the caller must check for non-zero and
interpolate their own error code as appropriate.
The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"
The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.
A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack. So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).
Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS. CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Clean up pnfs_read_done_resend_to_mds and pnfs_write_done_resend_to_mds:
- instead of passing all arguments from a nfs_pgio_header, just pass the header
- share the common code
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The refcounting on nfs_pgio_header was related to there being (possibly)
more than one nfs_pgio_data. Now that nfs_pgio_data has been merged into
nfs_pgio_header, there is no reason to do this ref counting. Just call
the completion callback on nfs_pgio_release/nfs_pgio_error.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
struct nfs_pgio_data only exists as a member of nfs_pgio_header, but is
passed around everywhere, because there used to be multiple _data structs
per _header. Many of these functions then use the _data to find a pointer
to the _header. This patch cleans this up by merging the nfs_pgio_data
structure into nfs_pgio_header and passing nfs_pgio_header around instead.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs_rw_header was used to allocate an nfs_pgio_header along with an
nfs_pgio_data, because a _header would need at least one _data.
Now there is only ever one nfs_pgio_data for each nfs_pgio_header -- move
it to nfs_pgio_header and get rid of nfs_rw_header.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Highlights include:
- Massive cleanup of the NFS read/write code by Anna and Dros
- Support multiple NFS read/write requests per page in order to deal with
non-page aligned pNFS striping. Also cleans up the r/wsize < page size
code nicely.
- stable fix for ensuring inode is declared uptodate only after all the
attributes have been checked.
- stable fix for a kernel Oops when remounting
- NFS over RDMA client fixes
- move the pNFS files layout driver into its own subdirectory
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=OyXR
-----END PGP SIGNATURE-----
Merge tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
- massive cleanup of the NFS read/write code by Anna and Dros
- support multiple NFS read/write requests per page in order to deal
with non-page aligned pNFS striping. Also cleans up the r/wsize <
page size code nicely.
- stable fix for ensuring inode is declared uptodate only after all
the attributes have been checked.
- stable fix for a kernel Oops when remounting
- NFS over RDMA client fixes
- move the pNFS files layout driver into its own subdirectory"
* tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits)
NFS: populate ->net in mount data when remounting
pnfs: fix lockup caused by pnfs_generic_pg_test
NFSv4.1: Fix typo in dprintk
NFSv4.1: Comment is now wrong and redundant to code
NFS: Use raw_write_seqcount_begin/end int nfs4_reclaim_open_state
xprtrdma: Disconnect on registration failure
xprtrdma: Remove BUG_ON() call sites
xprtrdma: Avoid deadlock when credit window is reset
SUNRPC: Move congestion window constants to header file
xprtrdma: Reset connection timeout after successful reconnect
xprtrdma: Use macros for reconnection timeout constants
xprtrdma: Allocate missing pagelist
xprtrdma: Remove Tavor MTU setting
xprtrdma: Ensure ia->ri_id->qp is not NULL when reconnecting
xprtrdma: Reduce the number of hardway buffer allocations
xprtrdma: Limit work done by completion handler
xprtrmda: Reduce calls to ib_poll_cq() in completion handlers
xprtrmda: Reduce lock contention in completion handlers
xprtrdma: Split the completion queue
xprtrdma: Make rpcrdma_ep_destroy() return void
...
Remove alignment checks that would revert to MDS and change pg_test
to return the max ammount left in the segment (or other pg_test call)
up to size of passed request, or 0 if no space is left.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Since the ability to split pages into subpage requests has been added,
nfs_pgio_header->rpc_list only ever has one pgio data.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Now that pg_test can change the size of the request (by returning a non-zero
size smaller than the request), pg_test functions that call other
pg_test functions must return the minimum of the result - or 0 if any fail.
Also clean up the logic of some pg_test functions so that all checks are
for contitions where coalescing is not possible.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This is a step toward allowing pg_test to inform the the
coalescing code to reduce the size of requests so they may fit in
whatever scheme the pg_test callback wants to define.
For now, just return the size of the request if there is space, or 0
if there is not. This shouldn't change any behavior as it acts
the same as when the pg_test functions returned bool.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
These functions are almost identical on both the read and write side.
FLUSH_COND_STABLE will never be set for the read path, so leaving it in
the generic code won't hurt anything.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
I create a new struct nfs_rw_ops to decide the differences between reads
and writes. This struct will be set when initializing a new
nfs_pgio_descriptor, and then passed on to the nfs_rw_header when a new
header is allocated.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
These functions are identical for the read and write paths so they can
be combined.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The only difference is the write verifier field, but we can keep that
for a little bit longer.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
At this point, the only difference between nfs_read_data and
nfs_write_data is the write verifier.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The read_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector. The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_read based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The write_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector. The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_write based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the server returns a completely new layout stateid in response to our
LAYOUTGET, then make sure to free any existing layout segments.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Subtraction of signed integers does not have well defined wraparound
semantics in the C99 standard. In order to be wraparound-safe, we
have to use unsigned subtraction, and then cast the result.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs4_write_inode() must not be allowed to exit until the layoutcommit
is done. That means that both NFS_INO_LAYOUTCOMMIT and
NFS_INO_LAYOUTCOMMITTING have to be cleared.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Set up tracepoints to track read, write and commit, as well as
pNFS reads and writes and commits to the data server.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Give them names that are a bit more consistent with the general
pNFS naming scheme.
- lo_seg_contained -> pnfs_lseg_range_contained
- lo_seg_intersecting -> pnfs_lseg_range_intersecting
- cmp_layout -> pnfs_lseg_range_cmp
- is_matching_lseg -> pnfs_lseg_range_match
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We need to use the same credential as was used for the layoutget
and/or layoutcommit operations.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If state recovery fails with an ESTALE or a ENOENT, then we shouldn't
keep retrying. Instead, mark the stateid as being invalid and
fail the I/O with an EIO error.
For other operations such as POSIX and BSD file locking, truncate
etc, fail with an EBADF to indicate that this file descriptor is no
longer valid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In order to be able to safely return the layout in nfs4_proc_setattr,
we need to block new uses of the layout, wait for all outstanding
users of the layout to complete, commit the layout and then return it.
This patch adds a helper in order to do all this safely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Note that clearing NFS_INO_LAYOUTCOMMIT is tricky, since it requires
you to also clear the NFS_LSEG_LAYOUTCOMMIT bits from the layout
segments.
The only two sites that need to do this are the ones that call
pnfs_return_layout() without first doing a layout commit.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
We need to clear the NFS_LSEG_LAYOUTCOMMIT bits atomically with the
NFS_INO_LAYOUTCOMMIT bit, otherwise we may end up with situations
where the two are out of sync.
The first half of the problem is to ensure that pnfs_layoutcommit_inode
clears the NFS_LSEG_LAYOUTCOMMIT bit through pnfs_list_write_lseg.
We still need to keep the reference to those segments until the RPC call
is finished, so in order to make it clear _where_ those references come
from, we add a helper pnfs_list_write_lseg_done() that cleans up after
pnfs_list_write_lseg.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
The client will currently try LAYOUTGETs forever if a server is returning
NFS4ERR_LAYOUTTRYLATER or NFS4ERR_RECALLCONFLICT - even if the client no
longer needs the layout (ie process killed, unmounted).
This patch uses the DS timeout value (module parameter 'dataserver_timeo'
via rpc layer) to set an upper limit of how long the client tries LATOUTGETs
in this situation. Once the timeout is reached, IO is redirected to the MDS.
This also changes how the client checks if a layout is on the clp list
to avoid a double list_add.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The current code in pnfs_destroy_all_layouts() assumes that removing
the layout from the server->layouts list is sufficient to make it
invisible to other processes. This ignores the fact that most
users access the layout through the nfs_inode->layout...
There is further breakage due to lack of reference counting of the
layouts, meaning that the whole thing Oopses at the drop of a hat.
The code in initiate_bulk_draining() is almost correct, and can be
used as a model for pnfs_destroy_all_layouts(), so move that
code to pnfs.c, and refactor the code to allow us to choose between
a single filesystem bulk recall, and a recall of all layouts.
Also note that initiate_bulk_draining() currently calls iput() while
holding locks. Fix that too.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
The layout will be set unusable if LAYOUTGET fails. Is it reasonable to
increase the refcount iff LAYOUTGET fails the first time?
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>= 3.7]
The new layout pointer in pnfs_find_alloc_layout() may be NULL because of
out of memory. we must do some check work, otherwise pnfs_free_layout_hdr()
will go wrong because it can not deal with a NULL pointer.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
For buffer read, use offst-to-isize.
For direct read, use dreq->bytes_left.
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
For buffer write, block layout client scan inode mapping to find
next hole and use offset-to-hole as layoutget length. Object
layout client uses offset-to-isize as layoutget length.
For direct write, both block layout and object layout use dreq->bytes_left.
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Split it into two functions, one which checks if layoutgets are blocked,
and one which checks if the layout stateid has expired.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clamp the layout barrier sequence id to the current sequence id
minus the maximum number of outstanding layoutget requests.
Also ensure that we correctly initialise lo->plh_barrier if there are
no layout segments associated to this layout header.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Failure of the layoutreturn allocation fails is not a good reason to
mark the pnfs_layout_hdr as having failed a layoutget or i/o. Just
exit cleanly.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It serves no purpose that the test for whether or not we have valid
layout segments doesn't already serve.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Once all the affected layout segments have been freed up, clear the
NFS_LAYOUT_BULK_RECALL flag so that we can reuse the pnfs_layout_hdr
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We already have a mechanism for blocking LAYOUTGET by means of the
plh_block_lgets counter. The only "service" that NFS_LAYOUT_DESTROYED
provides at this point is to block layoutget once the layout segment
list is empty, which basically means that you have to wait until
the pnfs_layout_hdr is destroyed before you can do pNFS on that file
again.
This patch enables the reuse of the pnfs_layout_hdr if the layout
segment list is empty.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that the reference count for pnfs_layout_hdr reverts to the
original value after a call to pnfs_layout_remove_lseg().
Note that the caller is expected to hold a reference to the struct
pnfs_layout_hdr.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There is no longer a need to use pnfs_free_lseg_list(). Just call
pnfs_free_lseg() directly.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the code into pnfs_free_layout_hdr(), and add checks to
get_layout_by_fh_locked to ensure that they don't reference a layout
that is being freed.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
None of the existing pNFS layout drivers seem to require the inode
to be locked while they free the layout header.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Each layout segment already holds a reference to the pnfs_layout_hdr,
so there is no need to hold an extra reference that is released once
the last layout segment is freed.
Ensure that pnfs_find_alloc_layout() always returns a reference
to the pnfs_layout_hdr, which will be matched by the final call to
pnfs_put_layout_hdr() in pnfs_update_layout().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The latter name is more descriptive of the actual function.
Also rename pnfs_insert_layout to pnfs_layout_insert_lseg.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead of resetting the inode MDS threshold counters when we mark
the layout for destruction, do it as part of freeing the layout.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we sleep after dropping the inode->i_lock, then we are no longer
atomic with respect to the rpc_wake_up() call in pnfs_layout_remove_lseg().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If pnfs_layout_io_test_failed() authorises a retry of the failed layoutgets,
we should clear the existing layout segments so that we start afresh. Do
this in pnfs_layout_io_set_failed().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We want to cache the pnfs_layout_hdr after a layoutget or i/o
failure so that pnfs_update_layout() can find it and know when
it is time to retry.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we exit after the call to pnfs_find_alloc_layout(), we have to ensure
that we put the struct pnfs_layout_hdr.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we had to fall back to read/write through MDS, then assume that we should
retry pNFS after a suitable timeout period.
The following patch sets a timeout of 2 minutes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Dereferencing nfsi->layout in order to read plh_flags without holding
a spin lock is bug prone. Furthermore, the dprintk() tells you nothing
about whether or not the call succeeded.
Replace it with something that tells you about whether or not a valid
layout segment was returned for the inode in question.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that we do return errors from nfs4_proc_layoutget() and that we
don't mark the layout as having failed if the error was due to a
signal or resource problem on the client side.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
we have encountered a bug whereby reading a lot of files (copying
fedora's /bin) from a pNFS mount and hitting Ctrl+C in the middle caused
a general protection fault in xdr_shrink_bufhead. this function is
called when decoding the response from LAYOUTGET. the decoding is done
by a worker thread, and the caller of LAYOUTGET waits for the worker
thread to complete.
hitting Ctrl+C caused the synchronous wait to end and the next thing the
caller does is to free the pages, so when the worker thread calls
xdr_shrink_bufhead, the pages are gone. therefore, the cleanup of these
pages has been moved to nfs4_layoutget_release.
Signed-off-by: Idan Kedar <idank@tonian.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch exports symbols needed by the v4 module. In addition, I also
switch over to using IS_ENABLED() to check if CONFIG_NFS_V4 or
CONFIG_NFS_V4_MODULE are set.
The module (nfs4.ko) will be created in the same directory as nfs.ko and
will be automatically loaded the first time you try to mount over NFS v4.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
mark_matching_lsegs_invalid() resets the mds_threshold counters and can
dereference the layout hdr on an initial empty plh_segs list. It returns 0 both
in the case of an initial empty list and in a non-emtpy list that was cleared
by calls to mark_lseg_invalid.
Don't send a LAYOUTRETURN if the list was initially empty.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When the file layout driver is fencing a DS, _pnfs_return_layout can be
called mulitple times per inode due to in-flight i/o referencing lsegs on it's
plh_segs list.
Remember that LAYOUTRETURN has been called, and do not call it again.
Allow LAYOUTRETURNs after a subsequent LAYOUTGET.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
pNFS needs to select a write function based on the layout driver
currently in use, so I let each NFS version decide how to best handle
initializing writes.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
pNFS needs to select a read function based on the layout driver
currently in use, so I let each NFS version decide how to best handle
initializing reads.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The call to try_module_get() dereferences ld_type outside the
spin locks, which means that it may be pointing to garbage if
a module unload was in progress.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently there is a 'chicken and egg' issue when the DS is also the mounted
MDS. The nfs_match_client() reference from nfs4_set_ds_client bumps the
cl_count, the nfs_client is not freed at umount, and nfs4_deviceid_purge_client
is not called to dereference the MDS usage of a deviceid which holds a
reference to the DS nfs_client. The result is the umount program returns,
but the nfs_client is not freed, and the cl_session hearbeat continues.
The MDS (and all other nfs mounts) lose their last nfs_client reference in
nfs_free_server when the last nfs_server (fsid) is umounted.
The file layout DS lose their last nfs_client reference in destroy_ds
when the last deviceid referencing the data server is put and destroy_ds is
called. This is triggered by a call to nfs4_deviceid_purge_client which
removes references to a pNFS deviceid used by an MDS mount.
The fix is to track how many pnfs enabled filesystems are mounted from
this server, and then to purge the device id cache once that count reaches
zero.
Reported-by: Jorge Mora <Jorge.Mora@netapp.com>
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Keep track of the number of bytes read or written via buffered, direct, and
mem-mapped i/o for use by mdsthreshold size_io hints.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The "invalid layout" class of errors is handled by destroying the layout and
getting a new layout from the server. Currently, the layout must be
destroyed before a new layout can be obtained.
This means that all references (e.g.lsegs) to the "to be destroyed" layout
header must be dropped before it can be destroyed. This in turn means waiting
for all in flight RPC's using the old layout as well as draining the data
server session slot table wait queue.
Set the NFS_LAYOUT_INVALID flag to redirect I/O to the MDS while waiting for
the old layout to be destroyed.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Let the MDS know that you are redirecting I/O from pNFS to MDS.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This prevents the use of any layout for i/o that references the deviceid.
I/O is redirected through the MDS.
Redirect the unhandled failed I/O to the MDS without marking either the
layout or the deviceid invalid.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the error handling for nfs_generic_pagein() into a single function.
Ditto for nfs_generic_flush().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>
If the allocation of nfs_write_header fails, the list of nfs_pages that
needs to be cleaned up is still on desc->pg_list...
Reported-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Fred Isaman <iisaman@netapp.com>
The coalesce code made assumptions that will no longer be true once
non-page aligned io occurs. This introduces no change in
current behavior, but allows for more general situations to come.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Factors out the code that will need to change when directio
starts using these code paths. This will allow directio to use
the generic pagein and flush routines
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Decouple nfs_pgio_header and nfs_write_data, and have (possibly
multiple) nfs_write_datas each take a refcount on nfs_pgio_header.
For the moment keeps nfs_write_header as a way to preallocate a single
nfs_write_data with the nfs_pgio_header. The code doesn't need this,
and would be prettier without, but given the amount of churn I am
already introducing I didn't want to play with tuning new mempools.
This also fixes bug in pnfs_ld_handle_write_error. In the case of
desc->pg_bsize < PAGE_CACHE_SIZE, the pages list was empty, causing
replay attempt to do nothing.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Decouple nfs_pgio_header and nfs_read_data, and have (possibly
multiple) nfs_read_datas each take a refcount on nfs_pgio_header.
For the moment keeps nfs_read_header as a way to preallocate a single
nfs_read_data with the nfs_pgio_header. The code doesn't need this,
and would be prettier without, but given the amount of churn I am
already introducing I didn't want to play with tuning new mempools.
This also fixes bug in pnfs_ld_handle_read_error. In the case of
desc->pg_bsize < PAGE_CACHE_SIZE, the pages list was empty, causing
replay attempt to do nothing.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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 <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The two functions had diverged quite a bit, with the write function
being a bit more robust than the read.
However, these still break badly in the desc->pg_bsize < PAGE_CACHE_SIZE case,
as then there is nothing hanging on the data->pages list, and the resend
ends up doing nothing. This will be fixed in a patch later in the series.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move more pnfs-isms out of the generic commit code.
Bugfixes:
- filelayout_scan_commit_lists doesn't need to get/put the lseg.
In fact since it is run under the inode->i_lock, the lseg_put()
can deadlock.
- Ensure that we distinguish between what needs to be done for
commit-to-data server and what needs to be done for commit-to-MDS
using the new flag PG_COMMIT_TO_DS. Otherwise we may end up calling
put_lseg() on a bucket for a struct nfs_page that got written
through the MDS.
- Fix a case where we were using list_del() on an nfs_page->wb_list
instead of list_del_init().
- filelayout_initiate_commit needs to call filelayout_commit_release
on error instead of the mds_ops->rpc_release(). Otherwise it won't
clear the commit lock.
Cleanups:
- Let the files layout manage the commit lists for the pNFS case.
Don't expose stuff like pnfs_choose_commit_list, and the fact
that the commit buckets hold references to the layout segment
in common code.
- Cast out the put_lseg() calls for the struct nfs_read/write_data->lseg
into the pNFS layer from whence they came.
- Let the pNFS layer manage the NFS_INO_PNFS_COMMIT bit.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>
Replace the union with the common struct stateid4 as defined in both
RFC3530 and RFC5661. This makes it easier to access the sequence id,
which will again make implementing support for parallel OPEN calls
easier.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The NFS4CLNT_LAYOUTRECALL tests in pnfs_layout_process and
pnfs_update_layout are redundant.
In the case of a bulk layout recall, we're always testing for
the NFS_LAYOUT_BULK_RECALL flay anyway.
In the case of a file or segment recall, the call to
pnfs_set_layout_stateid() updates the layout_header 'barrier'
sequence id, which triggers the test in pnfs_layoutgets_blocked()
and is less race-prone than NFS4CLNT_LAYOUTRECALL anyway.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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 <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We have no business doing any this in the standard write release path.
Get rid of it, and put it in the pNFS layer.
Also, while we're at it, get rid of the completely bogus unlock/relock
semantics that were present in nfs_writeback_release_full(). It is
not only unnecessary, but actually dangerous to release the write lock
just in order to take it again in nfs_page_async_flush(). Better just
to open code the pgio operations in a pnfs helper.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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 <stable@kernel.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: Revert pnfs ugliness from the generic NFS read code path
SUNRPC: destroy freshly allocated transport in case of sockaddr init error
NFS: Fix a regression in the referral code
nfs: move nfs_file_operations declaration to bottom of file.c (try #2)
nfs: when attempting to open a directory, fall back on normal lookup (try #5)
pNFS-specific code belongs in the pnfs layer. It should not be
hijacking generic NFS read or write code paths.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
Some files were using the complete module.h infrastructure without
actually including the header at all. Fix them up in advance so
once the implicit presence is removed, we won't get failures like this:
CC [M] fs/nfsd/nfssvc.o
fs/nfsd/nfssvc.c: In function 'nfsd_create_serv':
fs/nfsd/nfssvc.c:335: error: 'THIS_MODULE' undeclared (first use in this function)
fs/nfsd/nfssvc.c:335: error: (Each undeclared identifier is reported only once
fs/nfsd/nfssvc.c:335: error: for each function it appears in.)
fs/nfsd/nfssvc.c: In function 'nfsd':
fs/nfsd/nfssvc.c:555: error: implicit declaration of function 'module_put_and_exit'
make[3]: *** [fs/nfsd/nfssvc.o] Error 1
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Current pnfs_layoutcommit_inode can not handle parallel layoutcommit.
And as Trond suggested , there is no need for client to optimize for
parallel layoutcommit. So add NFS_INO_LAYOUTCOMMITTING flag to
mark inflight layoutcommit and serialize lalyoutcommit with it.
Also mark_inode_dirty_sync if pnfs_layoutcommit_inode fails to issue
layoutcommit.
Reported-by: Vitaliy Gusev <gusev.vitaliy@nexenta.com>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
For pnfs pagelist read failure, we need to pg_recoalesce and resend IO to
mds.
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Cc: stable@kernel.org [3.0]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
For pnfs pagelist write failure, we need to pg_recoalesce and resend IO to
mds.
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Cc: stable@kernel.org [3.0]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
file layout and block layout both use it to set mark layout io failure
bit. So make it generic.
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Cc: stable@kernel.org [3.0]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This gives layout driver a chance to cleanup structures they put in at
encode_layoutcommit.
Signed-off-by: Andy Adamson <andros@netapp.com>
[fixup layout header pointer for layoutcommit]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
[rm inode and pnfs_layout_hdr args from cleanup_layoutcommit()]
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
To allow layout driver to issue getdevicelist at mount time, and clean up
at umount time.
[fixup non NFS_V4_1 set_pnfs_layoutdriver definition]
[pnfs: pass mntfh down the init_pnfs path]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There can be multiple lseg per file, so layoutcommit should be
able to handle it.
[Needed in v3.0]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
No need to save it for every lseg.
No need to save it at every pnfs_set_layoutcommit.
[Needed in v3.0]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
No need to save it for every lseg.
[Needed in v3.0]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use nfs_pageio_reset_read_mds and nfs_pageio_reset_write_mds instead of
completely reinitialising the struct nfs_pageio_descriptor.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
...and ensure that we recoalese to take into account differences in
differences in block sizes when falling back to write through the MDS.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
...and ensure that we recoalese to take into account differences in
block sizes when falling back to read through the MDS.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Mark all deviceids established under an expired MDS clientid as invalid.
Stop all new i/o through DS and send through the MDS.
Don't use any new LAYOUTGETs that use the invalid deviceid. Purge all layouts
established under the expired MDS clientid.
Remove the MDS clientid deviceid and data servers reference
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since we take a reference to it, we really ought to pass the a pointer to
the layout header in the arguments instead of assuming that
NFS_I(inode)->layout will forever point to the correct object.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ask for whole file layouts. Until support for layout segments is fully
supported in the file layout code, discard non-whole file layouts.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We need to ensure that the layouts are set up before we can decide to
coalesce requests. To do so, we want to further split up the struct
nfs_pageio_descriptor operations into an initialisation callback, a
coalescing test callback, and a 'do i/o' callback.
This patch cleans up the existing callback methods before adding the
'initialisation' callback.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Layouts should be tracked per nfs_server (aka superblock)
instead of per struct nfs_client, which may have multiple FSIDs associated
with it.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
1. If the intention is to coalesce requests 'prev' and 'req' then we
have to ensure at least that we have a layout starting at
req_offset(prev).
2. If we're only requesting a minimal layout of length desc->pg_count,
we need to test the length actually returned by the server before
we allow the coalescing to occur.
3. We need to deal correctly with (pgio->lseg == NULL)
4. Fixup the test guarding the pnfs_update_layout.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
mark_matching_lsegs_invalid could put the last ref to the layout, so
the get_layout_hdr needs to be called first.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We always get a reference on the layout header and we rely on
nfs4_layoutreturn_release to put it. If we hit an allocation error
before starting the rpc proc we bail out early without dereferncing
the layout header properly.
Signed-off-by: Benny Halevy <benny@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The break condition to skip out of the loop got broken when cmp_layout
was change. Essentially, we want to stop looking once we know no layout
on the remainder of the list can match the first byte of the looked-up
range.
Reported-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Benny Halevy <benny@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
_pnfs_return_layout had the following problems:
- it did not call pnfs_free_lseg_list on all paths
- it unintentionally did a forgetful return when there was no outstanding io
- it raced with concurrent LAYOUTGETS
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use common code for pnfs_pageio_init_{read,write} and use
a common generic pg_test function.
Note that this function always assumes the the layout driver's
pg_test method is implemented.
[Fix BUG]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
NFSv4.1 LAYOUTRETURN implementation
Currently, does not support layout-type payload encoding.
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Zhang Jingwang <zhangjingwang@nrchpc.ac.cn>
[call pnfs_return_layout right before pnfs_destroy_layout]
[remove assert_spin_locked from pnfs_clear_lseg_list]
[remove wait parameter from the layoutreturn path.]
[remove return_type field from nfs4_layoutreturn_args]
[remove range from nfs4_layoutreturn_args]
[no need to send layoutcommit from _pnfs_return_layout]
[don't wait on sync layoutreturn]
[fix layout stateid in layoutreturn args]
[fixed NULL deref in _pnfs_return_layout]
[removed recaim member of nfs4_layoutreturn_args]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Non-rpc layout driver such as for objects and blocks
implement their own I/O path and error handling logic.
Therefore bypass NFS-based error handling for these layout drivers.
[fix lseg ref-count bugs, and null de-refs]
[Fall out from: non-rpc layout drivers]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
[get rid of PNFS_USE_RPC_CODE]
[get rid of __nfs4_write_done_cb]
[revert useless change in nfs4_write_done_cb]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Add offset and count parameters to pnfs_update_layout and use them to get
the layout in the pageio path.
Order cache layout segments in the following order:
* offset (ascending)
* length (descending)
* iomode (RW before READ)
Test byte range against the layout segment in use in pnfs_{read,write}_pg_test
so not to coalesce pages not using the same layout segment.
[fix lseg ordering]
[clean up pnfs_find_lseg lseg arg]
[remove unnecessary FIXME]
[fix ordering in pnfs_insert_layout]
[clean up pnfs_insert_layout]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
A client sends offset to MDS as it was seen by DS. As result,
file size after copy is only half of original file size in case
of 2 DS.
Signed-off-by: Vitaliy Gusev <gusev.vitaliy@nexenta.com>
Cc: stable@kernel.org [2.6.39]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, writebacks may end up recursing back into the filesystem due to
GFP_KERNEL direct reclaims in the pnfs subsystem.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Prevents an infinite loop as list was never emptied.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
mark_inode_dirty_sync() grabs the same inode lock!
race conditions between holding the lock in pnfs_set_layoutcommit() and in
mark_inode_dirty_sync() can result in a second call to pnfs_layoutcommit_inode(), but
this will be a noop as NFS_INO_LAYOUTCOMMIT won't be set in the second call
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
changes LAYOUTGET and GETDEVICEINFO XDR parsing to:
- not use vmap, which doesn't work on incoherent archs
- use xdr_stream parsing for all xdr
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Test NFS_INO_LAYOUTCOMMIT before kzalloc
Mark inode dirty to retry LAYOUTCOMMIT on kzalloc failure.
Add comments.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The filelayout driver sends LAYOUTCOMMIT only when COMMIT goes to
the data server (as opposed to the MDS) and the data server WRITE
is not NFS_FILE_SYNC.
Only whole file layout support means that there is only one IOMODE_RW layout
segment.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Zhang Jingwang <zhangjingwang@nrchpc.ac.cn>
Tested-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Implement all the hooks created in the previous patches.
This requires exporting quite a few functions and adding a few
structure fields.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If a data server is unavailable, go through MDS.
Mark the deviceid containing the data server as a negative cache entry.
Do not try to connect to any data server on a deviceid marked as a negative
cache entry. Mark any layout that tries to use the marked deviceid as failed.
Inodes with a layout marked as fails will not use the layout for I/O, and will
not perform any more layoutgets.
Inodes without a layout will still do layoutget, but the layout will get
marked immediately.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
No need for generic cache with only one user.
Keep a simple hash of deviceids in the filelayout driver.
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Separate the rpc run portion of nfs_read_rpcsetup into a new function
nfs_initiate_read that is called for normal NFS I/O.
Add a pNFS read_pagelist function that is called instead of nfs_intitate_read
for pNFS reads.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the pnfs_update_layout call location to nfs_pageio_do_add_request().
Grab the lseg sent in the doio function to nfs_read_rpcsetup and attach
it to each nfs_read_data so it can be sent to the layout driver.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Add a pg_test layout driver hook which is used to avoid coelescing I/O across
layout stripes.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Prepare put_lseg and get_lseg to be called from the pNFS I/O code.
Pull common code from pnfs_lseg_locked to call from pnfs_lseg.
Inline pnfs_lseg_locked into it's only caller.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Prevents an Oops triggered by CB_LAYOUTRECALL and LAYOUTGET race on a
pnfs_layout_hdr first pnfs_layout_segment.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The pnfs code was using throughout the lock order i_lock, cl_lock.
This conflicts with the nfs delegation code. Rework the pnfs code
to avoid taking both locks simultaneously.
Currently the code takes the double lock to add/remove the layout to a
nfs_client list, while atomically checking that the list of lsegs is
empty. To avoid this, we rely on existing serializations. When a
layout is initialized with lseg count equal zero, LAYOUTGET's
openstateid serialization is in effect, making it safe to assume it
stays zero unless we change it. And once a layout's lseg count drops
to zero, it is set as DESTROYED and so will stay at zero.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We do not need to clear the NFS_LAYOUT_BULK_RECALL, as setting it
guarantees that NFS_LAYOUT_DESTROYED will be set once any outstanding
io is finished.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The code could violate the following from RFC5661, section 12.5.3:
"Once a client has no more layouts on a file, the layout stateid is no
longer valid and MUST NOT be used."
This can occur when a layout already has a lseg, starts another
non-everlapping LAYOUTGET, and a CB_LAYOUTRECALL for the existing lseg
is processed before we hit pnfs_layout_process().
Solve by setting, each time the client has no more lsegs for a file, a
flag which blocks further use of the layout and triggers its removal.
This also fixes a second bug which occurs in the same instance as
above. If we actually use pnfs_layout_process, we add the new lseg to
the layout, but the layout has been removed from the nfs_client list
by the intervening CB_LAYOUTRECALL and will not be added back. Thus
the newly acquired lseg will not be properly returned in the event of
a subsequent CB_LAYOUTRECALL.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
What we really want to know is the ref count.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
A layout can request return-on-close. How this interacts with the
forgetful model of never sending LAYOUTRETURNS is a bit ambiguous.
We forget any layouts marked roc, and wait for them to be completely
forgotten before continuing with the close. In addition, to compensate
for races with any inflight LAYOUTGETs, and the fact that we do not get
any layout stateid back from the server, we set the barrier to the worst
case scenario of current_seqid + number of outstanding LAYOUTGETS.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This is the heart of the wave 2 submission. Add the code to trigger
drain and forget of any afected layouts. In addition, we set a
"barrier", below which any LAYOUTGET reply is ignored. This is to
compensate for the fact that we do not wait for outstanding LAYOUTGETs
to complete as per section 12.5.5.2.1 of RFC 5661.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This will be required to allow us to grab reference outside of i_lock.
While we are at it, make put_layout_hdr take the same argument as all the
related functions.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Either a bad server reply, or our ignoring of multiple array segments in
a reply, can cause a reply to not meet our requirements. Ensure
that we ignore such replies.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since this list will be used to search for layouts to recall,
this is necessary to avoid a race where the recall comes in,
sees there is nothing in the client list, and prepares to return
NOMATCHING, while the LAYOUTGET gets processed before the recall
updates the stateid.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We shouldn't send a LAYOUTGET(openstateid) unless all outstanding RPCs
using the previous stateid are completed. This requires choosing the
stateid to encode earlier, so we can abort if one is not available (we
want to use the open stateid, but a LAYOUTGET is already out using
it), and adding a count of the number of outstanding rpc calls using
layout state (which for now consist solely of LAYOUTGETs).
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This is to prepare the way for sensible io draining. Instead of just
removing the lseg from the list, we instead clear the VALID flag
(preventing new io from grabbing references to the lseg) and remove
the reference holding it in the list. Thus the lseg will be removed
once any io in progress completes and any references still held are
dropped.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This prepares for future changes, where the layout state needs
to change atomically with several other variables. In particular,
it will need to know if lo->segs is empty, as we test that instead
of manipulating the NFS_LAYOUT_STATEID_SET bit. Moreover, the
layoutstateid is not really a read-mostly structure, as it is
written almost as often as it is read.
The behavior of pnfs_get_layout_stateid is also slightly changed, so that
it no longer changes the stateid. Its name is changed to +pnfs_choose_layoutget_stateid.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
While we are renaming all the fields, change lo->state to lo->plh_flags.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Comment references get_layout_hdr_locked, which never existed in
submitted code.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The initialize_mountpoint/uninitialise_mountpoint functions are really about
setting or clearing the layout driver to be used on this filesystem. Change
the names to the more descriptive 'set_layoutdriver/clear_layoutdriver'.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Add the ability to actually send LAYOUTGET and GETDEVICEINFO. This also adds
in the machinery to handle layout state and the deviceid cache. Note that
GETDEVICEINFO is not called directly by the generic layer. Instead it
is called by the drivers while parsing the LAYOUTGET opaque data in response
to an unknown device id embedded therein. RFC 5661 only encodes
device ids within the driver-specific opaque data.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Dean Hildebrand <dhildebz@umich.edu>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Ricardo Labiaga <ricardo.labiaga@netapp.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In particular, server reboot will invalidate all layouts.
Note that in order to have an active layout, we must get a successful response
from the server. To avoid adding that machinery, this patch just includes a
stub that fakes up a successful return. Since the layout is never referenced
for io, this is not a problem.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Dean Hildebrand <dhildebz@umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
At the start of the io paths, try to grab the relevant layout
information. This will initiate the inode's layout cache, but
stubs ensure the cache stays empty.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Dean Hildebrand <dhildebz@umich.edu>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Ricardo Labiaga <ricardo.labiaga@netapp.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Allow a module implementing a layout type to register, and
have its mount/umount routines called for filesystems that
the server declares support it.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Bian Naimeng <biannm@cn.fujitsu.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Put in the infrastructure that uses information returned from the
server at mount to select a layout driver module.
In this patch, a stub is used that always returns "no driver found".
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Dean Hildebrand <dhildebz@umich.edu>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
