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>
