Convert the NFS buffered read code paths to corresponding netfs APIs,
but only when fscache is configured and enabled.
The netfs API defines struct netfs_request_ops which must be filled
in by the network filesystem. For NFS, we only need to define 5 of
the functions, the main one being the issue_read() function.
The issue_read() function is called by the netfs layer when a read
cannot be fulfilled locally, and must be sent to the server (either
the cache is not active, or it is active but the data is not available).
Once the read from the server is complete, netfs requires a call to
netfs_subreq_terminated() which conveys either how many bytes were read
successfully, or an error. Note that issue_read() is called with a
structure, netfs_io_subrequest, which defines the IO requested, and
contains a start and a length (both in bytes), and assumes the underlying
netfs will return a either an error on the whole region, or the number
of bytes successfully read.
The NFS IO path is page based and the main APIs are the pgio APIs defined
in pagelist.c. For the pgio APIs, there is no way for the caller to
know how many RPCs will be sent and how the pages will be broken up
into underlying RPCs, each of which will have their own completion and
return code. In contrast, netfs is subrequest based, a single
subrequest may contain multiple pages, and a single subrequest is
initiated with issue_read() and terminated with netfs_subreq_terminated().
Thus, to utilze the netfs APIs, NFS needs some way to accommodate
the netfs API requirement on the single response to the whole
subrequest, while also minimizing disruptive changes to the NFS
pgio layer.
The approach taken with this patch is to allocate a small structure
for each nfs_netfs_issue_read() call, store the final error and number
of bytes successfully transferred in the structure, and update these values
as each RPC completes. The refcount on the structure is used as a marker
for the last RPC completion, is incremented in nfs_netfs_read_initiate(),
and decremented inside nfs_netfs_read_completion(), when a nfs_pgio_header
contains a valid pointer to the data. On the final put (which signals
the final outstanding RPC is complete) in nfs_netfs_read_completion(),
call netfs_subreq_terminated() with either the final error value (if
one or more READs complete with an error) or the number of bytes
successfully transferred (if all RPCs complete successfully). Note
that when all RPCs complete successfully, the number of bytes transferred
is capped to the length of the subrequest. Capping the transferred length
to the subrequest length prevents "Subreq overread" warnings from netfs.
This is due to the "aligned_len" in nfs_pageio_add_page(), and the
corner case where NFS requests a full page at the end of the file,
even when i_size reflects only a partial page (NFS overread).
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-by: Daire Byrne <daire@dneg.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
New Features:
* Convert the read and write paths to use folios
Bugfixes and Cleanups:
* Fix tracepoint state manager flag printing
* Fix disabling swap files
* Fix NFSv4 client identifier sysfs path in the documentation
* Don't clear NFS_CAP_COPY if server returns NFS4ERR_OFFLOAD_DENIED
* Treat GETDEVICEINFO errors as a layout failure
* Replace kmap_atomic() calls with kmap_local_page()
* Constify sunrpc sysfs kobj_type structures
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Merge tag 'nfs-for-6.3-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker:
"New Features:
- Convert the read and write paths to use folios
Bugfixes and Cleanups:
- Fix tracepoint state manager flag printing
- Fix disabling swap files
- Fix NFSv4 client identifier sysfs path in the documentation
- Don't clear NFS_CAP_COPY if server returns NFS4ERR_OFFLOAD_DENIED
- Treat GETDEVICEINFO errors as a layout failure
- Replace kmap_atomic() calls with kmap_local_page()
- Constify sunrpc sysfs kobj_type structures"
* tag 'nfs-for-6.3-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (25 commits)
fs/nfs: Replace kmap_atomic() with kmap_local_page() in dir.c
pNFS/filelayout: treat GETDEVICEINFO errors as layout failure
Documentation: Fix sysfs path for the NFSv4 client identifier
nfs42: do not fail with EIO if ssc returns NFS4ERR_OFFLOAD_DENIED
NFS: fix disabling of swap
SUNRPC: make kobj_type structures constant
nfs4trace: fix state manager flag printing
NFS: Remove unnecessary check in nfs_read_folio()
NFS: Improve tracing of nfs_wb_folio()
NFS: Enable tracing of nfs_invalidate_folio() and nfs_launder_folio()
NFS: fix up nfs_release_folio() to try to release the page
NFS: Clean up O_DIRECT request allocation
NFS: Fix up nfs_vm_page_mkwrite() for folios
NFS: Convert nfs_write_begin/end to use folios
NFS: Remove unused function nfs_wb_page()
NFS: Convert buffered writes to use folios
NFS: Convert the function nfs_wb_page() to use folios
NFS: Convert buffered reads to use folios
NFS: Add a helper nfs_wb_folio()
NFS: Convert the remaining pagelist helper functions to support folios
...
Rather than adjusting the index+offset after the call to
nfs_create_request(), add a function nfs_page_create_from_page() that
takes an offset.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Perform a largely mechanical conversion of references to struct page and
page-specific functions to use the folio equivalents.
Note that the fscache functionality remains untouched. Instead we just
pass in the folio page. This should be OK, as long as we use order 0
folios together with fscache.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Allow creation of subrequests from a request that is carrying a folio.
Add helpers to set up and tear down requests carrying folios.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Replace all the open coded calls to page_file_mapping(req->wb_page)->host.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Use the helper folio_size() where appropriate.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Add support for multi-page folios in the generic NFS i/o engine.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If the same page and data is being used for multiple requests,
then ignore that when the request indicates we're reading from the start
of the page.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The file locking definitions have lived in fs.h since the dawn of time,
but they are only used by a small subset of the source files that
include it.
Move the file locking definitions to a new header file, and add the
appropriate #include directives to the source files that need them. By
doing this we trim down fs.h a bit and limit the amount of rebuilding
that has to be done when we make changes to the file locking APIs.
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Steve French <stfrench@microsoft.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
nfs currently doesn't access i_flctx safely. This requires a
smp_load_acquire, as the pointer is set via cmpxchg (a release
operation).
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Mark async operations such as RENAME, REMOVE, COMMIT MOVEABLE
for the nfsv4.1+ sessions.
Fixes: 85e39feead ("NFSv4.1 identify and mark RPC tasks that can move between transports")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If __nfs_pageio_add_request() fails to add the request, it will return
with either desc->pg_error < 0, or mirror->pg_recoalesce will be set, so
we are guaranteed either to exit the function altogether, or to loop.
However if there is nothing left in mirror->pg_list to coalesce, we must
exit, so make sure that we clear mirror->pg_recoalesce every time we
loop.
Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 70536bf4eb ("NFS: Clean up reset of the mirror accounting variables")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
In a low memory situation, allow the NFS writeback code to fail without
getting stuck in infinite loops in mempool_alloc().
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
In preparation for when we can re-try a task on a different transport,
identify and mark such RPC tasks as moveable. Only 4.1+ operarations can
be re-tried on a different transport.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Now that nfs_pageio_do_add_request() resets the pg_count, we don't need
these other inlined resets.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The value of mirror->pg_bytes_written should only be updated after a
successful attempt to flush out the requests on the list.
Fixes: a7d42ddb30 ("nfs: add mirroring support to pgio layer")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that nfs_pageio_error_cleanup() resets the mirror array contents,
so that the structure reflects the fact that it is now empty.
Also change the test in nfs_pageio_do_add_request() to be more robust by
checking whether or not the list is empty rather than relying on the
value of pg_count.
Fixes: a7d42ddb30 ("nfs: add mirroring support to pgio layer")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the flexfiles mirroring is enabled, then the read code expects to be
able to set pgio->pg_mirror_idx to point to the data server that is
being used for this particular read. However it does not change the
pg_mirror_count because we only need to send a single read.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When we're doing pnfs then the credential being used for the RPC call
is not necessarily the same as the one used in the open context, so
don't use RPC_TASK_CRED_NOREF.
Fixes: 6129650720 ("NFSv4: Avoid referencing the cred unnecessarily during NFSv4 I/O")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Refactor nfs_lock_and_join_requests() in order to separate out the
subrequest merging into its own function nfs_lock_and_join_group()
that can be used by O_DIRECT.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If we have to split the request up into subrequests, we have to submit
the request pointed to by the function call parameter last, in case
there is an error or other issue that causes us to exit before the
last request is submitted. The reason is that the caller is expected
to perform cleanup in those cases.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Clean up nfs_lock_and_join_requests() to simplify the calculation
of the range covered by the page group, taking into account the
presence of mirrors.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We need to trust that desc->pg_mirror_idx is set correctly, whether
or not mirroring is enabled.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If we just set the mirror count to 1 without first clearing out
the mirrors, we can leak queued up requests.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We need to ensure that we create the mirror requests before calling
nfs_pageio_add_request_mirror() on the request we are adding.
Otherwise, we can end up with a use-after-free if the call to
nfs_pageio_add_request_mirror() triggers I/O.
Fixes: c917cfaf9b ("NFS: Fix up NFS I/O subrequest creation")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When a subrequest is being detached from the subgroup, we want to
ensure that it is not holding the group lock, or in the process
of waiting for the group lock.
Fixes: 5b2b5187fa ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the FLUSH_SYNC flag is set, nfs_initiate_pgio() will currently
wait for completion, and then return the status of the I/O operation.
What we actually want to report in nfs_pageio_doio() is whether or
not the RPC call was launched successfully, whereas actual I/O
status is intended handled in the reply callbacks.
Since FLUSH_SYNC is never set by any of the callers anyway, let's
just remove that code altogether.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
In read/write/commit, we should be able to assume that the cred is
pinned by the open context.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Initialise the result count to 0 rather than initialising it to the
argument count. The reason is that we want to ensure we record the
I/O stats correctly in the case where an error is returned (for
instance in the layoutstats).
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the attempt to resend the I/O results in no bytes being read/written,
we must ensure that we report the error.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Fixes: 0a00b77b33 ("nfs: mirroring support for direct io")
Cc: stable@vger.kernel.org # v3.20+
If the attempt to resend the pages fails, we need to ensure that we
clean up those pages that were not transmitted.
Fixes: d600ad1f2b ("NFS41: pop some layoutget errors to application")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.5+
Now that the VM promises never to recurse back into the filesystem
layer on writeback, remove all the GFP_NOFS references etc from
the generic writeback code.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lock context already references and tracks the open context, so
take the opportunity to save some space in struct nfs_page.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Add a helper for when we remove the explicit pointer to the open
context.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When the client is reading or writing using pNFS, and hits an error
on the DS, then it typically sends a LAYOUTERROR and/or LAYOUTRETURN
to the MDS, before redirtying the failed pages, and going for a new
round of reads/writebacks. The problem is that if the server has no
way to fix the DS, then we may need a way to interrupt this loop
after a set number of attempts have been made.
This patch adds an optional module parameter that allows the admin
to specify how many times to retry the read/writeback process before
failing with a fatal error.
The default behaviour is to retry forever.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
All the callers of nfs_create_request() are now creating page group
heads, so we can remove the redundant 'last' page argument.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
We require all NFS I/O subrequests to duplicate the lock context as well
as the open context.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Fix up some compiler warnings about function parameters, etc not being
correctly described or formatted.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Allow the caller to pass error information when cleaning up a failed
I/O request so that we can conditionally take action to cancel the
request altogether if the error turned out to be fatal.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
In several places we're just moving the struct nfs_page from one list to
another by first removing from the existing list, then adding to the new
one.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the I/O completion failed with a fatal error, then we should just
exit nfs_pageio_complete_mirror() rather than try to recoalesce.
Fixes: a7d42ddb30 ("nfs: add mirroring support to pgio layer")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.0+
Whether we need to exit early, or just reprocess the list, we
must not lost track of the request which failed to get recoalesced.
Fixes: 03d5eb65b5 ("NFS: Fix a memory leak in nfs_do_recoalesce")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.0+
