NFS: Use the correct commit info in nfs_join_page_group()

Ensure that nfs_clear_request_commit() updates the correct counters when
it removes them from the commit list.

Fixes: ed5d588fe47f ("NFS: T

NFS: Use the correct commit info in nfs_join_page_group()

Ensure that nfs_clear_request_commit() updates the correct counters when
it removes them from the commit list.

Fixes: ed5d588fe47f ("NFS: Try to join page groups before an O_DIRECT retransmission")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Convert buffered read paths to use netfs when fscache is enabled

Convert the NFS buffered read code paths to corresponding netfs APIs,
but only when fscache is configured and enabled.

The netf

NFS: Convert buffered read paths to use netfs when fscache is enabled

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>

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NFS: Clean up O_DIRECT request allocation

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-

NFS: Clean up O_DIRECT request allocation

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>

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NFS: Convert buffered reads to use folios

Perform a largely mechanical conversion of references to struct page and
page-specific functions to use the folio equivalents.

Note that the fscache functi

NFS: Convert buffered reads to use folios

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>

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NFS: Add a helper to convert a struct nfs_page into an inode

Replace all the open coded calls to page_file_mapping(req->wb_page)->host.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.c

NFS: Add a helper to convert a struct nfs_page into an inode

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>

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NFS: Fix nfs_coalesce_size() to work with folios

Use the helper folio_size() where appropriate.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.

NFS: Fix nfs_coalesce_size() to work with folios

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>

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NFS: Add basic functionality for tracking folios in struct nfs_page

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Improve write error tracing

Don't leak request pointers, but use the "device:inode" labelling that
is used by all the other trace points. Furthermore, replace use of page
indexes with an offset

NFS: Improve write error tracing

Don't leak request pointers, but use the "device:inode" labelling that
is used by all the other trace points. Furthermore, replace use of page
indexes with an offset, again in order to align behaviour with other
NFS trace points.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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pNFS/flexfiles: Fix array overflow when flexfiles mirroring is enabled

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 se

pNFS/flexfiles: Fix array overflow when flexfiles mirroring is enabled

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>

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NFS: Try to join page groups before an O_DIRECT retransmission

If we have to retransmit requests, try to join their page groups
first.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.co

NFS: Try to join page groups before an O_DIRECT retransmission

If we have to retransmit requests, try to join their page groups
first.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Refactor nfs_lock_and_join_requests()

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

NFS: Refactor nfs_lock_and_join_requests()

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>

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NFS: Clean up nfs_lock_and_join_requests()

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.

Sig

NFS: Clean up nfs_lock_and_join_requests()

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>

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NFS: Fix races nfs_page_group_destroy() vs nfs_destroy_unlinked_subrequests()

When a subrequest is being detached from the subgroup, we want to
ensure that it is not holding the group lock, or in th

NFS: Fix races nfs_page_group_destroy() vs nfs_destroy_unlinked_subrequests()

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: 5b2b5187fa85 ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Remove redundant open context from nfs_page

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

NFS: Remove redundant open context from nfs_page

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>

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NFS: Add a helper to return a pointer to the open context of a struct nfs_page

Add a helper for when we remove the explicit pointer to the open
context.

Signed-off-by: Trond Myklebust <trond.mykleb

NFS: Add a helper to return a pointer to the open context of a struct nfs_page

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>

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pNFS: Add tracking to limit the number of pNFS retries

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

pNFS: Add tracking to limit the number of pNFS retries

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>

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NFS: Remove unused argument from nfs_create_request()

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:

NFS: Remove unused argument from nfs_create_request()

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>

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NFS: Clean up list moves of struct nfs_page

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.

Si

NFS: Clean up list moves of struct nfs_page

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>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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NFS: Remove unused parameter gfp_flags from nfs_pageio_init()

Now that the mirror allocation has been moved, the parameter can go.
Also remove the redundant symbol export.

Signed-off-by: Trond Mykl

NFS: Remove unused parameter gfp_flags from nfs_pageio_init()

Now that the mirror allocation has been moved, the parameter can go.
Also remove the redundant symbol export.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

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NFS: Remove unused parameter from nfs_page_group_lock()

nfs_page_group_lock() is now always called with the 'nonblock'
parameter set to 'false'.

Signed-off-by: Trond Myklebust <trond.myklebust@prim

NFS: Remove unused parameter from nfs_page_group_lock()

nfs_page_group_lock() is now always called with the 'nonblock'
parameter set to 'false'.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

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NFS: Remove unuse function nfs_page_group_lock_wait()

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Don't run wake_up_bit() when nobody is waiting...

"perf lock" shows fairly heavy contention for the bit waitqueue locks
when doing an I/O heavy workload.
Use a bit to tell whether or not there

NFS: Don't run wake_up_bit() when nobody is waiting...

"perf lock" shows fairly heavy contention for the bit waitqueue locks
when doing an I/O heavy workload.
Use a bit to tell whether or not there has been contention for a lock
so that we can optimise away the bit waitqueue options in those cases.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Don't run wake_up_bit() when nobody is waiting...

"perf lock" shows fairly heavy contention for the bit waitqueue locks
when doing an I/O heavy workload.
Use a bit to tell whether or not there

NFS: Don't run wake_up_bit() when nobody is waiting...

"perf lock" shows fairly heavy contention for the bit waitqueue locks
when doing an I/O heavy workload.
Use a bit to tell whether or not there has been contention for a lock
so that we can optimise away the bit waitqueue options in those cases.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Ensure we commit after writeback is complete

If the page cache is being flushed, then we want to ensure that we
do start a commit once the pages are done being flushed.
If we just wait until al

NFS: Ensure we commit after writeback is complete

If the page cache is being flushed, then we want to ensure that we
do start a commit once the pages are done being flushed.
If we just wait until all I/O is done to that file, we can end up
livelocking until the balance_dirty_pages() mechanism puts its
foot down and forces I/O to stop.
So instead we do more or less the same thing that O_DIRECT does,
and set up a counter to tell us when the flush is done,

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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