Commit Graph

87 Commits

Author SHA1 Message Date
Chuck Lever
a28faaddb2 Documentation: Add an explanation of NFSv4 client identifiers
To enable NFSv4 to work correctly, NFSv4 client identifiers have
to be globally unique and persistent over client reboots. We
believe that in many cases, a good default identifier can be
chosen and set when a client system is imaged.

Because there are many different ways a system can be imaged,
provide an explanation of how NFSv4 client identifiers and
principals can be set by install scripts and imaging tools.

Additional cases, such as NFSv4 clients running in containers, also
need unique and persistent identifiers. The Linux NFS community
sets forth this explanation to aid those who create and manage
container environments.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2022-05-17 15:33:21 -04:00
J. Bruce Fields
dc451bbc6f nfs: reexport documentation
We've supported reexport for a while but documentation is limited.  This
is mainly a simplified version of the text I wrote for the linux-nfs
wiki at https://wiki.linux-nfs.org/wiki/index.php/NFS_re-export.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-09-21 17:51:47 -04:00
Jeff Layton
7f84b488f9 nfsd: close cached files prior to a REMOVE or RENAME that would replace target
It's not uncommon for some workloads to do a bunch of I/O to a file and
delete it just afterward. If knfsd has a cached open file however, then
the file may still be open when the dentry is unlinked. If the
underlying filesystem is nfs, then that could trigger it to do a
sillyrename.

On a REMOVE or RENAME scan the nfsd_file cache for open files that
correspond to the inode, and proactively unhash and put their
references. This should prevent any delete-on-last-close activity from
occurring, solely due to knfsd's open file cache.

This must be done synchronously though so we use the variants that call
flush_delayed_fput. There are deadlock possibilities if you call
flush_delayed_fput while holding locks, however. In the case of
nfsd_rename, we don't even do the lookups of the dentries to be renamed
until we've locked for rename.

Once we've figured out what the target dentry is for a rename, check to
see whether there are cached open files associated with it. If there
are, then unwind all of the locking, close them all, and then reattempt
the rename.

None of this is really necessary for "typical" filesystems though. It's
mostly of use for NFS, so declare a new export op flag and use that to
determine whether to close the files beforehand.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-12-09 09:39:38 -05:00
Jeff Layton
ba5e8187c5 nfsd: allow filesystems to opt out of subtree checking
When we start allowing NFS to be reexported, then we have some problems
when it comes to subtree checking. In principle, we could allow it, but
it would mean encoding parent info in the filehandles and there may not
be enough space for that in a NFSv3 filehandle.

To enforce this at export upcall time, we add a new export_ops flag
that declares the filesystem ineligible for subtree checking.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-12-09 09:39:38 -05:00
Jeff Layton
daab110e47 nfsd: add a new EXPORT_OP_NOWCC flag to struct export_operations
With NFSv3 nfsd will always attempt to send along WCC data to the
client. This generally involves saving off the in-core inode information
prior to doing the operation on the given filehandle, and then issuing a
vfs_getattr to it after the op.

Some filesystems (particularly clustered or networked ones) have an
expensive ->getattr inode operation. Atomicity is also often difficult
or impossible to guarantee on such filesystems. For those, we're best
off not trying to provide WCC information to the client at all, and to
simply allow it to poll for that information as needed with a GETATTR
RPC.

This patch adds a new flags field to struct export_operations, and
defines a new EXPORT_OP_NOWCC flag that filesystems can use to indicate
that nfsd should not attempt to provide WCC info in NFSv3 replies. It
also adds a blurb about the new flags field and flag to the exporting
documentation.

The server will also now skip collecting this information for NFSv2 as
well, since that info is never used there anyway.

Note that this patch does not add this flag to any filesystem
export_operations structures. This was originally developed to allow
reexporting nfs via nfsd.

Other filesystems may want to consider enabling this flag too. It's hard
to tell however which ones have export operations to enable export via
knfsd and which ones mostly rely on them for open-by-filehandle support,
so I'm leaving that up to the individual maintainers to decide. I am
cc'ing the relevant lists for those filesystems that I think may want to
consider adding this though.

Cc: HPDD-discuss@lists.01.org
Cc: ceph-devel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: fuse-devel@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-12-09 09:39:38 -05:00
J. Bruce Fields
ade3dbad14 Documentation: update RPCSEC_GSSv3 RFC link
This draft is an official RFC now.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-09-25 18:01:27 -04:00
Alexander A. Klimov
c69f22f25f Replace HTTP links with HTTPS ones: Documentation/filesystems
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
          If both the HTTP and HTTPS versions
          return 200 OK and serve the same content:
            Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200621133552.46371-1-grandmaster@al2klimov.de
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-26 11:14:12 -06:00
Daniel W. S. Almeida
cb63032b12 Documentation: nfs: knfsd-stats: convert to ReST
Convert knfsd-stats.txt to ReST. Content remains mostly the same.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20200129044917.566906-6-dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13 11:21:35 -07:00
Daniel W. S. Almeida
04f81fb08d Documentation: nfs: nfs41-server: convert to ReST
Convert nfs41-server.txt to ReST. ASCII tables were converted to ReST grid
table format.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20200129044917.566906-5-dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13 11:21:31 -07:00
Daniel W. S. Almeida
250baf06aa Documentation: nfs: rpc-server-gss: convert to ReST
Convert rpc-server-gss.txt to ReST. Content remains mostly unchanged.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20200129044917.566906-4-dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13 11:21:28 -07:00
Daniel W. S. Almeida
f0bf8a988b Documentation: nfs: rpc-cache: convert to ReST
Convert rpc-cache.txt to ReST. Changes aim to improve presentation
but the content itself remains mostly the same.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20200129044917.566906-3-dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13 11:21:23 -07:00
Daniel W. S. Almeida
34e75cf4be Documentation: nfs: convert pnfs.txt to ReST
Convert pnfs.txt to ReST. Content remains mostly unchanged.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20200129044917.566906-2-dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13 11:21:08 -07:00
Daniel W. S. Almeida
6996e8ca8b Documentation: nfs: fault_injection: convert to ReST
Convert fault_injection.txt to ReST and move it to admin-guide.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/f7b0cf8fb1159a668f75ce82a581e7590568c2b8.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:05 -07:00
Daniel W. S. Almeida
98600b71f2 Documentation: nfs: pnfs-scsi-server: convert to ReST
Convert pnfs-scsi-server to ReST and move it to admin-guide. Content
remains mostly unchanged.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/5c4b8af41ca0a427a3987535815bccf47a65d320.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:05 -07:00
Daniel W. S. Almeida
26f6225fa5 Documentation: nfs: convert pnfs-block-server to ReST
Convert pnfs-block-server.txt to ReST and move it to admin-guide.
Content remains mostly unchanged.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/c06903760e690c16d9df92f5e75f80381d6326d8.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:05 -07:00
Daniel W. S. Almeida
fbdcd0b8e5 Documentation: nfs: idmapper: convert to ReST
Convert idmapper.txt to ReST and move it to admin-guide.
Content remains mostly unchanged otherwise.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/069e40cd551ea778538f8fe9ad15ee26e45fc748.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:05 -07:00
Daniel W. S. Almeida
0f3456ba9f Documentation: convert nfsd-admin-interfaces to ReST
Convert nfsd-admin-interfaces to ReST and move it into admin-guide.
Content remains mostly untouched.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/d471305e9c96dec38f18d2ff816fca2269a88e29.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:05 -07:00
Daniel W. S. Almeida
f8b8d03059 Documentation: nfs-rdma: convert to ReST
Convert nfs-rdma to ReST and move it to admin-guide. Content
remais mostly untouched. Also, mark the doc as obsolete.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/9c88f184f9de2a3eb5181563e258559efc02f58a.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:04 -07:00
Daniel W. S. Almeida
f9a9349846 Documentation: nfsroot.txt: convert to ReST
Convert nfsroot.txt to RST and move it to admin-guide. Content remains
mostly the same.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/442d35917351f5260dd8ed7362e9b5f1264ef8ad.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:04 -07:00
Daniel W. S. Almeida
2f123b9a35 Documentation: convert nfs.txt to ReST
This patch converts nfs.txt to RST. It also moves it to admin-guide.
The reason for moving it is because this document contains information
useful for system administrators, as noted on the following paragraph:

'The purpose of this document is to provide information on some of the
special features of the NFS client that can be configured by system
administrators'.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/cb9f2da2f2f6dd432b4cf9e05f79f74f4d54b6ab.1578697871.git.dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-16 12:43:04 -07:00
Mauro Carvalho Chehab
ec23eb54fb docs: fs: convert docs without extension to ReST
There are 3 remaining files without an extension inside the fs docs
dir.

Manually convert them to ReST.

In the case of the nfs/exporting.rst file, as the nfs docs
aren't ported yet, I opted to convert and add a :orphan: there,
with should be removed when it gets added into a nfs-specific
part of the fs documentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-31 13:31:05 -06:00
Mauro Carvalho Chehab
ec4b78a0e7 docs: early-userspace: move to driver-api guide
Those documents describe a kAPI. So, add to the driver-api
book.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 11:03:01 -03:00
Mauro Carvalho Chehab
0d07cf5e53 docs: early-userspace: convert docs to ReST and rename to *.rst
The two files there describes a Kernel API feature, used to
support early userspace stuff. Prepare for moving them to
the kernel API book by converting to ReST format.

The conversion itself was quite trivial: just add/mark a few
titles as such, add a literal block markup, add a table markup
and a few blank lines, in order to make Sphinx to properly parse it.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 09:20:23 -03:00
Linus Torvalds
310c7585e8 Olga added support for the NFSv4.2 asynchronous copy protocol. We
already supported COPY, by copying a limited amount of data and then
 returning a short result, letting the client resend.  The asynchronous
 protocol should offer better performance at the expense of some
 complexity.
 
 The other highlight is Trond's work to convert the duplicate reply cache
 to a red-black tree, and to move it and some other server caches to RCU.
 (Previously these have meant taking global spinlocks on every RPC.)
 
 Otherwise, some RDMA work and miscellaneous bugfixes.
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Merge tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Olga added support for the NFSv4.2 asynchronous copy protocol. We
  already supported COPY, by copying a limited amount of data and then
  returning a short result, letting the client resend. The asynchronous
  protocol should offer better performance at the expense of some
  complexity.

  The other highlight is Trond's work to convert the duplicate reply
  cache to a red-black tree, and to move it and some other server caches
  to RCU. (Previously these have meant taking global spinlocks on every
  RPC)

  Otherwise, some RDMA work and miscellaneous bugfixes"

* tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux: (30 commits)
  lockd: fix access beyond unterminated strings in prints
  nfsd: Fix an Oops in free_session()
  nfsd: correctly decrement odstate refcount in error path
  svcrdma: Increase the default connection credit limit
  svcrdma: Remove try_module_get from backchannel
  svcrdma: Remove ->release_rqst call in bc reply handler
  svcrdma: Reduce max_send_sges
  nfsd: fix fall-through annotations
  knfsd: Improve lookup performance in the duplicate reply cache using an rbtree
  knfsd: Further simplify the cache lookup
  knfsd: Simplify NFS duplicate replay cache
  knfsd: Remove dead code from nfsd_cache_lookup
  SUNRPC: Simplify TCP receive code
  SUNRPC: Replace the cache_detail->hash_lock with a regular spinlock
  SUNRPC: Remove non-RCU protected lookup
  NFS: Fix up a typo in nfs_dns_ent_put
  NFS: Lockless DNS lookups
  knfsd: Lockless lookup of NFSv4 identities.
  SUNRPC: Lockless server RPCSEC_GSS context lookup
  knfsd: Allow lockless lookups of the exports
  ...
2018-10-30 13:03:29 -07:00
Trond Myklebust
d48cf356a1 SUNRPC: Remove non-RCU protected lookup
Clean up the cache code by removing the non-RCU protected lookup.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29 16:58:04 -04:00
Henrik Austad
a7ddcea58a Drop all 00-INDEX files from Documentation/
This is a respin with a wider audience (all that get_maintainer returned)
and I know this spams a *lot* of people. Not sure what would be the correct
way, so my apologies for ruining your inbox.

The 00-INDEX files are supposed to give a summary of all files present
in a directory, but these files are horribly out of date and their
usefulness is brought into question. Often a simple "ls" would reveal
the same information as the filenames are generally quite descriptive as
a short introduction to what the file covers (it should not surprise
anyone what Documentation/sched/sched-design-CFS.txt covers)

A few years back it was mentioned that these files were no longer really
needed, and they have since then grown further out of date, so perhaps
it is time to just throw them out.

A short status yields the following _outdated_ 00-INDEX files, first
counter is files listed in 00-INDEX but missing in the directory, last
is files present but not listed in 00-INDEX.

List of outdated 00-INDEX:
Documentation: (4/10)
Documentation/sysctl: (0/1)
Documentation/timers: (1/0)
Documentation/blockdev: (3/1)
Documentation/w1/slaves: (0/1)
Documentation/locking: (0/1)
Documentation/devicetree: (0/5)
Documentation/power: (1/1)
Documentation/powerpc: (0/5)
Documentation/arm: (1/0)
Documentation/x86: (0/9)
Documentation/x86/x86_64: (1/1)
Documentation/scsi: (4/4)
Documentation/filesystems: (2/9)
Documentation/filesystems/nfs: (0/2)
Documentation/cgroup-v1: (0/2)
Documentation/kbuild: (0/4)
Documentation/spi: (1/0)
Documentation/virtual/kvm: (1/0)
Documentation/scheduler: (0/2)
Documentation/fb: (0/1)
Documentation/block: (0/1)
Documentation/networking: (6/37)
Documentation/vm: (1/3)

Then there are 364 subdirectories in Documentation/ with several files that
are missing 00-INDEX alltogether (and another 120 with a single file and no
00-INDEX).

I don't really have an opinion to whether or not we /should/ have 00-INDEX,
but the above 00-INDEX should either be removed or be kept up to date. If
we should keep the files, I can try to keep them updated, but I rather not
if we just want to delete them anyway.

As a starting point, remove all index-files and references to 00-INDEX and
see where the discussion is going.

Signed-off-by: Henrik Austad <henrik@austad.us>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Just-do-it-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: [Almost everybody else]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-09-09 15:08:58 -06:00
Chris Novakovic
c04d2cb200 ipconfig: Write NTP server IPs to /proc/net/ipconfig/ntp_servers
Distributed filesystems are most effective when the server and client
clocks are synchronised. Embedded devices often use NFS for their
root filesystem but typically do not contain an RTC, so the clocks of
the NFS server and the embedded device will be out-of-sync when the root
filesystem is mounted (and may not be synchronised until late in the
boot process).

Extend ipconfig with the ability to export IP addresses of NTP servers
it discovers to /proc/net/ipconfig/ntp_servers. They can be supplied as
follows:

 - If ipconfig is configured manually via the "ip=" or "nfsaddrs="
   kernel command line parameters, one NTP server can be specified in
   the new "<ntp0-ip>" parameter.
 - If ipconfig is autoconfigured via DHCP, request DHCP option 42 in
   the DHCPDISCOVER message, and record the IP addresses of up to three
   NTP servers sent by the responding DHCP server in the subsequent
   DHCPOFFER message.

ipconfig will only write the NTP server IP addresses it discovers to
/proc/net/ipconfig/ntp_servers, one per line (in the order received from
the DHCP server, if DHCP autoconfiguration is used); making use of these
NTP servers is the responsibility of a user space process (e.g. an
initrd/initram script that invokes an NTP client before mounting an NFS
root filesystem).

Signed-off-by: Chris Novakovic <chris@chrisn.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-24 13:40:42 -04:00
Chris Novakovic
8b0b37c564 ipconfig: Document /proc/net/pnp
Fully document the format used by the /proc/net/pnp file written by
ipconfig, explain where its values originate from, and clarify that the
tertiary name server IP and DNS domain name are only written to the file
when autoconfiguration is used.

Signed-off-by: Chris Novakovic <chris@chrisn.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-24 13:40:41 -04:00
Chris Novakovic
660de409e2 ipconfig: Document setting of NIS domain name
ic_do_bootp_ext() is responsible for parsing the "ip=" and "nfsaddrs="
kernel parameters. If a "." character is found in parameter 4 (the
client's hostname), everything before the first "." is used as the
hostname, and everything after it is used as the NIS domain name (but
not necessarily the DNS domain name).

Document this behaviour in Documentation/filesystems/nfs/nfsroot.txt,
as it is not made explicit.

Signed-off-by: Chris Novakovic <chris@chrisn.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-24 13:40:41 -04:00
NeilBrown
f1ee616214 VFS: don't keep disconnected dentries on d_anon
The original purpose of the per-superblock d_anon list was to
keep disconnected dentries in the cache between consecutive
requests to the NFS server.  Dentries can be disconnected if
a client holds a file open and repeatedly performs IO on it,
and if the server drops the dentry, whether due to memory
pressure, server restart, or "echo 3 > /proc/sys/vm/drop_caches".

This purpose was thwarted by commit 75a6f82a0d ("freeing unlinked
file indefinitely delayed") which caused disconnected dentries
to be freed as soon as their refcount reached zero.

This means that, when a dentry being used by nfsd gets disconnected, a
new one needs to be allocated for every request (unless requests
overlap).  As the dentry has no name, no parent, and no children,
there is little of value to cache.  As small memory allocations are
typically fast (from per-cpu free lists) this likely has little cost.

This means that the original purpose of s_anon is no longer relevant:
there is no longer any need to keep disconnected dentries on a list so
they appear to be hashed.

However, s_anon now has a new use.  When you mount an NFS filesystem,
the dentry stored in s_root is just a placebo.  The "real" root dentry
is allocated using d_obtain_root() and so it kept on the s_anon list.
I don't know the reason for this, but suspect it related to NFSv4
where a mount of "server:/some/path" require NFS to look up the root
filehandle on the server, then walk down "/some" and "/path" to get
the filehandle to mount.

Whatever the reason, NFS depends on the s_anon list and on
shrink_dcache_for_umount() pruning all dentries on this list.  So we
cannot simply remove s_anon.

We could just leave the code unchanged, but apart from that being
potentially confusing, the (unfair) bit-spin-lock which protects
s_anon can become a bottle neck when lots of disconnected dentries are
being created.

So this patch renames s_anon to s_roots, and stops storing
disconnected dentries on the list.  Only dentries obtained with
d_obtain_root() are now stored on this list.  There are many fewer of
these (only NFS and NILFS2 use the call, and only during filesystem
mount) so contention on the bit-lock will not be a problem.

Possibly an alternate solution should be found for NFS and NILFS2, but
that would require understanding their needs first.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-12-25 20:22:07 -05:00
Kees Cook
3db38ed768 doc: ReSTify keys-request-key.txt
Adjusts for ReST markup and moves under keys security devel index.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:51 -06:00
Linus Torvalds
73ccb023a2 NFS client updates for Linux 4.12
Highlights include:
 
 Stable bugfixes:
 - Fix use after free in write error path
 - Use GFP_NOIO for two allocations in writeback
 - Fix a hang in OPEN related to server reboot
 - Check the result of nfs4_pnfs_ds_connect
 - Fix an rcu lock leak
 
 Features:
 - Removal of the unmaintained and unused OSD pNFS layout
 - Cleanup and removal of lots of unnecessary dprintk()s
 - Cleanup and removal of some memory failure paths now that
   GFP_NOFS is guaranteed to never fail.
 - Remove the v3-only data server limitation on pNFS/flexfiles
 
 Bugfixes:
 - RPC/RDMA connection handling bugfixes
 - Copy offload: fixes to ensure the copied data is COMMITed to disk.
 - Readdir: switch back to using the ->iterate VFS interface
 - File locking fixes from Ben Coddington
 - Various use-after-free and deadlock issues in pNFS
 - Write path bugfixes
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Merge tag 'nfs-for-4.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable bugfixes:
   - Fix use after free in write error path
   - Use GFP_NOIO for two allocations in writeback
   - Fix a hang in OPEN related to server reboot
   - Check the result of nfs4_pnfs_ds_connect
   - Fix an rcu lock leak

  Features:
   - Removal of the unmaintained and unused OSD pNFS layout
   - Cleanup and removal of lots of unnecessary dprintk()s
   - Cleanup and removal of some memory failure paths now that GFP_NOFS
     is guaranteed to never fail.
   - Remove the v3-only data server limitation on pNFS/flexfiles

  Bugfixes:
   - RPC/RDMA connection handling bugfixes
   - Copy offload: fixes to ensure the copied data is COMMITed to disk.
   - Readdir: switch back to using the ->iterate VFS interface
   - File locking fixes from Ben Coddington
   - Various use-after-free and deadlock issues in pNFS
   - Write path bugfixes"

* tag 'nfs-for-4.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (89 commits)
  pNFS/flexfiles: Always attempt to call layoutstats when flexfiles is enabled
  NFSv4.1: Work around a Linux server bug...
  NFS append COMMIT after synchronous COPY
  NFSv4: Fix exclusive create attributes encoding
  NFSv4: Fix an rcu lock leak
  nfs: use kmap/kunmap directly
  NFS: always treat the invocation of nfs_getattr as cache hit when noac is on
  Fix nfs_client refcounting if kmalloc fails in nfs4_proc_exchange_id and nfs4_proc_async_renew
  NFSv4.1: RECLAIM_COMPLETE must handle NFS4ERR_CONN_NOT_BOUND_TO_SESSION
  pNFS: Fix NULL dereference in pnfs_generic_alloc_ds_commits
  pNFS: Fix a typo in pnfs_generic_alloc_ds_commits
  pNFS: Fix a deadlock when coalescing writes and returning the layout
  pNFS: Don't clear the layout return info if there are segments to return
  pNFS: Ensure we commit the layout if it has been invalidated
  pNFS: Don't send COMMITs to the DSes if the server invalidated our layout
  pNFS/flexfiles: Fix up the ff_layout_write_pagelist failure path
  pNFS: Ensure we check layout validity before marking it for return
  NFS4.1 handle interrupted slot reuse from ERR_DELAY
  NFSv4: check return value of xdr_inline_decode
  nfs/filelayout: fix NULL pointer dereference in fl_pnfs_update_layout()
  ...
2017-05-10 13:03:38 -07:00
Christoph Hellwig
6d22323b2e nfs: remove the objlayout driver
The objlayout code has been in the tree, but it's been unmaintained and
no server product for it actually ever shipped.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-04-20 15:51:23 -04:00
SeongJae Park
3bdadc86dc Documentation: Fix dead URLs to ftp.kernel.org
As ftp.kernel.org is closed [0], this commit fixes dead URLs in
documents to use www.kernel.org instead.

[0] https://www.kernel.org/shutting-down-ftp-services.html

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-03-29 15:46:06 -06:00
Mauro Carvalho Chehab
8c27ceff36 docs: fix locations of several documents that got moved
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24 08:12:35 -02:00
Linus Torvalds
8b306a2e7c Various bugfixes, a RDMA update from Chuck Lever, and support for a new
pnfs layout type from Christoph Hellwig.  The new layout type is a
 variant of the block layout which uses SCSI features to offer improved
 fencing and device identification.
 
 Note this pull request also includes the client side of SCSI layout,
 with Trond's permission.
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Merge tag 'nfsd-4.6-1' of git://linux-nfs.org/~bfields/linux

Pull more nfsd updates from Bruce Fields:
 "Apologies for the previous request, which omitted the top 8 commits
  from my for-next branch (including the SCSI layout commits).  Thanks
  to Trond for spotting my error!"

This actually includes the new layout types, so here's that part of
the pull message repeated:

 "Support for a new pnfs layout type from Christoph Hellwig.  The new
  layout type is a variant of the block layout which uses SCSI features
  to offer improved fencing and device identification.

  Note this pull request also includes the client side of SCSI layout,
  with Trond's permission"

* tag 'nfsd-4.6-1' of git://linux-nfs.org/~bfields/linux:
  nfsd: use short read as well as i_size to set eof
  nfsd: better layoutupdate bounds-checking
  nfsd: block and scsi layout drivers need to depend on CONFIG_BLOCK
  nfsd: add SCSI layout support
  nfsd: move some blocklayout code
  nfsd: add a new config option for the block layout driver
  nfs/blocklayout: add SCSI layout support
  nfs4.h: add SCSI layout definitions
2016-03-24 19:50:32 -07:00
Christoph Hellwig
f99d4fbdae nfsd: add SCSI layout support
This is a simple extension to the block layout driver to use SCSI
persistent reservations for access control and fencing, as well as
SCSI VPD pages for device identification.

For this we need to pass the nfs4_client to the proc_getdeviceinfo method
to generate the reservation key, and add a new fence_client method
to allow for fence actions in the layout driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-18 11:42:53 -04:00
Masanari Iida
0d6f3ebf9e Doc: nfs: Fix typos in Documentation/filesystems/nfs
This patch fix spelling typos found in Documentation/filesystems/nfs

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-03-09 16:13:04 -07:00
Li RongQing
26fb342c73 ipconfig: send Client-identifier in DHCP requests
A dhcp server may provide parameters to a client from a pool of IP
addresses and using a shared rootfs, or provide a specific set of
parameters for a specific client, usually using the MAC address to
identify each client individually. The dhcp protocol also specifies
a client-id field which can be used to determine the correct
parameters to supply when no MAC address is available. There is
currently no way to tell the kernel to supply a specific client-id,
only the userspace dhcp clients support this feature, but this can
not be used when the network is needed before userspace is available
such as when the root filesystem is on NFS.

This patch is to be able to do something like "ip=dhcp,client_id_type,
client_id_value", as a kernel parameter to enable the kernel to
identify itself to the server.

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-18 19:23:52 -07:00
J. Bruce Fields
28e51af7c6 Revert "Documentation: NFS/RDMA: Document separate Kconfig symbols"
This reverts commit 731d5cca82.

Commit ffe1f0df58 ("rpcrdma: Merge svcrdma and xprtrdma modules into
one") forgot to update the corresponding documentation.

Reported-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-07-20 14:58:46 -04:00
Scott Mayhew
72faedae8b Documentation: remove overloads-avoided counter from knfsd-stats.txt
The 'overloads-avoided' counter itself was removed several years ago by
commit 78c210e (Revert "knfsd: avoid overloading the CPU scheduler with
enormous load averages").

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-04 12:02:44 -04:00
Stephen Hemminger
b962dc0a48 rdma: replace deprecated ifconfig in doc
The ifconfig command has been deprecated for many years.
To encourage new users not to continue using it and learning
iproute2; the ifconfig should not be used in examples.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15 16:06:39 -04:00
Linus Torvalds
61845143fe Merge branch 'for-3.20' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 "The main change is the pNFS block server support from Christoph, which
  allows an NFS client connected to shared disk to do block IO to the
  shared disk in place of NFS reads and writes.  This also requires xfs
  patches, which should arrive soon through the xfs tree, barring
  unexpected problems.  Support for other filesystems is also possible
  if there's interest.

  Thanks also to Chuck Lever for continuing work to get NFS/RDMA into
  shape"

* 'for-3.20' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd: default NFSv4.2 to on
  nfsd: pNFS block layout driver
  exportfs: add methods for block layout exports
  nfsd: add trace events
  nfsd: update documentation for pNFS support
  nfsd: implement pNFS layout recalls
  nfsd: implement pNFS operations
  nfsd: make find_any_file available outside nfs4state.c
  nfsd: make find/get/put file available outside nfs4state.c
  nfsd: make lookup/alloc/unhash_stid available outside nfs4state.c
  nfsd: add fh_fsid_match helper
  nfsd: move nfsd_fh_match to nfsfh.h
  fs: add FL_LAYOUT lease type
  fs: track fl_owner for leases
  nfs: add LAYOUT_TYPE_MAX enum value
  nfsd: factor out a helper to decode nfstime4 values
  sunrpc/lockd: fix references to the BKL
  nfsd: fix year-2038 nfs4 state problem
  svcrdma: Handle additional inline content
  svcrdma: Move read list XDR round-up logic
  ...
2015-02-12 10:39:41 -08:00
Christoph Hellwig
8650b8a058 nfsd: pNFS block layout driver
Add a small shim between core nfsd and filesystems to translate the
somewhat cumbersome pNFS data structures and semantics to something
more palatable for Linux filesystems.

Thanks to Rick McNeal for the old prototype pNFS blocklayout server
code, which gave a lot of inspiration to this version even if no
code is left from it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-05 14:35:18 +01:00
Tom Haynes
8f9cdcb26b pnfs: Update documentation on the Layout Drivers
Signed-off-by: Tom Haynes <loghyr@primarydata.com>
2015-02-03 11:06:53 -08:00
Christoph Hellwig
18d1aef89e nfsd: update documentation for pNFS support
Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:43 +01:00
Al Viro
41d28bca2d switch d_materialise_unique() users to d_splice_alias()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19 13:01:20 -05:00
Paul Bolle
731d5cca82 Documentation: NFS/RDMA: Document separate Kconfig symbols
The NFS/RDMA Kconfig symbol was split into separate options for client
and server in commit 2e8c12e1b7 ("xprtrdma: add separate Kconfig
options for NFSoRDMA client and server support").

Update the documentation to reflect this split.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "J. Bruce Fields" <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-07 15:21:13 -07:00
J. Bruce Fields
9635389534 exportfs: update Exporting documentation
Minor documentation updates:
	- refer to d_obtain_alias rather than d_alloc_anon
	- explain when to use d_splice_alias and when
	  d_materialise_unique.
	- cut some details of d_splice_alias/d_materialise_unique
	  implementation.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:10 -04:00
J. Bruce Fields
b042098063 nfsd4: allow exotic read compounds
I'm not sure why a client would want to stuff multiple reads in a
single compound rpc, but it's legal for them to do it, and we should
really support it.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:12 -04:00