Commit Graph

363 Commits

Author SHA1 Message Date
NeilBrown
a37b0715dd mm/writeback: replace PF_LESS_THROTTLE with PF_LOCAL_THROTTLE
PF_LESS_THROTTLE exists for loop-back nfsd (and a similar need in the
loop block driver and callers of prctl(PR_SET_IO_FLUSHER)), where a
daemon needs to write to one bdi (the final bdi) in order to free up
writes queued to another bdi (the client bdi).

The daemon sets PF_LESS_THROTTLE and gets a larger allowance of dirty
pages, so that it can still dirty pages after other processses have been
throttled.  The purpose of this is to avoid deadlock that happen when
the PF_LESS_THROTTLE process must write for any dirty pages to be freed,
but it is being thottled and cannot write.

This approach was designed when all threads were blocked equally,
independently on which device they were writing to, or how fast it was.
Since that time the writeback algorithm has changed substantially with
different threads getting different allowances based on non-trivial
heuristics.  This means the simple "add 25%" heuristic is no longer
reliable.

The important issue is not that the daemon needs a *larger* dirty page
allowance, but that it needs a *private* dirty page allowance, so that
dirty pages for the "client" bdi that it is helping to clear (the bdi
for an NFS filesystem or loop block device etc) do not affect the
throttling of the daemon writing to the "final" bdi.

This patch changes the heuristic so that the task is not throttled when
the bdi it is writing to has a dirty page count below below (or equal
to) the free-run threshold for that bdi.  This ensures it will always be
able to have some pages in flight, and so will not deadlock.

In a steady-state, it is expected that PF_LOCAL_THROTTLE tasks might
still be throttled by global threshold, but that is acceptable as it is
only the deadlock state that is interesting for this flag.

This approach of "only throttle when target bdi is busy" is consistent
with the other use of PF_LESS_THROTTLE in current_may_throttle(), were
it causes attention to be focussed only on the target bdi.

So this patch
 - renames PF_LESS_THROTTLE to PF_LOCAL_THROTTLE,
 - removes the 25% bonus that that flag gives, and
 - If PF_LOCAL_THROTTLE is set, don't delay at all unless the
   global and the local free-run thresholds are exceeded.

Note that previously realtime threads were treated the same as
PF_LESS_THROTTLE threads.  This patch does *not* change the behvaiour
for real-time threads, so it is now different from the behaviour of nfsd
and loop tasks.  I don't know what is wanted for realtime.

[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Chuck Lever <chuck.lever@oracle.com>	[nfsd]
Cc: Christoph Hellwig <hch@lst.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Link: http://lkml.kernel.org/r/87ftbf7gs3.fsf@notabene.neil.brown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:08 -07:00
Trond Myklebust
19e0663ff9 nfsd: Ensure sampling of the write verifier is atomic with the write
When doing an unstable write, we need to ensure that we sample the
write verifier before releasing the lock, and allowing a commit to
the same file to proceed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:41 -05:00
Trond Myklebust
524ff1af22 nfsd: Ensure sampling of the commit verifier is atomic with the commit
When we have a successful commit, ensure we sample the commit verifier
before releasing the lock.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:41 -05:00
Trond Myklebust
1b28d756b2 nfsd: Ensure exclusion between CLONE and WRITE errors
Ensure that we can distinguish between synchronous CLONE and
WRITE errors, and that we can assign them correctly.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:41 -05:00
Trond Myklebust
b66ae6dd0c nfsd: Pass the nfsd_file as arguments to nfsd4_clone_file_range()
Needed in order to fix exclusion w.r.t. writes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:40 -05:00
Trond Myklebust
7bf94c6ba9 nfsd: Update the boot verifier on stable writes too.
We don't know if the error returned by the fsync() call is
exclusive to the data written by the stable write, so play it
safe.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:40 -05:00
Trond Myklebust
5011af4c69 nfsd: Fix stable writes
Strictly speaking, a stable write error needs to reflect the
write + the commit of that write (and only that write). To
ensure that we don't pick up the write errors from other
writebacks, add a rw_semaphore to provide exclusion.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:40 -05:00
Trond Myklebust
16f8f89410 nfsd: Allow nfsd_vfs_write() to take the nfsd_file as an argument
Needed in order to fix stable writes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:40 -05:00
zhengbin
384a7ccaa3 nfsd: use true,false for bool variable in vfs.c
Fixes coccicheck warning:

fs/nfsd/vfs.c:1389:5-13: WARNING: Assignment of 0/1 to bool variable
fs/nfsd/vfs.c:1398:5-13: WARNING: Assignment of 0/1 to bool variable
fs/nfsd/vfs.c:1415:2-10: WARNING: Assignment of 0/1 to bool variable

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-03 11:21:12 -05:00
Arnd Bergmann
2a1aa48929 nfsd: pass a 64-bit guardtime to nfsd_setattr()
Guardtime handling in nfs3 differs between 32-bit and 64-bit
architectures, and uses the deprecated time_t type.

Change it to using time64_t, which behaves the same way on
64-bit and 32-bit architectures, treating the number as an
unsigned 32-bit entity with a range of year 1970 to 2106
consistently, and avoiding the y2038 overflow.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-12-19 17:46:08 -05:00
Trond Myklebust
57f6403496 nfsd: Clone should commit src file metadata too
vfs_clone_file_range() can modify the metadata on the source file too,
so we need to commit that to stable storage as well.

Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Acked-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-12-19 17:46:08 -05:00
Trond Myklebust
09a80f2aef nfsd: Return the correct number of bytes written to the file
We must allow for the fact that iov_iter_write() could have returned
a short write (e.g. if there was an ENOSPC issue).

Fixes: d890be159a "nfsd: Add I/O trace points in the NFSv4 write path"
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-12-17 14:32:20 -05:00
NeilBrown
466e16f092 nfsd: check for EBUSY from vfs_rmdir/vfs_unink.
vfs_rmdir and vfs_unlink can return -EBUSY if the
target is a mountpoint.  This currently gets passed to
nfserrno() by nfsd_unlink(), and that results in a WARNing,
which is not user-friendly.

Possibly the best NFSv4 error is NFS4ERR_FILE_OPEN, because
there is a sense in which the object is currently in use
by some other task.  The Linux NFSv4 client will map this
back to EBUSY, which is an added benefit.

For NFSv3, the best we can do is probably NFS3ERR_ACCES, which isn't
true, but is not less true than the other options.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-11-30 14:59:52 -05:00
Trond Myklebust
a25e3726b3 nfsd: Ensure CLONE persists data and metadata changes to the target file
The NFSv4.2 CLONE operation has implicit persistence requirements on the
target file, since there is no protocol requirement that the client issue
a separate operation to persist data.
For that reason, we should call vfs_fsync_range() on the destination file
after a successful call to vfs_clone_file_range().

Fixes: ffa0160a10 ("nfsd: implement the NFSv4.2 CLONE operation")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-11-30 14:55:38 -05:00
Trond Myklebust
83a63072c8 nfsd: fix nfs read eof detection
Currently, the knfsd server assumes that a short read indicates an
end of file. That assumption is incorrect. The short read means that
either we've hit the end of file, or we've hit a read error.

In the case of a read error, the client may want to retry (as per the
implementation recommendations in RFC1813 and RFC7530), but currently it
is being told that it hit an eof.

Move the code to detect eof from version specific code into the generic
nfsd read.

Report eof only in the two following cases:
1) read() returns a zero length short read with no error.
2) the offset+length of the read is >= the file size.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-09-23 16:24:08 -04:00
Trond Myklebust
bbf2f09883 nfsd: Reset the boot verifier on all write I/O errors
If multiple clients are writing to the same file, then due to the fact
we share a single file descriptor between all NFSv3 clients writing
to the file, we have a situation where clients can miss the fact that
their file data was not persisted. While this should be rare, it
could cause silent data loss in situations where multiple clients
are using NLM locking or O_DIRECT to write to the same file.
Unfortunately, the stateless nature of NFSv3 and the fact that we
can only identify clients by their IP address means that we cannot
trivially cache errors; we would not know when it is safe to
release them from the cache.

So the solution is to declare a reboot. We understand that this
should be a rare occurrence, since disks are usually stable. The
most frequent occurrence is likely to be ENOSPC, at which point
all writes to the given filesystem are likely to fail anyway.

So the expectation is that clients will be forced to retry their
writes until they hit the fatal error.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-09-10 09:23:41 -04:00
Jeff Layton
7775ec57f4 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.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:09:10 -04:00
Jeff Layton
501cb1849f nfsd: rip out the raparms cache
The raparms cache was set up in order to ensure that we carry readahead
information forward from one RPC call to the next. In other words, it
was set up because each RPC call was forced to open a struct file, then
close it, causing the loss of readahead information that is normally
cached in that struct file, and used to keep the page cache filled when
a user calls read() multiple times on the same file descriptor.

Now that we cache the struct file, and reuse it for all the I/O calls
to a given file by a given user, we no longer have to keep a separate
readahead cache.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:09:09 -04:00
Jeff Layton
5920afa3c8 nfsd: hook nfsd_commit up to the nfsd_file cache
Use cached filps if possible instead of opening a new one every time.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:00:40 -04:00
Jeff Layton
48cd7b5125 nfsd: hook up nfsd_read to the nfsd_file cache
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:00:40 -04:00
Jeff Layton
b493523926 nfsd: hook up nfsd_write to the new nfsd_file cache
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:00:39 -04:00
Jeff Layton
65294c1f2c nfsd: add a new struct file caching facility to nfsd
Currently, NFSv2/3 reads and writes have to open a file, do the read or
write and then close it again for each RPC. This is highly inefficient,
especially when the underlying filesystem has a relatively slow open
routine.

This patch adds a new open file cache to knfsd. Rather than doing an
open for each RPC, the read/write handlers can call into this cache to
see if there is one already there for the correct filehandle and
NFS_MAY_READ/WRITE flags.

If there isn't an entry, then we create a new one and attempt to
perform the open. If there is, then we wait until the entry is fully
instantiated and return it if it is at the end of the wait. If it's
not, then we attempt to take over construction.

Since the main goal is to speed up NFSv2/3 I/O, we don't want to
close these files on last put of these objects. We need to keep them
around for a little while since we never know when the next READ/WRITE
will come in.

Cache entries have a hardcoded 1s timeout, and we have a recurring
workqueue job that walks the cache and purges any entries that have
expired.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Richard Sharpe <richard.sharpe@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:00:39 -04:00
Geert Uytterhoeven
e977cc8308 nfsd: Spelling s/EACCESS/EACCES/
The correct spelling is EACCES:

include/uapi/asm-generic/errno-base.h:#define EACCES 13 /* Permission denied */

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-07-03 17:52:09 -04:00
J. Bruce Fields
0ca0c9d7ed nfsd: fh_drop_write in nfsd_unlink
fh_want_write() can now be called twice, but I'm also fixing up the
callers not to do that.

Other cases include setattr and create.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-24 09:46:35 -04:00
Trond Myklebust
e3fdc89ca4 nfsd: Fix error return values for nfsd4_clone_file_range()
If the parameter 'count' is non-zero, nfsd4_clone_file_range() will
currently clobber all errors returned by vfs_clone_file_range() and
replace them with EINVAL.

Fixes: 42ec3d4c02 ("vfs: make remap_file_range functions take and...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-02-06 15:32:05 -05:00
zhengbin
255fbca651 nfsd: Return EPERM, not EACCES, in some SETATTR cases
As the man(2) page for utime/utimes states, EPERM is returned when the
second parameter of utime or utimes is not NULL, the caller's effective UID
does not match the owner of the file, and the caller is not privileged.

However, in a NFS directory mounted from knfsd, it will return EACCES
(from nfsd_setattr-> fh_verify->nfsd_permission).  This patch fixes
that.

Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-04 20:48:07 -05:00
Linus Torvalds
c2aa1a444c vfs: rework data cloning infrastructure
Rework the vfs_clone_file_range and vfs_dedupe_file_range infrastructure to use
 a common .remap_file_range method and supply generic bounds and sanity checking
 functions that are shared with the data write path. The current VFS
 infrastructure has problems with rlimit, LFS file sizes, file time stamps,
 maximum filesystem file sizes, stripping setuid bits, etc and so they are
 addressed in these commits.
 
 We also introduce the ability for the ->remap_file_range methods to return short
 clones so that clones for vfs_copy_file_range() don't get rejected if the entire
 range can't be cloned. It also allows filesystems to sliently skip deduplication
 of partial EOF blocks if they are not capable of doing so without requiring
 errors to be thrown to userspace.
 
 All existing filesystems are converted to user the new .remap_file_range method,
 and both XFS and ocfs2 are modified to make use of the new generic checking
 infrastructure.
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Merge tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull vfs dedup fixes from Dave Chinner:
 "This reworks the vfs data cloning infrastructure.

  We discovered many issues with these interfaces late in the 4.19 cycle
  - the worst of them (data corruption, setuid stripping) were fixed for
  XFS in 4.19-rc8, but a larger rework of the infrastructure fixing all
  the problems was needed. That rework is the contents of this pull
  request.

  Rework the vfs_clone_file_range and vfs_dedupe_file_range
  infrastructure to use a common .remap_file_range method and supply
  generic bounds and sanity checking functions that are shared with the
  data write path. The current VFS infrastructure has problems with
  rlimit, LFS file sizes, file time stamps, maximum filesystem file
  sizes, stripping setuid bits, etc and so they are addressed in these
  commits.

  We also introduce the ability for the ->remap_file_range methods to
  return short clones so that clones for vfs_copy_file_range() don't get
  rejected if the entire range can't be cloned. It also allows
  filesystems to sliently skip deduplication of partial EOF blocks if
  they are not capable of doing so without requiring errors to be thrown
  to userspace.

  Existing filesystems are converted to user the new remap_file_range
  method, and both XFS and ocfs2 are modified to make use of the new
  generic checking infrastructure"

* tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (28 commits)
  xfs: remove [cm]time update from reflink calls
  xfs: remove xfs_reflink_remap_range
  xfs: remove redundant remap partial EOF block checks
  xfs: support returning partial reflink results
  xfs: clean up xfs_reflink_remap_blocks call site
  xfs: fix pagecache truncation prior to reflink
  ocfs2: remove ocfs2_reflink_remap_range
  ocfs2: support partial clone range and dedupe range
  ocfs2: fix pagecache truncation prior to reflink
  ocfs2: truncate page cache for clone destination file before remapping
  vfs: clean up generic_remap_file_range_prep return value
  vfs: hide file range comparison function
  vfs: enable remap callers that can handle short operations
  vfs: plumb remap flags through the vfs dedupe functions
  vfs: plumb remap flags through the vfs clone functions
  vfs: make remap_file_range functions take and return bytes completed
  vfs: remap helper should update destination inode metadata
  vfs: pass remap flags to generic_remap_checks
  vfs: pass remap flags to generic_remap_file_range_prep
  vfs: combine the clone and dedupe into a single remap_file_range
  ...
2018-11-02 09:33:08 -07:00
Linus Torvalds
9931a07d51 Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull AFS updates from Al Viro:
 "AFS series, with some iov_iter bits included"

* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  missing bits of "iov_iter: Separate type from direction and use accessor functions"
  afs: Probe multiple fileservers simultaneously
  afs: Fix callback handling
  afs: Eliminate the address pointer from the address list cursor
  afs: Allow dumping of server cursor on operation failure
  afs: Implement YFS support in the fs client
  afs: Expand data structure fields to support YFS
  afs: Get the target vnode in afs_rmdir() and get a callback on it
  afs: Calc callback expiry in op reply delivery
  afs: Fix FS.FetchStatus delivery from updating wrong vnode
  afs: Implement the YFS cache manager service
  afs: Remove callback details from afs_callback_break struct
  afs: Commit the status on a new file/dir/symlink
  afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
  afs: Don't invoke the server to read data beyond EOF
  afs: Add a couple of tracepoints to log I/O errors
  afs: Handle EIO from delivery function
  afs: Fix TTL on VL server and address lists
  afs: Implement VL server rotation
  afs: Improve FS server rotation error handling
  ...
2018-11-01 19:58:52 -07:00
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
Darrick J. Wong
452ce65951 vfs: plumb remap flags through the vfs clone functions
Plumb a remap_flags argument through the {do,vfs}_clone_file_range
functions so that clone can take advantage of it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30 10:41:56 +11:00
Darrick J. Wong
42ec3d4c02 vfs: make remap_file_range functions take and return bytes completed
Change the remap_file_range functions to take a number of bytes to
operate upon and return the number of bytes they operated on.  This is a
requirement for allowing fs implementations to return short clone/dedupe
results to the user, which will enable us to obey resource limits in a
graceful manner.

A subsequent patch will enable copy_file_range to signal to the
->clone_file_range implementation that it can handle a short length,
which will be returned in the function's return value.  For now the
short return is not implemented anywhere so the behavior won't change --
either copy_file_range manages to clone the entire range or it tries an
alternative.

Neither clone ioctl can take advantage of this, alas.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30 10:41:49 +11:00
Gustavo A. R. Silva
0ac203cb1f nfsd: fix fall-through annotations
Replace "fallthru" with a proper "fall through" annotation.

Also, add an annotation were it is expected to fall through.

These fixes are part of the ongoing efforts to enabling
-Wimplicit-fallthrough

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29 16:58:04 -04:00
David Howells
aa563d7bca iov_iter: Separate type from direction and use accessor functions
In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
YueHaibing
7d20b6a272 nfsd: remove set but not used variable 'dirp'
Fixes gcc '-Wunused-but-set-variable' warning:

fs/nfsd/vfs.c: In function 'nfsd_create':
fs/nfsd/vfs.c:1279:16: warning:
 variable 'dirp' set but not used [-Wunused-but-set-variable]

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-09-25 20:35:13 -04:00
Amir Goldstein
a725356b66 vfs: swap names of {do,vfs}_clone_file_range()
Commit 031a072a0b ("vfs: call vfs_clone_file_range() under freeze
protection") created a wrapper do_clone_file_range() around
vfs_clone_file_range() moving the freeze protection to former, so
overlayfs could call the latter.

The more common vfs practice is to call do_xxx helpers from vfs_xxx
helpers, where freeze protecction is taken in the vfs_xxx helper, so
this anomality could be a source of confusion.

It seems that commit 8ede205541 ("ovl: add reflink/copyfile/dedup
support") may have fallen a victim to this confusion -
ovl_clone_file_range() calls the vfs_clone_file_range() helper in the
hope of getting freeze protection on upper fs, but in fact results in
overlayfs allowing to bypass upper fs freeze protection.

Swap the names of the two helpers to conform to common vfs practice
and call the correct helpers from overlayfs and nfsd.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-24 10:54:01 +02:00
Al Viro
6035a27b25 IMA: don't propagate opened through the entire thing
just check ->f_mode in ima_appraise_measurement()

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:19 -04:00
Al Viro
3819bb0d79 nfsd: vfs_mkdir() might succeed leaving dentry negative unhashed
That can (and does, on some filesystems) happen - ->mkdir() (and thus
vfs_mkdir()) can legitimately leave its argument negative and just
unhash it, counting upon the lookup to pick the object we'd created
next time we try to look at that name.

Some vfs_mkdir() callers forget about that possibility...

Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:10 -04:00
Chuck Lever
87c5942e8f nfsd: Add I/O trace points in the NFSv4 read proc
NFSv4 read compound processing invokes nfsd_splice_read and
nfs_readv directly, so the trace points currently in nfsd_read are
not invoked for NFSv4 reads.

Move the NFSD READ trace points to common helpers so that NFSv4
reads are captured.

Also, record any local I/O error that occurs, the total count of
bytes that were actually returned, and whether splice or vectored
read was used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03 15:08:15 -04:00
Chuck Lever
d890be159a nfsd: Add I/O trace points in the NFSv4 write path
NFSv4 write compound processing invokes nfsd_vfs_write directly. The
trace points currently in nfsd_write are not effective for NFSv4
writes.

Move the trace points into the shared nfsd_vfs_write() helper.

After the I/O, we also want to record any local I/O error that
might have occurred, and the total count of bytes that were actually
moved (rather than the requested number).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03 15:08:15 -04:00
Chuck Lever
f394b62b7b nfsd: Add "nfsd_" to trace point names
Follow naming convention used in client and in sunrpc layers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03 15:08:14 -04:00
Chuck Lever
79e0b4e247 nfsd: Record request byte count, not count of vectors
Byte count is more helpful to know than vector count.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03 15:08:14 -04:00
Greg Kroah-Hartman
b24413180f 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>
2017-11-02 11:10:55 +01:00
Christoph Hellwig
ddef7ed2b5 annotate RWF_... flags
[AV: added missing annotations in syscalls.h/compat.h]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-08-31 17:32:38 -04:00
Linus Torvalds
89fbf5384d Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull read/write updates from Al Viro:
 "Christoph's fs/read_write.c series - consolidation and cleanups"

* 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  nfsd: remove nfsd_vfs_read
  nfsd: use vfs_iter_read/write
  fs: implement vfs_iter_write using do_iter_write
  fs: implement vfs_iter_read using do_iter_read
  fs: move more code into do_iter_read/do_iter_write
  fs: remove __do_readv_writev
  fs: remove do_compat_readv_writev
  fs: remove do_readv_writev
2017-07-05 14:35:57 -07:00
Christoph Hellwig
a4058c5bce nfsd: remove nfsd_vfs_read
Simpler done in the only caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-29 17:49:24 -04:00
Christoph Hellwig
73da852e38 nfsd: use vfs_iter_read/write
Instead of messing with the address limit to use vfs_read/vfs_writev.

Note that this requires that exported file implement ->read_iter and
->write_iter.  All currently exportable file systems do this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-29 17:49:24 -04:00
Al Viro
4d7edbc34c nfsd_readlink(): switch to vfs_get_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-27 16:11:23 -04:00
Linus Torvalds
c70422f760 Another RDMA update from Chuck Lever, and a bunch of miscellaneous
bugfixes.
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Merge tag 'nfsd-4.12' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Another RDMA update from Chuck Lever, and a bunch of miscellaneous
  bugfixes"

* tag 'nfsd-4.12' of git://linux-nfs.org/~bfields/linux: (26 commits)
  nfsd: Fix up the "supattr_exclcreat" attributes
  nfsd: encoders mustn't use unitialized values in error cases
  nfsd: fix undefined behavior in nfsd4_layout_verify
  lockd: fix lockd shutdown race
  NFSv4: Fix callback server shutdown
  SUNRPC: Refactor svc_set_num_threads()
  NFSv4.x/callback: Create the callback service through svc_create_pooled
  lockd: remove redundant check on block
  svcrdma: Clean out old XDR encoders
  svcrdma: Remove the req_map cache
  svcrdma: Remove unused RDMA Write completion handler
  svcrdma: Reduce size of sge array in struct svc_rdma_op_ctxt
  svcrdma: Clean up RPC-over-RDMA backchannel reply processing
  svcrdma: Report Write/Reply chunk overruns
  svcrdma: Clean up RDMA_ERROR path
  svcrdma: Use rdma_rw API in RPC reply path
  svcrdma: Introduce local rdma_rw API helpers
  svcrdma: Clean up svc_rdma_get_inv_rkey()
  svcrdma: Add helper to save pages under I/O
  svcrdma: Eliminate RPCRDMA_SQ_DEPTH_MULT
  ...
2017-05-10 13:29:23 -07:00
NeilBrown
99bbf6ecc6 NFS: don't try to cross a mountpount when there isn't one there.
consider the sequence of commands:
 mkdir -p /import/nfs /import/bind /import/etc
 mount --bind / /import/bind
 mount --make-private /import/bind
 mount --bind /import/etc /import/bind/etc

 exportfs -o rw,no_root_squash,crossmnt,async,no_subtree_check localhost:/
 mount -o vers=4 localhost:/ /import/nfs
 ls -l /import/nfs/etc

You would not expect this to report a stale file handle.
Yet it does.

The manipulations under /import/bind cause the dentry for
/etc to get the DCACHE_MOUNTED flag set, even though nothing
is mounted on /etc.  This causes nfsd to call
nfsd_cross_mnt() even though there is no mountpoint.  So an
upcall to mountd for "/etc" is performed.

The 'crossmnt' flag on the export of / causes mountd to
report that /etc is exported as it is a descendant of /.  It
assumes the kernel wouldn't ask about something that wasn't
a mountpoint.  The filehandle returned identifies the
filesystem and the inode number of /etc.

When this filehandle is presented to rpc.mountd, via
"nfsd.fh", the inode cannot be found associated with any
name in /etc/exports, or with any mountpoint listed by
getmntent().  So rpc.mountd says the filehandle doesn't
exist. Hence ESTALE.

This is fixed by teaching nfsd not to trust DCACHE_MOUNTED
too much.  It is just a hint, not a guarantee.
Change nfsd_mountpoint() to return '1' for a certain mountpoint,
'2' for a possible mountpoint, and 0 otherwise.

Then change nfsd_crossmnt() to check if follow_down()
actually found a mountpount and, if not, to avoid performing
a lookup if the location is not known to certainly require
an export-point.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:54 -04:00
NeilBrown
717a94b5fc sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags()
It is not safe for one thread to modify the ->flags
of another thread as there is no locking that can protect
the update.

So tsk_restore_flags(), which takes a task pointer and modifies
the flags, is an invitation to do the wrong thing.

All current users pass "current" as the task, so no developers have
accepted that invitation.  It would be best to ensure it remains
that way.

So rename tsk_restore_flags() to current_restore_flags() and don't
pass in a task_struct pointer.  Always operate on current->flags.

Signed-off-by: NeilBrown <neilb@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-11 09:06:32 +02:00