We check if ->ki_pos is positive.  However, by that point we have
already done rw_verify_area(), which would have rejected such
unless the file had been one of /dev/mem, /dev/kmem and /proc/kcore.
All of which do not have vectored rw methods, so we would've bailed
out even earlier.

This check had been introduced before rw_verify_area() had been added there
- in fact, it was a subset of checks done on sync paths by rw_verify_area()
(back then the /dev/mem exception didn't exist at all).  The rest of checks
(mandatory locking, etc.) hadn't been added until later.  Unfortunately,
by the time the call of rw_verify_area() got added, the /dev/mem exception
had already appeared, so it wasn't obvious that the older explicit check
downstream had become dead code.  It *is* a dead code, though, since the few
files for which the exception applies do not have ->aio_{read,write}() or
->{read,write}_iter() and for them we won't reach that check anyway.

What's more, even if we ever introduce vectored methods for /dev/mem
and friends, they'll have to cope with negative positions anyway, since
readv(2) and writev(2) are using the same checks as read(2) and write(2) -
i.e. rw_verify_area().

Let's bury it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Way, way back kiocb used to be picked from arrays, so ioctx_alloc()
checked for multiplication overflow when calculating the size of
such array.  By the time fs/aio.c went into the tree (in 2002) they
were already allocated one-by-one by kmem_cache_alloc(), so that
check had already become pointless.  Let's bury it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

it's actually shorter that way *and* later we'll want iocb in scope
of generic_write_check() caller.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

identical to import_single_range()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We don't need req in either of those.  We don't need nr_segs in caller.
We don't really need len in caller either - iov_iter_count(&iter) will do.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

the only non-trivial detail is that we do it before rw_verify_area(),
so we'd better cap the length ourselves in aio_setup_single_rw()
case (for vectored case rw_copy_check_uvector() will do that for us).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

get it closer to matching {compat_,}rw_copy_check_uvector().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We have observed a BUG() crash in fs/attr.c:notify_change(). The crash
occurs during an rsync into a filesystem that is exported via NFS.

1.) fs/attr.c:notify_change() modifies the caller's version of attr.
2.) 6de0ec00 ("VFS: make notify_change pass ATTR_KILL_S*ID to
    setattr operations") introduced a BUG() restriction such that "no
    function will ever call notify_change() with both ATTR_MODE and
    ATTR_KILL_S*ID set". Under some circumstances though, it will have
    assisted in setting the caller's version of attr to this very
    combination.
3.) 27ac0ffe ("locks: break delegations on any attribute
    modification") introduced code to handle breaking
    delegations. This can result in notify_change() being re-called. attr
    _must_ be explicitly reset to avoid triggering the BUG() established
    in #2.
4.) The path that that triggers this is via fs/open.c:chmod_common().
    The combination of attr flags set here and in the first call to
    notify_change() along with a later failed break_deleg_wait()
    results in notify_change() being called again via retry_deleg
    without resetting attr.

Solution is to move retry_deleg in chmod_common() a bit further up to
ensure attr is completely reset.

There are other places where this seemingly could occur, such as
fs/utimes.c:utimes_common(), but the attr flags are not initially
set in such a way to trigger this.

Fixes: 27ac0ffe ("locks: break delegations on any attribute modification")
Reported-by: Eric Meddaugh <etmsys@rit.edu>
Tested-by: Eric Meddaugh <etmsys@rit.edu>
Signed-off-by: Andrew Elble <aweits@rit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

On a distributed filesystem it's possible for lookup to discover that a
directory it just found is already cached elsewhere in the directory
heirarchy.  The dcache won't let us keep the directory in both places,
so we have to move the dentry to the new location from the place we
previously had it cached.

If the parent has changed, then this requires all the same locks as we'd
need to do a cross-directory rename.  But we're already in lookup
holding one parent's i_mutex, so it's too late to acquire those locks in
the right order.

The (unreliable) solution in __d_unalias is to trylock() the required
locks and return -EBUSY if it fails.

I see no particular reason for returning -EBUSY, and -ESTALE is already
the result of some other lookup races on NFS.  I think -ESTALE is the
more helpful error return.  It also allows us to take advantage of the
logic Jeff Layton added in c6a94284 "vfs: fix renameat to retry on
ESTALE errors" and ancestors, which hopefully resolves some of these
errors before they're returned to userspace.

I can reproduce these cases using NFS with:

	ssh root@$client '
		mount -olookupcache=pos '$server':'$export' /mnt/
		mkdir /mnt/TO
		mkdir /mnt/DIR
		touch /mnt/DIR/test.txt
		while true; do
			strace -e open cat /mnt/DIR/test.txt 2>&1 | grep EBUSY
		done
	'
	ssh root@$server '
		while true; do
			mv $export/DIR $export/TO/DIR
			mv $export/TO/DIR $export/DIR
		done
	'

It also helps to add some other concurrent use of the directory on the
client (e.g., "ls /mnt/TO").  And you can replace the server-side mv's
by client-side mv's that are repeatedly killed.  (If the client is
interrupted while waiting for the RENAME response then it's left with a
dentry that has to go under one parent or the other, but it doesn't yet
know which.)

Acked-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

For one thing, LOOKUP_DIRECTORY will be dealt with in do_last().
For another, name can be an empty string, but not NULL - no callers
pass that and it would oops immediately if they would.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

just make const char iname[] the last member and compare name->name with
name->iname instead of checking name->separate

We need to make sure that out-of-line name doesn't end up allocated adjacent
to struct filename refering to it; fortunately, it's easy to achieve - just
allocate that struct filename with one byte in ->iname[], so that ->iname[0]
will be inside the same object and thus have an address different from that
of out-of-line name [spotted by Boqun Feng <boqun.feng@gmail.com>]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This is needed if user space wants to know supported bnep features
by kernel, e.g. if kernel supports sending response to bnep setup
control message. By now there is no possibility to know supported
features by kernel in case of bnep. Ioctls allows only to add connection,
delete connection, get connection list, get connection info. Adding
connection if it's possible (establishing network device connection) is
equivalent to starting bnep session. Bnep session handles data queue of
transmit, receive messages over bnep channel. It means that if we add
connection the received/transmitted data will be parsed immediately. In
case of get bnep features we want to know before session start, if we
should leave setup data on socket queue and let kernel to handle with it,
or in case of no setup handling support, if we should pull this message
and handle setup response within user space.

Signed-off-by: Grzegorz Kolodziejczyk <grzegorz.kolodziejczyk@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This should cover the set emitted by viced and the volume server.

Signed-off-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu>
Signed-off-by: David Howells <dhowells@redhat.com>

afs_send_empty_reply() doesn't require an iovec array with which to initialise
the msghdr, but can pass NULL instead.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>

Coverity reports a warning due to unitialized attr structure in one
code path.

Reported by Coverity (CID 728535)

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>

null tcon is not possible in these paths so
remove confusing null check

Reported by Coverity (CID 728519)

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>

remove impossible check

Pointed out by Coverity (CID 115422)

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>

workstation_RFC1001_name is part of the struct and can't be null,
remove impossible comparison (array vs. null)

Pointed out by Coverity (CID 140095)

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>

Coverity reports a warning for referencing the beginning of the
SMB2/SMB3 frame using the ProtocolId field as an array. Although
it works the same either way, this patch should quiet the warning
and might be a little clearer.

Reported by Coverity (CID 741269)

Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>

null tcon is not likely in these paths in current
code, but obviously it does clarify the code to
check for null (if at all) before derefrencing
rather than after.

Reported by Coverity (CID 1042666)

Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>

Although unlikely to fail (and tree connect does not commonly send
a password since SECMODE_USER is the default for most servers)
do not ignore errors on SMBNTEncrypt in SMB Tree Connect.

Reported by Coverity (CID 1226853)

Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>

Pointed out by coverity analyzer.  resp_buftype is
not initialized in one path which can rarely log
a spurious warning (buf is null so there will
not be a problem with freeing data, but if buf_type
were randomly set to wrong value could log a warning)

Reported by Coverity (CID 1269144)

Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>

Turns out sending out layouts to any client is a bad idea if they
can't get at the storage device, so require explicit admin action
to enable pNFS.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

locks_delete_lock_ctx() is called inside the loop, so we
should use list_for_each_entry_safe.

Fixes: 8634b51f (locks: convert lease handling to file_lock_context)
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>

With return layout as, (seg is return layout, lo is record layout)
seg->offset <= lo->offset and layout_end(seg) < layout_end(lo),
nfsd should update lo's offset to seg's end,
and,
seg->offset > lo->offset and layout_end(seg) >= layout_end(lo),
nfsd should update lo's end to seg's offset.

Fixes: 9cf514cc ("nfsd: implement pNFS operations")
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

When testing pnfs with nfsd_debug on, nfsd print a negative number
of layout length and foff in nfsd4_block_proc_layoutget as,
"GET: -xxxx:-xxx 2"

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

alloc_init_lock_stateowner can return an already freed entry if there is
a race to put openowners in the hashtable.

Noticed by inspection after Jeff Layton fixed the same bug for open
owners.  Depending on client behavior, this one may be trickier to
trigger in practice.

Fixes: c58c6610 "nfsd: Protect adding/removing lock owners using client_lock"
Cc: <stable@vger.kernel.org>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Acked-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

alloc_init_open_stateowner can return an already freed entry if there is
a race to put openowners in the hashtable.

In commit 7ffb5880, we changed it so that we allocate and initialize
an openowner, and then check to see if a matching one got stuffed into
the hashtable in the meantime. If it did, then we free the one we just
allocated and take a reference on the one already there. There is a bug
here though. The code will then return the pointer to the one that was
allocated (and has now been freed).

This wasn't evident before as this race almost never occurred. The Linux
kernel client used to serialize requests for a single openowner.  That
has changed now with v4.0 kernels, and this race can now easily occur.

Fixes: 7ffb5880
Cc: <stable@vger.kernel.org> # v3.17+
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Reported-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Fix B-tree corruption when a new record is inserted at position 0 in the
node in hfs_brec_insert().  In this case a hfs_brec_update_parent() is
called to update the parent index node (if exists) and it is passed
hfs_find_data with a search_key containing a newly inserted key instead
of the key to be updated.  This results in an inconsistent index node.
The bug reproduces on my machine after an extents overflow record for
the catalog file (CNID=4) is inserted into the extents overflow B-tree.
Because of a low (reserved) value of CNID=4, it has to become the first
record in the first leaf node.

The resulting first leaf node is correct:

  ----------------------------------------------------
  | key0.CNID=4 | key1.CNID=123 | key2.CNID=456, ... |
  ----------------------------------------------------

But the parent index key0 still contains the previous key CNID=123:

  -----------------------
  | key0.CNID=123 | ... |
  -----------------------

A change in hfs_brec_insert() makes hfs_brec_update_parent() work
correctly by preventing it from getting fd->record=-1 value from
__hfs_brec_find().

Along the way, I removed duplicate code with unification of the if
condition.  The resulting code is equivalent to the original code
because node is never 0.

Also hfs_brec_update_parent() will now return an error after getting a
negative fd->record value.  However, the return value of
hfs_brec_update_parent() is not checked anywhere in the file and I'm
leaving it unchanged by this patch.  brec.c lacks error checking after
some other calls too, but this issue is of less importance than the one
being fixed by this patch.

Signed-off-by: Sergei Antonov <saproj@gmail.com>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>