If the NFSv4.2 server supports the 'change_attr_type' attribute, then
allow the client to optimise its attribute cache update strategy.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

The change_attr_type allows the server to provide a description of how
the change attribute will behave. This again will allow the client to
optimise its behaviour w.r.t. attribute revalidation.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

When the client is caching data and a write delegation is held, then the
server may send a CB_GETATTR to query the attributes. When this happens,
the client is supposed to bump the change attribute value that it
returns if it holds cached data.
However that process uses a value that is stored in the delegation. We
do not want to bump the change attribute held in the inode.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

At least two extra fields have been added to fsinfo since this was last
updated.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

We should not be invalidating the access or acl caches in
nfs_check_inode_attributes(), since the point is we're unsure about
whether the contents of the struct nfs_fattr are fully up to date.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Commit 0b467264 ("NFS: Fix attribute revalidation") changed the way
we populate the 'invalid' attribute, and made the line that strips away
the NFS_INO_INVALID_ATTR bits redundant.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

If there is an outstanding layoutcommit, then the list of attributes
whose values are expected to change is not the full set. So let's
be explicit about the full list.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

chown()/chgrp() and chmod() are separate operations, and in addition,
there are mode operations that are performed automatically by the
server. So let's track mode validity separately from the file ownership
validity.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Rename can cause us to revalidate the access cache, so lets track the
nlinks separately from the mode/uid/gid.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Don't remove flags from the set retrieved from the cache_validity.
We do want to retrieve all attributes that are listed as being
invalid, whether or not there is a delegation set.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

It is no longer necessary to preserve the NFS_INO_REVAL_PAGECACHE flag.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

When checking cache validity, be more specific than just 'we want to
check the page cache validity'. In almost all cases, we want to check
that change attribute, and possibly also the size.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Add an argument to nfs_revalidate_inode() to allow callers to specify
which attributes they need to check for validity.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

When we do a 'chown' or 'chgrp', the server will clear the suid/sgid
bits. Ensure that we mirror that in nfs_setattr_update_inode().
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

If statx has valid attributes available that weren't asked for, then
return them and set the result mask appropriately.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

If the user doesn't set STATX_UID/GID/MODE, then don't care if they are
known to be stale. Ditto if we're not being asked for the file size.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Ensure that when the change attribute or the size change, we also
remember to revalidate the space used.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

When we're looking to revalidate the page cache, we should just ensure
that we mark the change attribute invalid.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

We don't currently support STATX_BTIME, so don't advertise it in the
return values for nfs_getattr().
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Add missing enum definitions and missing entries for
nfs_show_cache_validity().
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

We need to use unsigned long subtraction and then convert to signed in
order to deal correcly with C overflow rules.

Fixes: f5062003 ("NFS: Set an attribute barrier on all updates")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Whether we're allocating or delallocating space, we should flush out the
pending writes in order to avoid races with attribute updates.

Fixes: 1e564d3d ("NFSv4.2: Fix a race in nfs42_proc_deallocate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

We can't use nfs4_fattr_bitmap as a bitmask, because it hasn't been
filtered to represent the attributes supported by the server. Instead,
let's revert to using server->cache_consistency_bitmask after adding in
the missing SPACE_USED attribute.

Fixes: 913eca1a ("NFS: Fallocate should use the nfs4_fattr_bitmap")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

As currently set, the calls to nfs4_bitmask_adjust() will end up
overwriting the contents of the nfs_server cache_consistency_bitmask
field.
The intention here should be to modify a private copy of that mask in
the close/delegreturn/write arguments.

Fixes: 76bd5c01 ("NFSv4: make cache consistency bitmask dynamic")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Ensure that we invalidate the fscache before we strip the
NFS_INO_INVALID_DATA flag.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

The change attribute is always set by all NFS client versions so get rid
of the open-coded version.

Fixes: 3cc55f44 ("nfs: use change attribute for NFS re-exports")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

If the server sends CB_ calls on a connection that is not associated
with the backchannel, refuse to process the call and shut down the
connection.  This avoids a NULL dereference crash in
xprt_complete_bc_request().  There's not much more we can do in this
situation unless we want to look into allowing all connections to be
associated with the fore and back channel.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Mounting NFSv3 uses default timeout parameters specified by underlying
sunrpc transport, and mount options like 'timeo' and 'retrans', unlike
NFSv4, are not honored.

But sometimes we want to set non-default timeout value when mounting
NFSv3, so pass 'timeo' and 'retrans' to nfs_mount() and fill the
'timeout' field of struct rpc_create_args before creating RPC
connection. This is also consistent with NFSv4 behavior.

Note that this only sets the timeout value of rpc connection to mountd,
but the timeout of rpcbind connection should be set as well. A later
patch will fix the rpcbind part.
Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Currently rpcbind client is created without setting rpc timeout (thus
using the default value). But if the rpc_task already has a customized
timeout in its tk_client field, it's also ignored.

Let's use the same timeout setting in rpc_task->tk_client->cl_timeout
for rpcbind connection.
Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Rather than removing the support in nfs_init_timeout_values(), we should
just fix up the validation checks in the mount option parsers.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

s/attribues/attributes/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Fix shift out-of-bounds in xprt_calc_majortimeo(). This is caused
by a garbage timeout (retrans) mount option being passed to nfs mount,
in this case from syzkaller.

If the protocol is XPRT_TRANSPORT_UDP, then 'retrans' is a shift
value for a 64-bit long integer, so 'retrans' cannot be >= 64.
If it is >= 64, fail the mount and return an error.

Fixes: 9954bf92 ("NFS: Move mount parameterisation bits into their own file")
Reported-by: syzbot+ba2e91df8f74809417fa@syzkaller.appspotmail.com
Reported-by: syzbot+f3a0fa110fd630ab56c8@syzkaller.appspotmail.com
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

The cached NFSv3/v4 readdir cookies are associated with a verifier,
which is checked by the server on subsequent calls to readdir, and is
only expected to change when the cookies (and hence also the page cache
contents) are considered invalid.
We therefore do have to store the verifier, but only when the page cache
is empty.

Fixes: b593c09f ("NFS: Improve handling of directory verifiers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

If we're doing uncached readdir(), then the readdir cookie could be
different from the one cached in the nfs_inode. We should therefore
ensure that we save that one in the struct nfs_open_dir_context.

Fixes: 35df59d3 ("NFS: Reduce number of RPC calls when doing uncached readdir")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

If the loop in nfs_readdir_xdr_to_array() runs more than once, subsequent
READDIR RPCs may wrongly carry a zero cookie verifier and non-zero cookie.
Make sure subsequent calls to READDIR carry the cookie verifier returned
by the first call.
Signed-off-by: Nagendra S Tomar <natomar@microsoft.com>
Fixes: b593c09f ("NFS: Improve handling of directory verifiers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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

When we have multiple RPC requests queued up, it makes sense to set the
TCP_CORK option while the transmit queue is non-empty.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Simplify the code that retries locks based on notification events.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

For each device, the nosy driver allocates a pcilynx structure.
A use-after-free might happen in the following scenario:

 1. Open nosy device for the first time and call ioctl with command
    NOSY_IOC_START, then a new client A will be malloced and added to
    doubly linked list.
 2. Open nosy device for the second time and call ioctl with command
    NOSY_IOC_START, then a new client B will be malloced and added to
    doubly linked list.
 3. Call ioctl with command NOSY_IOC_START for client A, then client A
    will be readded to the doubly linked list. Now the doubly linked
    list is messed up.
 4. Close the first nosy device and nosy_release will be called. In
    nosy_release, client A will be unlinked and freed.
 5. Close the second nosy device, and client A will be referenced,
    resulting in UAF.

The root cause of this bug is that the element in the doubly linked list
is reentered into the list.

Fix this bug by adding a check before inserting a client.  If a client
is already in the linked list, don't insert it.

The following KASAN report reveals it:

   BUG: KASAN: use-after-free in nosy_release+0x1ea/0x210
   Write of size 8 at addr ffff888102ad7360 by task poc
   CPU: 3 PID: 337 Comm: poc Not tainted 5.12.0-rc5+ #6
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
   Call Trace:
     nosy_release+0x1ea/0x210
     __fput+0x1e2/0x840
     task_work_run+0xe8/0x180
     exit_to_user_mode_prepare+0x114/0x120
     syscall_exit_to_user_mode+0x1d/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xae

   Allocated by task 337:
     nosy_open+0x154/0x4d0
     misc_open+0x2ec/0x410
     chrdev_open+0x20d/0x5a0
     do_dentry_open+0x40f/0xe80
     path_openat+0x1cf9/0x37b0
     do_filp_open+0x16d/0x390
     do_sys_openat2+0x11d/0x360
     __x64_sys_open+0xfd/0x1a0
     do_syscall_64+0x33/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xae

   Freed by task 337:
     kfree+0x8f/0x210
     nosy_release+0x158/0x210
     __fput+0x1e2/0x840
     task_work_run+0xe8/0x180
     exit_to_user_mode_prepare+0x114/0x120
     syscall_exit_to_user_mode+0x1d/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xae

   The buggy address belongs to the object at ffff888102ad7300 which belongs to the cache kmalloc-128 of size 128
   The buggy address is located 96 bytes inside of 128-byte region [ffff888102ad7300, ffff888102ad7380)

[ Modified to use 'list_empty()' inside proper lock  - Linus ]

Link: https://lore.kernel.org/lkml/1617433116-5930-1-git-send-email-zheyuma97@gmail.com/Reported-and-tested-by: 马哲宇 (Zheyu Ma) <zheyuma97@gmail.com>
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>