linux-stable.git/fs/nfs, branch linux-3.16.y

NFS: Directory page cache pages need to be locked when read

2020-05-22T20:19:43+00:00

commit 114de38225d9b300f027e2aec9afbb6e0def154b upstream.

When a NFS directory page cache page is removed from the page cache,
its contents are freed through a call to nfs_readdir_clear_array().
To prevent the removal of the page cache entry until after we've
finished reading it, we must take the page lock.

Fixes: 11de3b11e08c ("NFS: Fix a memory leak in nfs_readdir")
Signed-off-by: Trond Myklebust 
Reviewed-by: Benjamin Coddington 
Signed-off-by: Anna Schumaker 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

NFS: Fix memory leaks and corruption in readdir

2020-05-22T20:19:42+00:00

commit 4b310319c6a8ce708f1033d57145e2aa027a883c upstream.

nfs_readdir_xdr_to_array() must not exit without having initialised
the array, so that the page cache deletion routines can safely
call nfs_readdir_clear_array().
Furthermore, we should ensure that if we exit nfs_readdir_filler()
with an error, we free up any page contents to prevent a leak
if we try to fill the page again.

Fixes: 11de3b11e08c ("NFS: Fix a memory leak in nfs_readdir")
Signed-off-by: Trond Myklebust 
Reviewed-by: Benjamin Coddington 
Signed-off-by: Anna Schumaker 
Signed-off-by: Ben Hutchings

nfs: use kmap/kunmap directly

2020-05-22T20:19:42+00:00

commit 0795bf8357c1887e2a95e6e4f5b89d0896a0d929 upstream.

This patch removes useless nfs_readdir_get_array() and
nfs_readdir_release_array() as suggested by Trond Myklebust

nfs_readdir() calls nfs_revalidate_mapping() before
readdir_search_pagecache() , nfs_do_filldir(), uncached_readdir()
so mapping should be correct.

While kmap() can't fail, all subsequent error checks were removed
as well as unused labels.

Signed-off-by: Fabian Frederick 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

nfs: NFS_SWAP should depend on SWAP

2020-05-22T20:19:28+00:00

commit 474c4f306eefbb21b67ebd1de802d005c7d7ecdc upstream.

If CONFIG_SWAP=n, it does not make much sense to offer the user the
option to enable support for swapping over NFS, as that will still fail
at run time:

    # swapon /swap
    swapon: /swap: swapon failed: Function not implemented

Fix this by adding a dependency on CONFIG_SWAP.

Fixes: a564b8f0398636ba ("nfs: enable swap on NFS")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Anna Schumaker 
Signed-off-by: Ben Hutchings

NFSv4: Fix a potential sleep while atomic in nfs4_do_reclaim()

2019-11-22T15:57:11+00:00

commit c77e22834ae9a11891cb613bd9a551be1b94f2bc upstream.

John Hubbard reports seeing the following stack trace:

nfs4_do_reclaim
   rcu_read_lock /* we are now in_atomic() and must not sleep */
       nfs4_purge_state_owners
           nfs4_free_state_owner
               nfs4_destroy_seqid_counter
                   rpc_destroy_wait_queue
                       cancel_delayed_work_sync
                           __cancel_work_timer
                               __flush_work
                                   start_flush_work
                                       might_sleep:
                                        (kernel/workqueue.c:2975: BUG)

The solution is to separate out the freeing of the state owners
from nfs4_purge_state_owners(), and perform that outside the atomic
context.

Reported-by: John Hubbard 
Fixes: 0aaaf5c424c7f ("NFS: Cache state owners after files are closed")
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

NFSv4: Handle the special Linux file open access mode

2019-10-31T22:15:02+00:00

commit 44942b4e457beda00981f616402a1a791e8c616e upstream.

According to the open() manpage, Linux reserves the access mode 3
to mean "check for read and write permission on the file and return
a file descriptor that can't be used for reading or writing."

Currently, the NFSv4 code will ask the server to open the file,
and will use an incorrect share access mode of 0. Since it has
an incorrect share access mode, the client later forgets to send
a corresponding close, meaning it can leak stateids on the server.

Fixes: ce4ef7c0a8a05 ("NFS: Split out NFS v4 file operations")
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

NFS4: Fix v4.0 client state corruption when mount

2019-09-23T20:12:03+00:00

commit f02f3755dbd14fb935d24b14650fff9ba92243b8 upstream.

stat command with soft mount never return after server is stopped.

When alloc a new client, the state of the client will be set to
NFS4CLNT_LEASE_EXPIRED.

When the server is stopped, the state manager will work, and accord
the state to recover. But the state is NFS4CLNT_LEASE_EXPIRED, it
will drain the slot table and lead other task to wait queue, until
the client recovered. Then the stat command is hung.

When discover server trunking, the client will renew the lease,
but check the client state, it lead the client state corruption.

So, we need to call state manager to recover it when detect server
ip trunking.

Signed-off-by: ZhangXiaoxu 
Signed-off-by: Anna Schumaker 
Signed-off-by: Ben Hutchings

NFSv4.1: Reinitialise sequence results before retransmitting a request

2019-07-09T21:04:09+00:00

commit c1dffe0bf7f9c3d57d9f237a7cb2a81e62babd2b upstream.

If we have to retransmit a request, we should ensure that we reinitialise
the sequence results structure, since in the event of a signal
we need to treat the request as if it had not been sent.

Signed-off-by: Trond Myklebust 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

fs/nfs: Fix nfs_parse_devname to not modify it's argument

2019-07-09T21:04:04+00:00

commit 40cc394be1aa18848b8757e03bd8ed23281f572e upstream.

In the rare and unsupported case of a hostname list nfs_parse_devname
will modify dev_name.  There is no need to modify dev_name as the all
that is being computed is the length of the hostname, so the computed
length can just be shorted.

Fixes: dc04589827f7 ("NFS: Use common device name parsing logic for NFSv4 and NFSv2/v3")
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

NFSv4: Don't exit the state manager without clearing NFS4CLNT_MANAGER_RUNNING

2019-02-11T17:54:02+00:00

commit 21a446cf186570168b7281b154b1993968598aca upstream.

If we exit the NFSv4 state manager due to a umount, then we can end up
leaving the NFS4CLNT_MANAGER_RUNNING flag set. If another mount causes
the nfs4_client to be rereferenced before it is destroyed, then we end
up never being able to recover state.

Fixes: 47c2199b6eb5 ("NFSv4.1: Ensure state manager thread dies on last ...")
Signed-off-by: Trond Myklebust 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings