linux-stable.git/fs, branch v4.8.9

NFSv4.1: work around -Wmaybe-uninitialized warning

2016-11-18T09:51:52+00:00

commit 68a564006a21ae59c7c51b4359e2e8efa42ae4af upstream.

A bugfix introduced a harmless gcc warning in nfs4_slot_seqid_in_use
if we enable -Wmaybe-uninitialized again:

fs/nfs/nfs4session.c:203:54: error: 'cur_seq' may be used uninitialized in this function [-Werror=maybe-uninitialized]

gcc is not smart enough to conclude that the IS_ERR/PTR_ERR pair
results in a nonzero return value here. Using PTR_ERR_OR_ZERO()
instead makes this clear to the compiler.

The warning originally did not appear in v4.8 as it was globally
disabled, but the bugfix that introduced the warning got backported
to stable kernels which again enable it, and this is now the only
warning in the v4.7 builds.

Fixes: e09c978aae5b ("NFSv4.1: Fix Oopsable condition in server callback races")
Signed-off-by: Arnd Bergmann 
Cc: Trond Myklebust 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

coredump: fix unfreezable coredumping task

2016-11-18T09:51:45+00:00

commit 70d78fe7c8b640b5acfad56ad341985b3810998a upstream.

It could be not possible to freeze coredumping task when it waits for
'core_state->startup' completion, because threads are frozen in
get_signal() before they got a chance to complete 'core_state->startup'.

Inability to freeze a task during suspend will cause suspend to fail.
Also CRIU uses cgroup freezer during dump operation.  So with an
unfreezable task the CRIU dump will fail because it waits for a
transition from 'FREEZING' to 'FROZEN' state which will never happen.

Use freezer_do_not_count() to tell freezer to ignore coredumping task
while it waits for core_state->startup completion.

Link: http://lkml.kernel.org/r/1475225434-3753-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin 
Acked-by: Pavel Machek 
Acked-by: Oleg Nesterov 
Cc: Alexander Viro 
Cc: Tejun Heo 
Cc: "Rafael J. Wysocki" 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

btrfs: qgroup: Prevent qgroup->reserved from going subzero

2016-11-10T15:38:57+00:00

commit 0b34c261e235a5c74dcf78bd305845bd15fe2b42 upstream.

While free'ing qgroup->reserved resources, we much check if
the page has not been invalidated by a truncate operation
by checking if the page is still dirty before reducing the
qgroup resources. Resources in such a case are free'd when
the entire extent is released by delayed_ref.

This fixes a double accounting while releasing resources
in case of truncating a file, reproduced by the following testcase.

SCRATCH_DEV=/dev/vdb
SCRATCH_MNT=/mnt
mkfs.btrfs -f $SCRATCH_DEV
mount -t btrfs $SCRATCH_DEV $SCRATCH_MNT
cd $SCRATCH_MNT
btrfs quota enable $SCRATCH_MNT
btrfs subvolume create a
btrfs qgroup limit 500m a $SCRATCH_MNT
sync
for c in {1..15}; do
dd if=/dev/zero  bs=1M count=40 of=$SCRATCH_MNT/a/file;
done

sleep 10
sync
sleep 5

touch $SCRATCH_MNT/a/newfile

echo "Removing file"
rm $SCRATCH_MNT/a/file

Fixes: b9d0b38928 ("btrfs: Add handler for invalidate page")
Signed-off-by: Goldwyn Rodrigues 
Reviewed-by: Qu Wenruo 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

ovl: fsync after copy-up

2016-11-10T15:38:51+00:00

commit 641089c1549d8d3df0b047b5de7e9a111362cdce upstream.

Make sure the copied up file hits the disk before renaming to the final
destination.  If this is not done then the copy-up may corrupt the data in
the file in case of a crash.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

ovl: update S_ISGID when setting posix ACLs

2016-11-10T15:38:51+00:00

commit fd3220d37b1f6f0cab6142d98b0e6c4082e63299 upstream.

This change fixes xfstest generic/375, which failed to clear the
setgid bit in the following test case on overlayfs:

  touch $testfile
  chown 100:100 $testfile
  chmod 2755 $testfile
  _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile

Reported-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi 
Tested-by: Amir Goldstein 
Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting")
Signed-off-by: Greg Kroah-Hartman

ovl: fix get_acl() on tmpfs

2016-11-10T15:38:51+00:00

commit b93d4a0eb308d4400b84c8b24c1b80e09a9497d0 upstream.

tmpfs doesn't have ->get_acl() because it only uses cached acls.

This fixes the acl tests in pjdfstest when tmpfs is used as the upper layer
of the overlay.

Reported-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi 
Fixes: 39a25b2b3762 ("ovl: define ->get_acl() for overlay inodes")
Signed-off-by: Greg Kroah-Hartman

nfsd: Fix general protection fault in release_lock_stateid()

2016-11-10T15:38:51+00:00

commit f46c445b79906a9da55c13e0a6f6b6a006b892fe upstream.

When I push NFSv4.1 / RDMA hard, (xfstests generic/089, for example),
I get this crash on the server:

Oct 28 22:04:30 klimt kernel: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
Oct 28 22:04:30 klimt kernel: Modules linked in: cts rpcsec_gss_krb5 iTCO_wdt iTCO_vendor_support sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm btrfs irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd xor pcspkr raid6_pq i2c_i801 i2c_smbus lpc_ich mfd_core sg mei_me mei ioatdma shpchp wmi ipmi_si ipmi_msghandler rpcrdma ib_ipoib rdma_ucm acpi_power_meter acpi_pad ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb ahci libahci ptp mlx4_core pps_core dca libata i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod
Oct 28 22:04:30 klimt kernel: CPU: 7 PID: 1558 Comm: nfsd Not tainted 4.9.0-rc2-00005-g82cd754 #8
Oct 28 22:04:30 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Oct 28 22:04:30 klimt kernel: task: ffff880835c3a100 task.stack: ffff8808420d8000
Oct 28 22:04:30 klimt kernel: RIP: 0010:[]  [] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP: 0018:ffff8808420dbce0  EFLAGS: 00010246
Oct 28 22:04:30 klimt kernel: RAX: ffff88084e6660f0 RBX: ffff88084e667020 RCX: 0000000000000000
Oct 28 22:04:30 klimt kernel: RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff88084e667020
Oct 28 22:04:30 klimt kernel: RBP: ffff8808420dbcf8 R08: 0000000000000001 R09: 0000000000000000
Oct 28 22:04:30 klimt kernel: R10: ffff880835c3a100 R11: ffff880835c3aca8 R12: 6b6b6b6b6b6b6b6b
Oct 28 22:04:30 klimt kernel: R13: ffff88084e6670d8 R14: ffff880835f546f0 R15: ffff880835f1c548
Oct 28 22:04:30 klimt kernel: FS:  0000000000000000(0000) GS:ffff88087bdc0000(0000) knlGS:0000000000000000
Oct 28 22:04:30 klimt kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 28 22:04:30 klimt kernel: CR2: 00007ff020389000 CR3: 0000000001c06000 CR4: 00000000001406e0
Oct 28 22:04:30 klimt kernel: Stack:
Oct 28 22:04:30 klimt kernel: ffff88084e667020 0000000000000000 ffff88084e6670d8 ffff8808420dbd20
Oct 28 22:04:30 klimt kernel: ffffffffa05ac80d ffff880835f54548 ffff88084e640008 ffff880835f545b0
Oct 28 22:04:30 klimt kernel: ffff8808420dbd70 ffffffffa059803d ffff880835f1c768 0000000000000870
Oct 28 22:04:30 klimt kernel: Call Trace:
Oct 28 22:04:30 klimt kernel: [] nfsd4_free_stateid+0xfd/0x1b0 [nfsd]
Oct 28 22:04:30 klimt kernel: [] nfsd4_proc_compound+0x40d/0x690 [nfsd]
Oct 28 22:04:30 klimt kernel: [] nfsd_dispatch+0xd4/0x1d0 [nfsd]
Oct 28 22:04:30 klimt kernel: [] svc_process_common+0x3d9/0x700 [sunrpc]
Oct 28 22:04:30 klimt kernel: [] svc_process+0xf4/0x330 [sunrpc]
Oct 28 22:04:30 klimt kernel: [] nfsd+0xfa/0x160 [nfsd]
Oct 28 22:04:30 klimt kernel: [] ? nfsd_destroy+0x170/0x170 [nfsd]
Oct 28 22:04:30 klimt kernel: [] kthread+0x10b/0x120
Oct 28 22:04:30 klimt kernel: [] ? kthread_stop+0x280/0x280
Oct 28 22:04:30 klimt kernel: [] ret_from_fork+0x2a/0x40
Oct 28 22:04:30 klimt kernel: Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 48 8b 87 b0 00 00 00 48 89 fb 4c 8b a0 98 00 00 00 <49> 8b 44 24 20 48 8d b8 80 03 00 00 e8 10 66 1a e1 48 89 df e8
Oct 28 22:04:30 klimt kernel: RIP  [] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP 
Oct 28 22:04:30 klimt kernel: ---[ end trace cf5d0b371973e167 ]---

Jeff Layton says:
> Hm...now that I look though, this is a little suspicious:
>
>    struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner);
>
> I wonder if it's possible for the openstateid to have already been
> destroyed at this point.
>
> We might be better off doing something like this to get the client pointer:
>
>    stp->st_stid.sc_client;
>
> ...which should be more direct and less dependent on other stateids
> staying valid.

With the suggested change, I am no longer able to reproduce the above oops.

v2: Fix unhash_lock_stateid() as well

Fix-suggested-by: Jeff Layton 
Fixes: 42691398be08 ('nfsd: Fix race between FREE_STATEID and LOCK')
Signed-off-by: Chuck Lever 
Reviewed-by: Jeff Layton 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

ubifs: Fix regression in ubifs_readdir()

2016-11-10T15:38:49+00:00

commit a00052a296e54205cf238c75bd98d17d5d02a6db upstream.

Commit c83ed4c9dbb35 ("ubifs: Abort readdir upon error") broke
overlayfs support because the fix exposed an internal error
code to VFS.

Reported-by: Peter Rosin 
Tested-by: Peter Rosin 
Reported-by: Ralph Sennhauser 
Tested-by: Ralph Sennhauser 
Fixes: c83ed4c9dbb35 ("ubifs: Abort readdir upon error")
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

ubifs: Abort readdir upon error

2016-11-10T15:38:49+00:00

commit c83ed4c9dbb358b9e7707486e167e940d48bfeed upstream.

If UBIFS is facing an error while walking a directory, it reports this
error and ubifs_readdir() returns the error code. But the VFS readdir
logic does not make the getdents system call fail in all cases. When the
readdir cursor indicates that more entries are present, the system call
will just return and the libc wrapper will try again since it also
knows that more entries are present.
This causes the libc wrapper to busy loop for ever when a directory is
corrupted on UBIFS.
A common approach do deal with corrupted directory entries is
skipping them by setting the cursor to the next entry. On UBIFS this
approach is not possible since we cannot compute the next directory
entry cursor position without reading the current entry. So all we can
do is setting the cursor to the "no more entries" position and make
getdents exit.

Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix races on root_log_ctx lists

2016-11-10T15:38:48+00:00

commit 570dd45042a7c8a7aba1ee029c5dd0f5ccf41b9b upstream.

btrfs_remove_all_log_ctxs takes a shortcut where it avoids walking the
list because it knows all of the waiters are patiently waiting for the
commit to finish.

But, there's a small race where btrfs_sync_log can remove itself from
the list if it finds a log commit is already done.  Also, it uses
list_del_init() to remove itself from the list, but there's no way to
know if btrfs_remove_all_log_ctxs has already run, so we don't know for
sure if it is safe to call list_del_init().

This gets rid of all the shortcuts for btrfs_remove_all_log_ctxs(), and
just calls it with the proper locking.

This is part two of the corruption fixed by cbd60aa7cd1.  I should have
done this in the first place, but convinced myself the optimizations were
safe.  A 12 hour run of dbench 2048 will eventually trigger a list debug
WARN_ON for the list_del_init() in btrfs_sync_log().

Fixes: d1433debe7f4346cf9fc0dafc71c3137d2a97bc4
Reported-by: Dave Jones 
Signed-off-by: Chris Mason 
Signed-off-by: Greg Kroah-Hartman