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61053 Commits (fa3c053b831318b9dba8c197026035f06889307a)

Author SHA1 Message Date
Ronnie Sahlberg 03f6c2bf95 cifs: make sure we do not overflow the max EA buffer size
commit 85db6b7ae6 upstream.

RHBZ: 1752437

Before we add a new EA we should check that this will not overflow
the maximum buffer we have available to read the EAs back.
Otherwise we can get into a situation where the EAs are so big that
we can not read them back to the client and thus we can not list EAs
anymore or delete them.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:53:03 +01:00
David Sterba cafaf6bcce btrfs: log message when rw remount is attempted with unclean tree-log
commit 10a3a3edc5 upstream.

A remount to a read-write filesystem is not safe when there's tree-log
to be replayed. Files that could be opened until now might be affected
by the changes in the tree-log.

A regular mount is needed to replay the log so the filesystem presents
the consistent view with the pending changes included.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:53:01 +01:00
David Sterba 2655c88c03 btrfs: print message when tree-log replay starts
commit e8294f2f6a upstream.

There's no logged information about tree-log replay although this is
something that points to previous unclean unmount. Other filesystems
report that as well.

Suggested-by: Chris Murphy <lists@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:53:00 +01:00
Wenwen Wang f3cdf024ed btrfs: ref-verify: fix memory leaks
commit f311ade3a7 upstream.

In btrfs_ref_tree_mod(), 'ref' and 'ra' are allocated through kzalloc() and
kmalloc(), respectively. In the following code, if an error occurs, the
execution will be redirected to 'out' or 'out_unlock' and the function will
be exited. However, on some of the paths, 'ref' and 'ra' are not
deallocated, leading to memory leaks. For example, if 'action' is
BTRFS_ADD_DELAYED_EXTENT, add_block_entry() will be invoked. If the return
value indicates an error, the execution will be redirected to 'out'. But,
'ref' is not deallocated on this path, causing a memory leak.

To fix the above issues, deallocate both 'ref' and 'ra' before exiting from
the function when an error is encountered.

CC: stable@vger.kernel.org # 4.15+
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:53:00 +01:00
Filipe Manana bf4a9715a9 Btrfs: fix race between using extent maps and merging them
commit ac05ca913e upstream.

We have a few cases where we allow an extent map that is in an extent map
tree to be merged with other extents in the tree. Such cases include the
unpinning of an extent after the respective ordered extent completed or
after logging an extent during a fast fsync. This can lead to subtle and
dangerous problems because when doing the merge some other task might be
using the same extent map and as consequence see an inconsistent state of
the extent map - for example sees the new length but has seen the old start
offset.

With luck this triggers a BUG_ON(), and not some silent bug, such as the
following one in __do_readpage():

  $ cat -n fs/btrfs/extent_io.c
  3061  static int __do_readpage(struct extent_io_tree *tree,
  3062                           struct page *page,
  (...)
  3127                  em = __get_extent_map(inode, page, pg_offset, cur,
  3128                                        end - cur + 1, get_extent, em_cached);
  3129                  if (IS_ERR_OR_NULL(em)) {
  3130                          SetPageError(page);
  3131                          unlock_extent(tree, cur, end);
  3132                          break;
  3133                  }
  3134                  extent_offset = cur - em->start;
  3135                  BUG_ON(extent_map_end(em) <= cur);
  (...)

Consider the following example scenario, where we end up hitting the
BUG_ON() in __do_readpage().

We have an inode with a size of 8KiB and 2 extent maps:

  extent A: file offset 0, length 4KiB, disk_bytenr = X, persisted on disk by
            a previous transaction

  extent B: file offset 4KiB, length 4KiB, disk_bytenr = X + 4KiB, not yet
            persisted but writeback started for it already. The extent map
	    is pinned since there's writeback and an ordered extent in
	    progress, so it can not be merged with extent map A yet

The following sequence of steps leads to the BUG_ON():

1) The ordered extent for extent B completes, the respective page gets its
   writeback bit cleared and the extent map is unpinned, at that point it
   is not yet merged with extent map A because it's in the list of modified
   extents;

2) Due to memory pressure, or some other reason, the MM subsystem releases
   the page corresponding to extent B - btrfs_releasepage() is called and
   returns 1, meaning the page can be released as it's not dirty, not under
   writeback anymore and the extent range is not locked in the inode's
   iotree. However the extent map is not released, either because we are
   not in a context that allows memory allocations to block or because the
   inode's size is smaller than 16MiB - in this case our inode has a size
   of 8KiB;

3) Task B needs to read extent B and ends up __do_readpage() through the
   btrfs_readpage() callback. At __do_readpage() it gets a reference to
   extent map B;

4) Task A, doing a fast fsync, calls clear_em_loggin() against extent map B
   while holding the write lock on the inode's extent map tree - this
   results in try_merge_map() being called and since it's possible to merge
   extent map B with extent map A now (the extent map B was removed from
   the list of modified extents), the merging begins - it sets extent map
   B's start offset to 0 (was 4KiB), but before it increments the map's
   length to 8KiB (4kb + 4KiB), task A is at:

   BUG_ON(extent_map_end(em) <= cur);

   The call to extent_map_end() sees the extent map has a start of 0
   and a length still at 4KiB, so it returns 4KiB and 'cur' is 4KiB, so
   the BUG_ON() is triggered.

So it's dangerous to modify an extent map that is in the tree, because some
other task might have got a reference to it before and still using it, and
needs to see a consistent map while using it. Generally this is very rare
since most paths that lookup and use extent maps also have the file range
locked in the inode's iotree. The fsync path is pretty much the only
exception where we don't do it to avoid serialization with concurrent
reads.

Fix this by not allowing an extent map do be merged if if it's being used
by tasks other then the one attempting to merge the extent map (when the
reference count of the extent map is greater than 2).

Reported-by: ryusuke1925 <st13s20@gm.ibaraki-ct.ac.jp>
Reported-by: Koki Mitani <koki.mitani.xg@hco.ntt.co.jp>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206211
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:53:00 +01:00
Theodore Ts'o c43f560acc ext4: improve explanation of a mount failure caused by a misconfigured kernel
commit d65d87a074 upstream.

If CONFIG_QFMT_V2 is not enabled, but CONFIG_QUOTA is enabled, when a
user tries to mount a file system with the quota or project quota
enabled, the kernel will emit a very confusing messsage:

    EXT4-fs warning (device vdc): ext4_enable_quotas:5914: Failed to enable quota tracking (type=0, err=-3). Please run e2fsck to fix.
    EXT4-fs (vdc): mount failed

We will now report an explanatory message indicating which kernel
configuration options have to be enabled, to avoid customer/sysadmin
confusion.

Link: https://lore.kernel.org/r/20200215012738.565735-1-tytso@mit.edu
Google-Bug-Id: 149093531
Fixes: 7c319d3285 ("ext4: make quota as first class supported feature")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:52:59 +01:00
Shijie Luo 94f0fe04da ext4: add cond_resched() to ext4_protect_reserved_inode
commit af133ade9a upstream.

When journal size is set too big by "mkfs.ext4 -J size=", or when
we mount a crafted image to make journal inode->i_size too big,
the loop, "while (i < num)", holds cpu too long. This could cause
soft lockup.

[  529.357541] Call trace:
[  529.357551]  dump_backtrace+0x0/0x198
[  529.357555]  show_stack+0x24/0x30
[  529.357562]  dump_stack+0xa4/0xcc
[  529.357568]  watchdog_timer_fn+0x300/0x3e8
[  529.357574]  __hrtimer_run_queues+0x114/0x358
[  529.357576]  hrtimer_interrupt+0x104/0x2d8
[  529.357580]  arch_timer_handler_virt+0x38/0x58
[  529.357584]  handle_percpu_devid_irq+0x90/0x248
[  529.357588]  generic_handle_irq+0x34/0x50
[  529.357590]  __handle_domain_irq+0x68/0xc0
[  529.357593]  gic_handle_irq+0x6c/0x150
[  529.357595]  el1_irq+0xb8/0x140
[  529.357599]  __ll_sc_atomic_add_return_acquire+0x14/0x20
[  529.357668]  ext4_map_blocks+0x64/0x5c0 [ext4]
[  529.357693]  ext4_setup_system_zone+0x330/0x458 [ext4]
[  529.357717]  ext4_fill_super+0x2170/0x2ba8 [ext4]
[  529.357722]  mount_bdev+0x1a8/0x1e8
[  529.357746]  ext4_mount+0x44/0x58 [ext4]
[  529.357748]  mount_fs+0x50/0x170
[  529.357752]  vfs_kern_mount.part.9+0x54/0x188
[  529.357755]  do_mount+0x5ac/0xd78
[  529.357758]  ksys_mount+0x9c/0x118
[  529.357760]  __arm64_sys_mount+0x28/0x38
[  529.357764]  el0_svc_common+0x78/0x130
[  529.357766]  el0_svc_handler+0x38/0x78
[  529.357769]  el0_svc+0x8/0xc
[  541.356516] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [mount:18674]

Link: https://lore.kernel.org/r/20200211011752.29242-1-luoshijie1@huawei.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:52:59 +01:00
Jan Kara 5b0a26514d ext4: fix checksum errors with indexed dirs
commit 48a3431195 upstream.

DIR_INDEX has been introduced as a compat ext4 feature. That means that
even kernels / tools that don't understand the feature may modify the
filesystem. This works because for kernels not understanding indexed dir
format, internal htree nodes appear just as empty directory entries.
Index dir aware kernels then check the htree structure is still
consistent before using the data. This all worked reasonably well until
metadata checksums were introduced. The problem is that these
effectively made DIR_INDEX only ro-compatible because internal htree
nodes store checksums in a different place than normal directory blocks.
Thus any modification ignorant to DIR_INDEX (or just clearing
EXT4_INDEX_FL from the inode) will effectively cause checksum mismatch
and trigger kernel errors. So we have to be more careful when dealing
with indexed directories on filesystems with checksumming enabled.

1) We just disallow loading any directory inodes with EXT4_INDEX_FL when
DIR_INDEX is not enabled. This is harsh but it should be very rare (it
means someone disabled DIR_INDEX on existing filesystem and didn't run
e2fsck), e2fsck can fix the problem, and we don't want to answer the
difficult question: "Should we rather corrupt the directory more or
should we ignore that DIR_INDEX feature is not set?"

2) When we find out htree structure is corrupted (but the filesystem and
the directory should in support htrees), we continue just ignoring htree
information for reading but we refuse to add new entries to the
directory to avoid corrupting it more.

Link: https://lore.kernel.org/r/20200210144316.22081-1-jack@suse.cz
Fixes: dbe8944404 ("ext4: Calculate and verify checksums for htree nodes")
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:52:59 +01:00
Theodore Ts'o 449e607322 ext4: fix support for inode sizes > 1024 bytes
commit 4f97a68192 upstream.

A recent commit, 9803387c55 ("ext4: validate the
debug_want_extra_isize mount option at parse time"), moved mount-time
checks around.  One of those changes moved the inode size check before
the blocksize variable was set to the blocksize of the file system.
After 9803387c55 was set to the minimum allowable blocksize, which
in practice on most systems would be 1024 bytes.  This cuased file
systems with inode sizes larger than 1024 bytes to be rejected with a
message:

EXT4-fs (sdXX): unsupported inode size: 4096

Fixes: 9803387c55 ("ext4: validate the debug_want_extra_isize mount option at parse time")
Link: https://lore.kernel.org/r/20200206225252.GA3673@mit.edu
Reported-by: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:52:58 +01:00
Andreas Dilger f080204b67 ext4: don't assume that mmp_nodename/bdevname have NUL
commit 14c9ca0583 upstream.

Don't assume that the mmp_nodename and mmp_bdevname strings are NUL
terminated, since they are filled in by snprintf(), which is not
guaranteed to do so.

Link: https://lore.kernel.org/r/1580076215-1048-1-git-send-email-adilger@dilger.ca
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:52:58 +01:00
Robert Milkowski f481812994 NFSv4.0: nfs4_do_fsinfo() should not do implicit lease renewals
commit 7dc2993a9e upstream.

Currently, each time nfs4_do_fsinfo() is called it will do an implicit
NFS4 lease renewal, which is not compliant with the NFS4 specification.
This can result in a lease being expired by an NFS server.

Commit 83ca7f5ab3 ("NFS: Avoid PUTROOTFH when managing leases")
introduced implicit client lease renewal in nfs4_do_fsinfo(),
which can result in the NFSv4.0 lease to expire on a server side,
and servers returning NFS4ERR_EXPIRED or NFS4ERR_STALE_CLIENTID.

This can easily be reproduced by frequently unmounting a sub-mount,
then stat'ing it to get it mounted again, which will delay or even
completely prevent client from sending RENEW operations if no other
NFS operations are issued. Eventually nfs server will expire client's
lease and return an error on file access or next RENEW.

This can also happen when a sub-mount is automatically unmounted
due to inactivity (after nfs_mountpoint_expiry_timeout), then it is
mounted again via stat(). This can result in a short window during
which client's lease will expire on a server but not on a client.
This specific case was observed on production systems.

This patch removes the implicit lease renewal from nfs4_do_fsinfo().

Fixes: 83ca7f5ab3 ("NFS: Avoid PUTROOTFH when managing leases")
Signed-off-by: Robert Milkowski <rmilkowski@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:11 -05:00
Robert Milkowski cf360732f8 NFSv4: try lease recovery on NFS4ERR_EXPIRED
commit 924491f2e4 upstream.

Currently, if an nfs server returns NFS4ERR_EXPIRED to open(),
we return EIO to applications without even trying to recover.

Fixes: 272289a3df ("NFSv4: nfs4_do_handle_exception() handle revoke/expiry of a single stateid")
Signed-off-by: Robert Milkowski <rmilkowski@gmail.com>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:11 -05:00
Trond Myklebust 5d0a6d77b6 NFSv4: pnfs_roc() must use cred_fscmp() to compare creds
commit 3871224787 upstream.

When comparing two 'struct cred' for equality w.r.t. behaviour under
filesystem access, we need to use cred_fscmp().

Fixes: a52458b48a ("NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:10 -05:00
Trond Myklebust 86065de0eb NFS: Fix fix of show_nfs_errors
commit 118b629219 upstream.

Casting a negative value to an unsigned long is not the same as
converting it to its absolute value.

Fixes: 96650e2eff ("NFS: Fix show_nfs_errors macros again")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:10 -05:00
Trond Myklebust 5d7030939d NFS/pnfs: Fix pnfs_generic_prepare_to_resend_writes()
commit 221203ce64 upstream.

Instead of making assumptions about the commit verifier contents, change
the commit code to ensure we always check that the verifier was set
by the XDR code.

Fixes: f54bcf2ece ("pnfs: Prepare for flexfiles by pulling out common code")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:10 -05:00
Trond Myklebust 1ef47a06d2 NFS: Revalidate the file size on a fatal write error
commit 0df68ced55 upstream.

If we suffer a fatal error upon writing a file, which causes us to
need to revalidate the entire mapping, then we should also revalidate
the file size.

Fixes: d2ceb7e570 ("NFS: Don't use page_file_mapping after removing the page")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:10 -05:00
Geert Uytterhoeven b7560b5b72 nfs: NFS_SWAP should depend on SWAP
commit 474c4f306e 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: a564b8f039 ("nfs: enable swap on NFS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:10 -05:00
Ronnie Sahlberg b64d7f7af8 cifs: fail i/o on soft mounts if sessionsetup errors out
commit b0dd940e58 upstream.

RHBZ: 1579050

If we have a soft mount we should fail commands for session-setup
failures (such as the password having changed/ account being deleted/ ...)
and return an error back to the application.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:54 -08:00
Josef Bacik 4987426257 btrfs: free block groups after free'ing fs trees
[ Upstream commit 4e19443da1 ]

Sometimes when running generic/475 we would trip the
WARN_ON(cache->reserved) check when free'ing the block groups on umount.
This is because sometimes we don't commit the transaction because of IO
errors and thus do not cleanup the tree logs until at umount time.

These blocks are still reserved until they are cleaned up, but they
aren't cleaned up until _after_ we do the free block groups work.  Fix
this by moving the free after free'ing the fs roots, that way all of the
tree logs are cleaned up and we have a properly cleaned fs.  A bunch of
loops of generic/475 confirmed this fixes the problem.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-11 04:35:53 -08:00
Anand Jain 26ca39ac55 btrfs: use bool argument in free_root_pointers()
[ Upstream commit 4273eaff9b ]

We don't need int argument bool shall do in free_root_pointers().  And
rename the argument as it confused two people.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-11 04:35:52 -08:00
Quanyang Wang c533cf50fd ubifs: Fix memory leak from c->sup_node
commit ff90bdfb20 upstream.

The c->sup_node is allocated in function ubifs_read_sb_node but
is not freed. This will cause memory leak as below:

unreferenced object 0xbc9ce000 (size 4096):
  comm "mount", pid 500, jiffies 4294952946 (age 315.820s)
  hex dump (first 32 bytes):
    31 18 10 06 06 7b f1 11 02 00 00 00 00 00 00 00  1....{..........
    00 10 00 00 06 00 00 00 00 00 00 00 08 00 00 00  ................
  backtrace:
    [<d1c503cd>] ubifs_read_superblock+0x48/0xebc
    [<a20e14bd>] ubifs_mount+0x974/0x1420
    [<8589ecc3>] legacy_get_tree+0x2c/0x50
    [<5f1fb889>] vfs_get_tree+0x28/0xfc
    [<bbfc7939>] do_mount+0x4f8/0x748
    [<4151f538>] ksys_mount+0x78/0xa0
    [<d59910a9>] ret_fast_syscall+0x0/0x54
    [<1cc40005>] 0x7ea02790

Free it in ubifs_umount and in the error path of mount_ubifs.

Fixes: fd6150051b ("ubifs: Store read superblock node")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:48 -08:00
Trond Myklebust 7eece787ed nfsd: Return the correct number of bytes written to the file
commit 09a80f2aef upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:47 -08:00
Arnd Bergmann e94829641e nfsd: fix jiffies/time_t mixup in LRU list
commit 9594497f2c upstream.

The nfsd4_blocked_lock->nbl_time timestamp is recorded in jiffies,
but then compared to a CLOCK_REALTIME timestamp later on, which makes
no sense.

For consistency with the other timestamps, change this to use a time_t.

This is a change in behavior, which may cause regressions, but the
current code is not sensible. On a system with CONFIG_HZ=1000,
the 'time_after((unsigned long)nbl->nbl_time, (unsigned long)cutoff))'
check is false for roughly the first 18 days of uptime and then true
for the next 49 days.

Fixes: 7919d0a27f ("nfsd: add a LRU list for blocked locks")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:47 -08:00
Arnd Bergmann 9f3fa8bea9 nfsd: fix delay timer on 32-bit architectures
commit 2561c92b12 upstream.

The nfsd4_cb_layout_done() function takes a 'time_t' value,
multiplied by NSEC_PER_SEC*2 to get a nanosecond value.

This works fine on 64-bit architectures, but on 32-bit, any
value over 1 second results in a signed integer overflow
with unexpected results.

Cast one input to a 64-bit type in order to produce the
same result that we have on 64-bit architectures, regarless
of the type of nfsd4_lease.

Fixes: 6b9b21073d ("nfsd: give up on CB_LAYOUTRECALLs after two lease periods")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:46 -08:00
Nathan Chancellor 0a7473b27e ext2: Adjust indentation in ext2_fill_super
commit d9e9866803 upstream.

Clang warns:

../fs/ext2/super.c:1076:3: warning: misleading indentation; statement is
not part of the previous 'if' [-Wmisleading-indentation]
        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
        ^
../fs/ext2/super.c:1074:2: note: previous statement is here
        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
        ^
1 warning generated.

This warning occurs because there is a space before the tab on this
line. Remove it so that the indentation is consistent with the Linux
kernel coding style and clang no longer warns.

Fixes: 41f04d852e ("[PATCH] ext2: fix mounts at 16T")
Link: https://github.com/ClangBuiltLinux/linux/issues/827
Link: https://lore.kernel.org/r/20191218031930.31393-1-natechancellor@gmail.com
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:45 -08:00
Miklos Szeredi 07fbef9a6e fix up iter on short count in fuse_direct_io()
commit f658adeea4 upstream.

fuse_direct_io() can end up advancing the iterator by more than the amount
of data read or written.  This case is handled by the generic code if going
through ->direct_IO(), but not in the FOPEN_DIRECT_IO case.

Fix by reverting the extra bytes from the iterator in case of error or a
short count.

To test: install lxcfs, then the following testcase
  int fd = open("/var/lib/lxcfs/proc/uptime", O_RDONLY);
  sendfile(1, fd, NULL, 16777216);
  sendfile(1, fd, NULL, 16777216);
will spew WARN_ON() in iov_iter_pipe().

Reported-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 3c3db095b6 ("fuse: use iov_iter based generic splice helpers")
Cc: <stable@vger.kernel.org> # v5.1
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:43 -08:00
Gang He 03c03090c3 ocfs2: fix oops when writing cloned file
commit 2d797e9ff9 upstream.

Writing a cloned file triggers a kernel oops and the user-space command
process is also killed by the system.  The bug can be reproduced stably
via:

1) create a file under ocfs2 file system directory.

  journalctl -b > aa.txt

2) create a cloned file for this file.

  reflink aa.txt bb.txt

3) write the cloned file with dd command.

  dd if=/dev/zero of=bb.txt bs=512 count=1 conv=notrunc

The dd command is killed by the kernel, then you can see the oops message
via dmesg command.

[  463.875404] BUG: kernel NULL pointer dereference, address: 0000000000000028
[  463.875413] #PF: supervisor read access in kernel mode
[  463.875416] #PF: error_code(0x0000) - not-present page
[  463.875418] PGD 0 P4D 0
[  463.875425] Oops: 0000 [#1] SMP PTI
[  463.875431] CPU: 1 PID: 2291 Comm: dd Tainted: G           OE     5.3.16-2-default
[  463.875433] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[  463.875500] RIP: 0010:ocfs2_refcount_cow+0xa4/0x5d0 [ocfs2]
[  463.875505] Code: 06 89 6c 24 38 89 eb f6 44 24 3c 02 74 be 49 8b 47 28
[  463.875508] RSP: 0018:ffffa2cb409dfce8 EFLAGS: 00010202
[  463.875512] RAX: ffff8b1ebdca8000 RBX: 0000000000000001 RCX: ffff8b1eb73a9df0
[  463.875515] RDX: 0000000000056a01 RSI: 0000000000000000 RDI: 0000000000000000
[  463.875517] RBP: 0000000000000001 R08: ffff8b1eb73a9de0 R09: 0000000000000000
[  463.875520] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
[  463.875522] R13: ffff8b1eb922f048 R14: 0000000000000000 R15: ffff8b1eb922f048
[  463.875526] FS:  00007f8f44d15540(0000) GS:ffff8b1ebeb00000(0000) knlGS:0000000000000000
[  463.875529] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  463.875532] CR2: 0000000000000028 CR3: 000000003c17a000 CR4: 00000000000006e0
[  463.875546] Call Trace:
[  463.875596]  ? ocfs2_inode_lock_full_nested+0x18b/0x960 [ocfs2]
[  463.875648]  ocfs2_file_write_iter+0xaf8/0xc70 [ocfs2]
[  463.875672]  new_sync_write+0x12d/0x1d0
[  463.875688]  vfs_write+0xad/0x1a0
[  463.875697]  ksys_write+0xa1/0xe0
[  463.875710]  do_syscall_64+0x60/0x1f0
[  463.875743]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  463.875758] RIP: 0033:0x7f8f4482ed44
[  463.875762] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00
[  463.875765] RSP: 002b:00007fff300a79d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  463.875769] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8f4482ed44
[  463.875771] RDX: 0000000000000200 RSI: 000055f771b5c000 RDI: 0000000000000001
[  463.875774] RBP: 0000000000000200 R08: 00007f8f44af9c78 R09: 0000000000000003
[  463.875776] R10: 000000000000089f R11: 0000000000000246 R12: 000055f771b5c000
[  463.875779] R13: 0000000000000200 R14: 0000000000000000 R15: 000055f771b5c000

This regression problem was introduced by commit e74540b285 ("ocfs2:
protect extent tree in ocfs2_prepare_inode_for_write()").

Link: http://lkml.kernel.org/r/20200121050153.13290-1-ghe@suse.com
Fixes: e74540b285 ("ocfs2: protect extent tree in ocfs2_prepare_inode_for_write()").
Signed-off-by: Gang He <ghe@suse.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:42 -08:00
Jens Axboe 8dcbf26833 aio: prevent potential eventfd recursion on poll
commit 01d7a35687 upstream.

If we have nested or circular eventfd wakeups, then we can deadlock if
we run them inline from our poll waitqueue wakeup handler. It's also
possible to have very long chains of notifications, to the extent where
we could risk blowing the stack.

Check the eventfd recursion count before calling eventfd_signal(). If
it's non-zero, then punt the signaling to async context. This is always
safe, as it takes us out-of-line in terms of stack and locking context.

Cc: stable@vger.kernel.org # 4.19+
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:37 -08:00
Jens Axboe 844d2025b6 eventfd: track eventfd_signal() recursion depth
commit b5e683d5ca upstream.

eventfd use cases from aio and io_uring can deadlock due to circular
or resursive calling, when eventfd_signal() tries to grab the waitqueue
lock. On top of that, it's also possible to construct notification
chains that are deep enough that we could blow the stack.

Add a percpu counter that tracks the percpu recursion depth, warn if we
exceed it. The counter is also exposed so that users of eventfd_signal()
can do the right thing if it's non-zero in the context where it is
called.

Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:37 -08:00
Andreas Gruenbacher ae35ac3c4b gfs2: fix O_SYNC write handling
commit 6e5e41e2dc upstream.

In gfs2_file_write_iter, for direct writes, the error checking in the buffered
write fallback case is incomplete.  This can cause inode write errors to go
undetected.  Fix and clean up gfs2_file_write_iter along the way.

Based on a proposed fix by Christoph Hellwig <hch@lst.de>.

Fixes: 967bcc91b0 ("gfs2: iomap direct I/O support")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:35 -08:00
Christoph Hellwig 6373486908 gfs2: move setting current->backing_dev_info
commit 4c0e8dda60 upstream.

Set current->backing_dev_info just around the buffered write calls to
prepare for the next fix.

Fixes: 967bcc91b0 ("gfs2: iomap direct I/O support")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:35 -08:00
Abhi Das c61b93fae6 gfs2: fix gfs2_find_jhead that returns uninitialized jhead with seq 0
commit 7582026f6f upstream.

When the first log header in a journal happens to have a sequence
number of 0, a bug in gfs2_find_jhead() causes it to prematurely exit,
and return an uninitialized jhead with seq 0. This can cause failures
in the caller. For instance, a mount fails in one test case.

The correct behavior is for it to continue searching through the journal
to find the correct journal head with the highest sequence number.

Fixes: f4686c26ec ("gfs2: read journal in large chunks")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:35 -08:00
Nikolay Borisov 9e78c0e742 btrfs: Correctly handle empty trees in find_first_clear_extent_bit
commit 5750c37523 upstream.

Raviu reported that running his regular fs_trim segfaulted with the
following backtrace:

[  237.525947] assertion failed: prev, in ../fs/btrfs/extent_io.c:1595
[  237.525984] ------------[ cut here ]------------
[  237.525985] kernel BUG at ../fs/btrfs/ctree.h:3117!
[  237.525992] invalid opcode: 0000 [#1] SMP PTI
[  237.525998] CPU: 4 PID: 4423 Comm: fstrim Tainted: G     U     OE     5.4.14-8-vanilla #1
[  237.526001] Hardware name: ASUSTeK COMPUTER INC.
[  237.526044] RIP: 0010:assfail.constprop.58+0x18/0x1a [btrfs]
[  237.526079] Call Trace:
[  237.526120]  find_first_clear_extent_bit+0x13d/0x150 [btrfs]
[  237.526148]  btrfs_trim_fs+0x211/0x3f0 [btrfs]
[  237.526184]  btrfs_ioctl_fitrim+0x103/0x170 [btrfs]
[  237.526219]  btrfs_ioctl+0x129a/0x2ed0 [btrfs]
[  237.526227]  ? filemap_map_pages+0x190/0x3d0
[  237.526232]  ? do_filp_open+0xaf/0x110
[  237.526238]  ? _copy_to_user+0x22/0x30
[  237.526242]  ? cp_new_stat+0x150/0x180
[  237.526247]  ? do_vfs_ioctl+0xa4/0x640
[  237.526278]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[  237.526283]  do_vfs_ioctl+0xa4/0x640
[  237.526288]  ? __do_sys_newfstat+0x3c/0x60
[  237.526292]  ksys_ioctl+0x70/0x80
[  237.526297]  __x64_sys_ioctl+0x16/0x20
[  237.526303]  do_syscall_64+0x5a/0x1c0
[  237.526310]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

That was due to btrfs_fs_device::aloc_tree being empty. Initially I
thought this wasn't possible and as a percaution have put the assert in
find_first_clear_extent_bit. Turns out this is indeed possible and could
happen when a file system with SINGLE data/metadata profile has a 2nd
device added. Until balance is run or a new chunk is allocated on this
device it will be completely empty.

In this case find_first_clear_extent_bit should return the full range
[0, -1ULL] and let the caller handle this i.e for trim the end will be
capped at the size of actual device.

Link: https://lore.kernel.org/linux-btrfs/izW2WNyvy1dEDweBICizKnd2KDwDiDyY2EYQr4YCwk7pkuIpthx-JRn65MPBde00ND6V0_Lh8mW0kZwzDiLDv25pUYWxkskWNJnVP0kgdMA=@protonmail.com/
Fixes: 45bfcfc168 ("btrfs: Implement find_first_clear_extent_bit")
CC: stable@vger.kernel.org # 5.2+
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:34 -08:00
Josef Bacik d82ff2d640 btrfs: flush write bio if we loop in extent_write_cache_pages
commit 42ffb0bf58 upstream.

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   #3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02e14 ("Btrfs: Add writepages support")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:34 -08:00
Filipe Manana 5e7a9ad78d Btrfs: fix race between adding and putting tree mod seq elements and nodes
commit 7227ff4de5 upstream.

There is a race between adding and removing elements to the tree mod log
list and rbtree that can lead to use-after-free problems.

Consider the following example that explains how/why the problems happens:

1) Task A has mod log element with sequence number 200. It currently is
   the only element in the mod log list;

2) Task A calls btrfs_put_tree_mod_seq() because it no longer needs to
   access the tree mod log. When it enters the function, it initializes
   'min_seq' to (u64)-1. Then it acquires the lock 'tree_mod_seq_lock'
   before checking if there are other elements in the mod seq list.
   Since the list it empty, 'min_seq' remains set to (u64)-1. Then it
   unlocks the lock 'tree_mod_seq_lock';

3) Before task A acquires the lock 'tree_mod_log_lock', task B adds
   itself to the mod seq list through btrfs_get_tree_mod_seq() and gets a
   sequence number of 201;

4) Some other task, name it task C, modifies a btree and because there
   elements in the mod seq list, it adds a tree mod elem to the tree
   mod log rbtree. That node added to the mod log rbtree is assigned
   a sequence number of 202;

5) Task B, which is doing fiemap and resolving indirect back references,
   calls btrfs get_old_root(), with 'time_seq' == 201, which in turn
   calls tree_mod_log_search() - the search returns the mod log node
   from the rbtree with sequence number 202, created by task C;

6) Task A now acquires the lock 'tree_mod_log_lock', starts iterating
   the mod log rbtree and finds the node with sequence number 202. Since
   202 is less than the previously computed 'min_seq', (u64)-1, it
   removes the node and frees it;

7) Task B still has a pointer to the node with sequence number 202, and
   it dereferences the pointer itself and through the call to
   __tree_mod_log_rewind(), resulting in a use-after-free problem.

This issue can be triggered sporadically with the test case generic/561
from fstests, and it happens more frequently with a higher number of
duperemove processes. When it happens to me, it either freezes the VM or
it produces a trace like the following before crashing:

  [ 1245.321140] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
  [ 1245.321200] CPU: 1 PID: 26997 Comm: pool Not tainted 5.5.0-rc6-btrfs-next-52 #1
  [ 1245.321235] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
  [ 1245.321287] RIP: 0010:rb_next+0x16/0x50
  [ 1245.321307] Code: ....
  [ 1245.321372] RSP: 0018:ffffa151c4d039b0 EFLAGS: 00010202
  [ 1245.321388] RAX: 6b6b6b6b6b6b6b6b RBX: ffff8ae221363c80 RCX: 6b6b6b6b6b6b6b6b
  [ 1245.321409] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8ae221363c80
  [ 1245.321439] RBP: ffff8ae20fcc4688 R08: 0000000000000002 R09: 0000000000000000
  [ 1245.321475] R10: ffff8ae20b120910 R11: 00000000243f8bb1 R12: 0000000000000038
  [ 1245.321506] R13: ffff8ae221363c80 R14: 000000000000075f R15: ffff8ae223f762b8
  [ 1245.321539] FS:  00007fdee1ec7700(0000) GS:ffff8ae236c80000(0000) knlGS:0000000000000000
  [ 1245.321591] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 1245.321614] CR2: 00007fded4030c48 CR3: 000000021da16003 CR4: 00000000003606e0
  [ 1245.321642] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [ 1245.321668] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [ 1245.321706] Call Trace:
  [ 1245.321798]  __tree_mod_log_rewind+0xbf/0x280 [btrfs]
  [ 1245.321841]  btrfs_search_old_slot+0x105/0xd00 [btrfs]
  [ 1245.321877]  resolve_indirect_refs+0x1eb/0xc60 [btrfs]
  [ 1245.321912]  find_parent_nodes+0x3dc/0x11b0 [btrfs]
  [ 1245.321947]  btrfs_check_shared+0x115/0x1c0 [btrfs]
  [ 1245.321980]  ? extent_fiemap+0x59d/0x6d0 [btrfs]
  [ 1245.322029]  extent_fiemap+0x59d/0x6d0 [btrfs]
  [ 1245.322066]  do_vfs_ioctl+0x45a/0x750
  [ 1245.322081]  ksys_ioctl+0x70/0x80
  [ 1245.322092]  ? trace_hardirqs_off_thunk+0x1a/0x1c
  [ 1245.322113]  __x64_sys_ioctl+0x16/0x20
  [ 1245.322126]  do_syscall_64+0x5c/0x280
  [ 1245.322139]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [ 1245.322155] RIP: 0033:0x7fdee3942dd7
  [ 1245.322177] Code: ....
  [ 1245.322258] RSP: 002b:00007fdee1ec6c88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [ 1245.322294] RAX: ffffffffffffffda RBX: 00007fded40210d8 RCX: 00007fdee3942dd7
  [ 1245.322314] RDX: 00007fded40210d8 RSI: 00000000c020660b RDI: 0000000000000004
  [ 1245.322337] RBP: 0000562aa89e7510 R08: 0000000000000000 R09: 00007fdee1ec6d44
  [ 1245.322369] R10: 0000000000000073 R11: 0000000000000246 R12: 00007fdee1ec6d48
  [ 1245.322390] R13: 00007fdee1ec6d40 R14: 00007fded40210d0 R15: 00007fdee1ec6d50
  [ 1245.322423] Modules linked in: ....
  [ 1245.323443] ---[ end trace 01de1e9ec5dff3cd ]---

Fix this by ensuring that btrfs_put_tree_mod_seq() computes the minimum
sequence number and iterates the rbtree while holding the lock
'tree_mod_log_lock' in write mode. Also get rid of the 'tree_mod_seq_lock'
lock, since it is now redundant.

Fixes: bd989ba359 ("Btrfs: add tree modification log functions")
Fixes: 097b8a7c9e ("Btrfs: join tree mod log code with the code holding back delayed refs")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:34 -08:00
Josef Bacik ce06684558 btrfs: drop log root for dropped roots
commit 889bfa3908 upstream.

If we fsync on a subvolume and create a log root for that volume, and
then later delete that subvolume we'll never clean up its log root.  Fix
this by making switch_commit_roots free the log for any dropped roots we
encounter.  The extra churn is because we need a btrfs_trans_handle, not
the btrfs_transaction.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:33 -08:00
Josef Bacik 7baf8f665b btrfs: set trans->drity in btrfs_commit_transaction
commit d62b23c949 upstream.

If we abort a transaction we have the following sequence

if (!trans->dirty && list_empty(&trans->new_bgs))
	return;
WRITE_ONCE(trans->transaction->aborted, err);

The idea being if we didn't modify anything with our trans handle then
we don't really need to abort the whole transaction, maybe the other
trans handles are fine and we can carry on.

However in the case of create_snapshot we add a pending_snapshot object
to our transaction and then commit the transaction.  We don't actually
modify anything.  sync() behaves the same way, attach to an existing
transaction and commit it.  This means that if we have an IO error in
the right places we could abort the committing transaction with our
trans->dirty being not set and thus not set transaction->aborted.

This is a problem because in the create_snapshot() case we depend on
pending->error being set to something, or btrfs_commit_transaction
returning an error.

If we are not the trans handle that gets to commit the transaction, and
we're waiting on the commit to happen we get our return value from
cur_trans->aborted.  If this was not set to anything because sync() hit
an error in the transaction commit before it could modify anything then
cur_trans->aborted would be 0.  Thus we'd return 0 from
btrfs_commit_transaction() in create_snapshot.

This is a problem because we then try to do things with
pending_snapshot->snap, which will be NULL because we didn't create the
snapshot, and then we'll get a NULL pointer dereference like the
following

"BUG: kernel NULL pointer dereference, address: 00000000000001f0"
RIP: 0010:btrfs_orphan_cleanup+0x2d/0x330
Call Trace:
 ? btrfs_mksubvol.isra.31+0x3f2/0x510
 btrfs_mksubvol.isra.31+0x4bc/0x510
 ? __sb_start_write+0xfa/0x200
 ? mnt_want_write_file+0x24/0x50
 btrfs_ioctl_snap_create_transid+0x16c/0x1a0
 btrfs_ioctl_snap_create_v2+0x11e/0x1a0
 btrfs_ioctl+0x1534/0x2c10
 ? free_debug_processing+0x262/0x2a3
 do_vfs_ioctl+0xa6/0x6b0
 ? do_sys_open+0x188/0x220
 ? syscall_trace_enter+0x1f8/0x330
 ksys_ioctl+0x60/0x90
 __x64_sys_ioctl+0x16/0x20
 do_syscall_64+0x4a/0x1b0

In order to fix this we need to make sure anybody who calls
commit_transaction has trans->dirty set so that they properly set the
trans->transaction->aborted value properly so any waiters know bad
things happened.

This was found while I was running generic/475 with my modified
fsstress, it reproduced within a few runs.  I ran with this patch all
night and didn't see the problem again.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:33 -08:00
Filipe Manana 78748f2491 Btrfs: fix infinite loop during fsync after rename operations
commit b5e4ff9d46 upstream.

Recently fsstress (from fstests) sporadically started to trigger an
infinite loop during fsync operations. This turned out to be because
support for the rename exchange and whiteout operations was added to
fsstress in fstests. These operations, unlike any others in fsstress,
cause file names to be reused, whence triggering this issue. However
it's not necessary to use rename exchange and rename whiteout operations
trigger this issue, simple rename operations and file creations are
enough to trigger the issue.

The issue boils down to when we are logging inodes that conflict (that
had the name of any inode we need to log during the fsync operation), we
keep logging them even if they were already logged before, and after
that we check if there's any other inode that conflicts with them and
then add it again to the list of inodes to log. Skipping already logged
inodes fixes the issue.

Consider the following example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/testdir                           # inode 257

  $ touch /mnt/testdir/zz                        # inode 258
  $ ln /mnt/testdir/zz /mnt/testdir/zz_link

  $ touch /mnt/testdir/a                         # inode 259

  $ sync

  # The following 3 renames achieve the same result as a rename exchange
  # operation (<rename_exchange> /mnt/testdir/zz_link to /mnt/testdir/a).

  $ mv /mnt/testdir/a /mnt/testdir/a/tmp
  $ mv /mnt/testdir/zz_link /mnt/testdir/a
  $ mv /mnt/testdir/a/tmp /mnt/testdir/zz_link

  # The following rename and file creation give the same result as a
  # rename whiteout operation (<rename_whiteout> zz to a2).

  $ mv /mnt/testdir/zz /mnt/testdir/a2
  $ touch /mnt/testdir/zz                        # inode 260

  $ xfs_io -c fsync /mnt/testdir/zz
    --> results in the infinite loop

The following steps happen:

1) When logging inode 260, we find that its reference named "zz" was
   used by inode 258 in the previous transaction (through the commit
   root), so inode 258 is added to the list of conflicting indoes that
   need to be logged;

2) After logging inode 258, we find that its reference named "a" was
   used by inode 259 in the previous transaction, and therefore we add
   inode 259 to the list of conflicting inodes to be logged;

3) After logging inode 259, we find that its reference named "zz_link"
   was used by inode 258 in the previous transaction - we add inode 258
   to the list of conflicting inodes to log, again - we had already
   logged it before at step 3. After logging it again, we find again
   that inode 259 conflicts with him, and we add again 259 to the list,
   etc - we end up repeating all the previous steps.

So fix this by skipping logging of conflicting inodes that were already
logged.

Fixes: 6b5fc433a7 ("Btrfs: fix fsync after succession of renames of different files")
CC: stable@vger.kernel.org # 5.1+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:33 -08:00
Filipe Manana 79a29dee90 Btrfs: make deduplication with range including the last block work
commit 831d2fa25a upstream.

Since btrfs was migrated to use the generic VFS helpers for clone and
deduplication, it stopped allowing for the last block of a file to be
deduplicated when the source file size is not sector size aligned (when
eof is somewhere in the middle of the last block). There are two reasons
for that:

1) The generic code always rounds down, to a multiple of the block size,
   the range's length for deduplications. This means we end up never
   deduplicating the last block when the eof is not block size aligned,
   even for the safe case where the destination range's end offset matches
   the destination file's size. That rounding down operation is done at
   generic_remap_check_len();

2) Because of that, the btrfs specific code does not expect anymore any
   non-aligned range length's for deduplication and therefore does not
   work if such nona-aligned length is given.

This patch addresses that second part, and it depends on a patch that
fixes generic_remap_check_len(), in the VFS, which was submitted ealier
and has the following subject:

  "fs: allow deduplication of eof block into the end of the destination file"

These two patches address reports from users that started seeing lower
deduplication rates due to the last block never being deduplicated when
the file size is not aligned to the filesystem's block size.

Link: https://lore.kernel.org/linux-btrfs/2019-1576167349.500456@svIo.N5dq.dFFD/
CC: stable@vger.kernel.org # 5.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:33 -08:00
Filipe Manana ddb36ab79b Btrfs: fix missing hole after hole punching and fsync when using NO_HOLES
commit 0e56315ca1 upstream.

When using the NO_HOLES feature, if we punch a hole into a file and then
fsync it, there are cases where a subsequent fsync will miss the fact that
a hole was punched, resulting in the holes not existing after replaying
the log tree.

Essentially these cases all imply that, tree-log.c:copy_items(), is not
invoked for the leafs that delimit holes, because nothing changed those
leafs in the current transaction. And it's precisely copy_items() where
we currenly detect and log holes, which works as long as the holes are
between file extent items in the input leaf or between the beginning of
input leaf and the previous leaf or between the last item in the leaf
and the next leaf.

First example where we miss a hole:

  *) The extent items of the inode span multiple leafs;

  *) The punched hole covers a range that affects only the extent items of
     the first leaf;

  *) The fsync operation is done in full mode (BTRFS_INODE_NEEDS_FULL_SYNC
     is set in the inode's runtime flags).

  That results in the hole not existing after replaying the log tree.

  For example, if the fs/subvolume tree has the following layout for a
  particular inode:

      Leaf N, generation 10:

      [ ... INODE_ITEM INODE_REF EXTENT_ITEM (0 64K) EXTENT_ITEM (64K 128K) ]

      Leaf N + 1, generation 10:

      [ EXTENT_ITEM (128K 64K) ... ]

  If at transaction 11 we punch a hole coverting the range [0, 128K[, we end
  up dropping the two extent items from leaf N, but we don't touch the other
  leaf, so we end up in the following state:

      Leaf N, generation 11:

      [ ... INODE_ITEM INODE_REF ]

      Leaf N + 1, generation 10:

      [ EXTENT_ITEM (128K 64K) ... ]

  A full fsync after punching the hole will only process leaf N because it
  was modified in the current transaction, but not leaf N + 1, since it
  was not modified in the current transaction (generation 10 and not 11).
  As a result the fsync will not log any holes, because it didn't process
  any leaf with extent items.

Second example where we will miss a hole:

  *) An inode as its items spanning 5 (or more) leafs;

  *) A hole is punched and it covers only the extents items of the 3rd
     leaf. This resulsts in deleting the entire leaf and not touching any
     of the other leafs.

  So the only leaf that is modified in the current transaction, when
  punching the hole, is the first leaf, which contains the inode item.
  During the full fsync, the only leaf that is passed to copy_items()
  is that first leaf, and that's not enough for the hole detection
  code in copy_items() to determine there's a hole between the last
  file extent item in the 2nd leaf and the first file extent item in
  the 3rd leaf (which was the 4th leaf before punching the hole).

Fix this by scanning all leafs and punch holes as necessary when doing a
full fsync (less common than a non-full fsync) when the NO_HOLES feature
is enabled. The lack of explicit file extent items to mark holes makes it
necessary to scan existing extents to determine if holes exist.

A test case for fstests follows soon.

Fixes: 16e7549f04 ("Btrfs: incompatible format change to remove hole extents")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:33 -08:00
Eric Biggers f0edd3abee ext4: fix race conditions in ->d_compare() and ->d_hash()
commit ec772f0130 upstream.

Since ->d_compare() and ->d_hash() can be called in RCU-walk mode,
->d_parent and ->d_inode can be concurrently modified, and in
particular, ->d_inode may be changed to NULL.  For ext4_d_hash() this
resulted in a reproducible NULL dereference if a lookup is done in a
directory being deleted, e.g. with:

	int main()
	{
		if (fork()) {
			for (;;) {
				mkdir("subdir", 0700);
				rmdir("subdir");
			}
		} else {
			for (;;)
				access("subdir/file", 0);
		}
	}

... or by running the 't_encrypted_d_revalidate' program from xfstests.
Both repros work in any directory on a filesystem with the encoding
feature, even if the directory doesn't actually have the casefold flag.

I couldn't reproduce a crash in ext4_d_compare(), but it appears that a
similar crash is possible there.

Fix these bugs by reading ->d_parent and ->d_inode using READ_ONCE() and
falling back to the case sensitive behavior if the inode is NULL.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: b886ee3e77 ("ext4: Support case-insensitive file name lookups")
Cc: <stable@vger.kernel.org> # v5.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200124041234.159740-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:32 -08:00
Eric Biggers d44fa04f08 ext4: fix deadlock allocating crypto bounce page from mempool
commit 547c556f4d upstream.

ext4_writepages() on an encrypted file has to encrypt the data, but it
can't modify the pagecache pages in-place, so it encrypts the data into
bounce pages and writes those instead.  All bounce pages are allocated
from a mempool using GFP_NOFS.

This is not correct use of a mempool, and it can deadlock.  This is
because GFP_NOFS includes __GFP_DIRECT_RECLAIM, which enables the "never
fail" mode for mempool_alloc() where a failed allocation will fall back
to waiting for one of the preallocated elements in the pool.

But since this mode is used for all a bio's pages and not just the
first, it can deadlock waiting for pages already in the bio to be freed.

This deadlock can be reproduced by patching mempool_alloc() to pretend
that pool->alloc() always fails (so that it always falls back to the
preallocations), and then creating an encrypted file of size > 128 KiB.

Fix it by only using GFP_NOFS for the first page in the bio.  For
subsequent pages just use GFP_NOWAIT, and if any of those fail, just
submit the bio and start a new one.

This will need to be fixed in f2fs too, but that's less straightforward.

Fixes: c9af28fdd4 ("ext4 crypto: don't let data integrity writebacks fail with ENOMEM")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231181149.47619-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:32 -08:00
Vasily Averin b19f130269 jbd2_seq_info_next should increase position index
commit 1a8e9cf40c upstream.

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

Script below generates endless output
 $ q=;while read -r r;do echo "$((++q)) $r";done </proc/fs/jbd2/DEV/info

https://bugzilla.kernel.org/show_bug.cgi?id=206283

Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code and interface")
Cc: stable@kernel.org
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/d13805e5-695e-8ac3-b678-26ca2313629f@virtuozzo.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:32 -08:00
Trond Myklebust 6282102dbc nfsd: fix filecache lookup
commit 28c7d86bb6 upstream.

If the lookup keeps finding a nfsd_file with an unhashed open file,
then retry once only.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org
Fixes: 65294c1f2c "nfsd: add a new struct file caching facility to nfsd"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:32 -08:00
Trond Myklebust 4544a69124 NFS: Directory page cache pages need to be locked when read
commit 114de38225 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: 11de3b11e0 ("NFS: Fix a memory leak in nfs_readdir")
Cc: stable@vger.kernel.org # v2.6.37+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:32 -08:00
Trond Myklebust 293cdcd89b NFS: Fix memory leaks and corruption in readdir
commit 4b310319c6 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: 11de3b11e0 ("NFS: Fix a memory leak in nfs_readdir")
Cc: stable@vger.kernel.org # v2.6.37+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:32 -08:00
Nikolay Borisov f3107a3c9b btrfs: Handle another split brain scenario with metadata uuid feature
commit 0584071014 upstream.

There is one more cases which isn't handled by the original metadata
uuid work. Namely, when a filesystem has METADATA_UUID incompat bit and
the user decides to change the FSID to the original one e.g. have
metadata_uuid and fsid match. In case of power failure while this
operation is in progress we could end up in a situation where some of
the disks have the incompat bit removed and the other half have both
METADATA_UUID_INCOMPAT and FSID_CHANGING_IN_PROGRESS flags.

This patch handles the case where a disk that has successfully changed
its FSID such that it equals METADATA_UUID is scanned first.
Subsequently when a disk with both
METADATA_UUID_INCOMPAT/FSID_CHANGING_IN_PROGRESS flags is scanned
find_fsid_changed won't be able to find an appropriate btrfs_fs_devices.
This is done by extending find_fsid_changed to correctly find
btrfs_fs_devices whose metadata_uuid/fsid are the same and they match
the metadata_uuid of the currently scanned device.

Fixes: cc5de4e702 ("btrfs: Handle final split-brain possibility during fsid change")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reported-by: Su Yue <Damenly_Su@gmx.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:28 -08:00
Josef Bacik dd9837259d btrfs: fix improper setting of scanned for range cyclic write cache pages
commit 556755a8a9 upstream.

We noticed that we were having regular CG OOM kills in cases where there
was still enough dirty pages to avoid OOM'ing.  It turned out there's
this corner case in btrfs's handling of range_cyclic where files that
were being redirtied were not getting fully written out because of how
we do range_cyclic writeback.

We unconditionally were setting scanned = 1; the first time we found any
pages in the inode.  This isn't actually what we want, we want it to be
set if we've scanned the entire file.  For range_cyclic we could be
starting in the middle or towards the end of the file, so we could write
one page and then not write any of the other dirty pages in the file
because we set scanned = 1.

Fix this by not setting scanned = 1 if we find pages.  The rules for
setting scanned should be

1) !range_cyclic.  In this case we have a specified range to write out.
2) range_cyclic && index == 0.  In this case we've started at the
   beginning and there is no need to loop around a second time.
3) range_cyclic && we started at index > 0 and we've reached the end of
   the file without satisfying our nr_to_write.

This patch fixes both of our writepages implementations to make sure
these rules hold true.  This fixed our over zealous CG OOMs in
production.

Fixes: d1310b2e0c ("Btrfs: Split the extent_map code into two parts")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:28 -08:00
Eric Biggers e9116299ff f2fs: fix race conditions in ->d_compare() and ->d_hash()
commit 80f2388afa upstream.

Since ->d_compare() and ->d_hash() can be called in RCU-walk mode,
->d_parent and ->d_inode can be concurrently modified, and in
particular, ->d_inode may be changed to NULL.  For f2fs_d_hash() this
resulted in a reproducible NULL dereference if a lookup is done in a
directory being deleted, e.g. with:

	int main()
	{
		if (fork()) {
			for (;;) {
				mkdir("subdir", 0700);
				rmdir("subdir");
			}
		} else {
			for (;;)
				access("subdir/file", 0);
		}
	}

... or by running the 't_encrypted_d_revalidate' program from xfstests.
Both repros work in any directory on a filesystem with the encoding
feature, even if the directory doesn't actually have the casefold flag.

I couldn't reproduce a crash in f2fs_d_compare(), but it appears that a
similar crash is possible there.

Fix these bugs by reading ->d_parent and ->d_inode using READ_ONCE() and
falling back to the case sensitive behavior if the inode is NULL.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 2c2eb7a300 ("f2fs: Support case-insensitive file name lookups")
Cc: <stable@vger.kernel.org> # v5.4+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:25 -08:00
Eric Biggers 6d722cd2e3 f2fs: fix dcache lookup of !casefolded directories
commit 5515eae647 upstream.

Do the name comparison for non-casefolded directories correctly.

This is analogous to ext4's commit 66883da1ee ("ext4: fix dcache
lookup of !casefolded directories").

Fixes: 2c2eb7a300 ("f2fs: Support case-insensitive file name lookups")
Cc: <stable@vger.kernel.org> # v5.4+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:25 -08:00