<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/fs, branch v4.19.136</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Revert "cifs: Fix the target file was deleted when rename failed."</title>
<updated>2020-07-29T08:16:55+00:00</updated>
<author>
<name>Steve French</name>
<email>stfrench@microsoft.com</email>
</author>
<published>2020-07-23T19:41:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1913ba0d5284f71812829dbb7053db69887711a'/>
<id>c1913ba0d5284f71812829dbb7053db69887711a</id>
<content type='text'>
commit 0e6705182d4e1b77248a93470d6d7b3013d59b30 upstream.

This reverts commit 9ffad9263b467efd8f8dc7ae1941a0a655a2bab2.

Upon additional testing with older servers, it was found that
the original commit introduced a regression when using the old SMB1
dialect and rsyncing over an existing file.

The patch will need to be respun to address this, likely including
a larger refactoring of the SMB1 and SMB3 rename code paths to make
it less confusing and also to address some additional rename error
cases that SMB3 may be able to workaround.

Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
Reported-by: Patrick Fernie &lt;patrick.fernie@gmail.com&gt;
CC: Stable &lt;stable@vger.kernel.org&gt;
Acked-by: Ronnie Sahlberg &lt;lsahlber@redhat.com&gt;
Acked-by: Pavel Shilovsky &lt;pshilov@microsoft.com&gt;
Acked-by: Zhang Xiaoxu &lt;zhangxiaoxu5@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0e6705182d4e1b77248a93470d6d7b3013d59b30 upstream.

This reverts commit 9ffad9263b467efd8f8dc7ae1941a0a655a2bab2.

Upon additional testing with older servers, it was found that
the original commit introduced a regression when using the old SMB1
dialect and rsyncing over an existing file.

The patch will need to be respun to address this, likely including
a larger refactoring of the SMB1 and SMB3 rename code paths to make
it less confusing and also to address some additional rename error
cases that SMB3 may be able to workaround.

Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
Reported-by: Patrick Fernie &lt;patrick.fernie@gmail.com&gt;
CC: Stable &lt;stable@vger.kernel.org&gt;
Acked-by: Ronnie Sahlberg &lt;lsahlber@redhat.com&gt;
Acked-by: Pavel Shilovsky &lt;pshilov@microsoft.com&gt;
Acked-by: Zhang Xiaoxu &lt;zhangxiaoxu5@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: fix page leaks after failure to lock page for delalloc</title>
<updated>2020-07-29T08:16:48+00:00</updated>
<author>
<name>Robbie Ko</name>
<email>robbieko@synology.com</email>
</author>
<published>2020-07-20T01:42:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf93dda2fd397fcb05d4425010f35f53ec747dac'/>
<id>bf93dda2fd397fcb05d4425010f35f53ec747dac</id>
<content type='text'>
commit 5909ca110b29aa16b23b52b8de8d3bb1035fd738 upstream.

When locking pages for delalloc, we check if it's dirty and mapping still
matches. If it does not match, we need to return -EAGAIN and release all
pages. Only the current page was put though, iterate over all the
remaining pages too.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Reviewed-by: Nikolay Borisov &lt;nborisov@suse.com&gt;
Signed-off-by: Robbie Ko &lt;robbieko@synology.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5909ca110b29aa16b23b52b8de8d3bb1035fd738 upstream.

When locking pages for delalloc, we check if it's dirty and mapping still
matches. If it does not match, we need to return -EAGAIN and release all
pages. Only the current page was put though, iterate over all the
remaining pages too.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Reviewed-by: Nikolay Borisov &lt;nborisov@suse.com&gt;
Signed-off-by: Robbie Ko &lt;robbieko@synology.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: fix mount failure caused by race with umount</title>
<updated>2020-07-29T08:16:48+00:00</updated>
<author>
<name>Boris Burkov</name>
<email>boris@bur.io</email>
</author>
<published>2020-07-16T20:29:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2fae5cc5af3e29b1e439414e10089ca7ef520b69'/>
<id>2fae5cc5af3e29b1e439414e10089ca7ef520b69</id>
<content type='text'>
commit 48cfa61b58a1fee0bc49eef04f8ccf31493b7cdd upstream.

It is possible to cause a btrfs mount to fail by racing it with a slow
umount. The crux of the sequence is generic_shutdown_super not yet
calling sop-&gt;put_super before btrfs_mount_root calls btrfs_open_devices.
If that occurs, btrfs_open_devices will decide the opened counter is
non-zero, increment it, and skip resetting fs_devices-&gt;total_rw_bytes to
0. From here, mount will call sget which will result in grab_super
trying to take the super block umount semaphore. That semaphore will be
held by the slow umount, so mount will block. Before up-ing the
semaphore, umount will delete the super block, resulting in mount's sget
reliably allocating a new one, which causes the mount path to dutifully
fill it out, and increment total_rw_bytes a second time, which causes
the mount to fail, as we see double the expected bytes.

Here is the sequence laid out in greater detail:

CPU0                                                    CPU1
down_write sb-&gt;s_umount
btrfs_kill_super
  kill_anon_super(sb)
    generic_shutdown_super(sb);
      shrink_dcache_for_umount(sb);
      sync_filesystem(sb);
      evict_inodes(sb); // SLOW

                                              btrfs_mount_root
                                                btrfs_scan_one_device
                                                fs_devices = device-&gt;fs_devices
                                                fs_info-&gt;fs_devices = fs_devices
                                                // fs_devices-opened makes this a no-op
                                                btrfs_open_devices(fs_devices, mode, fs_type)
                                                s = sget(fs_type, test, set, flags, fs_info);
                                                  find sb in s_instances
                                                  grab_super(sb);
                                                    down_write(&amp;s-&gt;s_umount); // blocks

      sop-&gt;put_super(sb)
        // sb-&gt;fs_devices-&gt;opened == 2; no-op
      spin_lock(&amp;sb_lock);
      hlist_del_init(&amp;sb-&gt;s_instances);
      spin_unlock(&amp;sb_lock);
      up_write(&amp;sb-&gt;s_umount);
                                                    return 0;
                                                  retry lookup
                                                  don't find sb in s_instances (deleted by CPU0)
                                                  s = alloc_super
                                                  return s;
                                                btrfs_fill_super(s, fs_devices, data)
                                                  open_ctree // fs_devices total_rw_bytes improperly set!
                                                    btrfs_read_chunk_tree
                                                      read_one_dev // increment total_rw_bytes again!!
                                                      super_total_bytes &lt; fs_devices-&gt;total_rw_bytes // ERROR!!!

To fix this, we clear total_rw_bytes from within btrfs_read_chunk_tree
before the calls to read_one_dev, while holding the sb umount semaphore
and the uuid mutex.

To reproduce, it is sufficient to dirty a decent number of inodes, then
quickly umount and mount.

  for i in $(seq 0 500)
  do
    dd if=/dev/zero of="/mnt/foo/$i" bs=1M count=1
  done
  umount /mnt/foo&amp;
  mount /mnt/foo

does the trick for me.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Boris Burkov &lt;boris@bur.io&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 48cfa61b58a1fee0bc49eef04f8ccf31493b7cdd upstream.

It is possible to cause a btrfs mount to fail by racing it with a slow
umount. The crux of the sequence is generic_shutdown_super not yet
calling sop-&gt;put_super before btrfs_mount_root calls btrfs_open_devices.
If that occurs, btrfs_open_devices will decide the opened counter is
non-zero, increment it, and skip resetting fs_devices-&gt;total_rw_bytes to
0. From here, mount will call sget which will result in grab_super
trying to take the super block umount semaphore. That semaphore will be
held by the slow umount, so mount will block. Before up-ing the
semaphore, umount will delete the super block, resulting in mount's sget
reliably allocating a new one, which causes the mount path to dutifully
fill it out, and increment total_rw_bytes a second time, which causes
the mount to fail, as we see double the expected bytes.

Here is the sequence laid out in greater detail:

CPU0                                                    CPU1
down_write sb-&gt;s_umount
btrfs_kill_super
  kill_anon_super(sb)
    generic_shutdown_super(sb);
      shrink_dcache_for_umount(sb);
      sync_filesystem(sb);
      evict_inodes(sb); // SLOW

                                              btrfs_mount_root
                                                btrfs_scan_one_device
                                                fs_devices = device-&gt;fs_devices
                                                fs_info-&gt;fs_devices = fs_devices
                                                // fs_devices-opened makes this a no-op
                                                btrfs_open_devices(fs_devices, mode, fs_type)
                                                s = sget(fs_type, test, set, flags, fs_info);
                                                  find sb in s_instances
                                                  grab_super(sb);
                                                    down_write(&amp;s-&gt;s_umount); // blocks

      sop-&gt;put_super(sb)
        // sb-&gt;fs_devices-&gt;opened == 2; no-op
      spin_lock(&amp;sb_lock);
      hlist_del_init(&amp;sb-&gt;s_instances);
      spin_unlock(&amp;sb_lock);
      up_write(&amp;sb-&gt;s_umount);
                                                    return 0;
                                                  retry lookup
                                                  don't find sb in s_instances (deleted by CPU0)
                                                  s = alloc_super
                                                  return s;
                                                btrfs_fill_super(s, fs_devices, data)
                                                  open_ctree // fs_devices total_rw_bytes improperly set!
                                                    btrfs_read_chunk_tree
                                                      read_one_dev // increment total_rw_bytes again!!
                                                      super_total_bytes &lt; fs_devices-&gt;total_rw_bytes // ERROR!!!

To fix this, we clear total_rw_bytes from within btrfs_read_chunk_tree
before the calls to read_one_dev, while holding the sb umount semaphore
and the uuid mutex.

To reproduce, it is sufficient to dirty a decent number of inodes, then
quickly umount and mount.

  for i in $(seq 0 500)
  do
    dd if=/dev/zero of="/mnt/foo/$i" bs=1M count=1
  done
  umount /mnt/foo&amp;
  mount /mnt/foo

does the trick for me.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Boris Burkov &lt;boris@bur.io&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: fix double free on ulist after backref resolution failure</title>
<updated>2020-07-29T08:16:47+00:00</updated>
<author>
<name>Filipe Manana</name>
<email>fdmanana@suse.com</email>
</author>
<published>2020-07-13T14:11:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=18a1602c2de19aa2d38b7932b7fc4cd15cb063bc'/>
<id>18a1602c2de19aa2d38b7932b7fc4cd15cb063bc</id>
<content type='text'>
commit 580c079b5766ac706f56eec5c79aee4bf929fef6 upstream.

At btrfs_find_all_roots_safe() we allocate a ulist and set the **roots
argument to point to it. However if later we fail due to an error returned
by find_parent_nodes(), we free that ulist but leave a dangling pointer in
the **roots argument. Upon receiving the error, a caller of this function
can attempt to free the same ulist again, resulting in an invalid memory
access.

One such scenario is during qgroup accounting:

btrfs_qgroup_account_extents()

 --&gt; calls btrfs_find_all_roots() passes &amp;new_roots (a stack allocated
     pointer) to btrfs_find_all_roots()

   --&gt; btrfs_find_all_roots() just calls btrfs_find_all_roots_safe()
       passing &amp;new_roots to it

     --&gt; allocates ulist and assigns its address to **roots (which
         points to new_roots from btrfs_qgroup_account_extents())

     --&gt; find_parent_nodes() returns an error, so we free the ulist
         and leave **roots pointing to it after returning

 --&gt; btrfs_qgroup_account_extents() sees btrfs_find_all_roots() returned
     an error and jumps to the label 'cleanup', which just tries to
     free again the same ulist

Stack trace example:

 ------------[ cut here ]------------
 BTRFS: tree first key check failed
 WARNING: CPU: 1 PID: 1763215 at fs/btrfs/disk-io.c:422 btrfs_verify_level_key+0xe0/0x180 [btrfs]
 Modules linked in: dm_snapshot dm_thin_pool (...)
 CPU: 1 PID: 1763215 Comm: fsstress Tainted: G        W         5.8.0-rc3-btrfs-next-64 #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:btrfs_verify_level_key+0xe0/0x180 [btrfs]
 Code: 28 5b 5d (...)
 RSP: 0018:ffffb89b473779a0 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff90397759bf08 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000000027 RDI: 00000000ffffffff
 RBP: ffff9039a419c000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffffb89b43301000 R12: 000000000000005e
 R13: ffffb89b47377a2e R14: ffffb89b473779af R15: 0000000000000000
 FS:  00007fc47e1e1000(0000) GS:ffff9039ac200000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fc47e1df000 CR3: 00000003d9e4e001 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  read_block_for_search+0xf6/0x350 [btrfs]
  btrfs_next_old_leaf+0x242/0x650 [btrfs]
  resolve_indirect_refs+0x7cf/0x9e0 [btrfs]
  find_parent_nodes+0x4ea/0x12c0 [btrfs]
  btrfs_find_all_roots_safe+0xbf/0x130 [btrfs]
  btrfs_qgroup_account_extents+0x9d/0x390 [btrfs]
  btrfs_commit_transaction+0x4f7/0xb20 [btrfs]
  btrfs_sync_file+0x3d4/0x4d0 [btrfs]
  do_fsync+0x38/0x70
  __x64_sys_fdatasync+0x13/0x20
  do_syscall_64+0x5c/0xe0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fc47e2d72e3
 Code: Bad RIP value.
 RSP: 002b:00007fffa32098c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc47e2d72e3
 RDX: 00007fffa3209830 RSI: 00007fffa3209830 RDI: 0000000000000003
 RBP: 000000000000072e R08: 0000000000000001 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000003e8
 R13: 0000000051eb851f R14: 00007fffa3209970 R15: 00005607c4ac8b50
 irq event stamp: 0
 hardirqs last  enabled at (0): [&lt;0000000000000000&gt;] 0x0
 hardirqs last disabled at (0): [&lt;ffffffffb8eb5e85&gt;] copy_process+0x755/0x1eb0
 softirqs last  enabled at (0): [&lt;ffffffffb8eb5e85&gt;] copy_process+0x755/0x1eb0
 softirqs last disabled at (0): [&lt;0000000000000000&gt;] 0x0
 ---[ end trace 8639237550317b48 ]---
 BTRFS error (device sdc): tree first key mismatch detected, bytenr=62324736 parent_transid=94 key expected=(262,108,1351680) has=(259,108,1921024)
 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
 CPU: 2 PID: 1763215 Comm: fsstress Tainted: G        W         5.8.0-rc3-btrfs-next-64 #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:ulist_release+0x14/0x60 [btrfs]
 Code: c7 07 00 (...)
 RSP: 0018:ffffb89b47377d60 EFLAGS: 00010282
 RAX: 6b6b6b6b6b6b6b6b RBX: ffff903959b56b90 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000270024 RDI: ffff9036e2adc840
 RBP: ffff9036e2adc848 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9036e2adc840
 R13: 0000000000000015 R14: ffff9039a419ccf8 R15: ffff90395d605840
 FS:  00007fc47e1e1000(0000) GS:ffff9039ac600000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f8c1c0a51c8 CR3: 00000003d9e4e004 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  ulist_free+0x13/0x20 [btrfs]
  btrfs_qgroup_account_extents+0xf3/0x390 [btrfs]
  btrfs_commit_transaction+0x4f7/0xb20 [btrfs]
  btrfs_sync_file+0x3d4/0x4d0 [btrfs]
  do_fsync+0x38/0x70
  __x64_sys_fdatasync+0x13/0x20
  do_syscall_64+0x5c/0xe0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fc47e2d72e3
 Code: Bad RIP value.
 RSP: 002b:00007fffa32098c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc47e2d72e3
 RDX: 00007fffa3209830 RSI: 00007fffa3209830 RDI: 0000000000000003
 RBP: 000000000000072e R08: 0000000000000001 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000003e8
 R13: 0000000051eb851f R14: 00007fffa3209970 R15: 00005607c4ac8b50
 Modules linked in: dm_snapshot dm_thin_pool (...)
 ---[ end trace 8639237550317b49 ]---
 RIP: 0010:ulist_release+0x14/0x60 [btrfs]
 Code: c7 07 00 (...)
 RSP: 0018:ffffb89b47377d60 EFLAGS: 00010282
 RAX: 6b6b6b6b6b6b6b6b RBX: ffff903959b56b90 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000270024 RDI: ffff9036e2adc840
 RBP: ffff9036e2adc848 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9036e2adc840
 R13: 0000000000000015 R14: ffff9039a419ccf8 R15: ffff90395d605840
 FS:  00007fc47e1e1000(0000) GS:ffff9039ad200000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f6a776f7d40 CR3: 00000003d9e4e002 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fix this by making btrfs_find_all_roots_safe() set *roots to NULL after
it frees the ulist.

Fixes: 8da6d5815c592b ("Btrfs: added btrfs_find_all_roots()")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 580c079b5766ac706f56eec5c79aee4bf929fef6 upstream.

At btrfs_find_all_roots_safe() we allocate a ulist and set the **roots
argument to point to it. However if later we fail due to an error returned
by find_parent_nodes(), we free that ulist but leave a dangling pointer in
the **roots argument. Upon receiving the error, a caller of this function
can attempt to free the same ulist again, resulting in an invalid memory
access.

One such scenario is during qgroup accounting:

btrfs_qgroup_account_extents()

 --&gt; calls btrfs_find_all_roots() passes &amp;new_roots (a stack allocated
     pointer) to btrfs_find_all_roots()

   --&gt; btrfs_find_all_roots() just calls btrfs_find_all_roots_safe()
       passing &amp;new_roots to it

     --&gt; allocates ulist and assigns its address to **roots (which
         points to new_roots from btrfs_qgroup_account_extents())

     --&gt; find_parent_nodes() returns an error, so we free the ulist
         and leave **roots pointing to it after returning

 --&gt; btrfs_qgroup_account_extents() sees btrfs_find_all_roots() returned
     an error and jumps to the label 'cleanup', which just tries to
     free again the same ulist

Stack trace example:

 ------------[ cut here ]------------
 BTRFS: tree first key check failed
 WARNING: CPU: 1 PID: 1763215 at fs/btrfs/disk-io.c:422 btrfs_verify_level_key+0xe0/0x180 [btrfs]
 Modules linked in: dm_snapshot dm_thin_pool (...)
 CPU: 1 PID: 1763215 Comm: fsstress Tainted: G        W         5.8.0-rc3-btrfs-next-64 #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:btrfs_verify_level_key+0xe0/0x180 [btrfs]
 Code: 28 5b 5d (...)
 RSP: 0018:ffffb89b473779a0 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff90397759bf08 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000000027 RDI: 00000000ffffffff
 RBP: ffff9039a419c000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffffb89b43301000 R12: 000000000000005e
 R13: ffffb89b47377a2e R14: ffffb89b473779af R15: 0000000000000000
 FS:  00007fc47e1e1000(0000) GS:ffff9039ac200000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fc47e1df000 CR3: 00000003d9e4e001 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  read_block_for_search+0xf6/0x350 [btrfs]
  btrfs_next_old_leaf+0x242/0x650 [btrfs]
  resolve_indirect_refs+0x7cf/0x9e0 [btrfs]
  find_parent_nodes+0x4ea/0x12c0 [btrfs]
  btrfs_find_all_roots_safe+0xbf/0x130 [btrfs]
  btrfs_qgroup_account_extents+0x9d/0x390 [btrfs]
  btrfs_commit_transaction+0x4f7/0xb20 [btrfs]
  btrfs_sync_file+0x3d4/0x4d0 [btrfs]
  do_fsync+0x38/0x70
  __x64_sys_fdatasync+0x13/0x20
  do_syscall_64+0x5c/0xe0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fc47e2d72e3
 Code: Bad RIP value.
 RSP: 002b:00007fffa32098c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc47e2d72e3
 RDX: 00007fffa3209830 RSI: 00007fffa3209830 RDI: 0000000000000003
 RBP: 000000000000072e R08: 0000000000000001 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000003e8
 R13: 0000000051eb851f R14: 00007fffa3209970 R15: 00005607c4ac8b50
 irq event stamp: 0
 hardirqs last  enabled at (0): [&lt;0000000000000000&gt;] 0x0
 hardirqs last disabled at (0): [&lt;ffffffffb8eb5e85&gt;] copy_process+0x755/0x1eb0
 softirqs last  enabled at (0): [&lt;ffffffffb8eb5e85&gt;] copy_process+0x755/0x1eb0
 softirqs last disabled at (0): [&lt;0000000000000000&gt;] 0x0
 ---[ end trace 8639237550317b48 ]---
 BTRFS error (device sdc): tree first key mismatch detected, bytenr=62324736 parent_transid=94 key expected=(262,108,1351680) has=(259,108,1921024)
 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
 CPU: 2 PID: 1763215 Comm: fsstress Tainted: G        W         5.8.0-rc3-btrfs-next-64 #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:ulist_release+0x14/0x60 [btrfs]
 Code: c7 07 00 (...)
 RSP: 0018:ffffb89b47377d60 EFLAGS: 00010282
 RAX: 6b6b6b6b6b6b6b6b RBX: ffff903959b56b90 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000270024 RDI: ffff9036e2adc840
 RBP: ffff9036e2adc848 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9036e2adc840
 R13: 0000000000000015 R14: ffff9039a419ccf8 R15: ffff90395d605840
 FS:  00007fc47e1e1000(0000) GS:ffff9039ac600000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f8c1c0a51c8 CR3: 00000003d9e4e004 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  ulist_free+0x13/0x20 [btrfs]
  btrfs_qgroup_account_extents+0xf3/0x390 [btrfs]
  btrfs_commit_transaction+0x4f7/0xb20 [btrfs]
  btrfs_sync_file+0x3d4/0x4d0 [btrfs]
  do_fsync+0x38/0x70
  __x64_sys_fdatasync+0x13/0x20
  do_syscall_64+0x5c/0xe0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fc47e2d72e3
 Code: Bad RIP value.
 RSP: 002b:00007fffa32098c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc47e2d72e3
 RDX: 00007fffa3209830 RSI: 00007fffa3209830 RDI: 0000000000000003
 RBP: 000000000000072e R08: 0000000000000001 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000003e8
 R13: 0000000051eb851f R14: 00007fffa3209970 R15: 00005607c4ac8b50
 Modules linked in: dm_snapshot dm_thin_pool (...)
 ---[ end trace 8639237550317b49 ]---
 RIP: 0010:ulist_release+0x14/0x60 [btrfs]
 Code: c7 07 00 (...)
 RSP: 0018:ffffb89b47377d60 EFLAGS: 00010282
 RAX: 6b6b6b6b6b6b6b6b RBX: ffff903959b56b90 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000270024 RDI: ffff9036e2adc840
 RBP: ffff9036e2adc848 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9036e2adc840
 R13: 0000000000000015 R14: ffff9039a419ccf8 R15: ffff90395d605840
 FS:  00007fc47e1e1000(0000) GS:ffff9039ad200000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f6a776f7d40 CR3: 00000003d9e4e002 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fix this by making btrfs_find_all_roots_safe() set *roots to NULL after
it frees the ulist.

Fixes: 8da6d5815c592b ("Btrfs: added btrfs_find_all_roots()")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>SUNRPC reverting d03727b248d0 ("NFSv4 fix CLOSE not waiting for direct IO compeletion")</title>
<updated>2020-07-29T08:16:46+00:00</updated>
<author>
<name>Olga Kornievskaia</name>
<email>kolga@netapp.com</email>
</author>
<published>2020-07-15T17:04:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8f0d0b36cec3dc51e978af069574eb1efac04ec9'/>
<id>8f0d0b36cec3dc51e978af069574eb1efac04ec9</id>
<content type='text'>
commit 65caafd0d2145d1dd02072c4ced540624daeab40 upstream.

Reverting commit d03727b248d0 "NFSv4 fix CLOSE not waiting for
direct IO compeletion". This patch made it so that fput() by calling
inode_dio_done() in nfs_file_release() would wait uninterruptably
for any outstanding directIO to the file (but that wait on IO should
be killable).

The problem the patch was also trying to address was REMOVE returning
ERR_ACCESS because the file is still opened, is supposed to be resolved
by server returning ERR_FILE_OPEN and not ERR_ACCESS.

Signed-off-by: Olga Kornievskaia &lt;kolga@netapp.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 65caafd0d2145d1dd02072c4ced540624daeab40 upstream.

Reverting commit d03727b248d0 "NFSv4 fix CLOSE not waiting for
direct IO compeletion". This patch made it so that fput() by calling
inode_dio_done() in nfs_file_release() would wait uninterruptably
for any outstanding directIO to the file (but that wait on IO should
be killable).

The problem the patch was also trying to address was REMOVE returning
ERR_ACCESS because the file is still opened, is supposed to be resolved
by server returning ERR_FILE_OPEN and not ERR_ACCESS.

Signed-off-by: Olga Kornievskaia &lt;kolga@netapp.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: fix weird page warning</title>
<updated>2020-07-29T08:16:46+00:00</updated>
<author>
<name>Miklos Szeredi</name>
<email>mszeredi@redhat.com</email>
</author>
<published>2020-07-21T18:54:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=02c4ddf1896324e1ad50e72ad2d467d2c85cf75c'/>
<id>02c4ddf1896324e1ad50e72ad2d467d2c85cf75c</id>
<content type='text'>
commit a5005c3cda6eeb6b95645e6cc32f58dafeffc976 upstream.

When PageWaiters was added, updating this check was missed.

Reported-by: Nikolaus Rath &lt;Nikolaus@rath.org&gt;
Reported-by: Hugh Dickins &lt;hughd@google.com&gt;
Fixes: 62906027091f ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: André Almeida &lt;andrealmeid@collabora.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a5005c3cda6eeb6b95645e6cc32f58dafeffc976 upstream.

When PageWaiters was added, updating this check was missed.

Reported-by: Nikolaus Rath &lt;Nikolaus@rath.org&gt;
Reported-by: Hugh Dickins &lt;hughd@google.com&gt;
Fixes: 62906027091f ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: André Almeida &lt;andrealmeid@collabora.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: Fix parameter for FS_IOC_{GET,SET}FLAGS</title>
<updated>2020-07-22T07:32:10+00:00</updated>
<author>
<name>Chirantan Ekbote</name>
<email>chirantan@chromium.org</email>
</author>
<published>2020-07-14T10:26:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d61cd1dcab2c675704eb4eb55d4392d25e55293a'/>
<id>d61cd1dcab2c675704eb4eb55d4392d25e55293a</id>
<content type='text'>
commit 31070f6ccec09f3bd4f1e28cd1e592fa4f3ba0b6 upstream.

The ioctl encoding for this parameter is a long but the documentation says
it should be an int and the kernel drivers expect it to be an int.  If the
fuse driver treats this as a long it might end up scribbling over the stack
of a userspace process that only allocated enough space for an int.

This was previously discussed in [1] and a patch for fuse was proposed in
[2].  From what I can tell the patch in [2] was nacked in favor of adding
new, "fixed" ioctls and using those from userspace.  However there is still
no "fixed" version of these ioctls and the fact is that it's sometimes
infeasible to change all userspace to use the new one.

Handling the ioctls specially in the fuse driver seems like the most
pragmatic way for fuse servers to support them without causing crashes in
userspace applications that call them.

[1]: https://lore.kernel.org/linux-fsdevel/20131126200559.GH20559@hall.aurel32.net/T/
[2]: https://sourceforge.net/p/fuse/mailman/message/31771759/

Signed-off-by: Chirantan Ekbote &lt;chirantan@chromium.org&gt;
Fixes: 59efec7b9039 ("fuse: implement ioctl support")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 31070f6ccec09f3bd4f1e28cd1e592fa4f3ba0b6 upstream.

The ioctl encoding for this parameter is a long but the documentation says
it should be an int and the kernel drivers expect it to be an int.  If the
fuse driver treats this as a long it might end up scribbling over the stack
of a userspace process that only allocated enough space for an int.

This was previously discussed in [1] and a patch for fuse was proposed in
[2].  From what I can tell the patch in [2] was nacked in favor of adding
new, "fixed" ioctls and using those from userspace.  However there is still
no "fixed" version of these ioctls and the fact is that it's sometimes
infeasible to change all userspace to use the new one.

Handling the ioctls specially in the fuse driver seems like the most
pragmatic way for fuse servers to support them without causing crashes in
userspace applications that call them.

[1]: https://lore.kernel.org/linux-fsdevel/20131126200559.GH20559@hall.aurel32.net/T/
[2]: https://sourceforge.net/p/fuse/mailman/message/31771759/

Signed-off-by: Chirantan Ekbote &lt;chirantan@chromium.org&gt;
Fixes: 59efec7b9039 ("fuse: implement ioctl support")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ovl: fix unneeded call to ovl_change_flags()</title>
<updated>2020-07-22T07:32:10+00:00</updated>
<author>
<name>Amir Goldstein</name>
<email>amir73il@gmail.com</email>
</author>
<published>2020-06-18T15:43:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00de23f4f90ed0bc7ed252844d2edbfd86f8d500'/>
<id>00de23f4f90ed0bc7ed252844d2edbfd86f8d500</id>
<content type='text'>
commit 81a33c1ee941c3bb9ffc6bac8f676be13351344e upstream.

The check if user has changed the overlay file was wrong, causing unneeded
call to ovl_change_flags() including taking f_lock on every file access.

Fixes: d989903058a8 ("ovl: do not generate duplicate fsnotify events for "fake" path")
Cc: &lt;stable@vger.kernel.org&gt; # v4.19+
Signed-off-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 81a33c1ee941c3bb9ffc6bac8f676be13351344e upstream.

The check if user has changed the overlay file was wrong, causing unneeded
call to ovl_change_flags() including taking f_lock on every file access.

Fixes: d989903058a8 ("ovl: do not generate duplicate fsnotify events for "fake" path")
Cc: &lt;stable@vger.kernel.org&gt; # v4.19+
Signed-off-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ovl: relax WARN_ON() when decoding lower directory file handle</title>
<updated>2020-07-22T07:32:10+00:00</updated>
<author>
<name>Amir Goldstein</name>
<email>amir73il@gmail.com</email>
</author>
<published>2020-06-17T06:57:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f03b3a039e2ffdce8f708a0cf9231a4d0b7f9275'/>
<id>f03b3a039e2ffdce8f708a0cf9231a4d0b7f9275</id>
<content type='text'>
commit 124c2de2c0aee96271e4ddab190083d8aa7aa71a upstream.

Decoding a lower directory file handle to overlay path with cold
inode/dentry cache may go as follows:

1. Decode real lower file handle to lower dir path
2. Check if lower dir is indexed (was copied up)
3. If indexed, get the upper dir path from index
4. Lookup upper dir path in overlay
5. If overlay path found, verify that overlay lower is the lower dir
   from step 1

On failure to verify step 5 above, user will get an ESTALE error and a
WARN_ON will be printed.

A mismatch in step 5 could be a result of lower directory that was renamed
while overlay was offline, after that lower directory has been copied up
and indexed.

This is a scripted reproducer based on xfstest overlay/052:

  # Create lower subdir
  create_dirs
  create_test_files $lower/lowertestdir/subdir
  mount_dirs
  # Copy up lower dir and encode lower subdir file handle
  touch $SCRATCH_MNT/lowertestdir
  test_file_handles $SCRATCH_MNT/lowertestdir/subdir -p -o $tmp.fhandle
  # Rename lower dir offline
  unmount_dirs
  mv $lower/lowertestdir $lower/lowertestdir.new/
  mount_dirs
  # Attempt to decode lower subdir file handle
  test_file_handles $SCRATCH_MNT -p -i $tmp.fhandle

Since this WARN_ON() can be triggered by user we need to relax it.

Fixes: 4b91c30a5a19 ("ovl: lookup connected ancestor of dir in inode cache")
Cc: &lt;stable@vger.kernel.org&gt; # v4.16+
Signed-off-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 124c2de2c0aee96271e4ddab190083d8aa7aa71a upstream.

Decoding a lower directory file handle to overlay path with cold
inode/dentry cache may go as follows:

1. Decode real lower file handle to lower dir path
2. Check if lower dir is indexed (was copied up)
3. If indexed, get the upper dir path from index
4. Lookup upper dir path in overlay
5. If overlay path found, verify that overlay lower is the lower dir
   from step 1

On failure to verify step 5 above, user will get an ESTALE error and a
WARN_ON will be printed.

A mismatch in step 5 could be a result of lower directory that was renamed
while overlay was offline, after that lower directory has been copied up
and indexed.

This is a scripted reproducer based on xfstest overlay/052:

  # Create lower subdir
  create_dirs
  create_test_files $lower/lowertestdir/subdir
  mount_dirs
  # Copy up lower dir and encode lower subdir file handle
  touch $SCRATCH_MNT/lowertestdir
  test_file_handles $SCRATCH_MNT/lowertestdir/subdir -p -o $tmp.fhandle
  # Rename lower dir offline
  unmount_dirs
  mv $lower/lowertestdir $lower/lowertestdir.new/
  mount_dirs
  # Attempt to decode lower subdir file handle
  test_file_handles $SCRATCH_MNT -p -i $tmp.fhandle

Since this WARN_ON() can be triggered by user we need to relax it.

Fixes: 4b91c30a5a19 ("ovl: lookup connected ancestor of dir in inode cache")
Cc: &lt;stable@vger.kernel.org&gt; # v4.16+
Signed-off-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ovl: inode reference leak in ovl_is_inuse true case.</title>
<updated>2020-07-22T07:32:10+00:00</updated>
<author>
<name>youngjun</name>
<email>her0gyugyu@gmail.com</email>
</author>
<published>2020-06-16T08:30:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=77cc397f6bb05121ef5544e9d78d29ecf4ba7165'/>
<id>77cc397f6bb05121ef5544e9d78d29ecf4ba7165</id>
<content type='text'>
commit 24f14009b8f1754ec2ae4c168940c01259b0f88a upstream.

When "ovl_is_inuse" true case, trap inode reference not put.  plus adding
the comment explaining sequence of ovl_is_inuse after ovl_setup_trap.

Fixes: 0be0bfd2de9d ("ovl: fix regression caused by overlapping layers detection")
Cc: &lt;stable@vger.kernel.org&gt; # v4.19+
Reviewed-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: youngjun &lt;her0gyugyu@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 24f14009b8f1754ec2ae4c168940c01259b0f88a upstream.

When "ovl_is_inuse" true case, trap inode reference not put.  plus adding
the comment explaining sequence of ovl_is_inuse after ovl_setup_trap.

Fixes: 0be0bfd2de9d ("ovl: fix regression caused by overlapping layers detection")
Cc: &lt;stable@vger.kernel.org&gt; # v4.19+
Reviewed-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: youngjun &lt;her0gyugyu@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
