Pull btrfs fixes from Chris Mason:
"Filipe fixed up a hard to trigger ENOSPC regression from our merge
window pull, and we have a few other smaller fixes"
* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix quick exhaustion of the system array in the superblock
btrfs: its btrfs_err() instead of btrfs_error()
btrfs: Avoid NULL pointer dereference of free_extent_buffer when read_tree_block() fail
btrfs: Fix lockdep warning of btrfs_run_delayed_iputs()
Pull xfs fixes from Dave Chinner:
"There are a couple of recently found, long standing remote attribute
corruption fixes caused by log recovery getting confused after a
crash, and the new DAX code in XFS (merged in 4.2-rc1) needs to
actually use the DAX fault path on read faults.
Summary:
- remote attribute log recovery corruption fixes
- DAX page faults need to use direct mappings, not a page cache
mapping"
* tag 'xfs-for-linus-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
xfs: remote attributes need to be considered data
xfs: remote attribute headers contain an invalid LSN
xfs: call dax_fault on read page faults for DAX
We don't log remote attribute contents, and instead write them
synchronously before we commit the block allocation and attribute
tree update transaction. As a result we are writing to the allocated
space before the allcoation has been made permanent.
As a result, we cannot consider this allocation to be a metadata
allocation. Metadata allocation can take blocks from the free list
and so reuse them before the transaction that freed the block is
committed to disk. This behaviour is perfectly fine for journalled
metadata changes as log recovery will ensure the free operation is
replayed before the overwrite, but for remote attribute writes this
is not the case.
Hence we have to consider the remote attribute blocks to contain
data and allocate accordingly. We do this by dropping the
XFS_BMAPI_METADATA flag from the block allocation. This means the
allocation will not use blocks that are on the busy list without
first ensuring that the freeing transaction has been committed to
disk and the blocks removed from the busy list. This ensures we will
never overwrite a freed block without first ensuring that it is
really free.
cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
In recent testing, a system that crashed failed log recovery on
restart with a bad symlink buffer magic number:
XFS (vda): Starting recovery (logdev: internal)
XFS (vda): Bad symlink block magic!
XFS: Assertion failed: 0, file: fs/xfs/xfs_log_recover.c, line: 2060
On examination of the log via xfs_logprint, none of the symlink
buffers in the log had a bad magic number, nor were any other types
of buffer log format headers mis-identified as symlink buffers.
Tracing was used to find the buffer the kernel was tripping over,
and xfs_db identified it's contents as:
000: 5841524d 00000000 00000346 64d82b48 8983e692 d71e4680 a5f49e2c b317576e
020: 00000000 00602038 00000000 006034ce d0020000 00000000 4d4d4d4d 4d4d4d4d
040: 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d
060: 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d 4d4d4d4d
.....
This is a remote attribute buffer, which are notable in that they
are not logged but are instead written synchronously by the remote
attribute code so that they exist on disk before the attribute
transactions are committed to the journal.
The above remote attribute block has an invalid LSN in it - cycle
0xd002000, block 0 - which means when log recovery comes along to
determine if the transaction that writes to the underlying block
should be replayed, it sees a block that has a future LSN and so
does not replay the buffer data in the transaction. Instead, it
validates the buffer magic number and attaches the buffer verifier
to it. It is this buffer magic number check that is failing in the
above assert, indicating that we skipped replay due to the LSN of
the underlying buffer.
The problem here is that the remote attribute buffers cannot have a
valid LSN placed into them, because the transaction that contains
the attribute tree pointer changes and the block allocation that the
attribute data is being written to hasn't yet been committed. Hence
the LSN field in the attribute block is completely unwritten,
thereby leaving the underlying contents of the block in the LSN
field. It could have any value, and hence a future overwrite of the
block by log recovery may or may not work correctly.
Fix this by always writing an invalid LSN to the remote attribute
block, as any buffer in log recovery that needs to write over the
remote attribute should occur. We are protected from having old data
written over the attribute by the fact that freeing the block before
the remote attribute is written will result in the buffer being
marked stale in the log and so all changes prior to the buffer stale
transaction will be cancelled by log recovery.
Hence it is safe to ignore the LSN in the case or synchronously
written, unlogged metadata such as remote attribute blocks, and to
ensure we do that correctly, we need to write an invalid LSN to all
remote attribute blocks to trigger immediate recovery of metadata
that is written over the top.
As a further protection for filesystems that may already have remote
attribute blocks with bad LSNs on disk, change the log recovery code
to always trigger immediate recovery of metadata over remote
attribute blocks.
cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
When modifying the patch series to handle the XFS MMAP_LOCK nesting
of page faults, I botched the conversion of the read page fault
path, and so it is only every calling through the page cache. Re-add
the necessary __dax_fault() call for such files.
Because the get_blocks callback on read faults may not set up the
mapping buffer correctly to allow unwritten extent completion to be
run, we need to allow callers of __dax_fault() to pass a null
complete_unwritten() callback. The DAX code always zeros the
unwritten page when it is read faulted so there are no stale data
exposure issues with not doing the conversion. The only downside
will be the potential for increased CPU overhead on repeated read
faults of the same page. If this proves to be a problem, then the
filesystem needs to fix it's get_block callback and provide a
convert_unwritten() callback to the read fault path.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
Stable patches:
- Fix a situation where the client uses the wrong (zero) stateid.
- Fix a memory leak in nfs_do_recoalesce
Bugfixes:
- Plug a memory leak when ->prepare_layoutcommit fails
- Fix an Oops in the NFSv4 open code
- Fix a backchannel deadlock
- Fix a livelock in sunrpc when sendmsg fails due to low memory
availability
- Don't revalidate the mapping if both size and change attr are up to
date
- Ensure we don't miss a file extension when doing pNFS
- Several fixes to handle NFSv4.1 sequence operation status bits
correctly
- Several pNFS layout return bugfixes"
* tag 'nfs-for-4.2-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (28 commits)
nfs: Fix an oops caused by using other thread's stack space in ASYNC mode
nfs: plug memory leak when ->prepare_layoutcommit fails
SUNRPC: Report TCP errors to the caller
sunrpc: translate -EAGAIN to -ENOBUFS when socket is writable.
NFSv4.2: handle NFS-specific llseek errors
NFS: Don't clear desc->pg_moreio in nfs_do_recoalesce()
NFS: Fix a memory leak in nfs_do_recoalesce
NFS: nfs_mark_for_revalidate should always set NFS_INO_REVAL_PAGECACHE
NFS: Remove the "NFS_CAP_CHANGE_ATTR" capability
NFS: Set NFS_INO_REVAL_PAGECACHE if the change attribute is uninitialised
NFS: Don't revalidate the mapping if both size and change attr are up to date
NFSv4/pnfs: Ensure we don't miss a file extension
NFSv4: We must set NFS_OPEN_STATE flag in nfs_resync_open_stateid_locked
SUNRPC: xprt_complete_bc_request must also decrement the free slot count
SUNRPC: Fix a backchannel deadlock
pNFS: Don't throw out valid layout segments
pNFS: pnfs_roc_drain() fix a race with open
pNFS: Fix races between return-on-close and layoutreturn.
pNFS: pnfs_roc_drain should return 'true' when sleeping
pNFS: Layoutreturn must invalidate all existing layout segments.
...
"data" is currently leaked when the prepare_layoutcommit operation
returns an error. Put the cred before taking the spinlock in that
case, take the lock and then goto out_unlock which will drop the
lock and then free "data".
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Recoalescing does not affect whether or not we've already sent off
I/O, and doing so means that we end up sending a bunch of synchronous
for cases where we actually need to be using unstable writes.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the function exits early, then we must put those requests that were
not processed back onto the &mirror->pg_list so they can be cleaned up
by nfs_pgio_error().
Fixes: a7d42ddb30 ("nfs: add mirroring support to pgio layer")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Pull block fixes from Jens Axboe:
"Four smaller fixes for the current series. This contains:
- A fix for clones of discard bio's, that can cause data corruption.
From Martin.
- A fix for null_blk, where in certain queue modes it could access a
request after it had been freed. From Mike Krinkin.
- An error handling leak fix for blkcg, from Tejun.
- Also from Tejun, export of the functions that a file system needs
to implement cgroup writeback support"
* 'for-linus' of git://git.kernel.dk/linux-block:
block: Do a full clone when splitting discard bios
block: export bio_associate_*() and wbc_account_io()
blkcg: fix gendisk reference leak in blkg_conf_prep()
null_blk: fix use-after-free problem
Pull namespace fixes from Eric Biederman:
"While reading through the code of detach_mounts I realized the code
was slightly off. Testing it revealed two buggy corner cases that can
send the code of detach_mounts into an infinite loop.
Fixing the code to do the right thing removes the possibility of these
user triggered infinite loops in the code"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
mnt: In detach_mounts detach the appropriate unmounted mount
mnt: Clarify and correct the disconnect logic in umount_tree
bio_associate_blkcg(), bio_associate_current() and wbc_account_io()
are used to implement cgroup writeback support for filesystems and
thus need to be exported. Export them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <axboe@fb.com>
The handling of in detach_mounts of unmounted but connected mounts is
buggy and can lead to an infinite loop.
Correct the handling of unmounted mounts in detach_mount. When the
mountpoint of an unmounted but connected mount is connected to a
dentry, and that dentry is deleted we need to disconnect that mount
from the parent mount and the deleted dentry.
Nothing changes for the unmounted and connected children. They can be
safely ignored.
Cc: stable@vger.kernel.org
Fixes: ce07d891a0 mnt: Honor MNT_LOCKED when detaching mounts
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
rmdir mntpoint will result in an infinite loop when there is
a mount locked on the mountpoint in another mount namespace.
This is because the logic to test to see if a mount should
be disconnected in umount_tree is buggy.
Move the logic to decide if a mount should remain connected to
it's mountpoint into it's own function disconnect_mount so that
clarity of expression instead of terseness of expression becomes
a virtue.
When the conditions where it is invalid to leave a mount connected
are first ruled out, the logic for deciding if a mount should
be disconnected becomes much clearer and simpler.
Fixes: e0c9c0afd2 mnt: Update detach_mounts to leave mounts connected
Fixes: ce07d891a0 mnt: Honor MNT_LOCKED when detaching mounts
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Omar reported that after commit 4fbcdf6694 ("Btrfs: fix -ENOSPC when
finishing block group creation"), introduced in 4.2-rc1, the following
test was failing due to exhaustion of the system array in the superblock:
#!/bin/bash
truncate -s 100T big.img
mkfs.btrfs big.img
mount -o loop big.img /mnt/loop
num=5
sz=10T
for ((i = 0; i < $num; i++)); do
echo fallocate $i $sz
fallocate -l $sz /mnt/loop/testfile$i
done
btrfs filesystem sync /mnt/loop
for ((i = 0; i < $num; i++)); do
echo rm $i
rm /mnt/loop/testfile$i
btrfs filesystem sync /mnt/loop
done
umount /mnt/loop
This made btrfs_add_system_chunk() fail with -EFBIG due to excessive
allocation of system block groups. This happened because the test creates
a large number of data block groups per transaction and when committing
the transaction we start the writeout of the block group caches for all
the new new (dirty) block groups, which results in pre-allocating space
for each block group's free space cache using the same transaction handle.
That in turn often leads to creation of more block groups, and all get
attached to the new_bgs list of the same transaction handle to the point
of getting a list with over 1500 elements, and creation of new block groups
leads to the need of reserving space in the chunk block reserve and often
creating a new system block group too.
So that made us quickly exhaust the chunk block reserve/system space info,
because as of the commit mentioned before, we do reserve space for each
new block group in the chunk block reserve, unlike before where we would
not and would at most allocate one new system block group and therefore
would only ensure that there was enough space in the system space info to
allocate 1 new block group even if we ended up allocating thousands of
new block groups using the same transaction handle. That worked most of
the time because the computed required space at check_system_chunk() is
very pessimistic (assumes a chunk tree height of BTRFS_MAX_LEVEL/8 and
that all nodes/leafs in a path will be COWed and split) and since the
updates to the chunk tree all happen at btrfs_create_pending_block_groups
it is unlikely that a path needs to be COWed more than once (unless
writepages() for the btree inode is called by mm in between) and that
compensated for the need of creating any new nodes/leads in the chunk
tree.
So fix this by ensuring we don't accumulate a too large list of new block
groups in a transaction's handles new_bgs list, inserting/updating the
chunk tree for all accumulated new block groups and releasing the unused
space from the chunk block reserve whenever the list becomes sufficiently
large. This is a generic solution even though the problem currently can
only happen when starting the writeout of the free space caches for all
dirty block groups (btrfs_start_dirty_block_groups()).
Reported-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
sorry I indented to use btrfs_err() and I have no idea
how btrfs_error() got there.
infact I was thinking about these kind of oversights
since these two func are too closely named.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Liu Bo <bo.li.liu@oracle.com> reported a lockdep warning of
delayed_iput_sem in xfstests generic/241:
[ 2061.345955] =============================================
[ 2061.346027] [ INFO: possible recursive locking detected ]
[ 2061.346027] 4.1.0+ #268 Tainted: G W
[ 2061.346027] ---------------------------------------------
[ 2061.346027] btrfs-cleaner/3045 is trying to acquire lock:
[ 2061.346027] (&fs_info->delayed_iput_sem){++++..}, at:
[<ffffffff814063ab>] btrfs_run_delayed_iputs+0x6b/0x100
[ 2061.346027] but task is already holding lock:
[ 2061.346027] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffff814063ab>] btrfs_run_delayed_iputs+0x6b/0x100
[ 2061.346027] other info that might help us debug this:
[ 2061.346027] Possible unsafe locking scenario:
[ 2061.346027] CPU0
[ 2061.346027] ----
[ 2061.346027] lock(&fs_info->delayed_iput_sem);
[ 2061.346027] lock(&fs_info->delayed_iput_sem);
[ 2061.346027]
*** DEADLOCK ***
It is rarely happened, about 1/400 in my test env.
The reason is recursion of btrfs_run_delayed_iputs():
cleaner_kthread
-> btrfs_run_delayed_iputs() *1
-> get delayed_iput_sem lock *2
-> iput()
-> ...
-> btrfs_commit_transaction()
-> btrfs_run_delayed_iputs() *1
-> get delayed_iput_sem lock (dead lock) *2
*1: recursion of btrfs_run_delayed_iputs()
*2: warning of lockdep about delayed_iput_sem
When fs is in high stress, new iputs may added into fs_info->delayed_iputs
list when btrfs_run_delayed_iputs() is running, which cause
second btrfs_run_delayed_iputs() run into down_read(&fs_info->delayed_iput_sem)
again, and cause above lockdep warning.
Actually, it will not cause real problem because both locks are read lock,
but to avoid lockdep warning, we can do a fix.
Fix:
Don't do btrfs_run_delayed_iputs() in btrfs_commit_transaction() for
cleaner_kthread thread to break above recursion path.
cleaner_kthread is calling btrfs_run_delayed_iputs() explicitly in code,
and don't need to call btrfs_run_delayed_iputs() again in
btrfs_commit_transaction(), it also give us a bonus to avoid stack overflow.
Test:
No above lockdep warning after patch in 1200 generic/241 tests.
Reported-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Setting the change attribute has been mandatory for all NFS versions, since
commit 3a1556e866 ("NFSv2/v3: Simulate the change attribute"). We should
therefore not have anything be conditional on it being set/unset.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We can't allow caching of data until the change attribute has been
initialised correctly.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If we've ensured that the size and the change attribute are both correct,
then there is no point in marking those attributes as needing revalidation
again. Only do so if we know the size is incorrect and was not updated.
Fixes: f2467b6f64 ("NFS: Clear NFS_INO_REVAL_PAGECACHE when...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
