Modify the calling convention for the iomap_dio_rw ->end_io() callback.
Rather than passing either dio->error or dio->size as the 'size' argument,
instead pass both the dio->error and the dio->size value separately.

In the instance that an error occurred during a write, we currently cannot
determine whether any blocks have been allocated beyond the current EOF and
data has subsequently been written to these blocks within the ->end_io()
callback. As a result, we cannot judge whether we should take the truncate
failed write path. Having both dio->error and dio->size will allow us to
perform such checks within this callback.
Signed-off-by: NMatthew Bobrowski <mbobrowski@mbobrowski.org>
[hch: minor cleanups]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

	We need to drop everything we remove from the tree, whether
mnt_has_parent() is true or not.  Usually the bug manifests as a slow
memory leak (leaked struct mount for initramfs); it becomes much more
visible in mount_subtree() users, such as btrfs.  There we leak
a struct mount for btrfs superblock being mounted, which prevents
fs shutdown on subsequent umount.

Fixes: 56cbb429 ("switch the remnants of releasing the mountpoint away from fs_pin")
Reported-by: NNikolay Borisov <nborisov@suse.com>
Tested-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

btrfs_lock_and_flush_ordered_range() loads given "*cached_state" into
cachedp, which, in general, is NULL. Then, lock_extent_bits() updates
"cachedp", but it never goes backs to the caller. Thus the caller still
see its "cached_state" to be NULL and never free the state allocated
under btrfs_lock_and_flush_ordered_range(). As a result, we will
see massive state leak with e.g. fstests btrfs/005. Fix this bug by
properly handling the pointers.

Fixes: bd80d94e ("btrfs: Always use a cached extent_state in btrfs_lock_and_flush_ordered_range")
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NNaohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

Warning level 3 was used: -Wimplicit-fallthrough=3

fs/afs/fsclient.c: In function ‘afs_deliver_fs_fetch_acl’:
fs/afs/fsclient.c:2199:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/fsclient.c:2202:2: note: here
  case 1:
  ^~~~
fs/afs/fsclient.c:2216:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/fsclient.c:2219:2: note: here
  case 2:
  ^~~~
fs/afs/fsclient.c:2225:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/fsclient.c:2228:2: note: here
  case 3:
  ^~~~

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

fs/afs/yfsclient.c: In function ‘yfs_deliver_fs_fetch_opaque_acl’:
fs/afs/yfsclient.c:1984:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/yfsclient.c:1987:2: note: here
  case 1:
  ^~~~
fs/afs/yfsclient.c:2005:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/yfsclient.c:2008:2: note: here
  case 2:
  ^~~~
fs/afs/yfsclient.c:2014:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/yfsclient.c:2017:2: note: here
  case 3:
  ^~~~
fs/afs/yfsclient.c:2035:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/yfsclient.c:2038:2: note: here
  case 4:
  ^~~~
fs/afs/yfsclient.c:2047:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
   call->unmarshall++;
   ~~~~~~~~~~~~~~~~^~
fs/afs/yfsclient.c:2050:2: note: here
  case 5:
  ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

Also, fix some commenting style issues.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>

Daniel reports that when testing an http server that uses io_uring
to poll for incoming connections, sometimes it hard crashes. This is
due to an uninitialized list member for the io_uring request. Normally
this doesn't trigger and none of the test cases caught it.
Reported-by: NDaniel Kozak <kozzi11@gmail.com>
Tested-by: NDaniel Kozak <kozzi11@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Commit 06297d8c ("btrfs: switch extent_buffer blocking_writers from
atomic to int") changed the type of blocking_writers but forgot to
adjust relevant code in btrfs_tree_unlock by converting the
smp_mb__after_atomic to smp_mb.  This opened up the possibility of a
deadlock due to re-ordering of setting blocking_writers and
checking/waking up the waiter. This particular lockup is explained in a
comment above waitqueue_active() function.

Fix it by converting the memory barrier to a full smp_mb, accounting
for the fact that blocking_writers is a simple integer.

Fixes: 06297d8c ("btrfs: switch extent_buffer blocking_writers from atomic to int")
Tested-by: NJohannes Thumshirn <jthumshirn@suse.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

When going through execve(), zero out the NUMA fault statistics instead of
freeing them.

During execve, the task is reachable through procfs and the scheduler. A
concurrent /proc/*/sched reader can read data from a freed ->numa_faults
allocation (confirmed by KASAN) and write it back to userspace.
I believe that it would also be possible for a use-after-free read to occur
through a race between a NUMA fault and execve(): task_numa_fault() can
lead to task_numa_compare(), which invokes task_weight() on the currently
running task of a different CPU.

Another way to fix this would be to make ->numa_faults RCU-managed or add
extra locking, but it seems easier to wipe the NUMA fault statistics on
execve.
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes: 82727018 ("sched/numa: Call task_numa_free() from do_execve()")
Link: https://lkml.kernel.org/r/20190716152047.14424-1-jannh@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Detected by:

  $ ./scripts/spdxcheck.py
  fs/iomap/Makefile: 1:27 Invalid License ID: GPL-2.0-or-newer

Fixes: 1c230208 ("iomap: start moving code to fs/iomap/")
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU
work because it installs a temporary credential that gets allocated and
freed for each system call.

The allocation and freeing overhead is mostly benign, but because
credentials can be accessed under the RCU read lock, the freeing
involves a RCU grace period.

Which is not a huge deal normally, but if you have a lot of access()
calls, this causes a fair amount of seconday damage: instead of having a
nice alloc/free patterns that hits in hot per-CPU slab caches, you have
all those delayed free's, and on big machines with hundreds of cores,
the RCU overhead can end up being enormous.

But it turns out that all of this is entirely unnecessary.  Exactly
because access() only installs the credential as the thread-local
subjective credential, the temporary cred pointer doesn't actually need
to be RCU free'd at all.  Once we're done using it, we can just free it
synchronously and avoid all the RCU overhead.

So add a 'non_rcu' flag to 'struct cred', which can be set by users that
know they only use it in non-RCU context (there are other potential
users for this).  We can make it a union with the rcu freeing list head
that we need for the RCU case, so this doesn't need any extra storage.

Note that this also makes 'get_current_cred()' clear the new non_rcu
flag, in case we have filesystems that take a long-term reference to the
cred and then expect the RCU delayed freeing afterwards.  It's not
entirely clear that this is required, but it makes for clear semantics:
the subjective cred remains non-RCU as long as you only access it
synchronously using the thread-local accessors, but you _can_ use it as
a generic cred if you want to.

It is possible that we should just remove the whole RCU markings for
->cred entirely.  Only ->real_cred is really supposed to be accessed
through RCU, and the long-term cred copies that nfs uses might want to
explicitly re-enable RCU freeing if required, rather than have
get_current_cred() do it implicitly.

But this is a "minimal semantic changes" change for the immediate
problem.
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NEric Dumazet <edumazet@google.com>
Acked-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Glauber <jglauber@marvell.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Jayachandran Chandrasekharan Nair <jnair@marvell.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are using PAGE_SIZE as the unit to determine if the total len in
async_list has exceeded max_pages, it's not fair for smaller io sizes.
For example, if we are doing 1k-size io streams, we will never exceed
max_pages since len >>= PAGE_SHIFT always gets zero. So use original
bytes to make it more accurate.
Signed-off-by: NZhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Hrvoje reports that when a large fixed buffer is registered and IO is
being done to the latter pages of said buffer, the IO submission time
is much worse:

reading to the start of the buffer: 11238 ns
reading to the end of the buffer:   1039879 ns

In fact, it's worse by two orders of magnitude. The reason for that is
how io_uring figures out how to setup the iov_iter. We point the iter
at the first bvec, and then use iov_iter_advance() to fast-forward to
the offset within that buffer we need.

However, that is abysmally slow, as it entails iterating the bvecs
that we setup as part of buffer registration. There's really no need
to use this generic helper, as we know it's a BVEC type iterator, and
we also know that each bvec is PAGE_SIZE in size, apart from possibly
the first and last. Hence we can just use a shift on the offset to
find the right index, and then adjust the iov_iter appropriately.
After this fix, the timings are:

reading to the start of the buffer: 10135 ns
reading to the end of the buffer:   1377 ns

Or about an 755x improvement for the tail page.
Reported-by: NHrvoje Zeba <zeba.hrvoje@gmail.com>
Tested-by: NHrvoje Zeba <zeba.hrvoje@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

A caller is supposed to pass in REQ_NOWAIT if we can't block for any
given operation, but O_DIRECT for block devices just ignore this. Hence
we'll block for various resource shortages on the block layer side,
like having to wait for requests.

Use the new REQ_NOWAIT_INLINE to ask for this error to be returned
inline, so we can handle it appropriately and return -EAGAIN to the
caller.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range.  This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.

On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.

The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:

    $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
    248

Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.

This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:

    # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
    add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
    Data                                         old     new   delta
    sysctl_vals                                    -      12     +12
    __kstrtab_sysctl_vals                          -      12     +12
    max                                           14      10      -4
    int_max                                       16       -     -16
    one                                           68       -     -68
    zero                                         128      28    -100
    Total: Before=20583249, After=20583085, chg -0.00%

[mcroce@redhat.com: tipc: remove two unused variables]
  Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
  Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.comSigned-off-by: NMatteo Croce <mcroce@redhat.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NAaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

migrate_page_move_mapping() doesn't use the mode argument.  Remove it
and update callers accordingly.

Link: http://lkml.kernel.org/r/20190508210301.8472-1-keith.busch@intel.comSigned-off-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 7635d9cb ("mm, thp, proc: report THP eligibility for each
vma") introduced THPeligible bit for processes' smaps.  But, when
checking the eligibility for shmem vma, __transparent_hugepage_enabled()
is called to override the result from shmem_huge_enabled().  It may
result in the anonymous vma's THP flag override shmem's.  For example,
running a simple test which create THP for shmem, but with anonymous THP
disabled, when reading the process's smaps, it may show:

  7fc92ec00000-7fc92f000000 rw-s 00000000 00:14 27764 /dev/shm/test
  Size:               4096 kB
  ...
  [snip]
  ...
  ShmemPmdMapped:     4096 kB
  ...
  [snip]
  ...
  THPeligible:    0

And, /proc/meminfo does show THP allocated and PMD mapped too:

  ShmemHugePages:     4096 kB
  ShmemPmdMapped:     4096 kB

This doesn't make too much sense.  The shmem objects should be treated
separately from anonymous THP.  Calling shmem_huge_enabled() with
checking MMF_DISABLE_THP sounds good enough.  And, we could skip stack
and dax vma check since we already checked if the vma is shmem already.

Also check if vma is suitable for THP by calling
transhuge_vma_suitable().

And minor fix to smaps output format and documentation.

Link: http://lkml.kernel.org/r/1560401041-32207-3-git-send-email-yang.shi@linux.alibaba.com
Fixes: 7635d9cb ("mm, thp, proc: report THP eligibility for each vma")
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To 2.21
Signed-off-by: NSteve French <stfrench@microsoft.com>

Servers can defer destaging any data and updating the mtime until close().
This means that if we do a setinfo to modify the mtime while other handles
are open for write the server may overwrite our setinfo timestamps when
if flushes the file on close() of the writeable handle.

To solve this we add an explicit flush when the mtime is about to
be updated.

This fixes "cp -p" to preserve mtime when copying a file onto an SMB2 share.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

We can cut one third of the traffic on open by not querying the
inode number explicitly via SMB3 query_info since it is now
returned on open in the qfid context.

This is better in multiple ways, and
speeds up file open about 10% (more if network is slow).
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Add tracepoints to allow debugging of the event chain leading to
a pnfs fallback to doing I/O through the MDS.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the client has to stop in pnfs_update_layout() to wait for another
layoutget to complete, it currently exits and defaults to I/O through
the MDS if the layoutget was successful.

Fixes: d03360aa ("pNFS: Ensure we return the error if someone kills...")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20+

cifs has both source and destination inodes locked throughout the copy.
Like ->write_iter(), we update mtime and strip setuid bits of destination
file before copy and like ->read_iter(), we update atime of source file
after copy.
Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Prevent deadlock between open_shroot() and
cifs_mark_open_files_invalid() by releasing the lock before entering
SMB2_open, taking it again after and checking if we still need to use
the result.

Link: https://lore.kernel.org/linux-cifs/684ed01c-cbca-2716-bc28-b0a59a0f8521@prodrive-technologies.com/T/#u
Fixes: 3d4ef9a1 ("smb3: fix redundant opens on root")
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>

mirror->mirror_ds can be NULL if uninitialised, but can contain
a PTR_ERR() if call to GETDEVICEINFO failed.

Fixes: 65990d1a ("pNFS/flexfiles: Fix a deadlock on LAYOUTGET")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # 4.10+

The NFSv4.1 protocol explicitly forbids us from using the zero stateid
together with layoutget, so when we see that nfs4_select_rw_stateid()
is unable to return a valid delegation, lock or open stateid, then
we should initiate recovery and retry.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

There is a hang issue while using fio to do some basic test. The issue
can be easily reproduced using the below script:

        while true
        do
                fio  --ioengine=io_uring  -rw=write -bs=4k -numjobs=1 \
                     -size=1G -iodepth=64 -name=uring   --filename=/dev/zero
        done

After several minutes (or more), fio would block at
io_uring_enter->io_cqring_wait in order to waiting for previously
committed sqes to be completed and can't return to user anymore until
we send a SIGTERM to fio. After receiving SIGTERM, fio hangs at
io_ring_ctx_wait_and_kill with a backtrace like this:

        [54133.243816] Call Trace:
        [54133.243842]  __schedule+0x3a0/0x790
        [54133.243868]  schedule+0x38/0xa0
        [54133.243880]  schedule_timeout+0x218/0x3b0
        [54133.243891]  ? sched_clock+0x9/0x10
        [54133.243903]  ? wait_for_completion+0xa3/0x130
        [54133.243916]  ? _raw_spin_unlock_irq+0x2c/0x40
        [54133.243930]  ? trace_hardirqs_on+0x3f/0xe0
        [54133.243951]  wait_for_completion+0xab/0x130
        [54133.243962]  ? wake_up_q+0x70/0x70
        [54133.243984]  io_ring_ctx_wait_and_kill+0xa0/0x1d0
        [54133.243998]  io_uring_release+0x20/0x30
        [54133.244008]  __fput+0xcf/0x270
        [54133.244029]  ____fput+0xe/0x10
        [54133.244040]  task_work_run+0x7f/0xa0
        [54133.244056]  do_exit+0x305/0xc40
        [54133.244067]  ? get_signal+0x13b/0xbd0
        [54133.244088]  do_group_exit+0x50/0xd0
        [54133.244103]  get_signal+0x18d/0xbd0
        [54133.244112]  ? _raw_spin_unlock_irqrestore+0x36/0x60
        [54133.244142]  do_signal+0x34/0x720
        [54133.244171]  ? exit_to_usermode_loop+0x7e/0x130
        [54133.244190]  exit_to_usermode_loop+0xc0/0x130
        [54133.244209]  do_syscall_64+0x16b/0x1d0
        [54133.244221]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The reason is that we had added a req to ctx->pending_async at the very
end, but it didn't get a chance to be processed. How could this happen?

        fio#cpu0                                        wq#cpu1

        io_add_to_prev_work                    io_sq_wq_submit_work

          atomic_read() <<< 1

                                                  atomic_dec_return() << 1->0
                                                  list_empty();    <<< true;

          list_add_tail()
          atomic_read() << 0 or 1?

As atomic_ops.rst states, atomic_read does not guarantee that the
runtime modification by any other thread is visible yet, so we must take
care of that with a proper implicit or explicit memory barrier.

This issue was detected with the help of Jackie's <liuyun01@kylinos.cn>

Fixes: 31b51510 ("io_uring: allow workqueue item to handle multiple buffered requests")
Signed-off-by: NZhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add a per-transport maximum limit in the socket case, and add
helpers to allow the NFSv4 code to discover that limit.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

btrfs_get_io_geometry() calls btrfs_get_chunk_map() to acquire a reference
on a extent_map, but on normal operation it does not drop this reference
anymore.

This leads to excessive kmemleak reports.

Always call free_extent_map(), not just in the error case.

Fixes: 5f141126 ("btrfs: Introduce btrfs_io_geometry infrastructure")
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs_info::csum_hash gets initialized in btrfs_init_csum_hash() which is
called by open_ctree().

But it only gets freed if open_ctree() fails, not on normal operation.

This leads to a memory leak like the following found by kmemleak:
unreferenced object 0xffff888132cb8720 (size 96):

  comm "mount", pid 450, jiffies 4294912436 (age 17.584s)
  hex dump (first 32 bytes):
    04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000000c9643d4>] crypto_create_tfm+0x2d/0xd0
    [<00000000ae577f68>] crypto_alloc_tfm+0x4b/0xb0
    [<000000002b5cdf30>] open_ctree+0xb84/0x2060 [btrfs]
    [<0000000043204297>] btrfs_mount_root+0x552/0x640 [btrfs]
    [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
    [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
    [<00000000f180080e>] fc_mount+0x9/0x30
    [<000000009e36cebd>] vfs_kern_mount.part.11+0x6a/0x80
    [<0000000004594c05>] btrfs_mount+0x174/0x910 [btrfs]
    [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
    [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
    [<00000000b86e92c5>] do_mount+0x6b0/0x940
    [<0000000097464494>] ksys_mount+0x7b/0xd0
    [<0000000057213c80>] __x64_sys_mount+0x1c/0x20
    [<00000000cb689b5e>] do_syscall_64+0x43/0x130
    [<000000002194e289>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Free fs_info::csum_hash in close_ctree() to avoid the memory leak.

Fixes: 6d97c6e3 ("btrfs: add boilerplate code for directly including the crypto framework")
Reviewed-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

If CONFIG_BTRFS_FS is y and CONFIG_LIBCRC32C is m,
building fails:

  fs/btrfs/super.o: In function `btrfs_mount_root':
  super.c:(.text+0xb7f9): undefined reference to `crc32c_impl'
  fs/btrfs/super.o: In function `init_btrfs_fs':
  super.c:(.init.text+0x3465): undefined reference to `crc32c_impl'
  fs/btrfs/extent-tree.o: In function `hash_extent_data_ref':
  extent-tree.c:(.text+0xe60): undefined reference to `crc32c'
  extent-tree.c:(.text+0xe78): undefined reference to `crc32c'
  extent-tree.c:(.text+0xe8b): undefined reference to `crc32c'
  fs/btrfs/dir-item.o: In function `btrfs_insert_xattr_item':
  dir-item.c:(.text+0x291): undefined reference to `crc32c'
  fs/btrfs/dir-item.o: In function `btrfs_insert_dir_item':
  dir-item.c:(.text+0x429): undefined reference to `crc32c'

Select LIBCRC32C to fix it.
Reported-by: NHulk Robot <hulkci@huawei.com>
Fixes: d5178578 ("btrfs: directly call into crypto framework for checksumming")
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

As btrfs(5) specified:

	Note
	If nodatacow or nodatasum are enabled, compression is disabled.

If NODATASUM or NODATACOW set, we should not compress the extent.

Normally NODATACOW is detected properly in run_delalloc_range() so
compression won't happen for NODATACOW.

However for NODATASUM we don't have any check, and it can cause
compressed extent without csum pretty easily, just by:
  mkfs.btrfs -f $dev
  mount $dev $mnt -o nodatasum
  touch $mnt/foobar
  mount -o remount,datasum,compress $mnt
  xfs_io -f -c "pwrite 0 128K" $mnt/foobar

And in fact, we have a bug report about corrupted compressed extent
without proper data checksum so even RAID1 can't recover the corruption.
(https://bugzilla.kernel.org/show_bug.cgi?id=199707)

Running compression without proper checksum could cause more damage when
corruption happens, as compressed data could make the whole extent
unreadable, so there is no need to allow compression for
NODATACSUM.

The fix will refactor the inode compression check into two parts:

- inode_can_compress()
  As the hard requirement, checked at btrfs_run_delalloc_range(), so no
  compression will happen for NODATASUM inode at all.

- inode_need_compress()
  As the soft requirement, checked at btrfs_run_delalloc_range() and
  compress_file_range().
Reported-by: NJames Harvey <jamespharvey20@gmail.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Move internal function declarations out of fs/internal.h into
include/linux/iomap.h so that our transition is complete.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the main iteration code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the buffered IO code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the direct IO code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the SEEK_HOLE/SEEK_DATA code into a separate file so that we can
group related functions in a single file instead of having a single
enormous source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the file mapping reporting code (FIEMAP/FIBMAP) into a separate
file so that we can group related functions in a single file instead of
having a single enormous source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the swapfile activation code into a separate file so that we can
group related functions in a single file instead of having a single
enormous source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

We used to need rather convoluted ordering trickery to guarantee
that dput() of ex-mountpoints happens before the final mntput()
of the same.  Since we don't need that anymore, there's no point
playing with fs_pin for that.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Lift getting the original mount (dentry is actually not needed at all)
of the mountpoint into the callers - to do_move_mount() and pivot_root()
level.  That simplifies the cleanup in those and allows to get saner
arguments for attach_mnt_recursive().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>