It is often the case that we mark buffer as having dirty metadata when
the buffer is already in that state (frequent for bitmaps, inode table
blocks, superblock). Thus it is unnecessary to contend on grabbing
journal head reference and bh_state lock. Avoid that by checking whether
any modification to the buffer is needed before grabbing any locks or
references.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

insert_revoke_hash does an open coded endless allocation loop if
journal_oom_retry is true. It doesn't implement any allocation fallback
strategy between the retries, though. The memory allocator doesn't know
about the never fail requirement so it cannot potentially help to move
on with the allocation (e.g. use memory reserves).

Get rid of the retry loop and use __GFP_NOFAIL instead. We will lose the
debugging message but I am not sure it is anyhow helpful.

Do the same for journal_alloc_journal_head which is doing a similar
thing.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Several ext4_warning() messages in the directory handling code do not
report the inode number of the (potentially corrupt) directory where a
problem is seen, and others report this in an ad-hoc manner.  Add an
ext4_warning_inode() helper to print the inode number and command name
consistent with ext4_error_inode().

Consolidate the place in ext4.h that these macros are defined.

Clean up some other directory error and warning messages to print the
calling function name.

Minor code style fixes in nearby lines.

Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

If updating journal superblock fails after journal data has been
flushed, the error is omitted and this will mislead the caller as a
normal case.  In ocfs2, the checkpoint will be treated successfully
and the other node can get the lock to update. Since the sb_start is
still pointing to the old log block, it will rewrite the journal data
during journal recovery by the other node. Thus the new updates will
be overwritten and ocfs2 corrupts.  So in above case we have to return
the error, and ocfs2_commit_cache will take care of the error and
prevent the other node to do update first.  And only after recovering
journal it can do the new updates.

The issue discussion mail can be found at:
https://oss.oracle.com/pipermail/ocfs2-devel/2015-June/010856.html
http://comments.gmane.org/gmane.comp.file-systems.ext4/48841



[ Fixed bug in patch which allowed a non-negative error return from
  jbd2_cleanup_journal_tail() to leak out of jbd2_fjournal_flush(); this
  was causing xfstests ext4/306 to fail. -- Ted ]

Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: stable@vger.kernel.org

Making a function call with 20 arguments is rather expensive in both
stack and .text. In this case, doing the formatting manually doesn't
make it any less readable, so we might as well save 155 bytes of .text
and 112 bytes of stack.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>

Currently existing dio workers can jump in and potentially increase
extent tree depth while we're allocating blocks in
ext4_alloc_file_blocks().  This may cause us to underestimate the
number of credits needed for the transaction because the extent tree
depth can change after our estimation.

Fix this by waiting for all the existing dio workers in the same way
as we do it in ext4_punch_hole.  We've seen errors caused by this in
xfstest generic/299, however it's really hard to reproduce.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Currently in ext4_alloc_file_blocks() the number of credits is
calculated only once before we enter the allocation loop. However within
the allocation loop the extent tree depth can change, hence the number
of credits needed can increase potentially exceeding the number of credits
reserved in the handle which can cause journal failures.

Fix this by recalculating number of credits when the inode depth
changes. Note that even though ext4_alloc_file_blocks() is only
currently used by extent base inodes we will avoid recalculating number
of credits unnecessarily in the case of indirect based inodes.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

jbd2_cleanup_journal_tail() can be invoked by jbd2__journal_start()
So allocations should be done with GFP_NOFS

[Full stack trace snipped from 3.10-rh7]
[<ffffffff815c4bd4>] dump_stack+0x19/0x1b
[<ffffffff8105dba1>] warn_slowpath_common+0x61/0x80
[<ffffffff8105dcca>] warn_slowpath_null+0x1a/0x20
[<ffffffff815c2142>] slab_pre_alloc_hook.isra.31.part.32+0x15/0x17
[<ffffffff8119c045>] kmem_cache_alloc+0x55/0x210
[<ffffffff811477f5>] ? mempool_alloc_slab+0x15/0x20
[<ffffffff811477f5>] mempool_alloc_slab+0x15/0x20
[<ffffffff81147939>] mempool_alloc+0x69/0x170
[<ffffffff815cb69e>] ? _raw_spin_unlock_irq+0xe/0x20
[<ffffffff8109160d>] ? finish_task_switch+0x5d/0x150
[<ffffffff811f1a8e>] bio_alloc_bioset+0x1be/0x2e0
[<ffffffff8127ee49>] blkdev_issue_flush+0x99/0x120
[<ffffffffa019a733>] jbd2_cleanup_journal_tail+0x93/0xa0 [jbd2] -->GFP_KERNEL
[<ffffffffa019aca1>] jbd2_log_do_checkpoint+0x221/0x4a0 [jbd2]
[<ffffffffa019afc7>] __jbd2_log_wait_for_space+0xa7/0x1e0 [jbd2]
[<ffffffffa01952d8>] start_this_handle+0x2d8/0x550 [jbd2]
[<ffffffff811b02a9>] ? __memcg_kmem_put_cache+0x29/0x30
[<ffffffff8119c120>] ? kmem_cache_alloc+0x130/0x210
[<ffffffffa019573a>] jbd2__journal_start+0xba/0x190 [jbd2]
[<ffffffff811532ce>] ? lru_cache_add+0xe/0x10
[<ffffffffa01c9549>] ? ext4_da_write_begin+0xf9/0x330 [ext4]
[<ffffffffa01f2c77>] __ext4_journal_start_sb+0x77/0x160 [ext4]
[<ffffffffa01c9549>] ext4_da_write_begin+0xf9/0x330 [ext4]
[<ffffffff811446ec>] generic_file_buffered_write_iter+0x10c/0x270
[<ffffffff81146918>] __generic_file_write_iter+0x178/0x390
[<ffffffff81146c6b>] __generic_file_aio_write+0x8b/0xb0
[<ffffffff81146ced>] generic_file_aio_write+0x5d/0xc0
[<ffffffffa01bf289>] ext4_file_write+0xa9/0x450 [ext4]
[<ffffffff811c31d9>] ? pipe_read+0x379/0x4f0
[<ffffffff811b93f0>] do_sync_write+0x90/0xe0
[<ffffffff811b9b6d>] vfs_write+0xbd/0x1e0
[<ffffffff811ba5b8>] SyS_write+0x58/0xb0
[<ffffffff815d4799>] system_call_fastpath+0x16/0x1b

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

The commit cf108bca

: "ext4: Invert the locking order of page_lock
and transaction start" caused __ext4_journalled_writepage() to drop
the page lock before the page was written back, as part of changing
the locking order to jbd2_journal_start -> page_lock.  However, this
introduced a potential race if there was a truncate racing with the
data=journalled writeback mode.

Fix this by grabbing the page lock after starting the journal handle,
and then checking to see if page had gotten truncated out from under
us.

This fixes a number of different warnings or BUG_ON's when running
xfstests generic/086 in data=journalled mode, including:

jbd2_journal_dirty_metadata: vdc-8: bad jh for block 115643: transaction (ee3fe7
c0, 164), jh->b_transaction (  (null), 0), jh->b_next_transaction (  (null), 0), jlist 0

	      	      	  - and -

kernel BUG at /usr/projects/linux/ext4/fs/jbd2/transaction.c:2200!
    ...
Call Trace:
 [<c02b2ded>] ? __ext4_journalled_invalidatepage+0x117/0x117
 [<c02b2de5>] __ext4_journalled_invalidatepage+0x10f/0x117
 [<c02b2ded>] ? __ext4_journalled_invalidatepage+0x117/0x117
 [<c027d883>] ? lock_buffer+0x36/0x36
 [<c02b2dfa>] ext4_journalled_invalidatepage+0xd/0x22
 [<c0229139>] do_invalidatepage+0x22/0x26
 [<c0229198>] truncate_inode_page+0x5b/0x85
 [<c022934b>] truncate_inode_pages_range+0x156/0x38c
 [<c0229592>] truncate_inode_pages+0x11/0x15
 [<c022962d>] truncate_pagecache+0x55/0x71
 [<c02b913b>] ext4_setattr+0x4a9/0x560
 [<c01ca542>] ? current_kernel_time+0x10/0x44
 [<c026c4d8>] notify_change+0x1c7/0x2be
 [<c0256a00>] do_truncate+0x65/0x85
 [<c0226f31>] ? file_ra_state_init+0x12/0x29

	      	      	  - and -

WARNING: CPU: 1 PID: 1331 at /usr/projects/linux/ext4/fs/jbd2/transaction.c:1396
irty_metadata+0x14a/0x1ae()
    ...
Call Trace:
 [<c01b879f>] ? console_unlock+0x3a1/0x3ce
 [<c082cbb4>] dump_stack+0x48/0x60
 [<c0178b65>] warn_slowpath_common+0x89/0xa0
 [<c02ef2cf>] ? jbd2_journal_dirty_metadata+0x14a/0x1ae
 [<c0178bef>] warn_slowpath_null+0x14/0x18
 [<c02ef2cf>] jbd2_journal_dirty_metadata+0x14a/0x1ae
 [<c02d8615>] __ext4_handle_dirty_metadata+0xd4/0x19d
 [<c02b2f44>] write_end_fn+0x40/0x53
 [<c02b4a16>] ext4_walk_page_buffers+0x4e/0x6a
 [<c02b59e7>] ext4_writepage+0x354/0x3b8
 [<c02b2f04>] ? mpage_release_unused_pages+0xd4/0xd4
 [<c02b1b21>] ? wait_on_buffer+0x2c/0x2c
 [<c02b5a4b>] ? ext4_writepage+0x3b8/0x3b8
 [<c02b5a5b>] __writepage+0x10/0x2e
 [<c0225956>] write_cache_pages+0x22d/0x32c
 [<c02b5a4b>] ? ext4_writepage+0x3b8/0x3b8
 [<c02b6ee8>] ext4_writepages+0x102/0x607
 [<c019adfe>] ? sched_clock_local+0x10/0x10e
 [<c01a8a7c>] ? __lock_is_held+0x2e/0x44
 [<c01a8ad5>] ? lock_is_held+0x43/0x51
 [<c0226dff>] do_writepages+0x1c/0x29
 [<c0276bed>] __writeback_single_inode+0xc3/0x545
 [<c0277c07>] writeback_sb_inodes+0x21f/0x36d
    ...

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

We currently don't correctly handle the case where blocksize !=
pagesize, so disallow the mount in those cases.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

This patch implements fallocate's FALLOC_FL_INSERT_RANGE for Ext4.

1) Make sure that both offset and len are block size aligned.
2) Update the i_size of inode by len bytes.
3) Compute the file's logical block number against offset. If the computed
   block number is not the starting block of the extent, split the extent
   such that the block number is the starting block of the extent.
4) Shift all the extents which are lying between [offset, last allocated extent]
   towards right by len bytes. This step will make a hole of len bytes
   at offset.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>

jbd2_journal_get_write_access() and jbd2_journal_get_create_access() are
frequently called for buffers that are already part of the running
transaction - most frequently it is the case for bitmaps, inode table
blocks, and superblock. Since in such cases we have nothing to do, it is
unfortunate we still grab reference to journal head, lock the bh, lock
bh_state only to find out there's nothing to do.

Improving this is a bit subtle though since until we find out journal
head is attached to the running transaction, it can disappear from under
us because checkpointing / commit decided it's no longer needed. We deal
with this by protecting journal_head slab with RCU. We still have to be
careful about journal head being freed & reallocated within slab and
about exposing journal head in consistent state (in particular
b_modified and b_frozen_data must be in correct state before we allow
user to touch the buffer).

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Check for the simple case of unjournaled buffer first, handle it and
bail out. This allows us to remove one if and unindent the difficult case
by one tab. The result is easier to read.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

We were acquiring bh_state_lock when allocation of buffer failed in
do_get_write_access() only to be able to jump to a label that releases
the lock and does all other checks that don't make sense for this error
path. Just jump into the right label instead.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

needs_copy is set only in one place in do_get_write_access(), just move
the frozen buffer copying into that place and factor it out to a
separate function to make do_get_write_access() slightly more readable.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

[ Added another sparse fix for EXT4_IOC_GET_ENCRYPTION_POLICY while
  we're at it. --tytso ]

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

During a source code review of fs/ext4/extents.c I noted identical
consecutive lines. An assertion is repeated for inode1 and never done
for inode2. This is not in keeping with the rest of the code in the
ext4_swap_extents function and appears to be a bug.

Assert that the inode2 mutex is not locked.

Signed-off-by: David Moore <dmoorefo@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Currently ext4_mb_good_group() only returns 0 or 1 depending on whether
the allocation group is suitable for use or not. However we might get
various errors and fail while initializing new group including -EIO
which would never get propagated up the call chain. This might lead to
an endless loop at writeback when we're trying to find a good group to
allocate from and we fail to initialize new group (read error for
example).

Fix this by returning proper error code from ext4_mb_good_group() and
using it in ext4_mb_regular_allocator(). In ext4_mb_regular_allocator()
we will always return only the first occurred error from
ext4_mb_good_group() and we only propagate it back  to the caller if we
do not get any other errors and we fail to allocate any blocks.

Note that with other modes than errors=continue, we will fail
immediately in ext4_mb_good_group() in case of error, however with
errors=continue we should try to continue using the file system, that's
why we're not going to fail immediately when we see an error from
ext4_mb_good_group(), but rather when we fail to find a suitable block
group to allocate from due to an problem in group initialization.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

Currently on the machines with page size > block size when initializing
block group buddy cache we initialize it for all the block group bitmaps
in the page. However in the case of read error, checksum error, or if
a single bitmap is in any way corrupted we would fail to initialize all
of the bitmaps. This is problematic because we will not have access to
the other allocation groups even though those might be perfectly fine
and usable.

Fix this by reading all the bitmaps instead of error out on the first
problem and simply skip the bitmaps which were either not read properly,
or are not valid.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

If we want to rely on the buffer_verified() flag of the block bitmap
buffer, we have to set it consistently. However currently if we're
initializing uninitialized block bitmap in
ext4_read_block_bitmap_nowait() we're not going to set buffer verified
at all.

We can do this by simply setting the flag on the buffer, but I think
it's actually better to run ext4_validate_block_bitmap() to make sure
that what we did in the ext4_init_block_bitmap() is right.

So run ext4_validate_block_bitmap() even after the block bitmap
initialization. Also bail out early from ext4_validate_block_bitmap() if
we see corrupt bitmap, since we already know it's corrupt and we do not
need to verify that.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

This basically reverts 47def826

 (jbd2: Remove __GFP_NOFAIL from jbd2
layer). The deprecation of __GFP_NOFAIL was a bad choice because it led
to open coding the endless loop around the allocator rather than
removing the dependency on the non failing allocation. So the
deprecation was a clear failure and the reality tells us that
__GFP_NOFAIL is not even close to go away.

It is still true that __GFP_NOFAIL allocations are generally discouraged
and new uses should be evaluated and an alternative (pre-allocations or
reservations) should be considered but it doesn't make any sense to lie
the allocator about the requirements. Allocator can take steps to help
making a progress if it knows the requirements.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: David Rientjes <rientjes@google.com>

Previously we allocated bounce pages using a combination of
alloc_page() and mempool_alloc() with the __GFP_WAIT bit set.
Instead, use mempool_alloc() with GFP_NOWAIT.  The mempool_alloc()
function will try using alloc_pages() initially, and then only use the
mempool reserve of pages if alloc_pages() is unable to fulfill the
request.

This minimizes the the impact on the mm layer when we need to do a
large amount of writeback of encrypted files, as Jaeguk Kim had
reported that under a heavy fio workload on a system with restricted
amounts memory (which unfortunately, includes many mobile handsets),
he had observed the the OOM killer getting triggered several times.
Using GFP_NOWAIT

If the mempool_alloc() function fails, we will retry the page
writeback at a later time; the function of the mempool is to ensure
that we can writeback at least 32 pages at a time, so we can more
efficiently dispatch I/O under high memory pressure situations.  In
the future we should make this be a tunable so we can determine the
best tradeoff between permanently sequestering memory and the ability
to quickly launder pages so we can free up memory quickly when
necessary.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Crypto resource should be released when ext4 module exits, otherwise
it will cause memory leak.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Fix up attempts by users to try to write to a file when they don't
have access to the encryption key.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Previously we were taking the required padding when allocating space
for the on-disk symlink.  This caused a buffer overrun which could
trigger a krenel crash when running fsstress.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Fix a potential memory leak where fname->crypto_buf.name wouldn't get
freed in some error paths, and also make the error handling easier to
understand/audit.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Thanks to Chao Yu <chao2.yu@samsung.com> for pointing out we were
missing this check.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Thanks to Chao Yu <chao2.yu@samsung.com> for pointing out the need for
this check.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Factor out calls to ext4_inherit_context() and move them to
__ext4_new_inode(); this fixes a problem where ext4_tmpfile() wasn't
calling calling ext4_inherit_context(), so the temporary file wasn't
getting protected.  Since the blocks for the tmpfile could end up on
disk, they really should be protected if the tmpfile is created within
the context of an encrypted directory.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Set up the encryption information for newly created inodes immediately
after they inherit their encryption context from their parent
directories.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4_encrypted_zeroout() could end up leaking a bio and bounce page.
Fortunately it's not used much.  While we're fixing things up,
refactor out common code into the static function alloc_bounce_page()
and fix up error handling if mempool_alloc() fails.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

As suggested by Herbert Xu, we shouldn't allocate a new tfm each time
we read or write a page.  Instead we can use a single tfm hanging off
the inode's crypt_info structure for all of our encryption needs for
that inode, since the tfm can be used by multiple crypto requests in
parallel.

Also use cmpxchg() to avoid races that could result in crypt_info
structure getting doubly allocated or doubly freed.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

On arm64 this is apparently needed for CTS mode to function correctly.
Otherwise attempts to use CTS return ENOENT.

Change-Id: I732ea9a5157acc76de5b89edec195d0365f4ca63
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Some fields are only used when the crypto_ctx is being used on the
read path, some are only used on the write path, and some are only
used when the structure is on free list.  Optimize memory use by using
a union.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

The ci_mode field was superfluous, and getting rid of it gets rid of
an unused hole in the structure.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Use slab caches the ext4_crypto_ctx and ext4_crypt_info structures for
slighly better memory efficiency and debuggability.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>