Now that we got rid of the bdi abuse on character devices we can always use
sb->s_bdi to get at the backing_dev_info for a file, except for the block
device special case.  Export inode_to_bdi and replace uses of
mapping->backing_dev_info with it to prepare for the removal of
mapping->backing_dev_info.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Signed-off-by: NJakub Wilk <jwilk@jwilk.net>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

This reverts commit 14516bb7.

This was causing regression test failures with generic/285 with an ext3
filesystem using CONFIG_EXT4_USE_FOR_EXT23.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Prevent BUG or corrupted file systems after the following:

mkfs.ext4 /dev/vdc 100M
mount -t ext4 -o sb=40961 /dev/vdc /vdc
resize2fs /dev/vdc

We previously prevented online resizing using the old resize ioctl.
Move the code to ext4_resize_begin(), so the check applies for all of
the resize ioctl's.
Reported-by: NMaxim Malkov <malkov@ispras.ru>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

... and comparing get_fs() with KERNEL_DS used only to initialize that
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Testcase:
xfstests generic/270
MKFS_OPTIONS="-q -I 256 -O inline_data,64bit"

Call Trace:
 [<ffffffff81144c76>] lock_page+0x35/0x39 -------> DEADLOCK
 [<ffffffff81145260>] pagecache_get_page+0x65/0x15a
 [<ffffffff811507fc>] truncate_inode_pages_range+0x1db/0x45c
 [<ffffffff8120ea63>] ? ext4_da_get_block_prep+0x439/0x4b6
 [<ffffffff811b29b7>] ? __block_write_begin+0x284/0x29c
 [<ffffffff8120e62a>] ? ext4_change_inode_journal_flag+0x16b/0x16b
 [<ffffffff81150af0>] truncate_inode_pages+0x12/0x14
 [<ffffffff81247cb4>] ext4_truncate_failed_write+0x19/0x25
 [<ffffffff812488cf>] ext4_da_write_inline_data_begin+0x196/0x31c
 [<ffffffff81210dad>] ext4_da_write_begin+0x189/0x302
 [<ffffffff810c07ac>] ? trace_hardirqs_on+0xd/0xf
 [<ffffffff810ddd13>] ? read_seqcount_begin.clone.1+0x9f/0xcc
 [<ffffffff8114309d>] generic_perform_write+0xc7/0x1c6
 [<ffffffff810c040e>] ? mark_held_locks+0x59/0x77
 [<ffffffff811445d1>] __generic_file_write_iter+0x17f/0x1c5
 [<ffffffff8120726b>] ext4_file_write_iter+0x2a5/0x354
 [<ffffffff81185656>] ? file_start_write+0x2a/0x2c
 [<ffffffff8107bcdb>] ? bad_area_nosemaphore+0x13/0x15
 [<ffffffff811858ce>] new_sync_write+0x8a/0xb2
 [<ffffffff81186e7b>] vfs_write+0xb5/0x14d
 [<ffffffff81186ffb>] SyS_write+0x5c/0x8c
 [<ffffffff816f2529>] system_call_fastpath+0x12/0x17
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

It is ridiculous practice to scan inode block by block, this technique
applicable only for old indirect files. This takes significant amount
of time for really large files. Let's reuse ext4_fiemap which already
traverse inode-tree in most optimal meaner.

TESTCASE:
ftruncate64(fd, 0);
ftruncate64(fd, 1ULL << 40);
/* lseek will spin very long time */
lseek64(fd, 0, SEEK_DATA);
lseek64(fd, 0, SEEK_HOLE);

Original report: https://lkml.org/lkml/2014/10/16/620Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently ext4_inline_data_fiemap ignores requested arguments (start
and len) which may lead endless loop if start != 0.  Also fix incorrect
extent length determination.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

ext4_da_convert_inline_data_to_extent() invokes
grab_cache_page_write_begin().  grab_cache_page_write_begin performs
memory allocation, so fs-reentrance should be prohibited because we
are inside journal transaction.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Option journal_async_commit breaks gurantees of data=ordered mode as it
sends only a single cache flush after writing a transaction commit
block. Thus even though the transaction including the commit block is
fully stored on persistent storage, file data may still linger in drives
caches and will be lost on power failure. Since all checksums match on
journal recovery, we replay the transaction thus possibly exposing stale
user data.

To fix this data exposure issue, remove the possibility to use
journal_async_commit in data=ordered mode.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

The iput() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Setting retval to zero is not needed in ext4_unlink.
Remove unneeded code.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

This was fixed for ext3 with:

e6d8fb34 ext3: Count internal journal as bsddf overhead in ext3_statfs

but was never fixed for ext4.

With a large external journal and no used disk blocks, df comes
out negative without this, as journal blocks are added to the
overhead & subtracted from used blocks unconditionally.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

path[depth].p_hdr can never be NULL for a path passed to us (and even if
it could, EXT_LAST_EXTENT() would make something != NULL from it). So
just remove the branch.

Coverity-id: 1196498
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Create a mount option to disable journal checksumming (because the
metadata_csum feature turns it on by default now), and fix remount not
to allow changing the journal checksumming option, since changing the
mount options has no effect on the journal.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

ext4_delete_inode() has been renamed for a long time, update
comments for this.
Signed-off-by: NWang Shilong <wshilong@ddn.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

We must use GFP_NOFS instead GFP_KERNEL inside ext4_mb_add_groupinfo
and ext4_calculate_overhead() because they are called from inside a
journal transaction. Call trace:

ioctl
 ->ext4_group_add
   ->journal_start
   ->ext4_setup_new_descs
     ->ext4_mb_add_groupinfo -> GFP_KERNEL
   ->ext4_flex_group_add
     ->ext4_update_super
       ->ext4_calculate_overhead  -> GFP_KERNEL
   ->journal_stop
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Introduce a simple aging to extent status tree. Each extent has a
REFERENCED bit which gets set when the extent is used. Shrinker then
skips entries with referenced bit set and clears the bit. Thus
frequently used extents have higher chances of staying in memory.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently flags for extent status tree are defined twice, once shifted
and once without a being shifted. Consolidate these definitions into one
place and make some computations automatic to make adding flags less
error prone. Compiler should be clever enough to figure out these are
constants and generate the same code.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently we scan extent status trees of inodes until we reclaim nr_to_scan
extents. This can however require a lot of scanning when there are lots
of delayed extents (as those cannot be reclaimed).

Change shrinker to work as shrinkers are supposed to and *scan* only
nr_to_scan extents regardless of how many extents did we actually
reclaim. We however need to be careful and avoid scanning each status
tree from the beginning - that could lead to a situation where we would
not be able to reclaim anything at all when first nr_to_scan extents in
the tree are always unreclaimable. We remember with each inode offset
where we stopped scanning and continue from there when we next come
across the inode.

Note that we also need to update places calling __es_shrink() manually
to pass reasonable nr_to_scan to have a chance of reclaiming anything and
not just 1.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently callers adding extents to extent status tree were responsible
for adding the inode to the list of inodes with freeable extents. This
is error prone and puts list handling in unnecessarily many places.

Just add inode to the list automatically when the first non-delay extent
is added to the tree and remove inode from the list when the last
non-delay extent is removed.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

In this commit we discard the lru algorithm for inodes with extent
status tree because it takes significant effort to maintain a lru list
in extent status tree shrinker and the shrinker can take a long time to
scan this lru list in order to reclaim some objects.

We replace the lru ordering with a simple round-robin.  After that we
never need to keep a lru list.  That means that the list needn't be
sorted if the shrinker can not reclaim any objects in the first round.

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently extent status tree doesn't cache extent hole when a write
looks up in extent tree to make sure whether a block has been allocated
or not.  In this case, we don't put extent hole in extent cache because
later this extent might be removed and a new delayed extent might be
added back.  But it will cause a defect when we do a lot of writes.  If
we don't put extent hole in extent cache, the following writes also need
to access extent tree to look at whether or not a block has been
allocated.  It brings a cache miss.  This commit fixes this defect.
Also if the inode doesn't have any extent, this extent hole will be
cached as well.

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

For bigalloc filesystems we have to check whether newly requested inode
block isn't already part of a cluster for which we already have delayed
allocation reservation. This check happens in ext4_ext_map_blocks() and
that function sets EXT4_MAP_FROM_CLUSTER if that's the case. However if
ext4_da_map_blocks() finds in extent cache information about the block,
we don't call into ext4_ext_map_blocks() and thus we always end up
getting new reservation even if the space for cluster is already
reserved. This results in overreservation and premature ENOSPC reports.

Fix the problem by checking for existing cluster reservation already in
ext4_da_map_blocks(). That simplifies the logic and actually allows us
to get rid of the EXT4_MAP_FROM_CLUSTER flag completely.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

ext4_ext_remove_space() can incorrectly free a partial_cluster if
EAGAIN is encountered while truncating or punching.  Extent removal
should be retried in this case.

It also fails to free a partial cluster when the punched region begins
at the start of a file on that unaligned cluster and where the entire
file has not been punched.  Remove the requirement that all blocks in
the file must have been freed in order to free the partial cluster.
Signed-off-by: NEric Whitney <enwlinux@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Add some casts and rearrange a few statements for improved readability.
Some code can also be simplified and made more readable if we set
partial_cluster to 0 rather than to a negative value when we can tell
we've hit the left edge of the punched region.
Signed-off-by: NEric Whitney <enwlinux@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

The fix in commit ad6599ab ("ext4: fix premature freeing of
partial clusters split across leaf blocks"), intended to avoid
dereferencing an invalid extent pointer when determining whether a
partial cluster should be freed, wasn't quite good enough.  Assure that
at least one extent remains at the start of the leaf once the hole has
been punched.  Otherwise, the pointer to the extent to the right of the
hole will be invalid and a partial cluster will be incorrectly freed.

Set partial_cluster to 0 when we can tell we've hit the left edge of
the punched region within the leaf.  This prevents incorrect freeing
of a partial cluster when ext4_ext_rm_leaf is called one last time
during extent tree traversal after the punched region has been removed.

Adjust comments to reflect code changes and a correction.  Remove a bit
of dead code.
Signed-off-by: NEric Whitney <enwlinux@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

The partial_cluster variable is not always initialized correctly when
hole punching on bigalloc file systems.  Although commit c0634493
("ext4: fix partial cluster handling for bigalloc file systems")
addressed the case where the right edge of the punched region and the
next extent to its right were within the same leaf, it didn't handle
the case where the next extent to its right is in the next leaf.  This
causes xfstest generic/300 to fail.

Fix this by replacing the code in c0634493922 with a more general
solution that can continue the search for the first cluster to the
right of the punched region into the next leaf if present.  If found,
partial_cluster is initialized to this cluster's negative value.
There's no need to determine if that cluster is actually shared;  we
simply record it so its blocks won't be freed in the event it does
happen to be shared.

Also, minimize the burden on non-bigalloc file systems with some minor
code simplification.
Signed-off-by: NEric Whitney <enwlinux@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

CC: linux-ext4@vger.kernel.org
Acked-by: N"Theodore Ts'o" <tytso@mit.edu>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

Xiaoguang Wang has reported sporadic EBUSY failures of ext4/302
Unfortunetly there is nothing we can do if some other task holds BH's
refenrence.  So we must return EBUSY in this case.  But we can try
kicking the journal to see if the other task releases the bh reference
after the commit is complete.  Also decrease false positives by
properly checking for ENOSPC and retrying the allocation after kicking
the journal --- which is done by ext4_should_retry_alloc().

[ Modified by tytso to properly check for ENOSPC. ]
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

ext4_ext_convert_to_initialized() can return more blocks than are
actually allocated from map->m_lblk in case where initial part of the
on-disk extent is zeroed out. Luckily this doesn't have serious
consequences because the caller currently uses the return value
only to unmap metadata buffers. Anyway this is a data
corruption/exposure problem waiting to happen so fix it.

Coverity-id: 1226848
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

When clearing inode journal flag, we call jbd2_journal_flush() to force
all the journalled data to their final locations. Currently we ignore
when this fails and continue clearing inode journal flag. This isn't a
big problem because when jbd2_journal_flush() fails, journal is likely
aborted anyway. But it can still lead to somewhat confusing results so
rather bail out early.

Coverity-id: 989044
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

When ext4_handle_dirty_dx_node() or ext4_handle_dirty_dirent_node()
fail, there's really something wrong with the fs and there's no point in
continuing further. Just return error from make_indexed_dir() in that
case. Also initialize frames array so that if we return early due to
error, dx_release() doesn't try to dereference uninitialized memory
(which could happen also due to error in do_split()).

Coverity-id: 741300
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

O_DIRECT flags can be toggeled via fcntl(F_SETFL). But this value checked
twice inside ext4_file_write_iter() and __generic_file_write() which
result in BUG_ON inside ext4_direct_IO.

Let's initialize iocb->private unconditionally.

TESTCASE: xfstest:generic/036  https://patchwork.ozlabs.org/patch/402445/

#TYPICAL STACK TRACE:
kernel BUG at fs/ext4/inode.c:2960!
invalid opcode: 0000 [#1] SMP
Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod
CPU: 6 PID: 5505 Comm: aio-dio-fcntl-r Not tainted 3.17.0-rc2-00176-gff5c017 #161
Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011
task: ffff88080e95a7c0 ti: ffff88080f908000 task.ti: ffff88080f908000
RIP: 0010:[<ffffffff811fabf2>]  [<ffffffff811fabf2>] ext4_direct_IO+0x162/0x3d0
RSP: 0018:ffff88080f90bb58  EFLAGS: 00010246
RAX: 0000000000000400 RBX: ffff88080fdb2a28 RCX: 00000000a802c818
RDX: 0000040000080000 RSI: ffff88080d8aeb80 RDI: 0000000000000001
RBP: ffff88080f90bbc8 R08: 0000000000000000 R09: 0000000000001581
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88080d8aeb80
R13: ffff88080f90bbf8 R14: ffff88080fdb28c8 R15: ffff88080fdb2a28
FS:  00007f23b2055700(0000) GS:ffff880818400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23b2045000 CR3: 000000080cedf000 CR4: 00000000000407e0
Stack:
 ffff88080f90bb98 0000000000000000 7ffffffffffffffe ffff88080fdb2c30
 0000000000000200 0000000000000200 0000000000000001 0000000000000200
 ffff88080f90bbc8 ffff88080fdb2c30 ffff88080f90be08 0000000000000200
Call Trace:
 [<ffffffff8112ca9d>] generic_file_direct_write+0xed/0x180
 [<ffffffff8112f2b2>] __generic_file_write_iter+0x222/0x370
 [<ffffffff811f495b>] ext4_file_write_iter+0x34b/0x400
 [<ffffffff811bd709>] ? aio_run_iocb+0x239/0x410
 [<ffffffff811bd709>] ? aio_run_iocb+0x239/0x410
 [<ffffffff810990e5>] ? local_clock+0x25/0x30
 [<ffffffff810abd94>] ? __lock_acquire+0x274/0x700
 [<ffffffff811f4610>] ? ext4_unwritten_wait+0xb0/0xb0
 [<ffffffff811bd756>] aio_run_iocb+0x286/0x410
 [<ffffffff810990e5>] ? local_clock+0x25/0x30
 [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190
 [<ffffffff811bc05b>] ? lookup_ioctx+0x4b/0xf0
 [<ffffffff811bde3b>] do_io_submit+0x55b/0x740
 [<ffffffff811bdcaa>] ? do_io_submit+0x3ca/0x740
 [<ffffffff811be030>] SyS_io_submit+0x10/0x20
 [<ffffffff815ce192>] system_call_fastpath+0x16/0x1b
Code: 01 48 8b 80 f0 01 00 00 48 8b 18 49 8b 45 10 0f 85 f1 01 00 00 48 03 45 c8 48 3b 43 48 0f 8f e3 01 00 00 49 83 7c
24 18 00 75 04 <0f> 0b eb fe f0 ff 83 ec 01 00 00 49 8b 44 24 18 8b 00 85 c0 89
RIP  [<ffffffff811fabf2>] ext4_direct_IO+0x162/0x3d0
 RSP <ffff88080f90bb58>
Reported-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Cc: stable@vger.kernel.org

If we can't load the journal, remove the procfs files for the extent
status information file to avoid leaking resources.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

ext4 does not permit changing the metadata or journal checksum feature
flag while mounted.  Until we decide to support that, don't allow a
remount to change the journal_csum flag (right now we silently fail to
change anything).
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

If metadata checksumming is turned on for the FS, we need to tell the
journal to use checksumming too.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

When we fail to load block bitmap in __ext4_new_inode() we will
dereference NULL pointer in ext4_journal_get_write_access(). So check
for error from ext4_read_block_bitmap().

Coverity-id: 989065
Cc: stable@vger.kernel.org
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

When there are no meta block groups update_backups() will compute the
backup block in 32-bit arithmetics thus possibly overflowing the block
number and corrupting the filesystem. OTOH filesystems without meta
block groups larger than 16 TB should be rare. Fix the problem by doing
the counting in 64-bit arithmetics.

Coverity-id: 741252
CC: stable@vger.kernel.org
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>