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>

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>

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>

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>

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>

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>

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>

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

Convert the ext4_has_group_desc_csum predicate to look for a checksum
driver instead of the metadata_csum flag and change the bg checksum
calculation function to look for GDT_CSUM before taking the crc16
path.

Without this patch, if we mount with ^uninit_bg,^metadata_csum and
later metadata_csum gets turned on by accident, the block group
checksum functions will incorrectly assume that checksumming is
enabled (metadata_csum) but that crc16 should be used
(!s_chksum_driver).  This is totally wrong, so fix the predicate
and the checksum formula selection.

(Granted, if the metadata_csum feature bit gets enabled on a live FS
then something underhanded is going on, but we could at least avoid
writing garbage into the on-disk fields.)
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NDmitry Monakhov <dmonakhov@openvz.org>
Cc: stable@vger.kernel.org

Besides the fact that this replacement improves code readability
it also protects from errors caused direct EXT4_S(sb)->s_es manipulation
which may result attempt to use uninitialized  csum machinery.

#Testcase_BEGIN
IMG=/dev/ram0
MNT=/mnt
mkfs.ext4 $IMG
mount $IMG $MNT
#Enable feature directly on disk, on mounted fs
tune2fs -O metadata_csum  $IMG
# Provoke metadata update, likey result in OOPS
touch $MNT/test
umount $MNT
#Testcase_END

# Replacement script
@@
expression E;
@@
- EXT4_HAS_RO_COMPAT_FEATURE(E, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
+ ext4_has_metadata_csum(E)

https://bugzilla.kernel.org/show_bug.cgi?id=82201Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

If there is a corrupted file system which has directory entries that
point at reserved, metadata inodes, prohibit them from being used by
treating them the same way we treat Boot Loader inodes --- that is,
mark them to be bad inodes.  This prohibits them from being opened,
deleted, or modified via chmod, chown, utimes, etc.

In particular, this prevents a corrupted file system which has a
directory entry which points at the journal inode from being deleted
and its blocks released, after which point Much Hilarity Ensues.
Reported-by: NSami Liedes <sami.liedes@iki.fi>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

There's no longer any need to have a separate set of super_operations
for nojournal mode.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Through an oversight, when we added nojournal support to ext4, we
didn't add support to allow file system freezing.  This is relatively
easy to add, so let's do it.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reported-by: NDexuan Cui <decui@microsoft.com>

This allows us to eliminate duplicate code, and eventually allow us to
also fold ext4_sops and ext4_nojournal_sops together.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

The check whether quota format is set even though there are no
quota files with journalled quota is pointless and it actually
makes it impossible to turn off journalled quotas (as there's
no way to unset journalled quota format). Just remove the check.

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

Production fs likely compiled/mounted w/o jbd debugging, so orphan
list clearing will be silent.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

If the external journal device has metadata_csum enabled, verify
that the superblock checksum matches the block before we try to
mount.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Clear all three journal checksum feature flags before turning on
whichever journal checksum options we want.  Rearrange the error
checking so that newer flags get complained about first.
Reported-by: NTR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently sysfs feature files uses ext4_attr_ops as the file operations
to show/store data. However the feature files is not supposed to contain
any data at all, the sole existence of the file means that the module
support the feature. Moreover, none of the sysfs feature attributes
actually register show/store functions so that would not be a problem.

However if a sysfs feature attribute register a show or store function
we might be in trouble because the kobject in this case is _not_ embedded
in the ext4_sb_info structure as ext4_attr_show/store expect.

So just to be safe, provide separate empty sysfs_ops to use in
ext4_feat_ktype. This might safe us from potential problems in the
future. As a bonus we can "store" something more descriptive than
nothing in the files, so let it contain "enabled" to make it clear that
the feature is really present in the module.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Currently there is no easy way to tell that the mounted file system
contains errors other than checking for log messages, or reading the
information directly from superblock.

This patch adds new sysfs entries:

errors_count		(number of fs errors we encounter)
first_error_time	(unix timestamp for the first error we see)
last_error_time		(unix timestamp for the last error we see)

If the file system is not marked as containing errors then any of the
file will return 0. Otherwise it will contain valid information. More
details about the errors should as always be found in the logs.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

MAXQUOTAS value defines maximum number of quota types VFS supports.
This isn't necessarily the number of types ext4 supports. Although
ext4 will support project quotas, use ext4 private definition for
consistency with other filesystems.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Percpu allocator now supports allocation mask.  Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.

We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion.  This is the one with
the most users.  Other percpu data structures are a lot easier to
convert.

This patch doesn't make any functional difference.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NJan Kara <jack@suse.cz>
Acked-by: N"David S. Miller" <davem@davemloft.net>
Cc: x86@kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>

Since the ext4 superblock is not released until the file system is
unmounted, allocate the buffer cache entry for the ext4 superblock out
of the non-moveable are to allow page migrations and thus CMA
allocations to more easily succeed if the CMA area is limited.
Signed-off-by: NGioh Kim <gioh.kim@lge.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>

This commit adds some statictics in extent status tree shrinker.  The
purpose to add these is that we want to collect more details when we
encounter a stall caused by extent status tree shrinker.  Here we count
the following statictics:
  stats:
    the number of all objects on all extent status trees
    the number of reclaimable objects on lru list
    cache hits/misses
    the last sorted interval
    the number of inodes on lru list
  average:
    scan time for shrinking some objects
    the number of shrunk objects
  maximum:
    the inode that has max nr. of objects on lru list
    the maximum scan time for shrinking some objects

The output looks like below:
  $ cat /proc/fs/ext4/sda1/es_shrinker_info
  stats:
    28228 objects
    6341 reclaimable objects
    5281/631 cache hits/misses
    586 ms last sorted interval
    250 inodes on lru list
  average:
    153 us scan time
    128 shrunk objects
  maximum:
    255 inode (255 objects, 198 reclaimable)
    125723 us max scan time

If the lru list has never been sorted, the following line will not be
printed:
    586ms last sorted interval
If there is an empty lru list, the following lines also will not be
printed:
    250 inodes on lru list
  ...
  maximum:
    255 inode (255 objects, 198 reclaimable)
    0 us max scan time

Meanwhile in this commit a new trace point is defined to print some
details in __ext4_es_shrink().

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

Enable by default the block_validity feature, which checks for
collisions between newly allocated blocks and critical system
metadata.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

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

It turns out that there are some serious problems with the on-disk
format of journal checksum v2.  The foremost is that the function to
calculate descriptor tag size returns sizes that are too big.  This
causes alignment issues on some architectures and is compounded by the
fact that some parts of jbd2 use the structure size (incorrectly) to
determine the presence of a 64bit journal instead of checking the
feature flags.

Therefore, introduce journal checksum v3, which enlarges the
descriptor block tag format to allow for full 32-bit checksums of
journal blocks, fix the journal tag function to return the correct
sizes, and fix the jbd2 recovery code to use feature flags to
determine 64bitness.

Add a few function helpers so we don't have to open-code quite so
many pieces.

Switching to a 16-byte block size was found to increase journal size
overhead by a maximum of 0.1%, to convert a 32-bit journal with no
checksumming to a 32-bit journal with checksum v3 enabled.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reported-by: NTR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

The EXT4FS_DEBUG is a *very* developer specific #ifdef designed for
ext4 developers only.  (You have to modify fs/ext4/ext4.h to enable
it.)

Rearrange how we initialize data structures to avoid calling
ext4_count_free_clusters() until the multiblock allocator has been
initialized.

This also allows us to only call ext4_count_free_clusters() once, and
simplifies the code somewhat.

(Thanks to Chen Gang <gang.chen.5i5j@gmail.com> for pointing out a
!CONFIG_SMP compile breakage in the original patch.)
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>

Commit 00764937 ("ext4: initialize multi-block allocator before
checking block descriptors") causes the block group descriptor's count
of the number of free blocks to become inconsistent with the number of
free blocks in the allocation bitmap.  This is a harmless form of fs
corruption, but it causes the kernel to potentially remount the file
system read-only, or to panic, depending on the file systems's error
behavior.

Thanks to Eric Whitney for his tireless work to reproduce and to find
the guilty commit.

Fixes: 00764937 ("ext4: initialize multi-block allocator before checking block descriptors"

Cc: stable@vger.kernel.org  # 3.15
Reported-by: NDavid Jander <david@protonic.nl>
Reported-by: NMatteo Croce <technoboy85@gmail.com>
Tested-by: NEric Whitney <enwlinux@gmail.com>
Suggested-by: NEric Whitney <enwlinux@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

The mount manpage says of the max_batch_time option,

	This optimization can be turned off entirely
	by setting max_batch_time to 0.

But the code doesn't do that.  So fix the code to do
that.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

Make it clear that values printed are times, and that it is error
since last fsck. Also add note about fsck version required.
Signed-off-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Cc: stable@vger.kernel.org

Make them more consistently
Signed-off-by: Nxieliang <xieliang@xiaomi.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

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

I have been running make namespacecheck to look for unneeded globals, and
found these in ext4.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>