There are some places in ext4_fill_super() where we would not return
proper error code if something fails. The confusion is caused probably
due to the fact that we have two "kind-of" return variables 'ret'and
'err'.

'ret' is used to return error code from ext4_fill_super() where err is
used to store return values from other functions within ext4_fill_super().
However some places were missing the obligatory 'ret = err'. We could
put the assignment where it is missing, but we can have better "future
proof" solution. Or we could convert the code to use just one, but it
would require more rewrites.

This commit fixes the problem by returning value from 'err' variable if
it is set and 'ret' otherwise in error handling branch of the
ext4_fill_super(). The reasoning is that 'ret' value is often set to
default "-EINVAL" or explicit value, where 'err' is used to store
return value from other functions and should be otherwise zero.

https://bugzilla.kernel.org/show_bug.cgi?id=48431Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Notify user when mounting the file system with -o discard option, but
the device does not support discard. Obviously we do not want to fail
the mount or disable the options, because the underlying device might
change in future even without file system remount.
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NZhao Hongjiang <zhaohongjiang@huawei.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

"overhead" was a write-only variable in this function after commit
952fc18e; we set it to 0 for minixdf, or to sbi->s_overhead if !minixdf,
but never read it again after that.

We need to use it, not sbi->s_overhead, when subtracting out overhead
for f_blocks, or we get the wrong answer for minixdf.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The result of the bit shift expression in
'1 << sbi->s_log_groups_per_flex' can be undefined in the case that
s_log_groups_per_flex is 31 because the result of the shift is bigger
than INT_MAX. In reality this probably should not cause much problems
since we'll end up with INT_MIN which will then be converted into
'unsigned int' type, but nevertheless according to the ISO C99 the
result is actually undefined.

Fix this by changing the left operand to 'unsigned int' type.

Note that the commit d50f2ab6 already
tried to fix the undefined behaviour, but this was missed.

Thanks to Laszlo Ersek for pointing this out and suggesting the fix.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Reported-by: NLaszlo Ersek <lersek@redhat.com>

The function ext4_handle_dirty_super() was calculating the superblock
on the wrong block data.  As a result, when the superblock is modified
while it is mounted (most commonly, when inodes are added or removed
from the orphan list), the superblock checksum would be wrong.  We
didn't notice because the superblock *was* being correctly calculated
in ext4_commit_super(), and this would get called when the file system
was unmounted.  So the problem only became obvious if the system
crashed while the file system was mounted.

Fix this by removing the poorly designed function signature for
ext4_superblock_csum_set(); if it only took a single argument, the
pointer to a struct superblock, the ambiguity which caused this
mistake would have been impossible.
Reported-by: NGeorge Spelvin <linux@horizon.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

AIO/DIO prefix is wrong because it account unwritten extents which
also may be scheduled from buffered write endio
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Generic inode has unused i_private pointer which may be used as cur_aio_dio
storage.

TODO: If cur_aio_dio will be passed as an argument to get_block_t this allow
      to have concurent AIO_DIO requests.
Reviewed-by: NZheng Liu <wenqing.lz@taobao.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Convert cpu_to_leXX(leXX_to_cpu(E1) + E2) to use leXX_add_cpu().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If the file system contains errors and it is being mounted read-only,
don't clear the orphan list.  We should minimize changes to the file
system if it is mounted read-only.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The crash was caused by a variable being erronously declared static in
token2str().

In addition to /proc/mounts, the problem can also be easily replicated
by accessing /proc/fs/ext4/<partition>/options in parallel:

$ cat /proc/fs/ext4/<partition>/options > options.txt

... and then running the following command in two different terminals:

$ while diff /proc/fs/ext4/<partition>/options options.txt; do true; done

This is also the cause of the following a crash while running xfstests
#234, as reported in the following bug reports:

	https://bugs.launchpad.net/bugs/1053019
	https://bugzilla.kernel.org/show_bug.cgi?id=47731Signed-off-by: NHerton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Brad Figg <brad.figg@canonical.com>
Cc: stable@vger.kernel.org

Change struct dquot dq_id to a struct kqid and remove the now
unecessary dq_type.

Make minimal changes to dquot, quota_tree, quota_v1, quota_v2, ext3,
ext4, and ocfs2 to deal with the change in quota structures and
signatures.  The ocfs2 changes are larger than most because of the
extensive tracing throughout the ocfs2 quota code that prints out
dq_id.

quota_tree.c:get_index is modified to take a struct kqid instead of a
qid_t because all of it's callers pass in dquot->dq_id and it allows
me to introduce only a single conversion.

The rest of the changes are either just replacing dq_type with dq_id.type,
adding conversions to deal with the change in type and occassionally
adding qid_eq to allow quota id comparisons in a user namespace safe way.

Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Theodore Tso <tytso@mit.edu>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Signed-off-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

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

Previously, we allocated the s_flex_groups array to the maximum size
that the file system could be resized.  There was two problems with
this approach.  First, it wasted memory in the common case where the
file system was not resized.  Secondly, once we start allowing online
resizing using the meta_bg scheme, there is no maximum size that the
file system can be resized.  So instead, we need to grow the
s_flex_groups at inline resize time.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Fixes the following sparse warning:
fs/ext4/super.c:1672:45: warning: Using plain integer as NULL pointer
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

We don't need lock_super()/unlock_super() any more, since the places
where it is used, we are protected by the s_umount r/w semaphore.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Marco Stornelli <marco.stornelli@gmail.com>

In the very unlikely case that kset_create_and_add() fails when the
ext4.ko module is being loaded (or during kernel startup) set err so
that it's clear that the module load failed.

https://bugzilla.kernel.org/show_bug.cgi?id=27912Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently in ext4 the length of zero-out chunk is set to 7 file system
blocks.  But if an inode has uninitailized extents from using
fallocate to preallocate space, and the workload issues many random
writes, this can cause a fragmented extent tree that will
unnecessarily grow the extent tree.

So create a new sysfs tunable, extent_max_zeroout_kb, which controls
the maximum size where blocks will be zeroed out instead of creating a
new uninitialized extent.  The default of this has been sent to 32kb.

CC: Zach Brown <zab@zabbo.net>
CC: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Very large directories can cause significant performance problems, or
perhaps even invoke the OOM killer, if the process is running in a
highly constrained memory environment (whether it is VM's with a small
amount of memory or in a small memory cgroup).

So it is useful, in cloud server/data center environments, to be able
to set a filesystem-wide cap on the maximum size of a directory, to
ensure that directories never get larger than a sane size.  We do this
via a new mount option, max_dir_size_kb.  If there is an attempt to
grow the directory larger than max_dir_size_kb, the system call will
return ENOSPC instead.

Google-Bug-Id: 6863013
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Commit 8aeb00ff85a: "ext4: fix overhead calculation used by
ext4_statfs()" introduced a O(n**2) calculation which makes very large
file systems take forever to mount.  Fix this with an optimization for
non-bigalloc file systems.  (For bigalloc file systems the overhead
needs to be set in the the superblock.)
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

Commit 03179fe9 introduced a kmemcheck complaint in
ext4_da_get_block_prep() because we save and restore
ei->i_da_metadata_calc_last_lblock even though it is left
uninitialized in the case where i_da_metadata_calc_len is zero.

This doesn't hurt anything, but silencing the kmemcheck complaint
makes it easier for people to find real bugs.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=45631
(which is marked as a regression).
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

After we transfer set the EXT4_ERROR_FS bit in the file system
superblock, it's not enough to call jbd2_journal_clear_err() to clear
the error indication from journal superblock --- we need to call
jbd2_journal_update_sb_errno() as well.  Otherwise, when the root file
system is mounted read-only, the journal is replayed, and the error
indicator is transferred to the superblock --- but the s_errno field
in the jbd2 superblock is left set (since although we cleared it in
memory, we never flushed it out to disk).

This can end up confusing e2fsck.  We should make e2fsck more robust
in this case, but the kernel shouldn't be leaving things in this
confused state, either.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from ext3.

Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We remove most of frozen checks since upper layer takes care of blocking all
writes. We have to handle protection in ext4_page_mkwrite() in a special way
because we cannot use generic block_page_mkwrite(). Also we add a freeze
protection to ext4_evict_inode() so that iput() of unlinked inode cannot modify
a frozen filesystem (we cannot easily instrument ext4_journal_start() /
ext4_journal_stop() with freeze protection because we are missing the
superblock pointer in ext4_journal_stop() in nojournal mode).

CC: linux-ext4@vger.kernel.org
CC: "Theodore Ts'o" <tytso@mit.edu>
BugLink: https://bugs.launchpad.net/bugs/897421Tested-by: NKamal Mostafa <kamal@canonical.com>
Tested-by: NPeter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: NDann Frazier <dann.frazier@canonical.com>
Tested-by: NMassimo Morana <massimo.morana@canonical.com>
Acked-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We do not depend on VFS's '->write_super()' anymore and do not need
the 's_dirt' flag anymore, so weed out 'ext4_write_super()' and
's_dirt'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>

This patch changes the 'ext4_handle_dirty_super()' function which
submits the superblock for I/O in the following cases:

1. When creating the first large file on a file system without
   EXT4_FEATURE_RO_COMPAT_LARGE_FILE feature.
2. When re-sizing the file-system.
3. When creating an xattr on a file-system without the
   EXT4_FEATURE_COMPAT_EXT_ATTR feature.

If the file-system has journal enabled, the superblock is written via
the journal. We do not modify this path.

If the file-system has no journal, this function, falls back to just
marking the superblock as dirty using the 's_dirt' superblock
flag. This means that it delays the actual superblock I/O submission
by 5 seconds (default setting).  Namely, the 'sync_supers()' kernel
thread will call 'ext4_write_super()' later and will actually submit
the superblock for I/O.

And this is the behavior this patch modifies: we stop using 's_dirt'
and just mark the superblock buffer as dirty right away. Indeed, all 3
cases above are extremely rare and it does not add any value to delay
the I/O submission for them.

Note: 'ext4_handle_dirty_super()' executes
'__ext4_handle_dirty_super()' with 'now = 0'. This patch basically
makes the 'now' argument unneeded and it will be deleted in one of the
next patches.

This patch also removes 's_dirt' condition on the unmount path because
we never set it anymore, so we should not test it.

Tested using xfstests for both journalled and non-journalled ext4.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>

This patch adds support for quotas as a first class feature in ext4;
which is to say, the quota files are stored in hidden inodes as file
system metadata, instead of as separate files visible in the file system
directory hierarchy.

It is based on the proposal at:                                                                                                           
https://ext4.wiki.kernel.org/index.php/Design_For_1st_Class_Quota_in_Ext4

This patch introduces a new feature - EXT4_FEATURE_RO_COMPAT_QUOTA
which, when turned on, enables quota accounting at mount time
iteself. Also, the quota inodes are stored in two additional superblock
fields.  Some changes introduced by this patch that should be pointed
out are:

1) Two new ext4-superblock fields - s_usr_quota_inum and
   s_grp_quota_inum for storing the quota inodes in use.
2) Default quota inodes are: inode#3 for tracking userquota and inode#4
   for tracking group quota. The superblock fields can be set to use
   other inodes as well.
3) If the QUOTA feature and corresponding quota inodes are set in
   superblock, the quota usage tracking is turned on at mount time. On
   'quotaon' ioctl, the quota limits enforcement is turned
   on. 'quotaoff' ioctl turns off only the limits enforcement in this
   case.
4) When QUOTA feature is in use, the quota mount options 'quota',
   'usrquota', 'grpquota' are ignored by the kernel.
5) mke2fs or tune2fs can be used to set the QUOTA feature and initialize
   quota inodes. The default reserved inodes will not be visible to user
   as regular files.
6) The quota-tools will need to be modified to support hidden quota
   files on ext4. E2fsprogs will also include support for creating and
   fixing quota files.
7) Support is only for the new V2 quota file format.
Tested-by: NJan Kara <jack@suse.cz>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NJohann Lombardi <johann@whamcloud.com>
Signed-off-by: NAditya Kali <adityakali@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Since the moment writes to quota files are using block device page cache and
space for quota structures is reserved at the moment they are first accessed we
have no reason to sync quota before inode writeback. In fact this order is now
only harmful since quota information can easily change during inode writeback
(either because conversion of delayed-allocated extents or simply because of
allocation of new blocks for simple filesystems not using page_mkwrite).

So move syncing of quota information after writeback of inodes into ->sync_fs
method. This way we do not have to use ->quota_sync callback which is primarily
intended for use by quotactl syscall anyway and we get rid of calling
->sync_fs() twice unnecessarily. We skip quota syncing for OCFS2 since it does
proper quota journalling in all cases (unlike ext3, ext4, and reiserfs which
also support legacy non-journalled quotas) and thus there are no dirty quota
structures.

CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Joel Becker <jlbec@evilplan.org>
CC: reiserfs-devel@vger.kernel.org
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
Acked-by: NDave Kleikamp <shaggy@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit f975d6bc introduced bug which caused ext4_statfs() to
miscalculate the number of file system overhead blocks.  This causes
the f_blocks field in the statfs structure to be larger than it should
be.  This would in turn cause the "df" output to show the number of
data blocks in the file system and the number of data blocks used to
be larger than they should be.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

The ext4_error() function is missing a call to save_error_info().
Since this is the function which marks the file system as containing
an error, this oversight (which was introduced in 2.6.36) is quite
significant, and should be backported to older stable kernels with
high urgency.
Reported-by: NKen Sumrall <ksumrall@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: ksumrall@google.com
Cc: stable@kernel.org

Make it easy to test whether or not the error handling subsystem in
ext4 is working correctly.  This allows us to simulate an ext4_error()
by echoing a string to /sys/fs/ext4/<dev>/trigger_fs_error.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: ksumrall@google.com

This is a port of the ext3 commit: 4569cd1bSigned-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The b_data field of the buffer_head is already a char *, so there's no
point casting it to a char *.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

needs_recovery in ext4_mb_init() is not used, remove it.
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.ne.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If ext4_setup_super() fails i.e. due to a too-high revision,
the error is logged in dmesg but the fs is not mounted RO as
indicated.

Tested by:

# mkfs.ext4 -r 4 /dev/sdb6
# mount /dev/sdb6 /mnt/test
# dmesg | grep "too high"
[164919.759248] EXT4-fs (sdb6): revision level too high, forcing read-only mode
# grep sdb6 /proc/mounts
/dev/sdb6 /mnt/test2 ext4 rw,seclabel,relatime,data=ordered 0 0
Reviewed-by: NAndreas Dilger <adilger@whamcloud.com>
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

Add in the necessary code so that journal clients can enable the new
journal checksumming features.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Previously we were only enabling the 64-bit jbd2 feature if the number
of blocks in the file system was greater 2**32-1.  The problem with
this is that it makes it harder to test the 64-bit journal code paths
with small file systems, since a small test file system would with the
64-bit ext4 feature enable would use a 64-bit file system on-disk data
structures, but use a 32-bit journal.

This would also cause problems when trying to do an online resize to
grow the filesystem above the 2**32-1 boundary.  Fortunately the patch
to support online resize for 64-bit file systems hasn't been merged
yet, so this problem hasn't arisen in practice.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>