Pull ext4 bug fixes from Ted Ts'o:
 "Ext4 bug fixes, including a regression fix"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: clarify impact of 'commit' mount option
  ext4: fix unused-but-set-variable warning in ext4_add_entry()
  jbd2: fix kernel-doc notation warning
  ext4: use RCU API in debug_print_tree
  ext4: validate the debug_want_extra_isize mount option at parse time
  ext4: reserve revoke credits in __ext4_new_inode
  ext4: unlock on error in ext4_expand_extra_isize()
  ext4: optimize __ext4_check_dir_entry()
  ext4: check for directory entries too close to block end
  ext4: fix ext4_empty_dir() for directories with holes

Instead of setting s_want_extra_size and then making sure that it is a
valid value afterwards, validate the field before we set it.  This
avoids races and other problems when remounting the file system.

Link: https://lore.kernel.org/r/20191215063020.GA11512@mit.edu
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-and-tested-by: syzbot+4a39a025912b265cacef@syzkaller.appspotmail.com

Pull ext2, quota, reiserfs cleanups and fixes from Jan Kara:

 - Refactor the quota on/off kernel internal interfaces (mostly for
   ubifs quota support as ubifs does not want to have inodes holding
   quota information)

 - A few other small quota fixes and cleanups

 - Various small ext2 fixes and cleanups

 - Reiserfs xattr fix and one cleanup

* tag 'for_v5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (28 commits)
  ext2: code cleanup for descriptor_loc()
  fs/quota: handle overflows of sysctl fs.quota.* and report as unsigned long
  ext2: fix improper function comment
  ext2: code cleanup for ext2_try_to_allocate()
  ext2: skip unnecessary operations in ext2_try_to_allocate()
  ext2: Simplify initialization in ext2_try_to_allocate()
  ext2: code cleanup by calling ext2_group_last_block_no()
  ext2: introduce new helper ext2_group_last_block_no()
  reiserfs: replace open-coded atomic_dec_and_mutex_lock()
  ext2: check err when partial != NULL
  quota: Handle quotas without quota inodes in dquot_get_state()
  quota: Make dquot_disable() work without quota inodes
  quota: Drop dquot_enable()
  fs: Use dquot_load_quota_inode() from filesystems
  quota: Rename vfs_load_quota_inode() to dquot_load_quota_inode()
  quota: Simplify dquot_resume()
  quota: Factor out setup of quota inode
  quota: Check that quota is not dirty before release
  quota: fix livelock in dquot_writeback_dquots
  ext2: don't set *count in the case of failure in ext2_try_to_allocate()
  ...

Pull ext4 updates from Ted Ts'o:
 "This merge window saw the the following new featuers added to ext4:

   - Direct I/O via iomap (required the iomap-for-next branch from
     Darrick as a prereq).

   - Support for using dioread-nolock where the block size < page size.

   - Support for encryption for file systems where the block size < page
     size.

   - Rework of journal credits handling so a revoke-heavy workload will
     not cause the journal to run out of space.

   - Replace bit-spinlocks with spinlocks in jbd2

  Also included were some bug fixes and cleanups, mostly to clean up
  corner cases from fuzzed file systems and error path handling"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (59 commits)
  ext4: work around deleting a file with i_nlink == 0 safely
  ext4: add more paranoia checking in ext4_expand_extra_isize handling
  jbd2: make jbd2_handle_buffer_credits() handle reserved handles
  ext4: fix a bug in ext4_wait_for_tail_page_commit
  ext4: bio_alloc with __GFP_DIRECT_RECLAIM never fails
  ext4: code cleanup for get_next_id
  ext4: fix leak of quota reservations
  ext4: remove unused variable warning in parse_options()
  ext4: Enable encryption for subpage-sized blocks
  fs/buffer.c: support fscrypt in block_read_full_page()
  ext4: Add error handling for io_end_vec struct allocation
  jbd2: Fine tune estimate of necessary descriptor blocks
  jbd2: Provide trace event for handle restarts
  ext4: Reserve revoke credits for freed blocks
  jbd2: Make credit checking more strict
  jbd2: Rename h_buffer_credits to h_total_credits
  jbd2: Reserve space for revoke descriptor blocks
  jbd2: Drop jbd2_space_needed()
  jbd2: Account descriptor blocks into t_outstanding_credits
  jbd2: Factor out common parts of stopping and restarting a handle
  ...

It's possible to specify a non-zero s_want_extra_isize via debugging
option, and this can cause bad things(tm) to happen when using a file
system with an inode size of 128 bytes.

Add better checking when the file system is mounted, as well as when
we are actually doing the trying to do the inode expansion.

Link: https://lore.kernel.org/r/20191110121510.GH23325@mit.edu
Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com
Reported-by: syzbot+33d7ea72e47de3bdf4e1@syzkaller.appspotmail.com
Reported-by: syzbot+44b6763edfc17144296f@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Now the checks in ext4_get_next_id() and dquot_get_next_id()
are almost the same, so just call dquot_get_next_id() instead
of ext4_get_next_id().

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Link: https://lore.kernel.org/r/20191006103028.31299-1-cgxu519@mykernel.net
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Commit 8fcc3a580651 ("ext4: rework reserved cluster accounting when
invalidating pages") moved freeing of delayed allocation reservations
from dirty page invalidation time to time when we evict corresponding
status extent from extent status tree. For inodes which don't have any
blocks allocated this may actually happen only in ext4_clear_blocks()
which is after we've dropped references to quota structures from the
inode. Thus reservation of quota leaked. Fix the problem by clearing
quota information from the inode only after evicting extent status tree
in ext4_clear_inode().

Link: https://lore.kernel.org/r/20191108115420.GI20863@quack2.suse.cz
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 8fcc3a580651 ("ext4: rework reserved cluster accounting when invalidating pages")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Commit c33fbe8f673c5 ("ext4: Enable blocksize < pagesize for
dioread_nolock") removed the only user of 'sbi' outside of the ifdef,
so it caused a new warning:

fs/ext4/super.c:2068:23: warning: unused variable 'sbi' [-Wunused-variable]

Fixes: c33fbe8f673c5 ("ext4: Enable blocksize < pagesize for dioread_nolock")
Signed-off-by: Olof Johansson <olof@lixom.net>
Link: https://lore.kernel.org/r/20191111022523.34256-1-olof@lixom.net
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>

Now that we have the code to support encryption for subpage-sized
blocks, this commit removes the conditional check in filesystem mount
code.

The commit also changes the support statement in
Documentation/filesystems/fscrypt.rst to reflect the fact that
encryption on filesystems with blocksize less than page size now works.

[EB: Tested with 'gce-xfstests -c ext4/encrypt_1k -g auto', using the
new "encrypt_1k" config I created.  All tests pass except for those that
already fail or are excluded with the encrypt or 1k configs, and 2 tests
that try to create 1023-byte symlinks which fails since encrypted
symlinks are limited to blocksize-3 bytes.  Also ran the dedicated
encryption tests using 'kvm-xfstests -c ext4/1k -g encrypt'; all pass,
including the on-disk ciphertext verification tests.]

Signed-off-by: Chandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191023033312.361355-3-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>