commit 2f974865ffdfe7b9f46a9940836c8b167342563d upstream.

The following commit introduced a bug when checking for zero length extent

5946d08 ext4: check for overlapping extents in ext4_valid_extent_entries()

Zero length extent could pass the check if lblock is zero.

Adding the explicit check for zero length back.

Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9d506594069355d1fb2de3f9104667312ff08ed3 upstream.

Currently when journal restart fails, we'll have the h_transaction of
the handle set to NULL to indicate that the handle has been effectively
aborted. We handle this situation quietly in the jbd2_journal_stop() and just
free the handle and exit because everything else has been done before we
attempted (and failed) to restart the journal.

Unfortunately there are a number of problems with that approach
introduced with commit

41a5b913197c "jbd2: invalidate handle if jbd2_journal_restart()
fails"

First of all in ext4 jbd2_journal_stop() will be called through
__ext4_journal_stop() where we would try to get a hold of the superblock
by dereferencing h_transaction which in this case would lead to NULL
pointer dereference and crash.

In addition we're going to free the handle regardless of the refcount
which is bad as well, because others up the call chain will still
reference the handle so we might potentially reference already freed
memory.

Moreover it's expected that we'll get aborted handle as well as detached
handle in some of the journalling function as the error propagates up
the stack, so it's unnecessary to call WARN_ON every time we get
detached handle.

And finally we might leak some memory by forgetting to free reserved
handle in jbd2_journal_stop() in the case where handle was detached from
the transaction (h_transaction is NULL).

Fix the NULL pointer dereference in __ext4_journal_stop() by just
calling jbd2_journal_stop() quietly as suggested by Jan Kara. Also fix
the potential memory leak in jbd2_journal_stop() and use proper
handle refcounting before we attempt to free it to avoid use-after-free
issues.

And finally remove all WARN_ON(!transaction) from the code so that we do
not get random traces when something goes wrong because when journal
restart fails we will get to some of those functions.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8f4d855839179f410fa910a26eb81d646d628f26 upstream.

We had a fencepost error in the lazytime optimization which means that
timestamp would get written to the wrong inode.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 280227a75b56ab5d35854f3a77ef74a7ad56a203 upstream.

fallocate() checks that the file is extent-based and returns
EOPNOTSUPP in case is not. Other tasks can convert from and to
indirect and extent so it's safe to check only after grabbing
the inode mutex.

Signed-off-by: Davide Italiano <dccitaliano@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d2dc317d564a46dfc683978a2e5a4f91434e9711 upstream.

Currently it is possible to lose whole file system block worth of data
when we hit the specific interaction with unwritten and delayed extents
in status extent tree.

The problem is that when we insert delayed extent into extent status
tree the only way to get rid of it is when we write out delayed buffer.
However there is a limitation in the extent status tree implementation
so that when inserting unwritten extent should there be even a single
delayed block the whole unwritten extent would be marked as delayed.

At this point, there is no way to get rid of the delayed extents,
because there are no delayed buffers to write out. So when a we write
into said unwritten extent we will convert it to written, but it still
remains delayed.

When we try to write into that block later ext4_da_map_blocks() will set
the buffer new and delayed and map it to invalid block which causes
the rest of the block to be zeroed loosing already written data.

For now we can fix this by simply not allowing to set delayed status on
written extent in the extent status tree. Also add WARN_ON() to make
sure that we notice if this happens in the future.

This problem can be easily reproduced by running the following xfs_io.

xfs_io -f -c "pwrite -S 0xaa 4096 2048" \
          -c "falloc 0 131072" \
          -c "pwrite -S 0xbb 65536 2048" \
          -c "fsync" /mnt/test/fff

echo 3 > /proc/sys/vm/drop_caches
xfs_io -c "pwrite -S 0xdd 67584 2048" /mnt/test/fff

This can be theoretically also reproduced by at random by running fsx,
but it's not very reliable, though on machines with bigger page size
(like ppc) this can be seen more often (especially xfstest generic/127)

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e12fb97222fc41e8442896934f76d39ef99b590a upstream.

Previously commit 14ece1028b3ed53ffec1b1213ffc6acaf79ad77c added a
support for for syncing parent directory of newly created inodes to
make sure that the inode is not lost after a power failure in
no-journal mode.

However this does not work in majority of cases, namely:
 - if the directory has inline data
 - if the directory is already indexed
 - if the directory already has at least one block and:
	- the new entry fits into it
	- or we've successfully converted it to indexed

So in those cases we might lose the inode entirely even after fsync in
the no-journal mode. This also includes ext2 default mode obviously.

I've noticed this while running xfstest generic/321 and even though the
test should fail (we need to run fsck after a crash in no-journal mode)
I could not find a newly created entries even when if it was fsynced
before.

Fix this by adjusting the ext4_add_entry() successful exit paths to set
the inode EXT4_STATE_NEWENTRY so that fsync has the chance to fsync the
parent directory as well.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Frank Mayhar <fmayhar@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull ext4 fixes from Ted Ts'o:
 "Ext4 bug fixes.

  We also reserved code points for encryption and read-only images (for
  which the implementation is mostly just the reserved code point for a
  read-only feature :-)"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix indirect punch hole corruption
  ext4: ignore journal checksum on remount; don't fail
  ext4: remove duplicate remount check for JOURNAL_CHECKSUM change
  ext4: fix mmap data corruption in nodelalloc mode when blocksize < pagesize
  ext4: support read-only images
  ext4: change to use setup_timer() instead of init_timer()
  ext4: reserve codepoints used by the ext4 encryption feature
  jbd2: complain about descriptor block checksum errors

Pull lazytime mount option support from Al Viro:
 "Lazytime stuff from tytso"

* 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ext4: add optimization for the lazytime mount option
  vfs: add find_inode_nowait() function
  vfs: add support for a lazytime mount option

This is a port of the DAX functionality found in the current version of
ext2.

[matthew.r.wilcox@intel.com: heavily tweaked]
[akpm@linux-foundation.org: remap_pages went away]
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 4f579ae7de56 (ext4: fix punch hole on files with indirect
mapping) rewrote FALLOC_FL_PUNCH_HOLE for ext4 files with indirect
mapping. However, there are bugs in several corner cases. This fixes 5
distinct bugs:

1. When there is at least one entire level of indirection between the
start and end of the punch range and the end of the punch range is the
first block of its level, we can't return early; we have to free the
intervening levels.

2. When the end is at a higher level of indirection than the start and
ext4_find_shared returns a top branch for the end, we still need to free
the rest of the shared branch it returns; we can't decrement partial2.

3. When a punch happens within one level of indirection, we need to
converge on an indirect block that contains the start and end. However,
because the branches returned from ext4_find_shared do not necessarily
start at the same level (e.g., the partial2 chain will be shallower if
the last block occurs at the beginning of an indirect group), the walk
of the two chains can end up "missing" each other and freeing a bunch of
extra blocks in the process. This mismatch can be handled by first
making sure that the chains are at the same level, then walking them
together until they converge.

4. When the punch happens within one level of indirection and
ext4_find_shared returns a top branch for the start, we must free it,
but only if the end does not occur within that branch.

5. When the punch happens within one level of indirection and
ext4_find_shared returns a top branch for the end, then we shouldn't
free the block referenced by the end of the returned chain (this mirrors
the different levels case).

Signed-off-by: Omar Sandoval <osandov@osandov.com>