jbd2: change disk layout for metadata checksumming

Define flags and allocate space in on-disk journal structures to support
checksumming of journal metadata.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 8f888ef846d4481e24c74b4a91ece771d2bcbcb5)
jbd2: enable journal clients to enable v2 checksumming

Add in the necessary code so that journal clients can enable the new
journal checksumming features.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 25ed6e8a54df904c875365eebedbd19138a47328)
jbd2: Grab a reference to the crc32c driver if necessary

Obtain a reference to the crc32c driver if needed for the v2 checksum.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 01b5adcebb977bc61b64167adce6d8260c9da33c)
jbd2: checksum journal superblock

Calculate and verify a checksum covering the journal superblock.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 4fd5ea43bc11602bfabe2c8f5378586d34bd2b0a)
jbd2: checksum revocation blocks

Compute and verify revoke blocks inside the journal.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 42a7106de636ebf9c0b93d25b4230e14f5f2682e)
jbd2: checksum descriptor blocks

Calculate and verify a checksum of each descriptor block.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 3caa487f53f65fd1e3950a6b6ae1709e6c43b334)
jbd2: checksum commit blocks

Calculate and verify the checksum of commit blocks.  In checksum v2,
deprecate most of the checksum v1 commit block checksum fields, since
each block has its own checksum.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 1f56c5890e3e815c6f4eabfc87a8a81f439b6f3d)
jbd2: checksum data blocks that are stored in the journal

Calculate and verify checksums of each data block being stored in the journal.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit c390087591dcbecd244c31d979ccdad49ae83364)
jbd2: use kmem_cache_zalloc wrapper instead of flag

Use kmem_cache_zalloc wrapper instead of flag __GFP_ZERO.

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit b2f4edb335f23626225a792e0669d1becf68312f)
jbd2: remove the second argument of kmap_atomic

Signed-off-by: Cong Wang <amwang@redhat.com>
(cherry picked from commit 906adea1536fe476c1068d86df01f8b130cde105)
jbd/jbd2: nuke write_super from comments

The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from various jbd and jbd2.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
(cherry picked from commit 12810ad70858af10f5e00b3c178085c03baa457b)
ext4: make sure the journal sb is written in ext4_clear_journal_err()

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: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

(cherry picked from commit d796c52ef0b71a988364f6109aeb63d79c5b116b)
ext4: calculate and verify checksums of directory leaf blocks

Calculate and verify the checksums for directory leaf blocks
(i.e. blocks that only contain actual directory entries).  The
checksum lives in what looks to be an unused directory entry with a 0
name_len at the end of the block.  This scheme is not used for
internal htree nodes because the mechanism in place there only costs
one dx_entry, whereas the "empty" directory entry would cost two
dx_entries.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit b0336e8d2108e6302aecaadd17c6c0bd686da22d)
ext4: Calculate and verify checksums of extended attribute blocks

Calculate and verify the checksums of extended attribute blocks.  This
only applies to separate EA blocks that are pointed to by
inode->i_file_acl (i.e.  external EA blocks); the checksum lives in
the EA header.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit cc8e94fd126ab2d2e4bcb1b65c7316196f0cec8c)
ext4: add checksums to the MMP block

Compute and verify a checksum for the MMP block.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 5c359a47e7d999a0ea7f397da2c15590d0a82815)
ext4: remove unnecessary check in add_dirent_to_buf()

None of this function callers ever pass in a NULL inode pointer, so
this check is unnecessary, and the else clause is dead code.  (This
change should make the code coverage people a little happier.  :-)

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit b09de7fa5217bbcb4caf3d19bd5e94816947ff7a)
ext4: Remove i_mutex use from ext4_quota_write()

We don't need i_mutex in ext4_quota_write() because writes to quota file
are serialized by dqio_mutex anyway. Changes to quota files outside of quota
code are forbidded and enforced by NOATIME and IMMUTABLE bits.

Signed-off-by: Jan Kara <jack@suse.cz>
(cherry picked from commit 0b7f7cefaea96ef25dbe54b8e16d2d61560d8b9d)
ext4: enable the 64-bit jbd2 feature based on the 64-bit ext4 feature

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: "Theodore Ts'o" <tytso@mit.edu>

(cherry picked from commit f32aaf2d2b996b14e993da1c23f7ee22ea7333a3)
ext4/jbd2: add metadata checksumming to the list of supported features

Activate the metadata checksumming feature by adding it to ext4 and
jbd2's lists of supported features.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit e93376c20b70d1e62bb3246acd1bbe21fe58859f)
ext4: fix potential NULL dereference in ext4_free_inodes_counts()

The ext4_get_group_desc() function returns NULL on error, and
ext4_free_inodes_count() function dereferences it without checking.
There is a check on the next line, but it's too late.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
(cherry picked from commit bb3d132a24cd8bf5e7773b2d9f9baa58b07a7dae)