user/sven/linux.git/include/linux/jbd2.h, branch v3.8-rc4

ext4: fix deadlock in journal_unmap_buffer()

2012-12-25T18:29:52Z

We cannot wait for transaction commit in journal_unmap_buffer() because we hold page lock which ranks below transaction start. We solve the issue by bailing out of journal_unmap_buffer() and jbd2_journal_invalidatepage() with -EBUSY. Caller is then responsible for waiting for transaction commit to finish and try invalidation again. Since the issue can happen only for page stradding i_size, it is simple enough to manually call jbd2_journal_invalidatepage() for such page from ext4_setattr(), check the return value and wait if necessary. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o"

jbd2: remove VLAIS usage from JBD2 code

2012-11-08T16:24:46Z

The use of variable length arrays in structs (VLAIS) in the Linux Kernel code precludes the use of compilers which don't implement VLAIS (for instance the Clang compiler). Since ctx is always a 32-bit CRC, hard coding a size of 4 bytes accomplishes the same thing without the use of VLAIS. This is the same technique already employed in fs/ext4/ext4.h Signed-off-by: Mark Charlebois Signed-off-by: Behan Webster Signed-off-by: "Theodore Ts'o"

ext4: remove ext4_handle_release_buffer()

2012-11-08T16:22:46Z

ext4_handle_release_buffer() was intended to remove journal write access from a buffer, but it doesn't actually do anything at all other than add a BUFFER_TRACE point, but it's not reliably used for that either. Remove all the associated dead code. Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" Reviewed-by: Carlos Maiolino

ext4: make sure the journal sb is written in ext4_clear_journal_err()

2012-08-05T23:04:57Z

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" Cc: stable@kernel.org

ext4/jbd2: add metadata checksumming to the list of supported features

2012-05-27T12:12:42Z

Activate the metadata checksumming feature by adding it to ext4 and jbd2's lists of supported features. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o"

jbd2: checksum journal superblock

2012-05-27T12:08:22Z

Calculate and verify a checksum covering the journal superblock. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o"

jbd2: Grab a reference to the crc32c driver if necessary

2012-05-27T11:50:56Z

Obtain a reference to the crc32c driver if needed for the v2 checksum. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o"

jbd2: change disk layout for metadata checksumming

2012-05-23T02:43:41Z

Define flags and allocate space in on-disk journal structures to support checksumming of journal metadata. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o"

jbd2: cleanup journal tail after transaction commit

2012-03-14T02:45:38Z

Normally, we have to issue a cache flush before we can update journal tail in journal superblock, effectively wiping out old transactions from the journal. So use the fact that during transaction commit we issue cache flush anyway and opportunistically push journal tail as far as we can. Since update of journal superblock is still costly (we have to use WRITE_FUA), we update log tail only if we can free significant amount of space. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o"

jbd2: issue cache flush after checkpointing even with internal journal

2012-03-14T02:22:54Z

When we reach jbd2_cleanup_journal_tail(), there is no guarantee that checkpointed buffers are on a stable storage - especially if buffers were written out by jbd2_log_do_checkpoint(), they are likely to be only in disk's caches. Thus when we update journal superblock effectively removing old transaction from journal, this write of superblock can get to stable storage before those checkpointed buffers which can result in filesystem corruption after a crash. Thus we must unconditionally issue a cache flush before we update journal superblock in these cases. A similar problem can also occur if journal superblock is written only in disk's caches, other transaction starts reusing space of the transaction cleaned from the log and power failure happens. Subsequent journal replay would still try to replay the old transaction but some of it's blocks may be already overwritten by the new transaction. For this reason we must use WRITE_FUA when updating log tail and we must first write new log tail to disk and update in-memory information only after that. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o"