lwn.git/fs/jbd2/commit.c, branch doc/4.4

jbd2: avoid infinite loop when destroying aborted journal

2015-07-28T18:57:14+00:00

Commit 6f6a6fda2945 "jbd2: fix ocfs2 corrupt when updating journal superblock fails" changed jbd2_cleanup_journal_tail() to return EIO when the journal is aborted. That makes logic in jbd2_log_do_checkpoint() bail out which is fine, except that jbd2_journal_destroy() expects jbd2_log_do_checkpoint() to always make a progress in cleaning the journal. Without it jbd2_journal_destroy() just loops in an infinite loop. Fix jbd2_journal_destroy() to cleanup journal checkpoint lists of jbd2_log_do_checkpoint() fails with error. Reported-by: Eryu Guan Tested-by: Eryu Guan Fixes: 6f6a6fda294506dfe0e3e0a253bb2d2923f28f0a Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

jbd2: fix descriptor block size handling errors with journal_csum

2014-08-29T02:22:29+00:00

It turns out that there are some serious problems with the on-disk format of journal checksum v2. The foremost is that the function to calculate descriptor tag size returns sizes that are too big. This causes alignment issues on some architectures and is compounded by the fact that some parts of jbd2 use the structure size (incorrectly) to determine the presence of a 64bit journal instead of checking the feature flags. Therefore, introduce journal checksum v3, which enlarges the descriptor block tag format to allow for full 32-bit checksums of journal blocks, fix the journal tag function to return the correct sizes, and fix the jbd2 recovery code to use feature flags to determine 64bitness. Add a few function helpers so we don't have to open-code quite so many pieces. Switching to a 16-byte block size was found to increase journal size overhead by a maximum of 0.1%, to convert a 32-bit journal with no checksumming to a 32-bit journal with checksum v3 enabled. Signed-off-by: Darrick J. Wong Reported-by: TR Reardon Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

arch: Mass conversion of smp_mb__*()

2014-04-18T12:20:48+00:00

Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar

jbd2: add transaction to checkpoint list earlier

2014-03-09T03:34:10+00:00

We don't otherwise need j_list_lock during the rest of commit phase #7, so add the transaction to the checkpoint list at the very end of commit phase #6. This allows us to drop j_list_lock earlier, which is a good thing since it is a super hot lock. Signed-off-by: "Theodore Ts'o"

jbd2: calculate statistics without holding j_state_lock and j_list_lock

2014-03-09T00:51:16+00:00

The two hottest locks, and thus the biggest scalability bottlenecks, in the jbd2 layer, are the j_list_lock and j_state_lock. This has inspired some people to do some truly unnatural things[1]. [1] https://www.usenix.org/system/files/conference/fast14/fast14-paper_kang.pdf We don't need to be holding both j_state_lock and j_list_lock while calculating the journal statistics, so move those calculations to the very end of jbd2_journal_commit_transaction. Signed-off-by: "Theodore Ts'o"

jbd2: don't unplug after writing revoke records

2014-03-08T23:13:52+00:00

During commit process, keep the block device plugged after we are done writing the revoke records, until we are finished writing the rest of the commit records in the journal. This will allow most of the journal blocks to be written in a single I/O operation, instead of separating the the revoke blocks from the rest of the journal blocks. Signed-off-by: "Theodore Ts'o"

jbd2: Fix endian mixing problems in the checksumming code

2013-08-28T18:59:58+00:00

In the jbd2 checksumming code, explicitly declare separate variables with endianness information so that we don't get confused and screw things up again. Also fixes sparse warnings. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o"

jbd2: fix duplicate debug label for phase 2

2013-06-13T02:56:35+00:00

Currently we see this output: $git grep phase fs/jbd2 fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 1\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 2\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 2\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 3\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 4\n"); [...] There is clearly a duplicate label for phase 2, and they are both active (i.e. not in #if ... #else block). Rename them to be "2a" and "2b" so the debug output is unambiguous. Signed-off-by: Paul Gortmaker Signed-off-by: "Theodore Ts'o"

jbd2: relocate assert after state lock in journal_commit_transaction()

2013-06-13T02:46:35+00:00

The state lock is taken after we are doing an assert on the state value, not before. So we might in fact be doing an assert on a transient value. Ensure the state check is within the scope of the state lock being taken. Signed-off-by: Paul Gortmaker Signed-off-by: "Theodore Ts'o"

jbd2: transaction reservation support

2013-06-04T16:35:11+00:00

In some cases we cannot start a transaction because of locking constraints and passing started transaction into those places is not handy either because we could block transaction commit for too long. Transaction reservation is designed to solve these issues. It reserves a handle with given number of credits in the journal and the handle can be later attached to the running transaction without blocking on commit or checkpointing. Reserved handles do not block transaction commit in any way, they only reduce maximum size of the running transaction (because we have to always be prepared to accomodate request for attaching reserved handle). Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o"