pm24.git/fs/jbd2/commit.c, branch v5.7

jbd2: improve comments about freeing data buffers whose page mapping is NULL

2020-03-06T01:25:05Z

Improve comments in jbd2_journal_commit_transaction() to describe why we don't need to clear the buffer_mapped bit for freeing file mapping buffers whose page mapping is NULL. Link: https://lore.kernel.org/r/20200217112706.20085-1-yi.zhang@huawei.com Fixes: c96dceeabf76 ("jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer") Suggested-by: Jan Kara Reviewed-by: Jan Kara Signed-off-by: zhangyi (F) Signed-off-by: Theodore Ts'o

jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer

2020-02-13T17:06:28Z

Commit 904cdbd41d74 ("jbd2: clear dirty flag when revoking a buffer from an older transaction") set the BH_Freed flag when forgetting a metadata buffer which belongs to the committing transaction, it indicate the committing process clear dirty bits when it is done with the buffer. But it also clear the BH_Mapped flag at the same time, which may trigger below NULL pointer oops when block_size < PAGE_SIZE. rmdir 1 kjournald2 mkdir 2 jbd2_journal_commit_transaction commit transaction N jbd2_journal_forget set_buffer_freed(bh1) jbd2_journal_commit_transaction commit transaction N+1 ... clear_buffer_mapped(bh1) ext4_getblk(bh2 ummapped) ... grow_dev_page init_page_buffers bh1->b_private=NULL bh2->b_private=NULL jbd2_journal_put_journal_head(jh1) __journal_remove_journal_head(hb1) jh1 is NULL and trigger oops *) Dir entry block bh1 and bh2 belongs to one page, and the bh2 has already been unmapped. For the metadata buffer we forgetting, we should always keep the mapped flag and clear the dirty flags is enough, so this patch pick out the these buffers and keep their BH_Mapped flag. Link: https://lore.kernel.org/r/20200213063821.30455-3-yi.zhang@huawei.com Fixes: 904cdbd41d74 ("jbd2: clear dirty flag when revoking a buffer from an older transaction") Reviewed-by: Jan Kara Signed-off-by: zhangyi (F) Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

jbd2: move the clearing of b_modified flag to the journal_unmap_buffer()

2020-02-13T17:06:17Z

There is no need to delay the clearing of b_modified flag to the transaction committing time when unmapping the journalled buffer, so just move it to the journal_unmap_buffer(). Link: https://lore.kernel.org/r/20200213063821.30455-2-yi.zhang@huawei.com Reviewed-by: Jan Kara Signed-off-by: zhangyi (F) Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

jbd2: switch to use jbd2_journal_abort() when failed to submit the commit record

2020-01-25T07:58:46Z

We invoke jbd2_journal_abort() to abort the journal and record errno in the jbd2 superblock when committing journal transaction besides the failure on submitting the commit record. But there is no need for the case and we can also invoke jbd2_journal_abort() instead of __jbd2_journal_abort_hard(). Fixes: 818d276ceb83a ("ext4: Add the journal checksum feature") Signed-off-by: zhangyi (F) Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20191204124614.45424-2-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o

Merge branch 'jk/jbd2-revoke-overflow'

2019-11-05T21:02:20Z

jbd2: Account descriptor blocks into t_outstanding_credits

2019-11-05T21:00:48Z

Currently, journal descriptor blocks were not accounted in transaction->t_outstanding_credits and we were just leaving some slack space in the journal for them (in jbd2_log_space_left() and jbd2_space_needed()). This is making proper accounting (and reservation we want to add) of descriptor blocks difficult so switch to accounting descriptor blocks in transaction->t_outstanding_credits and just reserve the same amount of credits in t_outstanding credits for journal descriptor blocks when creating transaction. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20191105164437.32602-18-jack@suse.cz Signed-off-by: Theodore Ts'o

jbd2: Fix statistics for the number of logged blocks

2019-11-05T21:00:48Z

jbd2 statistics counting number of blocks logged in a transaction was wrong. It didn't count the commit block and more importantly it didn't count revoke descriptor blocks. Make sure these get properly counted. Reviewed-by: Theodore Ts'o Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20191105164437.32602-13-jack@suse.cz Signed-off-by: Theodore Ts'o

jbd2: Fixup stale comment in commit code

2019-11-05T17:13:25Z

jbd2_journal_next_log_block() does not look at transaction->t_outstanding_credits. Remove the misleading comment. Reviewed-by: Theodore Ts'o Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20191105164437.32602-2-jack@suse.cz Signed-off-by: Theodore Ts'o

jbd2: Make state lock a spinlock

2019-10-21T13:16:46Z

Bit-spinlocks are problematic on PREEMPT_RT if functions which might sleep on RT, e.g. spin_lock(), alloc/free(), are invoked inside the lock held region because bit spinlocks disable preemption even on RT. A first attempt was to replace state lock with a spinlock placed in struct buffer_head and make the locking conditional on PREEMPT_RT and DEBUG_BIT_SPINLOCKS. Jan pointed out that there is a 4 byte hole in struct journal_head where a regular spinlock fits in and he would not object to convert the state lock to a spinlock unconditionally. Aside of solving the RT problem, this also gains lockdep coverage for the journal head state lock (bit-spinlocks are not covered by lockdep as it's hard to fit a lockdep map into a single bit). The trivial change would have been to convert the jbd_*lock_bh_state() inlines, but that comes with the downside that these functions take a buffer head pointer which needs to be converted to a journal head pointer which adds another level of indirection. As almost all functions which use this lock have a journal head pointer readily available, it makes more sense to remove the lock helper inlines and write out spin_*lock() at all call sites. Fixup all locking comments as well. Suggested-by: Jan Kara Signed-off-by: Thomas Gleixner Signed-off-by: Jan Kara Cc: "Theodore Ts'o" Cc: Mark Fasheh Cc: Joseph Qi Cc: Joel Becker Cc: Jan Kara Cc: linux-ext4@vger.kernel.org Link: https://lore.kernel.org/r/20190809124233.13277-7-jack@suse.cz Signed-off-by: Theodore Ts'o

jbd2: Move dropping of jh reference out of un/re-filing functions

2019-10-21T13:16:46Z

__jbd2_journal_unfile_buffer() and __jbd2_journal_refile_buffer() drop transaction's jh reference when they remove jh from a transaction. This will be however inconvenient once we move state lock into journal_head itself as we still need to unlock it and we'd need to grab jh reference just for that. Move dropping of jh reference out of these functions into the few callers. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20190809124233.13277-4-jack@suse.cz Signed-off-by: Theodore Ts'o