kernel.git/fs/gfs2/log.c, branch linux-5.12.y

gfs2: Clean up revokes on normal withdraws

2021-06-18T08:02:49Z

[ Upstream commit f5456b5d67cf812fd31fe3e130ca216b2e0908e5 ] Before this patch, the system ail lists were cleaned up if the logd process withdrew, but on other withdraws, they were not cleaned up. This included the cleaning up of the revokes as well. This patch reorganizes things a bit so that all withdraws (not just logd) clean up the ail lists, including any pending revokes. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: bypass log flush if the journal is not live

2021-03-12T14:52:48Z

Patch fe3e397668775 ("gfs2: Rework the log space allocation logic") changed gfs2_log_flush to reserve a set of journal blocks in case no transaction is active. However, gfs2_log_flush also gets called in cases where we don't have an active journal, for example, for spectator mounts. In that case, trying to reserve blocks would sleep forever, but we want gfs2_log_flush to be a no-op instead. Fixes: fe3e397668775 ("gfs2: Rework the log space allocation logic") Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher

gfs2: fix use-after-free in trans_drain

2021-03-07T16:04:55Z

This patch adds code to function trans_drain to remove drained bd elements from the ail lists, if queued, before freeing the bd. If we don't remove the bd from the ail, function ail_drain will try to reference the bd after it has been freed by trans_drain. Thanks to Andy Price for his analysis of the problem. Reported-by: Andy Price Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher

gfs2: Don't get stuck with I/O plugged in gfs2_ail1_flush

2021-02-23T18:01:42Z

In gfs2_ail1_flush, we're using I/O plugging to give the block layer a better chance of merging I/O requests. If we're too aggressive here, we can end up waiting on I/O to complete while still plugged. Fix that in a way similar to writeback_sb_inodes, except that we can't use blk_flush_plug because blk_flush_plug_list is not exported. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher

Merge branches 'rgrp-glock-sharing' and 'gfs2-revoke' from https://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git

2021-02-23T17:54:22Z

Merge the resource group glock sharing feature and the revoke accounting rework. Signed-off-by: Andreas Gruenbacher

gfs2: Per-revoke accounting in transactions

2021-02-22T20:16:23Z

In the log, revokes are stored as a revoke descriptor (struct gfs2_log_descriptor), followed by zero or more additional revoke blocks (struct gfs2_meta_header). On filesystems with a blocksize of 4k, the revoke descriptor contains up to 503 revokes, and the metadata blocks contain up to 509 revokes each. We've so far been reserving space for revokes in transactions in block granularity, so a lot more space than necessary was being allocated and then released again. This patch switches to assigning revokes to transactions individually instead. Initially, space for the revoke descriptor is reserved and handed out to transactions. When more revokes than that are reserved, additional revoke blocks are added. When the log is flushed, the space for the additional revoke blocks is released, but we keep the space for the revoke descriptor block allocated. Transactions may still reserve more revokes than they will actually need in the end, but now we won't overshoot the target as much, and by only returning the space for excess revokes at log flush time, we further reduce the amount of contention between processes. Signed-off-by: Andreas Gruenbacher

gfs2: Rework the log space allocation logic

2021-02-22T20:16:22Z

The current log space allocation logic is hard to understand or extend. The principle it that when the log is flushed, we may or may not have a transaction active that has space allocated in the log. To deal with that, we set aside a magical number of blocks to be used in case we don't have an active transaction. It isn't clear that the pool will always be big enough. In addition, we can't return unused log space at the end of a transaction, so the number of blocks allocated must exactly match the number of blocks used. Simplify this as follows: * When transactions are allocated or merged, always reserve enough blocks to flush the transaction (err on the safe side). * In gfs2_log_flush, return any allocated blocks that haven't been used. * Maintain a pool of spare blocks big enough to do one log flush, as before. * In gfs2_log_flush, when we have no active transaction, allocate a suitable number of blocks. For that, use the spare pool when called from logd, and leave the pool alone otherwise. This means that when the log is almost full, logd will still be able to do one more log flush, which will result in more log space becoming available. This will make the log space allocator code easier to work with in the future. Signed-off-by: Andreas Gruenbacher

gfs2: Minor calc_reserved cleanup

2021-02-22T20:16:22Z

No functional change. Signed-off-by: Andreas Gruenbacher

gfs2: Move function gfs2_ail_empty_tr

2021-02-03T17:37:25Z

Move this function further up in log.c so that we can use it in the next patch. Signed-off-by: Andreas Gruenbacher

gfs2: Get rid of current_tail()

2021-02-03T17:37:25Z

Keep the current value of the updated log tail in the super block as sb_log_flush_tail instead of computing it on the fly. This avoids unnecessary sd_ail_lock taking and cleans up the code. Signed-off-by: Andreas Gruenbacher