bcachefs: Fix two more deadlocks

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Deadlock on shutdown:

btree_update_nodes_written() unblocks btree nodes from being written;
after doing so, it has to check if they were marked as needing to be
written and if so kick off those writes - if that doesn't happen, we'll
never release journal pins and shutdown will get stuck when flushing the
journal.

There was an error path where this didn't happen, because in the error
path we don't actually want those btree nodes write to happen; however,
we still have to kick off the write path so the journal pins get
released. The btree write path checks if we're in a journal error state
and doesn't do the actual write if we are.

Also - there was another deadlock because btree_update_nodes_written()
was taking the btree update off of the unwritten_list too soon - before
getting a journal reservation, which could fail and have to be retried.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

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This commit is contained in:

Kent Overstreet 2020-05-02 16:21:35 -04:00 • committed by Kent Overstreet

parent 5b6d505a77

commit bc970cecd8

2 changed files with 64 additions and 53 deletions

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5

fs/bcachefs/btree_io.c

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116

fs/bcachefs/btree_update_interior.c

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