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| author |   NeilBrown <neilb@suse.de> | 2022-03-07 10:41:44 +1100 |
|---|---|---|
| committer |   Trond Myklebust <trond.myklebust@hammerspace.com> | 2022-03-13 12:59:35 -0400 |
| commit | 64158668ac8b31626a8ce48db4cad08496eb8340 (patch) | |
| tree | 7c2704c41a6f575b5a02dc8ef75479a8439fe6a6 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | NFSv4: keep state manager thread active if swap is enabled (diff) | |
| download | wireguard-linux-64158668ac8b31626a8ce48db4cad08496eb8340.tar.xz wireguard-linux-64158668ac8b31626a8ce48db4cad08496eb8340.zip | |
NFS: swap IO handling is slightly different for O_DIRECT IO
1/ Taking the i_rwsem for swap IO triggers lockdep warnings regarding
possible deadlocks with "fs_reclaim". These deadlocks could, I believe,
eventuate if a buffered read on the swapfile was attempted.
We don't need coherence with the page cache for a swap file, and
buffered writes are forbidden anyway. There is no other need for
i_rwsem during direct IO. So never take it for swap_rw()
2/ generic_write_checks() explicitly forbids writes to swap, and
performs checks that are not needed for swap. So bypass it
for swap_rw().
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions