diff options
| 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 /include | |
| parent | NFSv4: keep state manager thread active if swap is enabled (diff) | |
| download | linux-dev-64158668ac8b31626a8ce48db4cad08496eb8340.tar.xz linux-dev-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 'include')
| -rw-r--r-- | include/linux/nfs_fs.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 9074ed0b65aa..c47c448befc8 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -508,10 +508,10 @@ static inline const struct cred *nfs_file_cred(struct file *file) * linux/fs/nfs/direct.c */ extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *); -extern ssize_t nfs_file_direct_read(struct kiocb *iocb, - struct iov_iter *iter); -extern ssize_t nfs_file_direct_write(struct kiocb *iocb, - struct iov_iter *iter); +ssize_t nfs_file_direct_read(struct kiocb *iocb, + struct iov_iter *iter, bool swap); +ssize_t nfs_file_direct_write(struct kiocb *iocb, + struct iov_iter *iter, bool swap); /* * linux/fs/nfs/dir.c |