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| author | NeilBrown <neilb@suse.de> | 2022-03-07 10:41:44 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-15 14:18:35 +0200 |
| commit | 66cf5de08460c93964bac7e2ce868ea8ea3f7909 (patch) | |
| tree | 1363dd089af9814091598843af357b1586f417cc /include | |
| parent | fa47286c010a5bc23781855ce70f86f1c6768ade (diff) | |
| download | linux-stable-66cf5de08460c93964bac7e2ce868ea8ea3f7909.tar.gz linux-stable-66cf5de08460c93964bac7e2ce868ea8ea3f7909.tar.bz2 linux-stable-66cf5de08460c93964bac7e2ce868ea8ea3f7909.zip | |
NFS: swap IO handling is slightly different for O_DIRECT IO
[ Upstream commit 64158668ac8b31626a8ce48db4cad08496eb8340 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 978ef674f038..49cf5c855cbe 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -480,10 +480,10 @@ 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 |