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 /fs/nfs/file.c | |
| 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 'fs/nfs/file.c')
| -rw-r--r-- | fs/nfs/file.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c index d31bc430dce3..81c80548a5c6 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -157,7 +157,7 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to) ssize_t result; if (iocb->ki_flags & IOCB_DIRECT) - return nfs_file_direct_read(iocb, to); + return nfs_file_direct_read(iocb, to, false); dprintk("NFS: read(%pD2, %zu@%lu)\n", iocb->ki_filp, @@ -623,7 +623,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from) return result; if (iocb->ki_flags & IOCB_DIRECT) - return nfs_file_direct_write(iocb, from); + return nfs_file_direct_write(iocb, from, false); dprintk("NFS: write(%pD2, %zu@%Ld)\n", file, iov_iter_count(from), (long long) iocb->ki_pos); |