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| author |   Trond Myklebust <trond.myklebust@hammerspace.com> | 2018-09-02 15:57:01 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2018-09-30 15:35:17 -0400 |
| commit | 0de43976fbe716379084f954b1e370c35aa87bf0 (patch) | |
| tree | 64a6ea935fc8015c7369b9ece308771585cd3053 /fs/nfs/pnfs.c | |
| parent | NFS: Simplify internal check for whether file is open for write (diff) | |
| download | linux-dev-0de43976fbe716379084f954b1e370c35aa87bf0.tar.xz linux-dev-0de43976fbe716379084f954b1e370c35aa87bf0.zip | |
NFS: Convert lookups of the open context to RCU
Reduce contention on the inode->i_lock by ensuring that we use RCU
when looking up the NFS open context.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to '')
| -rw-r--r-- | fs/nfs/pnfs.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index c5672c02afd6..06cb90e9bc6e 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -1339,6 +1339,7 @@ bool pnfs_roc(struct inode *ino, if (!nfs_have_layout(ino)) return false; retry: + rcu_read_lock(); spin_lock(&ino->i_lock); lo = nfsi->layout; if (!lo || !pnfs_layout_is_valid(lo) || @@ -1349,6 +1350,7 @@ retry: pnfs_get_layout_hdr(lo); if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) { spin_unlock(&ino->i_lock); + rcu_read_unlock(); wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE); pnfs_put_layout_hdr(lo); @@ -1362,7 +1364,7 @@ retry: skip_read = true; } - list_for_each_entry(ctx, &nfsi->open_files, list) { + list_for_each_entry_rcu(ctx, &nfsi->open_files, list) { state = ctx->state; if (state == NULL) continue; @@ -1410,6 +1412,7 @@ retry: out_noroc: spin_unlock(&ino->i_lock); + rcu_read_unlock(); pnfs_layoutcommit_inode(ino, true); if (roc) { struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld; |