From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Don't set PF_LOCAL_THROTTLE on remote filesystems like NFS, since they
aren't expected to ever be subject to double buffering.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/export.c | 3 ++-
fs/nfsd/vfs.c | 13 +++++++++++--
include/linux/exportfs.h | 1 +
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/export.c b/fs/nfs/export.c
index 5428713af5fe..48b879cfe6e3 100644
--- a/fs/nfs/export.c
+++ b/fs/nfs/export.c
@@ -171,5 +171,6 @@ const struct export_operations nfs_export_ops = {
.encode_fh = nfs_encode_fh,
.fh_to_dentry = nfs_fh_to_dentry,
.get_parent = nfs_get_parent,
- .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK|EXPORT_OP_CLOSE_BEFORE_UNLINK,
+ .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK|
+ EXPORT_OP_CLOSE_BEFORE_UNLINK|EXPORT_OP_REMOTE_FS,
};
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 79cba942087e..04937e51de56 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -978,18 +978,25 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
__be32 *verf)
{
struct file *file = nf->nf_file;
+ struct super_block *sb = file_inode(file)->i_sb;
struct svc_export *exp;
struct iov_iter iter;
__be32 nfserr;
int host_err;
int use_wgather;
loff_t pos = offset;
+ unsigned long exp_op_flags = 0;
unsigned int pflags = current->flags;
rwf_t flags = 0;
+ bool restore_flags = false;
trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
- if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
+ if (sb->s_export_op)
+ exp_op_flags = sb->s_export_op->flags;
+
+ if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
+ !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
/*
* We want throttling in balance_dirty_pages()
* and shrink_inactive_list() to only consider
@@ -998,6 +1005,8 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
* the client's dirty pages or its congested queue.
*/
current->flags |= PF_LOCAL_THROTTLE;
+ restore_flags = true;
+ }
exp = fhp->fh_export;
use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
@@ -1049,7 +1058,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
trace_nfsd_write_err(rqstp, fhp, offset, host_err);
nfserr = nfserrno(host_err);
}
- if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
+ if (restore_flags)
current_restore_flags(pflags, PF_LOCAL_THROTTLE);
return nfserr;
}
diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
index 846df3c96730..d93e8a6737bb 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -216,6 +216,7 @@ struct export_operations {
#define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */
#define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */
#define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */
+#define EXPORT_OP_REMOTE_FS (0x8) /* Filesystem is remote */
unsigned long flags;
};
--
2.28.0
