2022-01-21 02:27:23

by Olga Kornievskaia

[permalink] [raw]
Subject: [RFC PATCH] NFSv4.1 support for NFS4_RESULT_PRESERVER_UNLINKED

From: Olga Kornievskaia <[email protected]>

In 4.1+, the server is allowed to set a flag
NFS4_RESULT_PRESERVE_UNLINKED in reply to the OPEN, that tells
the client that it does not need to do a silly rename of an
opened file when it's being removed.

Signed-off-by: Olga Kornievskaia <[email protected]>
---
fs/nfs/dir.c | 6 ++++--
fs/nfs/nfs4proc.c | 2 ++
include/linux/nfs_fs.h | 1 +
include/uapi/linux/nfs4.h | 1 +
4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 00b222e48d6f..71f72e102b42 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2319,8 +2319,10 @@ int nfs_unlink(struct inode *dir, struct dentry *dentry)
spin_unlock(&dentry->d_lock);
/* Start asynchronous writeout of the inode */
write_inode_now(d_inode(dentry), 0);
- error = nfs_sillyrename(dir, dentry);
- goto out;
+ if (!(NFS_I(d_inode(dentry))->flags & NFS_INO_PRESERVE_UNLINKED)) {
+ error = nfs_sillyrename(dir, dentry);
+ goto out;
+ }
}
if (!d_unhashed(dentry)) {
__d_drop(dentry);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2fbe04d12e44..1a9d25f23dcd 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2727,6 +2727,8 @@ static int _nfs4_proc_open(struct nfs4_opendata *data,
nfs4_sequence_free_slot(&o_res->seq_res);
nfs4_proc_getattr(server, &o_res->fh, o_res->f_attr, NULL);
}
+ if (o_res->rflags & NFS4_OPEN_RESULT_PRESERVE_UNLINKED)
+ set_bit(NFS_INO_PRESERVE_UNLINKED, &NFS_I(dir)->flags);
return 0;
}

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 7a134e4c03e8..36fcd8d0487c 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -297,6 +297,7 @@ struct nfs4_copy_state {
#define NFS_INO_LAYOUTCOMMITTING (10) /* layoutcommit inflight */
#define NFS_INO_LAYOUTSTATS (11) /* layoutstats inflight */
#define NFS_INO_ODIRECT (12) /* I/O setting is O_DIRECT */
+#define NFS_INO_PRESERVE_UNLINKED (13) /* preserve file if removed while open */

static inline struct nfs_inode *NFS_I(const struct inode *inode)
{
diff --git a/include/uapi/linux/nfs4.h b/include/uapi/linux/nfs4.h
index 800bb0ffa6e6..14acfe5300b7 100644
--- a/include/uapi/linux/nfs4.h
+++ b/include/uapi/linux/nfs4.h
@@ -46,6 +46,7 @@
#define NFS4_OPEN_RESULT_CONFIRM 0x0002
#define NFS4_OPEN_RESULT_LOCKTYPE_POSIX 0x0004
#define NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK 0x0020
+#define NFS4_OPEN_RESULT_PRESERVE_UNLINKED 0x0008

#define NFS4_SHARE_ACCESS_MASK 0x000F
#define NFS4_SHARE_ACCESS_READ 0x0001
--
2.27.0