The patch titled
NFS: Stop sillyname renames and unmounts from racing
has been removed from the -mm tree. Its filename was
nfs-stop-sillyname-renames-and-unmounts-from-racing.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
Subject: NFS: Stop sillyname renames and unmounts from racing
From: Steve Dickson <SteveD@xxxxxxxxxx>
The following patch stops NFS sillyname renames and umounts from racing.
I have a test script does the following:
1) start nfs server
2) mount loopback
3) open file in background
4) remove file
5) stop nfs server
6) kill -9 process which has file open
7) restart nfs server
8) umount looback mount.
After umount I got the "VFS: Busy inodes after unmount" message
because the processing of the rename has not finished.
Add an active/deactive mechanism to the nfs_server structure allowing async
operations to hold off umount until the operations are done.
[akpm@xxxxxxxxxxxxxxxxxxxx: coding style fixes]
Signed-off-by: Steve Dickson <steved@xxxxxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/nfs/client.c | 4 ++++
fs/nfs/super.c | 13 +++++++++++++
fs/nfs/unlink.c | 2 ++
include/linux/nfs_fs_sb.h | 16 ++++++++++++++++
4 files changed, 35 insertions(+)
diff -puN fs/nfs/client.c~nfs-stop-sillyname-renames-and-unmounts-from-racing fs/nfs/client.c
--- a/fs/nfs/client.c~nfs-stop-sillyname-renames-and-unmounts-from-racing
+++ a/fs/nfs/client.c
@@ -593,6 +593,10 @@ static int nfs_init_server(struct nfs_se
server->namelen = data->namlen;
/* Create a client RPC handle for the NFSv3 ACL management interface */
nfs_init_server_aclclient(server);
+
+ init_waitqueue_head(&server->active_wq);
+ atomic_set(&server->active, 0);
+
dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
return 0;
diff -puN fs/nfs/super.c~nfs-stop-sillyname-renames-and-unmounts-from-racing fs/nfs/super.c
--- a/fs/nfs/super.c~nfs-stop-sillyname-renames-and-unmounts-from-racing
+++ a/fs/nfs/super.c
@@ -202,6 +202,7 @@ static int nfs_get_sb(struct file_system
static int nfs_xdev_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static void nfs_kill_super(struct super_block *);
+static void nfs_put_super(struct super_block *);
static struct file_system_type nfs_fs_type = {
.owner = THIS_MODULE,
@@ -223,6 +224,7 @@ static const struct super_operations nfs
.alloc_inode = nfs_alloc_inode,
.destroy_inode = nfs_destroy_inode,
.write_inode = nfs_write_inode,
+ .put_super = nfs_put_super,
.statfs = nfs_statfs,
.clear_inode = nfs_clear_inode,
.umount_begin = nfs_umount_begin,
@@ -1767,6 +1769,17 @@ static void nfs4_kill_super(struct super
nfs_free_server(server);
}
+static void nfs_put_super(struct super_block *sb)
+{
+ struct nfs_server *server = NFS_SB(sb);
+ /*
+ * Make sure there are no outstanding ops to this server.
+ * If so, wait for them to finish before allowing the
+ * unmount to continue.
+ */
+ wait_event(server->active_wq, atomic_read(&server->active) == 0);
+}
+
/*
* Clone an NFS4 server record on xdev traversal (FSID-change)
*/
diff -puN fs/nfs/unlink.c~nfs-stop-sillyname-renames-and-unmounts-from-racing fs/nfs/unlink.c
--- a/fs/nfs/unlink.c~nfs-stop-sillyname-renames-and-unmounts-from-racing
+++ a/fs/nfs/unlink.c
@@ -29,6 +29,7 @@ struct nfs_unlinkdata {
static void
nfs_free_unlinkdata(struct nfs_unlinkdata *data)
{
+ nfs_sb_deactive(NFS_SERVER(data->dir));
iput(data->dir);
put_rpccred(data->cred);
kfree(data->args.name.name);
@@ -151,6 +152,7 @@ static int nfs_do_call_unlink(struct den
nfs_dec_sillycount(dir);
return 0;
}
+ nfs_sb_active(NFS_SERVER(dir));
data->args.fh = NFS_FH(dir);
nfs_fattr_init(&data->res.dir_attr);
diff -puN include/linux/nfs_fs_sb.h~nfs-stop-sillyname-renames-and-unmounts-from-racing include/linux/nfs_fs_sb.h
--- a/include/linux/nfs_fs_sb.h~nfs-stop-sillyname-renames-and-unmounts-from-racing
+++ a/include/linux/nfs_fs_sb.h
@@ -4,6 +4,8 @@
#include <linux/list.h>
#include <linux/backing-dev.h>
+#include <asm/atomic.h>
+
struct nfs_iostats;
/*
@@ -110,8 +112,22 @@ struct nfs_server {
filesystem */
#endif
void (*destroy)(struct nfs_server *);
+
+ atomic_t active; /* Keep trace of any activity to this server */
+ wait_queue_head_t active_wq; /* Wait for any activity to stop */
};
+static inline void nfs_sb_active(struct nfs_server *server)
+{
+ atomic_inc(&server->active);
+}
+
+static inline void nfs_sb_deactive(struct nfs_server *server)
+{
+ if (atomic_dec_and_test(&server->active))
+ wake_up(&server->active_wq);
+}
+
/* Server capabilities */
#define NFS_CAP_READDIRPLUS (1U << 0)
#define NFS_CAP_HARDLINKS (1U << 1)
_
Patches currently in -mm which might be from SteveD@xxxxxxxxxx are
nfs-stop-sillyname-renames-and-unmounts-from-racing-2.patch
nfs-fix-up-problems-with-steves-sillyrename-fix.patch
nfs-fix-nfs_free_unlinkdata.patch
nfs-stop-sillyname-renames-and-unmounts-from-racing.patch
nfs-stop-sillyname-renames-and-unmounts-from-racing-fix.patch
nfs-stop-sillyname-renames-and-unmounts-from-racing-fix-fix.patch
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