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authorBenjamin Coddington <bcodding@redhat.com>2017-06-16 11:13:00 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2017-07-13 15:58:04 -0400
commit818a8dbe83fddff534b814a7d4e0c75b511dff2e (patch)
tree153d8c114f65a8fb5d8c01dea04189db01a8351d
parenta7a3b1e971cd806b81ecea3a234d8dae9de0add0 (diff)
downloadlwn-818a8dbe83fddff534b814a7d4e0c75b511dff2e.tar.gz
lwn-818a8dbe83fddff534b814a7d4e0c75b511dff2e.zip
NFS: nfs_rename() - revalidate directories on -ERESTARTSYS
An interrupted rename will leave the old dentry behind if the rename succeeds. Fix this by forcing a lookup the next time through ->d_revalidate. A previous attempt at solving this problem took the approach to complete the work of the rename asynchronously, however that approach was wrong since it would allow the d_move() to occur after the directory's i_mutex had been dropped by the original process. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
-rw-r--r--fs/nfs/dir.c6
-rw-r--r--fs/nfs/unlink.c13
-rw-r--r--include/linux/nfs_xdr.h1
3 files changed, 19 insertions, 1 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 9688e9bb13dc..ab69ebb48350 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2056,7 +2056,11 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
}
error = rpc_wait_for_completion_task(task);
- if (error == 0)
+ if (error != 0) {
+ ((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1;
+ /* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */
+ smp_wmb();
+ } else
error = task->tk_status;
rpc_put_task(task);
out:
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index 191aa577dd1f..e3949d93085c 100644
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -288,6 +288,19 @@ static void nfs_async_rename_release(void *calldata)
if (d_really_is_positive(data->old_dentry))
nfs_mark_for_revalidate(d_inode(data->old_dentry));
+ /* The result of the rename is unknown. Play it safe by
+ * forcing a new lookup */
+ if (data->cancelled) {
+ spin_lock(&data->old_dir->i_lock);
+ nfs_force_lookup_revalidate(data->old_dir);
+ spin_unlock(&data->old_dir->i_lock);
+ if (data->new_dir != data->old_dir) {
+ spin_lock(&data->new_dir->i_lock);
+ nfs_force_lookup_revalidate(data->new_dir);
+ spin_unlock(&data->new_dir->i_lock);
+ }
+ }
+
dput(data->old_dentry);
dput(data->new_dentry);
iput(data->old_dir);
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 9b42bffbe07b..9463eeff9e3c 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1533,6 +1533,7 @@ struct nfs_renamedata {
struct nfs_fattr new_fattr;
void (*complete)(struct rpc_task *, struct nfs_renamedata *);
long timeout;
+ bool cancelled;
};
struct nfs_access_entry;