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authorJeff Layton <jlayton@redhat.com>2011-07-18 11:26:30 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2011-07-25 15:00:21 -0400
commit73ca1001ed6881b476e8252adcd0eede1ea368ea (patch)
tree41aca7b930405f1d50e552e22a272ece61835995
parent2773395b34883fe54418de188733a63bb38e0ad6 (diff)
downloadlinux-stericsson-73ca1001ed6881b476e8252adcd0eede1ea368ea.tar.gz
nfs: don't use d_move in nfs_async_rename_done
If the task that initiated the sillyrename ends up being killed by a fatal signal, then it will eventually return back to userspace and end up releasing the i_mutex. d_move however needs to be done while holding the i_mutex. Instead of using d_move here, just unhash the old and new dentries to prevent them from being found by lookups. With this change though, the dentries are now incorrect post-rename and do not reflect the actual name of the file on the server. I'm proceeding under the assumption that since they are unhashed that this isn't really a problem. In order for the sillydelete to still work though, the dname must be copied earlier when setting up the sillydelete info, and the name must be recopied if the sillydelete info has to be moved to a new dentry. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
-rw-r--r--fs/nfs/unlink.c29
1 files changed, 19 insertions, 10 deletions
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index 981298ce5124..b2fbbde58e44 100644
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -147,7 +147,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
alias = d_lookup(parent, &data->args.name);
if (alias != NULL) {
- int ret = 0;
+ int ret;
void *devname_garbage = NULL;
/*
@@ -155,14 +155,16 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
* the sillyrename information to the aliased dentry.
*/
nfs_free_dname(data);
+ ret = nfs_copy_dname(alias, data);
spin_lock(&alias->d_lock);
- if (alias->d_inode != NULL &&
+ if (ret == 0 && alias->d_inode != NULL &&
!(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
devname_garbage = alias->d_fsdata;
alias->d_fsdata = data;
alias->d_flags |= DCACHE_NFSFS_RENAMED;
ret = 1;
- }
+ } else
+ ret = 0;
spin_unlock(&alias->d_lock);
nfs_dec_sillycount(dir);
dput(alias);
@@ -171,8 +173,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
* point dentry is definitely not a root, so we won't need
* that anymore.
*/
- if (devname_garbage)
- kfree(devname_garbage);
+ kfree(devname_garbage);
return ret;
}
data->dir = igrab(dir);
@@ -204,8 +205,6 @@ static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
if (parent == NULL)
goto out_free;
dir = parent->d_inode;
- if (nfs_copy_dname(dentry, data) != 0)
- goto out_dput;
/* Non-exclusive lock protects against concurrent lookup() calls */
spin_lock(&dir->i_lock);
if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) {
@@ -366,6 +365,8 @@ static void nfs_async_rename_done(struct rpc_task *task, void *calldata)
struct nfs_renamedata *data = calldata;
struct inode *old_dir = data->old_dir;
struct inode *new_dir = data->new_dir;
+ struct dentry *old_dentry = data->old_dentry;
+ struct dentry *new_dentry = data->new_dentry;
if (!NFS_PROTO(old_dir)->rename_done(task, old_dir, new_dir)) {
nfs_restart_rpc(task, NFS_SERVER(old_dir)->nfs_client);
@@ -373,12 +374,12 @@ static void nfs_async_rename_done(struct rpc_task *task, void *calldata)
}
if (task->tk_status != 0) {
- nfs_cancel_async_unlink(data->old_dentry);
+ nfs_cancel_async_unlink(old_dentry);
return;
}
- nfs_set_verifier(data->old_dentry, nfs_save_change_attribute(old_dir));
- d_move(data->old_dentry, data->new_dentry);
+ d_drop(old_dentry);
+ d_drop(new_dentry);
}
/**
@@ -568,6 +569,14 @@ nfs_sillyrename(struct inode *dir, struct dentry *dentry)
if (error)
goto out_dput;
+ /* populate unlinkdata with the right dname */
+ error = nfs_copy_dname(sdentry,
+ (struct nfs_unlinkdata *)dentry->d_fsdata);
+ if (error) {
+ nfs_cancel_async_unlink(dentry);
+ goto out_dput;
+ }
+
/* run the rename task, undo unlink if it fails */
task = nfs_async_rename(dir, dir, dentry, sdentry);
if (IS_ERR(task)) {