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-rw-r--r--fs/nfs/unlink.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
new file mode 100644
index 0000000..f732541
--- /dev/null
+++ b/fs/nfs/unlink.c
@@ -0,0 +1,227 @@
+/*
+ * linux/fs/nfs/unlink.c
+ *
+ * nfs sillydelete handling
+ *
+ * NOTE: we rely on holding the BKL for list manipulation protection.
+ */
+
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/dcache.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+
+
+struct nfs_unlinkdata {
+ struct nfs_unlinkdata *next;
+ struct dentry *dir, *dentry;
+ struct qstr name;
+ struct rpc_task task;
+ struct rpc_cred *cred;
+ unsigned int count;
+};
+
+static struct nfs_unlinkdata *nfs_deletes;
+static RPC_WAITQ(nfs_delete_queue, "nfs_delete_queue");
+
+/**
+ * nfs_detach_unlinkdata - Remove asynchronous unlink from global list
+ * @data: pointer to descriptor
+ */
+static inline void
+nfs_detach_unlinkdata(struct nfs_unlinkdata *data)
+{
+ struct nfs_unlinkdata **q;
+
+ for (q = &nfs_deletes; *q != NULL; q = &((*q)->next)) {
+ if (*q == data) {
+ *q = data->next;
+ break;
+ }
+ }
+}
+
+/**
+ * nfs_put_unlinkdata - release data from a sillydelete operation.
+ * @data: pointer to unlink structure.
+ */
+static void
+nfs_put_unlinkdata(struct nfs_unlinkdata *data)
+{
+ if (--data->count == 0) {
+ nfs_detach_unlinkdata(data);
+ if (data->name.name != NULL)
+ kfree(data->name.name);
+ kfree(data);
+ }
+}
+
+#define NAME_ALLOC_LEN(len) ((len+16) & ~15)
+/**
+ * nfs_copy_dname - copy dentry name to data structure
+ * @dentry: pointer to dentry
+ * @data: nfs_unlinkdata
+ */
+static inline void
+nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
+{
+ char *str;
+ int len = dentry->d_name.len;
+
+ str = kmalloc(NAME_ALLOC_LEN(len), GFP_KERNEL);
+ if (!str)
+ return;
+ memcpy(str, dentry->d_name.name, len);
+ if (!data->name.len) {
+ data->name.len = len;
+ data->name.name = str;
+ } else
+ kfree(str);
+}
+
+/**
+ * nfs_async_unlink_init - Initialize the RPC info
+ * @task: rpc_task of the sillydelete
+ *
+ * We delay initializing RPC info until after the call to dentry_iput()
+ * in order to minimize races against rename().
+ */
+static void
+nfs_async_unlink_init(struct rpc_task *task)
+{
+ struct nfs_unlinkdata *data = (struct nfs_unlinkdata *)task->tk_calldata;
+ struct dentry *dir = data->dir;
+ struct rpc_message msg = {
+ .rpc_cred = data->cred,
+ };
+ int status = -ENOENT;
+
+ if (!data->name.len)
+ goto out_err;
+
+ status = NFS_PROTO(dir->d_inode)->unlink_setup(&msg, dir, &data->name);
+ if (status < 0)
+ goto out_err;
+ nfs_begin_data_update(dir->d_inode);
+ rpc_call_setup(task, &msg, 0);
+ return;
+ out_err:
+ rpc_exit(task, status);
+}
+
+/**
+ * nfs_async_unlink_done - Sillydelete post-processing
+ * @task: rpc_task of the sillydelete
+ *
+ * Do the directory attribute update.
+ */
+static void
+nfs_async_unlink_done(struct rpc_task *task)
+{
+ struct nfs_unlinkdata *data = (struct nfs_unlinkdata *)task->tk_calldata;
+ struct dentry *dir = data->dir;
+ struct inode *dir_i;
+
+ if (!dir)
+ return;
+ dir_i = dir->d_inode;
+ nfs_end_data_update(dir_i);
+ if (NFS_PROTO(dir_i)->unlink_done(dir, task))
+ return;
+ put_rpccred(data->cred);
+ data->cred = NULL;
+ dput(dir);
+}
+
+/**
+ * nfs_async_unlink_release - Release the sillydelete data.
+ * @task: rpc_task of the sillydelete
+ *
+ * We need to call nfs_put_unlinkdata as a 'tk_release' task since the
+ * rpc_task would be freed too.
+ */
+static void
+nfs_async_unlink_release(struct rpc_task *task)
+{
+ struct nfs_unlinkdata *data = (struct nfs_unlinkdata *)task->tk_calldata;
+ nfs_put_unlinkdata(data);
+}
+
+/**
+ * nfs_async_unlink - asynchronous unlinking of a file
+ * @dentry: dentry to unlink
+ */
+int
+nfs_async_unlink(struct dentry *dentry)
+{
+ struct dentry *dir = dentry->d_parent;
+ struct nfs_unlinkdata *data;
+ struct rpc_task *task;
+ struct rpc_clnt *clnt = NFS_CLIENT(dir->d_inode);
+ int status = -ENOMEM;
+
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ goto out;
+ memset(data, 0, sizeof(*data));
+
+ data->cred = rpcauth_lookupcred(clnt->cl_auth, 0);
+ if (IS_ERR(data->cred)) {
+ status = PTR_ERR(data->cred);
+ goto out_free;
+ }
+ data->dir = dget(dir);
+ data->dentry = dentry;
+
+ data->next = nfs_deletes;
+ nfs_deletes = data;
+ data->count = 1;
+
+ task = &data->task;
+ rpc_init_task(task, clnt, nfs_async_unlink_done , RPC_TASK_ASYNC);
+ task->tk_calldata = data;
+ task->tk_action = nfs_async_unlink_init;
+ task->tk_release = nfs_async_unlink_release;
+
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_NFSFS_RENAMED;
+ spin_unlock(&dentry->d_lock);
+
+ rpc_sleep_on(&nfs_delete_queue, task, NULL, NULL);
+ status = 0;
+ out:
+ return status;
+out_free:
+ kfree(data);
+ return status;
+}
+
+/**
+ * nfs_complete_unlink - Initialize completion of the sillydelete
+ * @dentry: dentry to delete
+ *
+ * Since we're most likely to be called by dentry_iput(), we
+ * only use the dentry to find the sillydelete. We then copy the name
+ * into the qstr.
+ */
+void
+nfs_complete_unlink(struct dentry *dentry)
+{
+ struct nfs_unlinkdata *data;
+
+ for(data = nfs_deletes; data != NULL; data = data->next) {
+ if (dentry == data->dentry)
+ break;
+ }
+ if (!data)
+ return;
+ data->count++;
+ nfs_copy_dname(dentry, data);
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
+ spin_unlock(&dentry->d_lock);
+ rpc_wake_up_task(&data->task);
+ nfs_put_unlinkdata(data);
+}
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