nfs41: destroy_session operation
[safe/jmp/linux-2.6] / fs / nfs / unlink.c
index a65c7b5..089a21b 100644 (file)
@@ -3,7 +3,6 @@
  *
  * nfs sillydelete handling
  *
- * NOTE: we rely on holding the BKL for list manipulation protection.
  */
 
 #include <linux/slab.h>
 #include <linux/sunrpc/sched.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/nfs_fs.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
 
+#include "internal.h"
+#include "nfs4_fs.h"
 
 struct nfs_unlinkdata {
-       struct nfs_unlinkdata   *next;
-       struct dentry   *dir, *dentry;
-       struct qstr     name;
-       struct rpc_task task;
+       struct hlist_node list;
+       struct nfs_removeargs args;
+       struct nfs_removeres res;
+       struct inode *dir;
        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.
+ * nfs_free_unlinkdata - release data from a sillydelete operation.
  * @data: pointer to unlink structure.
  */
 static void
-nfs_put_unlinkdata(struct nfs_unlinkdata *data)
+nfs_free_unlinkdata(struct nfs_unlinkdata *data)
 {
-       if (--data->count == 0) {
-               nfs_detach_unlinkdata(data);
-               kfree(data->name.name);
-               kfree(data);
-       }
+       iput(data->dir);
+       put_rpccred(data->cred);
+       kfree(data->args.name.name);
+       kfree(data);
 }
 
 #define NAME_ALLOC_LEN(len)    ((len+16) & ~15)
@@ -63,50 +44,31 @@ nfs_put_unlinkdata(struct nfs_unlinkdata *data)
  * @dentry: pointer to dentry
  * @data: nfs_unlinkdata
  */
-static inline void
-nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
+static int 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);
+       str = kmemdup(dentry->d_name.name, 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);
+               return -ENOMEM;
+       data->args.name.len = len;
+       data->args.name.name = str;
+       return 0;
 }
 
-/**
- * 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, void *calldata)
+static void nfs_free_dname(struct nfs_unlinkdata *data)
 {
-       struct nfs_unlinkdata   *data = 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);
+       kfree(data->args.name.name);
+       data->args.name.name = NULL;
+       data->args.name.len = 0;
+}
+
+static void nfs_dec_sillycount(struct inode *dir)
+{
+       struct nfs_inode *nfsi = NFS_I(dir);
+       if (atomic_dec_return(&nfsi->silly_count) == 1)
+               wake_up(&nfsi->waitqueue);
 }
 
 /**
@@ -117,19 +79,11 @@ static void nfs_async_unlink_init(struct rpc_task *task, void *calldata)
  */
 static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
 {
-       struct nfs_unlinkdata   *data = calldata;
-       struct dentry           *dir = data->dir;
-       struct inode            *dir_i;
+       struct nfs_unlinkdata *data = calldata;
+       struct inode *dir = data->dir;
 
-       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);
+       if (!NFS_PROTO(dir)->unlink_done(task, dir))
+               rpc_restart_call(task);
 }
 
 /**
@@ -142,83 +96,208 @@ static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
 static void nfs_async_unlink_release(void *calldata)
 {
        struct nfs_unlinkdata   *data = calldata;
-       nfs_put_unlinkdata(data);
+       struct super_block *sb = data->dir->i_sb;
+
+       nfs_dec_sillycount(data->dir);
+       nfs_free_unlinkdata(data);
+       nfs_sb_deactive(sb);
 }
 
+#if defined(CONFIG_NFS_V4_1)
+void nfs_unlink_prepare(struct rpc_task *task, void *calldata)
+{
+       struct nfs_unlinkdata *data = calldata;
+       struct nfs_server *server = NFS_SERVER(data->dir);
+
+       if (nfs4_setup_sequence(server->nfs_client, &data->args.seq_args,
+                               &data->res.seq_res, 1, task))
+               return;
+       rpc_call_start(task);
+}
+#endif /* CONFIG_NFS_V4_1 */
+
 static const struct rpc_call_ops nfs_unlink_ops = {
-       .rpc_call_prepare = nfs_async_unlink_init,
        .rpc_call_done = nfs_async_unlink_done,
        .rpc_release = nfs_async_unlink_release,
+#if defined(CONFIG_NFS_V4_1)
+       .rpc_call_prepare = nfs_unlink_prepare,
+#endif /* CONFIG_NFS_V4_1 */
 };
 
+static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
+{
+       struct rpc_message msg = {
+               .rpc_argp = &data->args,
+               .rpc_resp = &data->res,
+               .rpc_cred = data->cred,
+       };
+       struct rpc_task_setup task_setup_data = {
+               .rpc_message = &msg,
+               .callback_ops = &nfs_unlink_ops,
+               .callback_data = data,
+               .workqueue = nfsiod_workqueue,
+               .flags = RPC_TASK_ASYNC,
+       };
+       struct rpc_task *task;
+       struct dentry *alias;
+
+       alias = d_lookup(parent, &data->args.name);
+       if (alias != NULL) {
+               int ret = 0;
+
+               /*
+                * Hey, we raced with lookup... See if we need to transfer
+                * the sillyrename information to the aliased dentry.
+                */
+               nfs_free_dname(data);
+               spin_lock(&alias->d_lock);
+               if (alias->d_inode != NULL &&
+                   !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
+                       alias->d_fsdata = data;
+                       alias->d_flags |= DCACHE_NFSFS_RENAMED;
+                       ret = 1;
+               }
+               spin_unlock(&alias->d_lock);
+               nfs_dec_sillycount(dir);
+               dput(alias);
+               return ret;
+       }
+       data->dir = igrab(dir);
+       if (!data->dir) {
+               nfs_dec_sillycount(dir);
+               return 0;
+       }
+       nfs_sb_active(dir->i_sb);
+       data->args.fh = NFS_FH(dir);
+       nfs_fattr_init(&data->res.dir_attr);
+
+       NFS_PROTO(dir)->unlink_setup(&msg, dir);
+
+       task_setup_data.rpc_client = NFS_CLIENT(dir);
+       task = rpc_run_task(&task_setup_data);
+       if (!IS_ERR(task))
+               rpc_put_task(task);
+       return 1;
+}
+
+static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
+{
+       struct dentry *parent;
+       struct inode *dir;
+       int ret = 0;
+
+
+       parent = dget_parent(dentry);
+       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) {
+               /* Deferred delete */
+               hlist_add_head(&data->list, &NFS_I(dir)->silly_list);
+               spin_unlock(&dir->i_lock);
+               ret = 1;
+               goto out_dput;
+       }
+       spin_unlock(&dir->i_lock);
+       ret = nfs_do_call_unlink(parent, dir, data);
+out_dput:
+       dput(parent);
+out_free:
+       return ret;
+}
+
+void nfs_block_sillyrename(struct dentry *dentry)
+{
+       struct nfs_inode *nfsi = NFS_I(dentry->d_inode);
+
+       wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1);
+}
+
+void nfs_unblock_sillyrename(struct dentry *dentry)
+{
+       struct inode *dir = dentry->d_inode;
+       struct nfs_inode *nfsi = NFS_I(dir);
+       struct nfs_unlinkdata *data;
+
+       atomic_inc(&nfsi->silly_count);
+       spin_lock(&dir->i_lock);
+       while (!hlist_empty(&nfsi->silly_list)) {
+               if (!atomic_inc_not_zero(&nfsi->silly_count))
+                       break;
+               data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list);
+               hlist_del(&data->list);
+               spin_unlock(&dir->i_lock);
+               if (nfs_do_call_unlink(dentry, dir, data) == 0)
+                       nfs_free_unlinkdata(data);
+               spin_lock(&dir->i_lock);
+       }
+       spin_unlock(&dir->i_lock);
+}
+
 /**
  * nfs_async_unlink - asynchronous unlinking of a file
+ * @dir: parent directory of dentry
  * @dentry: dentry to unlink
  */
 int
-nfs_async_unlink(struct dentry *dentry)
+nfs_async_unlink(struct inode *dir, struct dentry *dentry)
 {
-       struct dentry   *dir = dentry->d_parent;
-       struct nfs_unlinkdata   *data;
-       struct rpc_clnt *clnt = NFS_CLIENT(dir->d_inode);
-       int             status = -ENOMEM;
+       struct nfs_unlinkdata *data;
+       int status = -ENOMEM;
 
-       data = kmalloc(sizeof(*data), GFP_KERNEL);
-       if (!data)
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (data == NULL)
                goto out;
-       memset(data, 0, sizeof(*data));
 
-       data->cred = rpcauth_lookupcred(clnt->cl_auth, 0);
+       data->cred = rpc_lookup_cred();
        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;
-
-       rpc_init_task(&data->task, clnt, RPC_TASK_ASYNC, &nfs_unlink_ops, data);
+       data->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
 
+       status = -EBUSY;
        spin_lock(&dentry->d_lock);
+       if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+               goto out_unlock;
        dentry->d_flags |= DCACHE_NFSFS_RENAMED;
+       dentry->d_fsdata = data;
        spin_unlock(&dentry->d_lock);
-
-       rpc_sleep_on(&nfs_delete_queue, &data->task, NULL, NULL);
-       status = 0;
- out:
-       return status;
+       return 0;
+out_unlock:
+       spin_unlock(&dentry->d_lock);
+       put_rpccred(data->cred);
 out_free:
        kfree(data);
+out:
        return status;
 }
 
 /**
  * nfs_complete_unlink - Initialize completion of the sillydelete
  * @dentry: dentry to delete
+ * @inode: inode
  *
  * 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)
+nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
 {
-       struct nfs_unlinkdata   *data;
+       struct nfs_unlinkdata   *data = NULL;
 
-       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;
+       if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+               dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
+               data = dentry->d_fsdata;
+       }
        spin_unlock(&dentry->d_lock);
-       rpc_wake_up_task(&data->task);
-       nfs_put_unlinkdata(data);
+
+       if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
+               nfs_free_unlinkdata(data);
 }