*
* 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>
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)
* @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;
+}
+
+static void nfs_free_dname(struct nfs_unlinkdata *data)
+{
+ 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);
}
/**
* 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().
+ * task: rpc_task of the sillydelete
*/
static void nfs_async_unlink_init(struct rpc_task *task, void *calldata)
{
- struct nfs_unlinkdata *data = calldata;
- struct dentry *dir = data->dir;
- struct rpc_message msg = {
- .rpc_cred = data->cred,
+ struct nfs_unlinkdata *data = calldata;
+ struct inode *dir = data->dir;
+ struct rpc_message msg = {
+ .rpc_argp = &data->args,
+ .rpc_resp = &data->res,
+ .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);
+ NFS_PROTO(dir)->unlink_setup(&msg, dir);
rpc_call_setup(task, &msg, 0);
- return;
- out_err:
- rpc_exit(task, status);
}
/**
*/
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;
-
- 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);
+ struct nfs_unlinkdata *data = calldata;
+ struct inode *dir = data->dir;
+
+ if (!NFS_PROTO(dir)->unlink_done(task, dir))
+ rpc_restart_call(task);
}
/**
static void nfs_async_unlink_release(void *calldata)
{
struct nfs_unlinkdata *data = calldata;
- nfs_put_unlinkdata(data);
+
+ nfs_dec_sillycount(data->dir);
+ nfs_free_unlinkdata(data);
}
static const struct rpc_call_ops nfs_unlink_ops = {
.rpc_release = nfs_async_unlink_release,
};
+static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
+{
+ 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_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;
+ }
+ data->args.fh = NFS_FH(dir);
+ nfs_fattr_init(&data->res.dir_attr);
+
+ task = rpc_run_task(NFS_CLIENT(dir), RPC_TASK_ASYNC, &nfs_unlink_ops, 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 = rpcauth_lookupcred(NFS_CLIENT(dir)->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;
-
- rpc_init_task(&data->task, clnt, RPC_TASK_ASYNC, &nfs_unlink_ops, data);
+ 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);
}