mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 12:43:55 +08:00
55b70a0300
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
283 lines
6.6 KiB
C
283 lines
6.6 KiB
C
/*
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* linux/fs/nfs/unlink.c
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*
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* nfs sillydelete handling
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*
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*/
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/dcache.h>
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#include <linux/sunrpc/sched.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/nfs_fs.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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struct nfs_unlinkdata {
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struct hlist_node list;
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struct nfs_removeargs args;
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struct nfs_removeres res;
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struct inode *dir;
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struct rpc_cred *cred;
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};
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/**
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* nfs_free_unlinkdata - release data from a sillydelete operation.
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* @data: pointer to unlink structure.
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*/
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static void
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nfs_free_unlinkdata(struct nfs_unlinkdata *data)
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{
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iput(data->dir);
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put_rpccred(data->cred);
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kfree(data->args.name.name);
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kfree(data);
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}
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#define NAME_ALLOC_LEN(len) ((len+16) & ~15)
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/**
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* nfs_copy_dname - copy dentry name to data structure
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* @dentry: pointer to dentry
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* @data: nfs_unlinkdata
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*/
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static int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
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{
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char *str;
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int len = dentry->d_name.len;
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str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL);
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if (!str)
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return -ENOMEM;
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data->args.name.len = len;
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data->args.name.name = str;
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return 0;
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}
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static void nfs_free_dname(struct nfs_unlinkdata *data)
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{
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kfree(data->args.name.name);
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data->args.name.name = NULL;
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data->args.name.len = 0;
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}
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static void nfs_dec_sillycount(struct inode *dir)
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{
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struct nfs_inode *nfsi = NFS_I(dir);
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if (atomic_dec_return(&nfsi->silly_count) == 1)
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wake_up(&nfsi->waitqueue);
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}
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/**
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* nfs_async_unlink_init - Initialize the RPC info
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* task: rpc_task of the sillydelete
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*/
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static void nfs_async_unlink_init(struct rpc_task *task, void *calldata)
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{
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struct nfs_unlinkdata *data = calldata;
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struct inode *dir = data->dir;
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struct rpc_message msg = {
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.rpc_argp = &data->args,
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.rpc_resp = &data->res,
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.rpc_cred = data->cred,
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};
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NFS_PROTO(dir)->unlink_setup(&msg, dir);
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rpc_call_setup(task, &msg, 0);
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}
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/**
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* nfs_async_unlink_done - Sillydelete post-processing
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* @task: rpc_task of the sillydelete
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*
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* Do the directory attribute update.
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*/
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static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
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{
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struct nfs_unlinkdata *data = calldata;
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struct inode *dir = data->dir;
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if (!NFS_PROTO(dir)->unlink_done(task, dir))
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rpc_restart_call(task);
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}
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/**
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* nfs_async_unlink_release - Release the sillydelete data.
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* @task: rpc_task of the sillydelete
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*
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* We need to call nfs_put_unlinkdata as a 'tk_release' task since the
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* rpc_task would be freed too.
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*/
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static void nfs_async_unlink_release(void *calldata)
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{
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struct nfs_unlinkdata *data = calldata;
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nfs_dec_sillycount(data->dir);
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nfs_free_unlinkdata(data);
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}
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static const struct rpc_call_ops nfs_unlink_ops = {
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.rpc_call_prepare = nfs_async_unlink_init,
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.rpc_call_done = nfs_async_unlink_done,
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.rpc_release = nfs_async_unlink_release,
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};
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static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
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{
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struct rpc_task *task;
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struct dentry *alias;
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alias = d_lookup(parent, &data->args.name);
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if (alias != NULL) {
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int ret = 0;
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/*
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* Hey, we raced with lookup... See if we need to transfer
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* the sillyrename information to the aliased dentry.
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*/
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nfs_free_dname(data);
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spin_lock(&alias->d_lock);
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if (!(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
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alias->d_fsdata = data;
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alias->d_flags ^= DCACHE_NFSFS_RENAMED;
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ret = 1;
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}
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spin_unlock(&alias->d_lock);
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nfs_dec_sillycount(dir);
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dput(alias);
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return ret;
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}
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data->dir = igrab(dir);
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if (!data->dir) {
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nfs_dec_sillycount(dir);
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return 0;
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}
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data->args.fh = NFS_FH(dir);
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nfs_fattr_init(&data->res.dir_attr);
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task = rpc_run_task(NFS_CLIENT(dir), RPC_TASK_ASYNC, &nfs_unlink_ops, data);
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if (!IS_ERR(task))
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rpc_put_task(task);
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return 1;
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}
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static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
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{
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struct dentry *parent;
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struct inode *dir;
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int ret = 0;
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parent = dget_parent(dentry);
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if (parent == NULL)
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goto out_free;
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dir = parent->d_inode;
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if (nfs_copy_dname(dentry, data) != 0)
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goto out_dput;
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/* Non-exclusive lock protects against concurrent lookup() calls */
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spin_lock(&dir->i_lock);
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if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) {
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/* Deferred delete */
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hlist_add_head(&data->list, &NFS_I(dir)->silly_list);
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spin_unlock(&dir->i_lock);
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ret = 1;
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goto out_dput;
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}
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spin_unlock(&dir->i_lock);
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ret = nfs_do_call_unlink(parent, dir, data);
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out_dput:
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dput(parent);
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out_free:
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return ret;
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}
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void nfs_block_sillyrename(struct dentry *dentry)
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{
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struct nfs_inode *nfsi = NFS_I(dentry->d_inode);
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wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1);
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}
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void nfs_unblock_sillyrename(struct dentry *dentry)
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{
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struct inode *dir = dentry->d_inode;
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struct nfs_inode *nfsi = NFS_I(dir);
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struct nfs_unlinkdata *data;
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atomic_inc(&nfsi->silly_count);
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spin_lock(&dir->i_lock);
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while (!hlist_empty(&nfsi->silly_list)) {
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if (!atomic_inc_not_zero(&nfsi->silly_count))
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break;
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data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list);
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hlist_del(&data->list);
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spin_unlock(&dir->i_lock);
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if (nfs_do_call_unlink(dentry, dir, data) == 0)
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nfs_free_unlinkdata(data);
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spin_lock(&dir->i_lock);
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}
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spin_unlock(&dir->i_lock);
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}
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/**
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* nfs_async_unlink - asynchronous unlinking of a file
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* @dir: parent directory of dentry
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* @dentry: dentry to unlink
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*/
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int
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nfs_async_unlink(struct inode *dir, struct dentry *dentry)
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{
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struct nfs_unlinkdata *data;
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int status = -ENOMEM;
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (data == NULL)
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goto out;
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data->cred = rpcauth_lookupcred(NFS_CLIENT(dir)->cl_auth, 0);
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if (IS_ERR(data->cred)) {
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status = PTR_ERR(data->cred);
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goto out_free;
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}
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status = -EBUSY;
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spin_lock(&dentry->d_lock);
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if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
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goto out_unlock;
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dentry->d_flags |= DCACHE_NFSFS_RENAMED;
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dentry->d_fsdata = data;
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spin_unlock(&dentry->d_lock);
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return 0;
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out_unlock:
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spin_unlock(&dentry->d_lock);
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put_rpccred(data->cred);
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out_free:
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kfree(data);
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out:
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return status;
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}
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/**
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* nfs_complete_unlink - Initialize completion of the sillydelete
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* @dentry: dentry to delete
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* @inode: inode
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*
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* Since we're most likely to be called by dentry_iput(), we
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* only use the dentry to find the sillydelete. We then copy the name
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* into the qstr.
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*/
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void
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nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
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{
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struct nfs_unlinkdata *data = NULL;
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spin_lock(&dentry->d_lock);
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if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
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dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
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data = dentry->d_fsdata;
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}
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spin_unlock(&dentry->d_lock);
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if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
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nfs_free_unlinkdata(data);
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}
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