unlink.c
4.44 KB
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/*
* linux/fs/nfs/unlink.c
*
* nfs sillydelete handling
*
*/
#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_removeargs args;
struct nfs_removeres res;
struct inode *dir;
struct rpc_cred *cred;
};
/**
* nfs_free_unlinkdata - release data from a sillydelete operation.
* @data: pointer to unlink structure.
*/
static void
nfs_free_unlinkdata(struct nfs_unlinkdata *data)
{
iput(data->dir);
put_rpccred(data->cred);
kfree(data->args.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 int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
{
char *str;
int len = dentry->d_name.len;
str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL);
if (!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
*/
static void nfs_async_unlink_init(struct rpc_task *task, void *calldata)
{
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,
};
nfs_begin_data_update(dir);
NFS_PROTO(dir)->unlink_setup(&msg, dir);
rpc_call_setup(task, &msg, 0);
}
/**
* 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, void *calldata)
{
struct nfs_unlinkdata *data = calldata;
struct inode *dir = data->dir;
if (!NFS_PROTO(dir)->unlink_done(task, dir))
rpc_restart_call(task);
else
nfs_end_data_update(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(void *calldata)
{
struct nfs_unlinkdata *data = calldata;
nfs_free_unlinkdata(data);
}
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,
};
static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
{
struct rpc_task *task;
struct dentry *parent;
struct inode *dir;
if (nfs_copy_dname(dentry, data) < 0)
goto out_free;
parent = dget_parent(dentry);
if (parent == NULL)
goto out_free;
dir = igrab(parent->d_inode);
dput(parent);
if (dir == NULL)
goto out_free;
data->dir = dir;
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;
out_free:
return 0;
}
/**
* nfs_async_unlink - asynchronous unlinking of a file
* @dir: parent directory of dentry
* @dentry: dentry to unlink
*/
int
nfs_async_unlink(struct inode *dir, struct dentry *dentry)
{
struct nfs_unlinkdata *data;
int status = -ENOMEM;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (data == NULL)
goto out;
data->cred = rpcauth_lookupcred(NFS_CLIENT(dir)->cl_auth, 0);
if (IS_ERR(data->cred)) {
status = PTR_ERR(data->cred);
goto out_free;
}
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);
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, struct inode *inode)
{
struct nfs_unlinkdata *data = NULL;
spin_lock(&dentry->d_lock);
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
data = dentry->d_fsdata;
}
spin_unlock(&dentry->d_lock);
if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
nfs_free_unlinkdata(data);
}