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SUNRPC: Clean up the sillyrename code

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Fix a couple of bugs:
 - Don't rely on the parent dentry still being valid when the call completes.
   Fixes a race with shrink_dcache_for_umount_subtree()

 - Don't remove the file if the filehandle has been labelled as stale.

Fix a couple of inefficiencies
 - Remove the global list of sillyrenamed files. Instead we can cache the
   sillyrename information in the dentry->d_fsdata
 - Move common code from unlink_setup/unlink_done into fs/nfs/unlink.c

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust
2007-07-14 15:39:58 -04:00
parent 4fdc17b2a7
commit e4eff1a622
7 changed files with 119 additions and 201 deletions
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193
fs/nfs/unlink.c
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@@ -3,7 +3,6 @@
*
* nfs sillydelete handling
*
* NOTE: we rely on holding the BKL for list manipulation protection.
*/
#include <linux/slab.h>
@@ -15,46 +14,23 @@
struct nfs_unlinkdata {
struct nfs_unlinkdata *next;
struct dentry *dir, *dentry;
struct qstr name;
struct rpc_task task;
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 +39,36 @@ 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().
* 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_begin_data_update(dir);
NFS_PROTO(dir)->unlink_setup(&msg, dir);
rpc_call_setup(task, &msg, 0);
return;
out_err:
rpc_exit(task, status);
}
/**
@@ -117,19 +79,13 @@ 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);
else
nfs_end_data_update(dir);
}
/**
@@ -142,7 +98,7 @@ 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);
nfs_free_unlinkdata(data);
}
static const struct rpc_call_ops nfs_unlink_ops = {
@@ -151,73 +107,94 @@ static const struct rpc_call_ops nfs_unlink_ops = {
.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 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 = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
if (data == NULL)
goto out;
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);
}