mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
![Al Viro](/assets/img/avatar_default.png)
part 2: make sure that disconnected roots have corresponding mnt_devname values stashed into them. Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the found root, provided that it is disconnected. Have ->d_release() free it when dentry goes away. Have the places where NFS uses ->d_fsdata for sillyrename (and that can *never* happen to a disconnected root - dentry will be attached to its parent) free old devname copies if they find those. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
580 lines
15 KiB
C
580 lines
15 KiB
C
/*
|
|
* 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>
|
|
#include <linux/sched.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/namei.h>
|
|
|
|
#include "internal.h"
|
|
#include "nfs4_fs.h"
|
|
#include "iostat.h"
|
|
#include "delegation.h"
|
|
|
|
struct nfs_unlinkdata {
|
|
struct hlist_node list;
|
|
struct nfs_removeargs args;
|
|
struct nfs_removeres res;
|
|
struct inode *dir;
|
|
struct rpc_cred *cred;
|
|
struct nfs_fattr dir_attr;
|
|
};
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
|
|
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_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))
|
|
nfs_restart_rpc(task, NFS_SERVER(dir)->nfs_client);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
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, &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_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;
|
|
void *devname_garbage = NULL;
|
|
|
|
/*
|
|
* 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)) {
|
|
devname_garbage = alias->d_fsdata;
|
|
alias->d_fsdata = data;
|
|
alias->d_flags |= DCACHE_NFSFS_RENAMED;
|
|
ret = 1;
|
|
}
|
|
spin_unlock(&alias->d_lock);
|
|
nfs_dec_sillycount(dir);
|
|
dput(alias);
|
|
/*
|
|
* If we'd displaced old cached devname, free it. At that
|
|
* point dentry is definitely not a root, so we won't need
|
|
* that anymore.
|
|
*/
|
|
if (devname_garbage)
|
|
kfree(devname_garbage);
|
|
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_async(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
|
|
*/
|
|
static int
|
|
nfs_async_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct nfs_unlinkdata *data;
|
|
int status = -ENOMEM;
|
|
void *devname_garbage = NULL;
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
if (data == NULL)
|
|
goto out;
|
|
|
|
data->cred = rpc_lookup_cred();
|
|
if (IS_ERR(data->cred)) {
|
|
status = PTR_ERR(data->cred);
|
|
goto out_free;
|
|
}
|
|
data->res.dir_attr = &data->dir_attr;
|
|
|
|
status = -EBUSY;
|
|
spin_lock(&dentry->d_lock);
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
|
|
goto out_unlock;
|
|
dentry->d_flags |= DCACHE_NFSFS_RENAMED;
|
|
devname_garbage = dentry->d_fsdata;
|
|
dentry->d_fsdata = data;
|
|
spin_unlock(&dentry->d_lock);
|
|
/*
|
|
* If we'd displaced old cached devname, free it. At that
|
|
* point dentry is definitely not a root, so we won't need
|
|
* that anymore.
|
|
*/
|
|
if (devname_garbage)
|
|
kfree(devname_garbage);
|
|
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;
|
|
dentry->d_fsdata = NULL;
|
|
}
|
|
spin_unlock(&dentry->d_lock);
|
|
|
|
if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
|
|
nfs_free_unlinkdata(data);
|
|
}
|
|
|
|
/* Cancel a queued async unlink. Called when a sillyrename run fails. */
|
|
static void
|
|
nfs_cancel_async_unlink(struct dentry *dentry)
|
|
{
|
|
spin_lock(&dentry->d_lock);
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
|
|
struct nfs_unlinkdata *data = dentry->d_fsdata;
|
|
|
|
dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
|
|
dentry->d_fsdata = NULL;
|
|
spin_unlock(&dentry->d_lock);
|
|
nfs_free_unlinkdata(data);
|
|
return;
|
|
}
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
|
|
struct nfs_renamedata {
|
|
struct nfs_renameargs args;
|
|
struct nfs_renameres res;
|
|
struct rpc_cred *cred;
|
|
struct inode *old_dir;
|
|
struct dentry *old_dentry;
|
|
struct nfs_fattr old_fattr;
|
|
struct inode *new_dir;
|
|
struct dentry *new_dentry;
|
|
struct nfs_fattr new_fattr;
|
|
};
|
|
|
|
/**
|
|
* nfs_async_rename_done - Sillyrename post-processing
|
|
* @task: rpc_task of the sillyrename
|
|
* @calldata: nfs_renamedata for the sillyrename
|
|
*
|
|
* Do the directory attribute updates and the d_move
|
|
*/
|
|
static void nfs_async_rename_done(struct rpc_task *task, void *calldata)
|
|
{
|
|
struct nfs_renamedata *data = calldata;
|
|
struct inode *old_dir = data->old_dir;
|
|
struct inode *new_dir = data->new_dir;
|
|
|
|
if (!NFS_PROTO(old_dir)->rename_done(task, old_dir, new_dir)) {
|
|
nfs_restart_rpc(task, NFS_SERVER(old_dir)->nfs_client);
|
|
return;
|
|
}
|
|
|
|
if (task->tk_status != 0) {
|
|
nfs_cancel_async_unlink(data->old_dentry);
|
|
return;
|
|
}
|
|
|
|
nfs_set_verifier(data->old_dentry, nfs_save_change_attribute(old_dir));
|
|
d_move(data->old_dentry, data->new_dentry);
|
|
}
|
|
|
|
/**
|
|
* nfs_async_rename_release - Release the sillyrename data.
|
|
* @calldata: the struct nfs_renamedata to be released
|
|
*/
|
|
static void nfs_async_rename_release(void *calldata)
|
|
{
|
|
struct nfs_renamedata *data = calldata;
|
|
struct super_block *sb = data->old_dir->i_sb;
|
|
|
|
if (data->old_dentry->d_inode)
|
|
nfs_mark_for_revalidate(data->old_dentry->d_inode);
|
|
|
|
dput(data->old_dentry);
|
|
dput(data->new_dentry);
|
|
iput(data->old_dir);
|
|
iput(data->new_dir);
|
|
nfs_sb_deactive(sb);
|
|
put_rpccred(data->cred);
|
|
kfree(data);
|
|
}
|
|
|
|
#if defined(CONFIG_NFS_V4_1)
|
|
static void nfs_rename_prepare(struct rpc_task *task, void *calldata)
|
|
{
|
|
struct nfs_renamedata *data = calldata;
|
|
struct nfs_server *server = NFS_SERVER(data->old_dir);
|
|
|
|
if (nfs4_setup_sequence(server, &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_rename_ops = {
|
|
.rpc_call_done = nfs_async_rename_done,
|
|
.rpc_release = nfs_async_rename_release,
|
|
#if defined(CONFIG_NFS_V4_1)
|
|
.rpc_call_prepare = nfs_rename_prepare,
|
|
#endif /* CONFIG_NFS_V4_1 */
|
|
};
|
|
|
|
/**
|
|
* nfs_async_rename - perform an asynchronous rename operation
|
|
* @old_dir: directory that currently holds the dentry to be renamed
|
|
* @new_dir: target directory for the rename
|
|
* @old_dentry: original dentry to be renamed
|
|
* @new_dentry: dentry to which the old_dentry should be renamed
|
|
*
|
|
* It's expected that valid references to the dentries and inodes are held
|
|
*/
|
|
static struct rpc_task *
|
|
nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
|
|
struct dentry *old_dentry, struct dentry *new_dentry)
|
|
{
|
|
struct nfs_renamedata *data;
|
|
struct rpc_message msg = { };
|
|
struct rpc_task_setup task_setup_data = {
|
|
.rpc_message = &msg,
|
|
.callback_ops = &nfs_rename_ops,
|
|
.workqueue = nfsiod_workqueue,
|
|
.rpc_client = NFS_CLIENT(old_dir),
|
|
.flags = RPC_TASK_ASYNC,
|
|
};
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
if (data == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
task_setup_data.callback_data = data;
|
|
|
|
data->cred = rpc_lookup_cred();
|
|
if (IS_ERR(data->cred)) {
|
|
struct rpc_task *task = ERR_CAST(data->cred);
|
|
kfree(data);
|
|
return task;
|
|
}
|
|
|
|
msg.rpc_argp = &data->args;
|
|
msg.rpc_resp = &data->res;
|
|
msg.rpc_cred = data->cred;
|
|
|
|
/* set up nfs_renamedata */
|
|
data->old_dir = old_dir;
|
|
ihold(old_dir);
|
|
data->new_dir = new_dir;
|
|
ihold(new_dir);
|
|
data->old_dentry = dget(old_dentry);
|
|
data->new_dentry = dget(new_dentry);
|
|
nfs_fattr_init(&data->old_fattr);
|
|
nfs_fattr_init(&data->new_fattr);
|
|
|
|
/* set up nfs_renameargs */
|
|
data->args.old_dir = NFS_FH(old_dir);
|
|
data->args.old_name = &old_dentry->d_name;
|
|
data->args.new_dir = NFS_FH(new_dir);
|
|
data->args.new_name = &new_dentry->d_name;
|
|
|
|
/* set up nfs_renameres */
|
|
data->res.old_fattr = &data->old_fattr;
|
|
data->res.new_fattr = &data->new_fattr;
|
|
|
|
nfs_sb_active(old_dir->i_sb);
|
|
|
|
NFS_PROTO(data->old_dir)->rename_setup(&msg, old_dir);
|
|
|
|
return rpc_run_task(&task_setup_data);
|
|
}
|
|
|
|
/**
|
|
* nfs_sillyrename - Perform a silly-rename of a dentry
|
|
* @dir: inode of directory that contains dentry
|
|
* @dentry: dentry to be sillyrenamed
|
|
*
|
|
* NFSv2/3 is stateless and the server doesn't know when the client is
|
|
* holding a file open. To prevent application problems when a file is
|
|
* unlinked while it's still open, the client performs a "silly-rename".
|
|
* That is, it renames the file to a hidden file in the same directory,
|
|
* and only performs the unlink once the last reference to it is put.
|
|
*
|
|
* The final cleanup is done during dentry_iput.
|
|
*/
|
|
int
|
|
nfs_sillyrename(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
static unsigned int sillycounter;
|
|
const int fileidsize = sizeof(NFS_FILEID(dentry->d_inode))*2;
|
|
const int countersize = sizeof(sillycounter)*2;
|
|
const int slen = sizeof(".nfs")+fileidsize+countersize-1;
|
|
char silly[slen+1];
|
|
struct dentry *sdentry;
|
|
struct rpc_task *task;
|
|
int error = -EIO;
|
|
|
|
dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
dentry->d_count);
|
|
nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
|
|
|
|
/*
|
|
* We don't allow a dentry to be silly-renamed twice.
|
|
*/
|
|
error = -EBUSY;
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
|
|
goto out;
|
|
|
|
sprintf(silly, ".nfs%*.*Lx",
|
|
fileidsize, fileidsize,
|
|
(unsigned long long)NFS_FILEID(dentry->d_inode));
|
|
|
|
/* Return delegation in anticipation of the rename */
|
|
nfs_inode_return_delegation(dentry->d_inode);
|
|
|
|
sdentry = NULL;
|
|
do {
|
|
char *suffix = silly + slen - countersize;
|
|
|
|
dput(sdentry);
|
|
sillycounter++;
|
|
sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
|
|
|
|
dfprintk(VFS, "NFS: trying to rename %s to %s\n",
|
|
dentry->d_name.name, silly);
|
|
|
|
sdentry = lookup_one_len(silly, dentry->d_parent, slen);
|
|
/*
|
|
* N.B. Better to return EBUSY here ... it could be
|
|
* dangerous to delete the file while it's in use.
|
|
*/
|
|
if (IS_ERR(sdentry))
|
|
goto out;
|
|
} while (sdentry->d_inode != NULL); /* need negative lookup */
|
|
|
|
/* queue unlink first. Can't do this from rpc_release as it
|
|
* has to allocate memory
|
|
*/
|
|
error = nfs_async_unlink(dir, dentry);
|
|
if (error)
|
|
goto out_dput;
|
|
|
|
/* run the rename task, undo unlink if it fails */
|
|
task = nfs_async_rename(dir, dir, dentry, sdentry);
|
|
if (IS_ERR(task)) {
|
|
error = -EBUSY;
|
|
nfs_cancel_async_unlink(dentry);
|
|
goto out_dput;
|
|
}
|
|
|
|
/* wait for the RPC task to complete, unless a SIGKILL intervenes */
|
|
error = rpc_wait_for_completion_task(task);
|
|
if (error == 0)
|
|
error = task->tk_status;
|
|
rpc_put_task(task);
|
|
out_dput:
|
|
dput(sdentry);
|
|
out:
|
|
return error;
|
|
}
|