/*
* Code common to create, mkdir, and mknod.
*/
static int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
struct nfs_fattr *fattr)
{
struct inode *inode;
int error = -EACCES;
/* We may have been initialized further down */
if (dentry->d_inode)
return 0;
if (fhandle->size == 0 || !(fattr->valid & NFS_ATTR_FATTR)) {
struct inode *dir = dentry->d_parent->d_inode;
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
if (error)
goto out_err;
}
inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
if (inode) {
d_instantiate(dentry, inode);
nfs_renew_times(dentry);
nfs_set_verifier(dentry, nfs_save_change_attribute(dentry->d_parent->d_inode));
return 0;
}
error = -ENOMEM;
out_err:
d_drop(dentry);
return error;
}
/* We do silly rename. In case sillyrename() returns -EBUSY, the inode
* belongs to an active ".nfs..." file and we return -EBUSY.
*
* If sillyrename() returns 0, we do nothing, otherwise we unlink.
*/
static int nfs_unlink(struct inode *dir, struct dentry *dentry)
{
int error;
int need_rehash = 0;
dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name);
lock_kernel();
spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (atomic_read(&dentry->d_count) > 1) {
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
error = nfs_sillyrename(dir, dentry);
unlock_kernel();
return error;
}
if (!d_unhashed(dentry)) {
__d_drop(dentry);
need_rehash = 1;
}
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
error = nfs_safe_remove(dentry);
if (!error) {
nfs_renew_times(dentry);
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
} else if (need_rehash)
d_rehash(dentry);
unlock_kernel();
return error;
}
static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = NULL;
int error = 0;
/* Check that we are indeed trying to open this file */
if (!is_atomic_open(dir, nd))
goto no_open;
if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
error = -ENAMETOOLONG;
goto out;
}
dentry->d_op = NFS_PROTO(dir)->dentry_ops;
/* Let vfs_create() deal with O_EXCL */
if (nd->intent.open.flags & O_EXCL)
goto no_entry;
/* Open the file on the server */
lock_kernel();
/* Revalidate parent directory attribute cache */
nfs_revalidate_inode(NFS_SERVER(dir), dir);
if (nd->intent.open.flags & O_CREAT) {
nfs_begin_data_update(dir);
inode = nfs4_atomic_open(dir, dentry, nd);
nfs_end_data_update(dir);
} else
inode = nfs4_atomic_open(dir, dentry, nd);
unlock_kernel();
if (IS_ERR(inode)) {
error = PTR_ERR(inode);
switch (error) {
/* Make a negative dentry */
case -ENOENT:
inode = NULL;
break;
/* This turned out not to be a regular file */
case -ELOOP:
if (!(nd->intent.open.flags & O_NOFOLLOW))
goto no_open;
/* case -EISDIR: */
/* case -EINVAL: */
default:
goto out;
}
}
no_entry:
d_add(dentry, inode);
nfs_renew_times(dentry);
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
out:
BUG_ON(error > 0);
return ERR_PTR(error);
no_open:
return nfs_lookup(dir, dentry, nd);
}
static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
struct inode *inode = NULL;
int error;
struct nfs_fh fhandle;
struct nfs_fattr fattr;
dfprintk(VFS, "NFS: lookup(%s/%s)\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
error = -ENAMETOOLONG;
if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
goto out;
error = -ENOMEM;
dentry->d_op = NFS_PROTO(dir)->dentry_ops;
lock_kernel();
/* Revalidate parent directory attribute cache */
nfs_revalidate_inode(NFS_SERVER(dir), dir);
/* If we're doing an exclusive create, optimize away the lookup */
if (nfs_is_exclusive_create(dir, nd))
goto no_entry;
error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
if (error != 0) {
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name,
&fhandle, &fattr);
if (error == -ENOENT)
goto no_entry;
if (error != 0)
goto out_unlock;
}
error = -EACCES;
inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
if (!inode)
goto out_unlock;
no_entry:
error = 0;
d_add(dentry, inode);
nfs_renew_times(dentry);
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
out_unlock:
unlock_kernel();
out:
BUG_ON(error > 0);
return ERR_PTR(error);
}
static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct dentry *parent = NULL;
struct inode *inode = dentry->d_inode;
struct inode *dir;
unsigned long verifier;
int openflags, ret = 0;
/* NFS only supports OPEN for regular files */
if (inode && !S_ISREG(inode->i_mode))
goto no_open;
parent = dget_parent(dentry);
dir = parent->d_inode;
if (!is_atomic_open(dir, nd))
goto no_open;
openflags = nd->intent.open.flags;
if (openflags & O_CREAT) {
/* If this is a negative dentry, just drop it */
if (!inode)
goto out;
/* If this is exclusive open, just revalidate */
if (openflags & O_EXCL)
goto no_open;
}
/* We can't create new files, or truncate existing ones here */
openflags &= ~(O_CREAT|O_TRUNC);
/*
* Note: we're not holding inode->i_sem and so may be racing with
* operations that change the directory. We therefore save the
* change attribute *before* we do the RPC call.
*/
lock_kernel();
verifier = nfs_save_change_attribute(dir);
ret = nfs4_open_revalidate(dir, dentry, openflags);
if (!ret)
nfs_set_verifier(dentry, verifier);
unlock_kernel();
out:
dput(parent);
if (!ret)
d_drop(dentry);
return ret;
no_open:
dput(parent);
return nfs_lookup_revalidate(dentry, nd);
}
/*
* Following a failed create operation, we drop the dentry rather
* than retain a negative dentry. This avoids a problem in the event
* that the operation succeeded on the server, but an error in the
* reply path made it appear to have failed.
*/
static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
struct iattr attr;
struct inode *inode;
int error;
int open_flags = 0;
dfprintk(VFS, "NFS: create(%s/%ld, %s\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name);
attr.ia_mode = mode;
attr.ia_valid = ATTR_MODE;
if (nd && (nd->flags & LOOKUP_CREATE))
open_flags = nd->intent.open.flags;
/*
* The 0 argument passed into the create function should one day
* contain the O_EXCL flag if requested. This allows NFSv3 to
* select the appropriate create strategy. Currently open_namei
* does not pass the create flags.
*/
lock_kernel();
nfs_begin_data_update(dir);
inode = NFS_PROTO(dir)->create(dir, &dentry->d_name, &attr, open_flags);
nfs_end_data_update(dir);
if (!IS_ERR(inode)) {
d_instantiate(dentry, inode);
nfs_renew_times(dentry);
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
error = 0;
} else {
error = PTR_ERR(inode);
d_drop(dentry);
}
unlock_kernel();
return error;
}
static int
nfs4_file_open(struct inode *inode, struct file *filp)
{
struct nfs_open_context *ctx;
struct dentry *dentry = filp->f_path.dentry;
struct dentry *parent = NULL;
struct inode *dir;
unsigned openflags = filp->f_flags;
struct iattr attr;
int opened = 0;
int err;
/*
* If no cached dentry exists or if it's negative, NFSv4 handled the
* opens in ->lookup() or ->create().
*
* We only get this far for a cached positive dentry. We skipped
* revalidation, so handle it here by dropping the dentry and returning
* -EOPENSTALE. The VFS will retry the lookup/create/open.
*/
dprintk("NFS: open file(%s/%s)\n",
dentry->d_parent->d_name.name,
dentry->d_name.name);
if ((openflags & O_ACCMODE) == 3)
openflags--;
/* We can't create new files here */
openflags &= ~(O_CREAT|O_EXCL);
parent = dget_parent(dentry);
dir = parent->d_inode;
ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
err = PTR_ERR(ctx);
if (IS_ERR(ctx))
goto out;
attr.ia_valid = ATTR_OPEN;
if (openflags & O_TRUNC) {
attr.ia_valid |= ATTR_SIZE;
attr.ia_size = 0;
nfs_wb_all(inode);
}
inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
switch (err) {
case -EPERM:
case -EACCES:
case -EDQUOT:
case -ENOSPC:
case -EROFS:
goto out_put_ctx;
default:
goto out_drop;
}
}
if (inode != dentry->d_inode)
goto out_drop;
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
nfs_file_set_open_context(filp, ctx);
nfs_fscache_open_file(inode, filp);
err = 0;
out_put_ctx:
put_nfs_open_context(ctx);
out:
dput(parent);
return err;
out_drop:
d_drop(dentry);
err = -EOPENSTALE;
goto out_put_ctx;
}
/**
* 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.
*
* (Note: NFSv4 is stateful, and has opens, so in theory an NFSv4 server
* could take responsibility for keeping open files referenced. The server
* would also need to ensure that opened-but-deleted files were kept over
* reboots. However, we may not assume a server does so. (RFC 5661
* does provide an OPEN4_RESULT_PRESERVE_UNLINKED flag that a server can
* use to advertise that it does this; some day we may take advantage of
* it.))
*/
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_PROTO(dentry->d_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;
/* populate unlinkdata with the right dname */
error = nfs_copy_dname(sdentry,
(struct nfs_unlinkdata *)dentry->d_fsdata);
if (error) {
nfs_cancel_async_unlink(dentry);
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;
switch (error) {
case 0:
/* The rename succeeded */
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
d_move(dentry, sdentry);
break;
case -ERESTARTSYS:
/* The result of the rename is unknown. Play it safe by
* forcing a new lookup */
d_drop(dentry);
d_drop(sdentry);
}
rpc_put_task(task);
out_dput:
dput(sdentry);
out:
return error;
}
/*
* This is called every time the dcache has a lookup hit,
* and we should check whether we can really trust that
* lookup.
*
* NOTE! The hit can be a negative hit too, don't assume
* we have an inode!
*
* If the parent directory is seen to have changed, we throw out the
* cached dentry and do a new lookup.
*/
static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
{
struct inode *dir;
struct inode *inode;
struct dentry *parent;
int error;
struct nfs_fh fhandle;
struct nfs_fattr fattr;
unsigned long verifier;
int isopen = 0;
parent = dget_parent(dentry);
lock_kernel();
dir = parent->d_inode;
inode = dentry->d_inode;
if (nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_OPEN))
isopen = 1;
if (!inode) {
if (nfs_neg_need_reval(dir, dentry, nd))
goto out_bad;
goto out_valid;
}
if (is_bad_inode(inode)) {
dfprintk(VFS, "nfs_lookup_validate: %s/%s has dud inode\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
goto out_bad;
}
/* Revalidate parent directory attribute cache */
nfs_revalidate_inode(NFS_SERVER(dir), dir);
/* Force a full look up iff the parent directory has changed */
if (nfs_check_verifier(dir, dentry)) {
if (nfs_lookup_verify_inode(inode, isopen))
goto out_zap_parent;
goto out_valid;
}
/*
* Note: we're not holding inode->i_sem and so may be racing with
* operations that change the directory. We therefore save the
* change attribute *before* we do the RPC call.
*/
verifier = nfs_save_change_attribute(dir);
error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
if (!error) {
if (memcmp(NFS_FH(inode), &fhandle, sizeof(struct nfs_fh))!= 0)
goto out_bad;
if (nfs_lookup_verify_inode(inode, isopen))
goto out_zap_parent;
goto out_valid_renew;
}
if (NFS_STALE(inode))
goto out_bad;
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
if (error)
goto out_bad;
if (memcmp(NFS_FH(inode), &fhandle, sizeof(struct nfs_fh))!= 0)
goto out_bad;
if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
goto out_bad;
out_valid_renew:
nfs_renew_times(dentry);
nfs_set_verifier(dentry, verifier);
out_valid:
unlock_kernel();
dput(parent);
return 1;
out_zap_parent:
nfs_zap_caches(dir);
out_bad:
NFS_CACHEINV(dir);
if (inode && S_ISDIR(inode->i_mode)) {
/* Purge readdir caches. */
nfs_zap_caches(inode);
/* If we have submounts, don't unhash ! */
if (have_submounts(dentry))
goto out_valid;
shrink_dcache_parent(dentry);
}
d_drop(dentry);
unlock_kernel();
dput(parent);
return 0;
}
/*
* RENAME
* FIXME: Some nfsds, like the Linux user space nfsd, may generate a
* different file handle for the same inode after a rename (e.g. when
* moving to a different directory). A fail-safe method to do so would
* be to look up old_dir/old_name, create a link to new_dir/new_name and
* rename the old file using the sillyrename stuff. This way, the original
* file in old_dir will go away when the last process iput()s the inode.
*
* FIXED.
*
* It actually works quite well. One needs to have the possibility for
* at least one ".nfs..." file in each directory the file ever gets
* moved or linked to which happens automagically with the new
* implementation that only depends on the dcache stuff instead of
* using the inode layer
*
* Unfortunately, things are a little more complicated than indicated
* above. For a cross-directory move, we want to make sure we can get
* rid of the old inode after the operation. This means there must be
* no pending writes (if it's a file), and the use count must be 1.
* If these conditions are met, we can drop the dentries before doing
* the rename.
*/
static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct inode *old_inode = old_dentry->d_inode;
struct inode *new_inode = new_dentry->d_inode;
struct dentry *dentry = NULL, *rehash = NULL;
int error = -EBUSY;
/*
* To prevent any new references to the target during the rename,
* we unhash the dentry and free the inode in advance.
*/
lock_kernel();
if (!d_unhashed(new_dentry)) {
d_drop(new_dentry);
rehash = new_dentry;
}
dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
atomic_read(&new_dentry->d_count));
/*
* First check whether the target is busy ... we can't
* safely do _any_ rename if the target is in use.
*
* For files, make a copy of the dentry and then do a
* silly-rename. If the silly-rename succeeds, the
* copied dentry is hashed and becomes the new target.
*/
if (!new_inode)
goto go_ahead;
if (S_ISDIR(new_inode->i_mode))
goto out;
else if (atomic_read(&new_dentry->d_count) > 1) {
int err;
/* copy the target dentry's name */
dentry = d_alloc(new_dentry->d_parent,
&new_dentry->d_name);
if (!dentry)
goto out;
/* silly-rename the existing target ... */
err = nfs_sillyrename(new_dir, new_dentry);
if (!err) {
new_dentry = rehash = dentry;
new_inode = NULL;
/* instantiate the replacement target */
d_instantiate(new_dentry, NULL);
}
/* dentry still busy? */
if (atomic_read(&new_dentry->d_count) > 1) {
#ifdef NFS_PARANOIA
printk("nfs_rename: target %s/%s busy, d_count=%d\n",
new_dentry->d_parent->d_name.name,
new_dentry->d_name.name,
atomic_read(&new_dentry->d_count));
#endif
goto out;
}
}
go_ahead:
/*
* ... prune child dentries and writebacks if needed.
*/
if (atomic_read(&old_dentry->d_count) > 1) {
nfs_wb_all(old_inode);
shrink_dcache_parent(old_dentry);
}
if (new_inode)
d_delete(new_dentry);
nfs_begin_data_update(old_dir);
nfs_begin_data_update(new_dir);
nfs_begin_data_update(old_inode);
error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
new_dir, &new_dentry->d_name);
nfs_end_data_update(old_inode);
nfs_end_data_update(new_dir);
nfs_end_data_update(old_dir);
out:
if (rehash)
d_rehash(rehash);
if (!error) {
if (!S_ISDIR(old_inode->i_mode))
d_move(old_dentry, new_dentry);
nfs_renew_times(new_dentry);
nfs_set_verifier(new_dentry, nfs_save_change_attribute(new_dir));
}
/* new dentry created? */
if (dentry)
dput(dentry);
unlock_kernel();
return error;
}
static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
{
static unsigned int sillycounter;
const int i_inosize = sizeof(dir->i_ino)*2;
const int countersize = sizeof(sillycounter)*2;
const int slen = strlen(".nfs") + i_inosize + countersize;
char silly[slen+1];
struct qstr qsilly;
struct dentry *sdentry;
int error = -EIO;
dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
atomic_read(&dentry->d_count));
#ifdef NFS_PARANOIA
if (!dentry->d_inode)
printk("NFS: silly-renaming %s/%s, negative dentry??\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
#endif
/*
* 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",
i_inosize, i_inosize, dentry->d_inode->i_ino);
sdentry = NULL;
do {
char *suffix = silly + slen - countersize;
dput(sdentry);
sillycounter++;
sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
dfprintk(VFS, "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 */
qsilly.name = silly;
qsilly.len = strlen(silly);
nfs_begin_data_update(dir);
if (dentry->d_inode) {
nfs_begin_data_update(dentry->d_inode);
error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
dir, &qsilly);
nfs_end_data_update(dentry->d_inode);
} else
error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
dir, &qsilly);
nfs_end_data_update(dir);
if (!error) {
nfs_renew_times(dentry);
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
d_move(dentry, sdentry);
error = nfs_async_unlink(dentry);
/* If we return 0 we don't unlink */
}
dput(sdentry);
out:
return error;
}
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);
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));
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);
if (IS_ERR(sdentry))
goto out;
} while (sdentry->d_inode != NULL);
error = nfs_async_unlink(dir, dentry);
if (error)
goto out_dput;
error = nfs_copy_dname(sdentry,
(struct nfs_unlinkdata *)dentry->d_fsdata);
if (error) {
nfs_cancel_async_unlink(dentry);
goto out_dput;
}
task = nfs_async_rename(dir, dir, dentry, sdentry);
if (IS_ERR(task)) {
error = -EBUSY;
nfs_cancel_async_unlink(dentry);
goto out_dput;
}
error = rpc_wait_for_completion_task(task);
if (error == 0)
error = task->tk_status;
switch (error) {
case 0:
/* The rename succeeded */
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
d_move(dentry, sdentry);
break;
case -ERESTARTSYS:
/* The result of the rename is unknown. Play it safe by
* forcing a new lookup */
d_drop(dentry);
d_drop(sdentry);
}
rpc_put_task(task);
out_dput:
dput(sdentry);
out:
return error;
}