/*
* Remove a file after making sure there are no pending writes,
* and after checking that the file has only one user.
*
* We invalidate the attribute cache and free the inode prior to the operation
* to avoid possible races if the server reuses the inode.
*/
static int nfs_safe_remove(struct dentry *dentry)
{
struct inode *dir = dentry->d_parent->d_inode;
struct inode *inode = dentry->d_inode;
int error = -EBUSY;
dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
/* If the dentry was sillyrenamed, we simply call d_delete() */
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
error = 0;
goto out;
}
nfs_begin_data_update(dir);
if (inode != NULL) {
nfs_begin_data_update(inode);
error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
/* The VFS may want to delete this inode */
if (error == 0)
inode->i_nlink--;
nfs_end_data_update(inode);
} else
error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
nfs_end_data_update(dir);
out:
return error;
}
static int
nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
{
struct inode *inode = old_dentry->d_inode;
int error;
dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
dentry->d_parent->d_name.name, dentry->d_name.name);
/*
* Drop the dentry in advance to force a new lookup.
* Since nfs_proc_link doesn't return a file handle,
* we can't use the existing dentry.
*/
lock_kernel();
d_drop(dentry);
nfs_begin_data_update(dir);
nfs_begin_data_update(inode);
error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
nfs_end_data_update(inode);
nfs_end_data_update(dir);
unlock_kernel();
return error;
}
/*
* See comments for nfs_proc_create regarding failed operations.
*/
static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct iattr attr;
struct nfs_fattr fattr;
struct nfs_fh fhandle;
int error;
dfprintk(VFS, "NFS: mkdir(%s/%ld, %s\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name);
attr.ia_valid = ATTR_MODE;
attr.ia_mode = mode | S_IFDIR;
lock_kernel();
#if 0
/*
* Always drop the dentry, we can't always depend on
* the fattr returned by the server (AIX seems to be
* broken). We're better off doing another lookup than
* depending on potentially bogus information.
*/
d_drop(dentry);
#endif
nfs_begin_data_update(dir);
error = NFS_PROTO(dir)->mkdir(dir, &dentry->d_name, &attr, &fhandle,
&fattr);
nfs_end_data_update(dir);
if (!error)
error = nfs_instantiate(dentry, &fhandle, &fattr);
else
d_drop(dentry);
unlock_kernel();
return error;
}
/*
* See comments for nfs_proc_create regarding failed operations.
*/
static int
nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
{
struct iattr attr;
struct nfs_fattr fattr;
struct nfs_fh fhandle;
int error;
dfprintk(VFS, "NFS: mknod(%s/%ld, %s\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name);
if (!new_valid_dev(rdev))
return -EINVAL;
attr.ia_mode = mode;
attr.ia_valid = ATTR_MODE;
lock_kernel();
nfs_begin_data_update(dir);
error = NFS_PROTO(dir)->mknod(dir, &dentry->d_name, &attr, rdev,
&fhandle, &fattr);
nfs_end_data_update(dir);
if (!error)
error = nfs_instantiate(dentry, &fhandle, &fattr);
else
d_drop(dentry);
unlock_kernel();
return error;
}
static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
struct posix_acl *dfacl)
{
struct nfs_server *server = NFS_SERVER(inode);
struct nfs_fattr fattr;
struct page *pages[NFSACL_MAXPAGES] = { };
struct nfs3_setaclargs args = {
.inode = inode,
.mask = NFS_ACL,
.acl_access = acl,
.pages = pages,
};
int status, count;
status = -EOPNOTSUPP;
if (!nfs_server_capable(inode, NFS_CAP_ACLS))
goto out;
/* We are doing this here, because XDR marshalling can only
return -ENOMEM. */
status = -ENOSPC;
if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
goto out;
if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
goto out;
if (S_ISDIR(inode->i_mode)) {
args.mask |= NFS_DFACL;
args.acl_default = dfacl;
}
dprintk("NFS call setacl\n");
nfs_begin_data_update(inode);
status = rpc_call(server->client_acl, ACLPROC3_SETACL,
&args, &fattr, 0);
spin_lock(&inode->i_lock);
NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS;
spin_unlock(&inode->i_lock);
nfs_end_data_update(inode);
dprintk("NFS reply setacl: %d\n", status);
/* pages may have been allocated at the xdr layer. */
for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
__free_page(args.pages[count]);
switch (status) {
case 0:
status = nfs_refresh_inode(inode, &fattr);
break;
case -EPFNOSUPPORT:
case -EPROTONOSUPPORT:
dprintk("NFS_V3_ACL SETACL RPC not supported"
"(will not retry)\n");
server->caps &= ~NFS_CAP_ACLS;
case -ENOTSUPP:
status = -EOPNOTSUPP;
}
out:
return status;
}
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 int
nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
struct iattr attr;
struct nfs_fattr sym_attr;
struct nfs_fh sym_fh;
struct qstr qsymname;
int error;
dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name, symname);
error = -ENAMETOOLONG;
switch (NFS_PROTO(dir)->version) {
case 2:
if (strlen(symname) > NFS2_MAXPATHLEN)
goto out;
break;
case 3:
if (strlen(symname) > NFS3_MAXPATHLEN)
goto out;
default:
break;
}
#ifdef NFS_PARANOIA
if (dentry->d_inode)
printk("nfs_proc_symlink: %s/%s not negative!\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
#endif
/*
* Fill in the sattr for the call.
* Note: SunOS 4.1.2 crashes if the mode isn't initialized!
*/
attr.ia_valid = ATTR_MODE;
attr.ia_mode = S_IFLNK | S_IRWXUGO;
qsymname.name = symname;
qsymname.len = strlen(symname);
lock_kernel();
nfs_begin_data_update(dir);
error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname,
&attr, &sym_fh, &sym_attr);
nfs_end_data_update(dir);
if (!error) {
error = nfs_instantiate(dentry, &sym_fh, &sym_attr);
} else {
if (error == -EEXIST)
printk("nfs_proc_symlink: %s/%s already exists??\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
d_drop(dentry);
}
unlock_kernel();
out:
return error;
}
static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
{
int error;
dfprintk(VFS, "NFS: rmdir(%s/%ld, %s\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name);
lock_kernel();
nfs_begin_data_update(dir);
error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
/* Ensure the VFS deletes this inode */
if (error == 0 && dentry->d_inode != NULL)
dentry->d_inode->i_nlink = 0;
nfs_end_data_update(dir);
unlock_kernel();
return error;
}
/*
* 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;
}
/*
* 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;
}
