39f60c1cce
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
364 lines
8.3 KiB
C
364 lines
8.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* Extended attribute handling for AFS. We use xattrs to get and set metadata
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* instead of providing pioctl().
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*
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* Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/xattr.h>
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#include "internal.h"
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/*
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* Deal with the result of a successful fetch ACL operation.
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*/
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static void afs_acl_success(struct afs_operation *op)
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{
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afs_vnode_commit_status(op, &op->file[0]);
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}
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static void afs_acl_put(struct afs_operation *op)
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{
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kfree(op->acl);
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}
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static const struct afs_operation_ops afs_fetch_acl_operation = {
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.issue_afs_rpc = afs_fs_fetch_acl,
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.success = afs_acl_success,
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.put = afs_acl_put,
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};
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/*
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* Get a file's ACL.
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*/
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static int afs_xattr_get_acl(const struct xattr_handler *handler,
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struct dentry *dentry,
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struct inode *inode, const char *name,
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void *buffer, size_t size)
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{
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struct afs_operation *op;
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struct afs_vnode *vnode = AFS_FS_I(inode);
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struct afs_acl *acl = NULL;
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int ret;
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op = afs_alloc_operation(NULL, vnode->volume);
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if (IS_ERR(op))
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return -ENOMEM;
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afs_op_set_vnode(op, 0, vnode);
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op->ops = &afs_fetch_acl_operation;
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afs_begin_vnode_operation(op);
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afs_wait_for_operation(op);
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acl = op->acl;
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op->acl = NULL;
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ret = afs_put_operation(op);
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if (ret == 0) {
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ret = acl->size;
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if (size > 0) {
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if (acl->size <= size)
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memcpy(buffer, acl->data, acl->size);
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else
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ret = -ERANGE;
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}
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}
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kfree(acl);
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return ret;
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}
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static bool afs_make_acl(struct afs_operation *op,
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const void *buffer, size_t size)
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{
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struct afs_acl *acl;
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acl = kmalloc(sizeof(*acl) + size, GFP_KERNEL);
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if (!acl) {
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afs_op_nomem(op);
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return false;
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}
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acl->size = size;
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memcpy(acl->data, buffer, size);
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op->acl = acl;
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return true;
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}
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static const struct afs_operation_ops afs_store_acl_operation = {
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.issue_afs_rpc = afs_fs_store_acl,
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.success = afs_acl_success,
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.put = afs_acl_put,
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};
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/*
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* Set a file's AFS3 ACL.
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*/
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static int afs_xattr_set_acl(const struct xattr_handler *handler,
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struct mnt_idmap *idmap,
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struct dentry *dentry,
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struct inode *inode, const char *name,
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const void *buffer, size_t size, int flags)
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{
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struct afs_operation *op;
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struct afs_vnode *vnode = AFS_FS_I(inode);
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if (flags == XATTR_CREATE)
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return -EINVAL;
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op = afs_alloc_operation(NULL, vnode->volume);
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if (IS_ERR(op))
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return -ENOMEM;
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afs_op_set_vnode(op, 0, vnode);
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if (!afs_make_acl(op, buffer, size))
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return afs_put_operation(op);
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op->ops = &afs_store_acl_operation;
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return afs_do_sync_operation(op);
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}
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static const struct xattr_handler afs_xattr_afs_acl_handler = {
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.name = "afs.acl",
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.get = afs_xattr_get_acl,
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.set = afs_xattr_set_acl,
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};
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static const struct afs_operation_ops yfs_fetch_opaque_acl_operation = {
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.issue_yfs_rpc = yfs_fs_fetch_opaque_acl,
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.success = afs_acl_success,
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/* Don't free op->yacl in .put here */
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};
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/*
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* Get a file's YFS ACL.
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*/
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static int afs_xattr_get_yfs(const struct xattr_handler *handler,
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struct dentry *dentry,
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struct inode *inode, const char *name,
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void *buffer, size_t size)
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{
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struct afs_operation *op;
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struct afs_vnode *vnode = AFS_FS_I(inode);
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struct yfs_acl *yacl = NULL;
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char buf[16], *data;
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int which = 0, dsize, ret = -ENOMEM;
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if (strcmp(name, "acl") == 0)
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which = 0;
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else if (strcmp(name, "acl_inherited") == 0)
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which = 1;
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else if (strcmp(name, "acl_num_cleaned") == 0)
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which = 2;
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else if (strcmp(name, "vol_acl") == 0)
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which = 3;
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else
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return -EOPNOTSUPP;
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yacl = kzalloc(sizeof(struct yfs_acl), GFP_KERNEL);
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if (!yacl)
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goto error;
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if (which == 0)
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yacl->flags |= YFS_ACL_WANT_ACL;
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else if (which == 3)
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yacl->flags |= YFS_ACL_WANT_VOL_ACL;
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op = afs_alloc_operation(NULL, vnode->volume);
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if (IS_ERR(op))
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goto error_yacl;
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afs_op_set_vnode(op, 0, vnode);
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op->yacl = yacl;
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op->ops = &yfs_fetch_opaque_acl_operation;
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afs_begin_vnode_operation(op);
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afs_wait_for_operation(op);
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ret = afs_put_operation(op);
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if (ret == 0) {
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switch (which) {
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case 0:
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data = yacl->acl->data;
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dsize = yacl->acl->size;
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break;
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case 1:
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data = buf;
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dsize = scnprintf(buf, sizeof(buf), "%u", yacl->inherit_flag);
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break;
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case 2:
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data = buf;
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dsize = scnprintf(buf, sizeof(buf), "%u", yacl->num_cleaned);
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break;
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case 3:
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data = yacl->vol_acl->data;
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dsize = yacl->vol_acl->size;
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break;
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default:
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ret = -EOPNOTSUPP;
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goto error_yacl;
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}
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ret = dsize;
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if (size > 0) {
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if (dsize <= size)
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memcpy(buffer, data, dsize);
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else
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ret = -ERANGE;
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}
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} else if (ret == -ENOTSUPP) {
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ret = -ENODATA;
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}
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error_yacl:
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yfs_free_opaque_acl(yacl);
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error:
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return ret;
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}
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static const struct afs_operation_ops yfs_store_opaque_acl2_operation = {
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.issue_yfs_rpc = yfs_fs_store_opaque_acl2,
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.success = afs_acl_success,
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.put = afs_acl_put,
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};
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/*
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* Set a file's YFS ACL.
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*/
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static int afs_xattr_set_yfs(const struct xattr_handler *handler,
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struct mnt_idmap *idmap,
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struct dentry *dentry,
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struct inode *inode, const char *name,
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const void *buffer, size_t size, int flags)
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{
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struct afs_operation *op;
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struct afs_vnode *vnode = AFS_FS_I(inode);
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int ret;
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if (flags == XATTR_CREATE ||
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strcmp(name, "acl") != 0)
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return -EINVAL;
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op = afs_alloc_operation(NULL, vnode->volume);
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if (IS_ERR(op))
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return -ENOMEM;
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afs_op_set_vnode(op, 0, vnode);
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if (!afs_make_acl(op, buffer, size))
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return afs_put_operation(op);
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op->ops = &yfs_store_opaque_acl2_operation;
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ret = afs_do_sync_operation(op);
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if (ret == -ENOTSUPP)
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ret = -ENODATA;
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return ret;
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}
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static const struct xattr_handler afs_xattr_yfs_handler = {
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.prefix = "afs.yfs.",
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.get = afs_xattr_get_yfs,
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.set = afs_xattr_set_yfs,
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};
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/*
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* Get the name of the cell on which a file resides.
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*/
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static int afs_xattr_get_cell(const struct xattr_handler *handler,
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struct dentry *dentry,
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struct inode *inode, const char *name,
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void *buffer, size_t size)
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{
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struct afs_vnode *vnode = AFS_FS_I(inode);
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struct afs_cell *cell = vnode->volume->cell;
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size_t namelen;
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namelen = cell->name_len;
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if (size == 0)
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return namelen;
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if (namelen > size)
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return -ERANGE;
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memcpy(buffer, cell->name, namelen);
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return namelen;
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}
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static const struct xattr_handler afs_xattr_afs_cell_handler = {
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.name = "afs.cell",
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.get = afs_xattr_get_cell,
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};
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/*
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* Get the volume ID, vnode ID and vnode uniquifier of a file as a sequence of
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* hex numbers separated by colons.
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*/
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static int afs_xattr_get_fid(const struct xattr_handler *handler,
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struct dentry *dentry,
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struct inode *inode, const char *name,
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void *buffer, size_t size)
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{
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struct afs_vnode *vnode = AFS_FS_I(inode);
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char text[16 + 1 + 24 + 1 + 8 + 1];
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size_t len;
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/* The volume ID is 64-bit, the vnode ID is 96-bit and the
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* uniquifier is 32-bit.
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*/
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len = scnprintf(text, sizeof(text), "%llx:", vnode->fid.vid);
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if (vnode->fid.vnode_hi)
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len += scnprintf(text + len, sizeof(text) - len, "%x%016llx",
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vnode->fid.vnode_hi, vnode->fid.vnode);
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else
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len += scnprintf(text + len, sizeof(text) - len, "%llx",
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vnode->fid.vnode);
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len += scnprintf(text + len, sizeof(text) - len, ":%x",
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vnode->fid.unique);
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if (size == 0)
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return len;
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if (len > size)
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return -ERANGE;
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memcpy(buffer, text, len);
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return len;
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}
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static const struct xattr_handler afs_xattr_afs_fid_handler = {
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.name = "afs.fid",
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.get = afs_xattr_get_fid,
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};
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/*
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* Get the name of the volume on which a file resides.
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*/
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static int afs_xattr_get_volume(const struct xattr_handler *handler,
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struct dentry *dentry,
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struct inode *inode, const char *name,
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void *buffer, size_t size)
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{
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struct afs_vnode *vnode = AFS_FS_I(inode);
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const char *volname = vnode->volume->name;
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size_t namelen;
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namelen = strlen(volname);
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if (size == 0)
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return namelen;
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if (namelen > size)
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return -ERANGE;
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memcpy(buffer, volname, namelen);
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return namelen;
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}
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static const struct xattr_handler afs_xattr_afs_volume_handler = {
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.name = "afs.volume",
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.get = afs_xattr_get_volume,
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};
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const struct xattr_handler *afs_xattr_handlers[] = {
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&afs_xattr_afs_acl_handler,
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&afs_xattr_afs_cell_handler,
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&afs_xattr_afs_fid_handler,
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&afs_xattr_afs_volume_handler,
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&afs_xattr_yfs_handler, /* afs.yfs. prefix */
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NULL
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};
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