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-rw-r--r--fs/afs/xattr.c363
1 files changed, 363 insertions, 0 deletions
diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
new file mode 100644
index 000000000..7751b0b3f
--- /dev/null
+++ b/fs/afs/xattr.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Extended attribute handling for AFS. We use xattrs to get and set metadata
+ * instead of providing pioctl().
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/xattr.h>
+#include "internal.h"
+
+/*
+ * Deal with the result of a successful fetch ACL operation.
+ */
+static void afs_acl_success(struct afs_operation *op)
+{
+ afs_vnode_commit_status(op, &op->file[0]);
+}
+
+static void afs_acl_put(struct afs_operation *op)
+{
+ kfree(op->acl);
+}
+
+static const struct afs_operation_ops afs_fetch_acl_operation = {
+ .issue_afs_rpc = afs_fs_fetch_acl,
+ .success = afs_acl_success,
+ .put = afs_acl_put,
+};
+
+/*
+ * Get a file's ACL.
+ */
+static int afs_xattr_get_acl(const struct xattr_handler *handler,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ struct afs_operation *op;
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct afs_acl *acl = NULL;
+ int ret;
+
+ op = afs_alloc_operation(NULL, vnode->volume);
+ if (IS_ERR(op))
+ return -ENOMEM;
+
+ afs_op_set_vnode(op, 0, vnode);
+ op->ops = &afs_fetch_acl_operation;
+
+ afs_begin_vnode_operation(op);
+ afs_wait_for_operation(op);
+ acl = op->acl;
+ op->acl = NULL;
+ ret = afs_put_operation(op);
+
+ if (ret == 0) {
+ ret = acl->size;
+ if (size > 0) {
+ if (acl->size <= size)
+ memcpy(buffer, acl->data, acl->size);
+ else
+ ret = -ERANGE;
+ }
+ }
+
+ kfree(acl);
+ return ret;
+}
+
+static bool afs_make_acl(struct afs_operation *op,
+ const void *buffer, size_t size)
+{
+ struct afs_acl *acl;
+
+ acl = kmalloc(sizeof(*acl) + size, GFP_KERNEL);
+ if (!acl) {
+ afs_op_nomem(op);
+ return false;
+ }
+
+ acl->size = size;
+ memcpy(acl->data, buffer, size);
+ op->acl = acl;
+ return true;
+}
+
+static const struct afs_operation_ops afs_store_acl_operation = {
+ .issue_afs_rpc = afs_fs_store_acl,
+ .success = afs_acl_success,
+ .put = afs_acl_put,
+};
+
+/*
+ * Set a file's AFS3 ACL.
+ */
+static int afs_xattr_set_acl(const struct xattr_handler *handler,
+ struct user_namespace *mnt_userns,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ const void *buffer, size_t size, int flags)
+{
+ struct afs_operation *op;
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+
+ if (flags == XATTR_CREATE)
+ return -EINVAL;
+
+ op = afs_alloc_operation(NULL, vnode->volume);
+ if (IS_ERR(op))
+ return -ENOMEM;
+
+ afs_op_set_vnode(op, 0, vnode);
+ if (!afs_make_acl(op, buffer, size))
+ return afs_put_operation(op);
+
+ op->ops = &afs_store_acl_operation;
+ return afs_do_sync_operation(op);
+}
+
+static const struct xattr_handler afs_xattr_afs_acl_handler = {
+ .name = "afs.acl",
+ .get = afs_xattr_get_acl,
+ .set = afs_xattr_set_acl,
+};
+
+static const struct afs_operation_ops yfs_fetch_opaque_acl_operation = {
+ .issue_yfs_rpc = yfs_fs_fetch_opaque_acl,
+ .success = afs_acl_success,
+ /* Don't free op->yacl in .put here */
+};
+
+/*
+ * Get a file's YFS ACL.
+ */
+static int afs_xattr_get_yfs(const struct xattr_handler *handler,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ struct afs_operation *op;
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct yfs_acl *yacl = NULL;
+ char buf[16], *data;
+ int which = 0, dsize, ret = -ENOMEM;
+
+ if (strcmp(name, "acl") == 0)
+ which = 0;
+ else if (strcmp(name, "acl_inherited") == 0)
+ which = 1;
+ else if (strcmp(name, "acl_num_cleaned") == 0)
+ which = 2;
+ else if (strcmp(name, "vol_acl") == 0)
+ which = 3;
+ else
+ return -EOPNOTSUPP;
+
+ yacl = kzalloc(sizeof(struct yfs_acl), GFP_KERNEL);
+ if (!yacl)
+ goto error;
+
+ if (which == 0)
+ yacl->flags |= YFS_ACL_WANT_ACL;
+ else if (which == 3)
+ yacl->flags |= YFS_ACL_WANT_VOL_ACL;
+
+ op = afs_alloc_operation(NULL, vnode->volume);
+ if (IS_ERR(op))
+ goto error_yacl;
+
+ afs_op_set_vnode(op, 0, vnode);
+ op->yacl = yacl;
+ op->ops = &yfs_fetch_opaque_acl_operation;
+
+ afs_begin_vnode_operation(op);
+ afs_wait_for_operation(op);
+ ret = afs_put_operation(op);
+
+ if (ret == 0) {
+ switch (which) {
+ case 0:
+ data = yacl->acl->data;
+ dsize = yacl->acl->size;
+ break;
+ case 1:
+ data = buf;
+ dsize = scnprintf(buf, sizeof(buf), "%u", yacl->inherit_flag);
+ break;
+ case 2:
+ data = buf;
+ dsize = scnprintf(buf, sizeof(buf), "%u", yacl->num_cleaned);
+ break;
+ case 3:
+ data = yacl->vol_acl->data;
+ dsize = yacl->vol_acl->size;
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ goto error_yacl;
+ }
+
+ ret = dsize;
+ if (size > 0) {
+ if (dsize <= size)
+ memcpy(buffer, data, dsize);
+ else
+ ret = -ERANGE;
+ }
+ } else if (ret == -ENOTSUPP) {
+ ret = -ENODATA;
+ }
+
+error_yacl:
+ yfs_free_opaque_acl(yacl);
+error:
+ return ret;
+}
+
+static const struct afs_operation_ops yfs_store_opaque_acl2_operation = {
+ .issue_yfs_rpc = yfs_fs_store_opaque_acl2,
+ .success = afs_acl_success,
+ .put = afs_acl_put,
+};
+
+/*
+ * Set a file's YFS ACL.
+ */
+static int afs_xattr_set_yfs(const struct xattr_handler *handler,
+ struct user_namespace *mnt_userns,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ const void *buffer, size_t size, int flags)
+{
+ struct afs_operation *op;
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ int ret;
+
+ if (flags == XATTR_CREATE ||
+ strcmp(name, "acl") != 0)
+ return -EINVAL;
+
+ op = afs_alloc_operation(NULL, vnode->volume);
+ if (IS_ERR(op))
+ return -ENOMEM;
+
+ afs_op_set_vnode(op, 0, vnode);
+ if (!afs_make_acl(op, buffer, size))
+ return afs_put_operation(op);
+
+ op->ops = &yfs_store_opaque_acl2_operation;
+ ret = afs_do_sync_operation(op);
+ if (ret == -ENOTSUPP)
+ ret = -ENODATA;
+ return ret;
+}
+
+static const struct xattr_handler afs_xattr_yfs_handler = {
+ .prefix = "afs.yfs.",
+ .get = afs_xattr_get_yfs,
+ .set = afs_xattr_set_yfs,
+};
+
+/*
+ * Get the name of the cell on which a file resides.
+ */
+static int afs_xattr_get_cell(const struct xattr_handler *handler,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct afs_cell *cell = vnode->volume->cell;
+ size_t namelen;
+
+ namelen = cell->name_len;
+ if (size == 0)
+ return namelen;
+ if (namelen > size)
+ return -ERANGE;
+ memcpy(buffer, cell->name, namelen);
+ return namelen;
+}
+
+static const struct xattr_handler afs_xattr_afs_cell_handler = {
+ .name = "afs.cell",
+ .get = afs_xattr_get_cell,
+};
+
+/*
+ * Get the volume ID, vnode ID and vnode uniquifier of a file as a sequence of
+ * hex numbers separated by colons.
+ */
+static int afs_xattr_get_fid(const struct xattr_handler *handler,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ char text[16 + 1 + 24 + 1 + 8 + 1];
+ size_t len;
+
+ /* The volume ID is 64-bit, the vnode ID is 96-bit and the
+ * uniquifier is 32-bit.
+ */
+ len = scnprintf(text, sizeof(text), "%llx:", vnode->fid.vid);
+ if (vnode->fid.vnode_hi)
+ len += scnprintf(text + len, sizeof(text) - len, "%x%016llx",
+ vnode->fid.vnode_hi, vnode->fid.vnode);
+ else
+ len += scnprintf(text + len, sizeof(text) - len, "%llx",
+ vnode->fid.vnode);
+ len += scnprintf(text + len, sizeof(text) - len, ":%x",
+ vnode->fid.unique);
+
+ if (size == 0)
+ return len;
+ if (len > size)
+ return -ERANGE;
+ memcpy(buffer, text, len);
+ return len;
+}
+
+static const struct xattr_handler afs_xattr_afs_fid_handler = {
+ .name = "afs.fid",
+ .get = afs_xattr_get_fid,
+};
+
+/*
+ * Get the name of the volume on which a file resides.
+ */
+static int afs_xattr_get_volume(const struct xattr_handler *handler,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ const char *volname = vnode->volume->name;
+ size_t namelen;
+
+ namelen = strlen(volname);
+ if (size == 0)
+ return namelen;
+ if (namelen > size)
+ return -ERANGE;
+ memcpy(buffer, volname, namelen);
+ return namelen;
+}
+
+static const struct xattr_handler afs_xattr_afs_volume_handler = {
+ .name = "afs.volume",
+ .get = afs_xattr_get_volume,
+};
+
+const struct xattr_handler *afs_xattr_handlers[] = {
+ &afs_xattr_afs_acl_handler,
+ &afs_xattr_afs_cell_handler,
+ &afs_xattr_afs_fid_handler,
+ &afs_xattr_afs_volume_handler,
+ &afs_xattr_yfs_handler, /* afs.yfs. prefix */
+ NULL
+};
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