[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/fs/ubifs/xattr.c b/src/kernel/linux/v4.19/fs/ubifs/xattr.c
new file mode 100644
index 0000000..f5ad1ed
--- /dev/null
+++ b/src/kernel/linux/v4.19/fs/ubifs/xattr.c
@@ -0,0 +1,679 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ * Adrian Hunter
+ */
+
+/*
+ * This file implements UBIFS extended attributes support.
+ *
+ * Extended attributes are implemented as regular inodes with attached data,
+ * which limits extended attribute size to UBIFS block size (4KiB). Names of
+ * extended attributes are described by extended attribute entries (xentries),
+ * which are almost identical to directory entries, but have different key type.
+ *
+ * In other words, the situation with extended attributes is very similar to
+ * directories. Indeed, any inode (but of course not xattr inodes) may have a
+ * number of associated xentries, just like directory inodes have associated
+ * directory entries. Extended attribute entries store the name of the extended
+ * attribute, the host inode number, and the extended attribute inode number.
+ * Similarly, direntries store the name, the parent and the target inode
+ * numbers. Thus, most of the common UBIFS mechanisms may be re-used for
+ * extended attributes.
+ *
+ * The number of extended attributes is not limited, but there is Linux
+ * limitation on the maximum possible size of the list of all extended
+ * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure
+ * the sum of all extended attribute names of the inode does not exceed that
+ * limit.
+ *
+ * Extended attributes are synchronous, which means they are written to the
+ * flash media synchronously and there is no write-back for extended attribute
+ * inodes. The extended attribute values are not stored in compressed form on
+ * the media.
+ *
+ * Since extended attributes are represented by regular inodes, they are cached
+ * in the VFS inode cache. The xentries are cached in the LNC cache (see
+ * tnc.c).
+ *
+ * ACL support is not implemented.
+ */
+
+#include "ubifs.h"
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+
+/*
+ * Limit the number of extended attributes per inode so that the total size
+ * (@xattr_size) is guaranteeded to fit in an 'unsigned int'.
+ */
+#define MAX_XATTRS_PER_INODE 65535
+
+/*
+ * Extended attribute type constants.
+ *
+ * USER_XATTR: user extended attribute ("user.*")
+ * TRUSTED_XATTR: trusted extended attribute ("trusted.*)
+ * SECURITY_XATTR: security extended attribute ("security.*")
+ */
+enum {
+ USER_XATTR,
+ TRUSTED_XATTR,
+ SECURITY_XATTR,
+};
+
+static const struct inode_operations empty_iops;
+static const struct file_operations empty_fops;
+
+/**
+ * create_xattr - create an extended attribute.
+ * @c: UBIFS file-system description object
+ * @host: host inode
+ * @nm: extended attribute name
+ * @value: extended attribute value
+ * @size: size of extended attribute value
+ *
+ * This is a helper function which creates an extended attribute of name @nm
+ * and value @value for inode @host. The host inode is also updated on flash
+ * because the ctime and extended attribute accounting data changes. This
+ * function returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+static int create_xattr(struct ubifs_info *c, struct inode *host,
+ const struct fscrypt_name *nm, const void *value, int size)
+{
+ int err, names_len;
+ struct inode *inode;
+ struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
+ struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+ .new_ino_d = ALIGN(size, 8), .dirtied_ino = 1,
+ .dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
+
+ if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE) {
+ ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more",
+ host->i_ino, host_ui->xattr_cnt);
+ return -ENOSPC;
+ }
+ /*
+ * Linux limits the maximum size of the extended attribute names list
+ * to %XATTR_LIST_MAX. This means we should not allow creating more
+ * extended attributes if the name list becomes larger. This limitation
+ * is artificial for UBIFS, though.
+ */
+ names_len = host_ui->xattr_names + host_ui->xattr_cnt + fname_len(nm) + 1;
+ if (names_len > XATTR_LIST_MAX) {
+ ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d",
+ host->i_ino, names_len, XATTR_LIST_MAX);
+ return -ENOSPC;
+ }
+
+ err = ubifs_budget_space(c, &req);
+ if (err)
+ return err;
+
+ inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_budg;
+ }
+
+ /* Re-define all operations to be "nothing" */
+ inode->i_mapping->a_ops = &empty_aops;
+ inode->i_op = &empty_iops;
+ inode->i_fop = &empty_fops;
+
+ inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME;
+ ui = ubifs_inode(inode);
+ ui->xattr = 1;
+ ui->flags |= UBIFS_XATTR_FL;
+ ui->data = kmemdup(value, size, GFP_NOFS);
+ if (!ui->data) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+ inode->i_size = ui->ui_size = size;
+ ui->data_len = size;
+
+ mutex_lock(&host_ui->ui_mutex);
+ host->i_ctime = current_time(host);
+ host_ui->xattr_cnt += 1;
+ host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size += CALC_XATTR_BYTES(size);
+ host_ui->xattr_names += fname_len(nm);
+
+ /*
+ * We handle UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT here because we
+ * have to set the UBIFS_CRYPT_FL flag on the host inode.
+ * To avoid multiple updates of the same inode in the same operation,
+ * let's do it here.
+ */
+ if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
+ host_ui->flags |= UBIFS_CRYPT_FL;
+
+ err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
+ if (err)
+ goto out_cancel;
+ ubifs_set_inode_flags(host);
+ mutex_unlock(&host_ui->ui_mutex);
+
+ ubifs_release_budget(c, &req);
+ insert_inode_hash(inode);
+ iput(inode);
+ return 0;
+
+out_cancel:
+ host_ui->xattr_cnt -= 1;
+ host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size -= CALC_XATTR_BYTES(size);
+ host_ui->xattr_names -= fname_len(nm);
+ host_ui->flags &= ~UBIFS_CRYPT_FL;
+ mutex_unlock(&host_ui->ui_mutex);
+out_free:
+ make_bad_inode(inode);
+ iput(inode);
+out_budg:
+ ubifs_release_budget(c, &req);
+ return err;
+}
+
+/**
+ * change_xattr - change an extended attribute.
+ * @c: UBIFS file-system description object
+ * @host: host inode
+ * @inode: extended attribute inode
+ * @value: extended attribute value
+ * @size: size of extended attribute value
+ *
+ * This helper function changes the value of extended attribute @inode with new
+ * data from @value. Returns zero in case of success and a negative error code
+ * in case of failure.
+ */
+static int change_xattr(struct ubifs_info *c, struct inode *host,
+ struct inode *inode, const void *value, int size)
+{
+ int err;
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ void *buf = NULL;
+ int old_size;
+ struct ubifs_budget_req req = { .dirtied_ino = 2,
+ .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) };
+
+ ubifs_assert(c, ui->data_len == inode->i_size);
+ err = ubifs_budget_space(c, &req);
+ if (err)
+ return err;
+
+ buf = kmemdup(value, size, GFP_NOFS);
+ if (!buf) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+ mutex_lock(&ui->ui_mutex);
+ kfree(ui->data);
+ ui->data = buf;
+ inode->i_size = ui->ui_size = size;
+ old_size = ui->data_len;
+ ui->data_len = size;
+ mutex_unlock(&ui->ui_mutex);
+
+ mutex_lock(&host_ui->ui_mutex);
+ host->i_ctime = current_time(host);
+ host_ui->xattr_size -= CALC_XATTR_BYTES(old_size);
+ host_ui->xattr_size += CALC_XATTR_BYTES(size);
+
+ /*
+ * It is important to write the host inode after the xattr inode
+ * because if the host inode gets synchronized (via 'fsync()'), then
+ * the extended attribute inode gets synchronized, because it goes
+ * before the host inode in the write-buffer.
+ */
+ err = ubifs_jnl_change_xattr(c, inode, host);
+ if (err)
+ goto out_cancel;
+ mutex_unlock(&host_ui->ui_mutex);
+
+ ubifs_release_budget(c, &req);
+ return 0;
+
+out_cancel:
+ host_ui->xattr_size -= CALC_XATTR_BYTES(size);
+ host_ui->xattr_size += CALC_XATTR_BYTES(old_size);
+ mutex_unlock(&host_ui->ui_mutex);
+ make_bad_inode(inode);
+out_free:
+ ubifs_release_budget(c, &req);
+ return err;
+}
+
+static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
+{
+ struct inode *inode;
+
+ inode = ubifs_iget(c->vfs_sb, inum);
+ if (IS_ERR(inode)) {
+ ubifs_err(c, "dead extended attribute entry, error %d",
+ (int)PTR_ERR(inode));
+ return inode;
+ }
+ if (ubifs_inode(inode)->xattr)
+ return inode;
+ ubifs_err(c, "corrupt extended attribute entry");
+ iput(inode);
+ return ERR_PTR(-EINVAL);
+}
+
+int ubifs_xattr_set(struct inode *host, const char *name, const void *value,
+ size_t size, int flags, bool check_lock)
+{
+ struct inode *inode;
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+ struct ubifs_dent_node *xent;
+ union ubifs_key key;
+ int err;
+
+ if (check_lock)
+ ubifs_assert(c, inode_is_locked(host));
+
+ if (size > UBIFS_MAX_INO_DATA)
+ return -ERANGE;
+
+ if (fname_len(&nm) > UBIFS_MAX_NLEN)
+ return -ENAMETOOLONG;
+
+ xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+ if (!xent)
+ return -ENOMEM;
+
+ /*
+ * The extended attribute entries are stored in LNC, so multiple
+ * look-ups do not involve reading the flash.
+ */
+ xent_key_init(c, &key, host->i_ino, &nm);
+ err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+ if (err) {
+ if (err != -ENOENT)
+ goto out_free;
+
+ if (flags & XATTR_REPLACE)
+ /* We are asked not to create the xattr */
+ err = -ENODATA;
+ else
+ err = create_xattr(c, host, &nm, value, size);
+ goto out_free;
+ }
+
+ if (flags & XATTR_CREATE) {
+ /* We are asked not to replace the xattr */
+ err = -EEXIST;
+ goto out_free;
+ }
+
+ inode = iget_xattr(c, le64_to_cpu(xent->inum));
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_free;
+ }
+
+ err = change_xattr(c, host, inode, value, size);
+ iput(inode);
+
+out_free:
+ kfree(xent);
+ return err;
+}
+
+ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
+ size_t size)
+{
+ struct inode *inode;
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+ struct ubifs_inode *ui;
+ struct ubifs_dent_node *xent;
+ union ubifs_key key;
+ int err;
+
+ if (fname_len(&nm) > UBIFS_MAX_NLEN)
+ return -ENAMETOOLONG;
+
+ xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+ if (!xent)
+ return -ENOMEM;
+
+ xent_key_init(c, &key, host->i_ino, &nm);
+ err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+ if (err) {
+ if (err == -ENOENT)
+ err = -ENODATA;
+ goto out_unlock;
+ }
+
+ inode = iget_xattr(c, le64_to_cpu(xent->inum));
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_unlock;
+ }
+
+ ui = ubifs_inode(inode);
+ ubifs_assert(c, inode->i_size == ui->data_len);
+ ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len);
+
+ mutex_lock(&ui->ui_mutex);
+ if (buf) {
+ /* If @buf is %NULL we are supposed to return the length */
+ if (ui->data_len > size) {
+ err = -ERANGE;
+ goto out_iput;
+ }
+
+ memcpy(buf, ui->data, ui->data_len);
+ }
+ err = ui->data_len;
+
+out_iput:
+ mutex_unlock(&ui->ui_mutex);
+ iput(inode);
+out_unlock:
+ kfree(xent);
+ return err;
+}
+
+static bool xattr_visible(const char *name)
+{
+ /* File encryption related xattrs are for internal use only */
+ if (strcmp(name, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
+ return false;
+
+ /* Show trusted namespace only for "power" users */
+ if (strncmp(name, XATTR_TRUSTED_PREFIX,
+ XATTR_TRUSTED_PREFIX_LEN) == 0 && !capable(CAP_SYS_ADMIN))
+ return false;
+
+ return true;
+}
+
+ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+ union ubifs_key key;
+ struct inode *host = d_inode(dentry);
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+ struct ubifs_dent_node *xent, *pxent = NULL;
+ int err, len, written = 0;
+ struct fscrypt_name nm = {0};
+
+ dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino,
+ dentry, size);
+
+ len = host_ui->xattr_names + host_ui->xattr_cnt;
+ if (!buffer)
+ /*
+ * We should return the minimum buffer size which will fit a
+ * null-terminated list of all the extended attribute names.
+ */
+ return len;
+
+ if (len > size)
+ return -ERANGE;
+
+ lowest_xent_key(c, &key, host->i_ino);
+ while (1) {
+ xent = ubifs_tnc_next_ent(c, &key, &nm);
+ if (IS_ERR(xent)) {
+ err = PTR_ERR(xent);
+ break;
+ }
+
+ fname_name(&nm) = xent->name;
+ fname_len(&nm) = le16_to_cpu(xent->nlen);
+
+ if (xattr_visible(xent->name)) {
+ memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1);
+ written += fname_len(&nm) + 1;
+ }
+
+ kfree(pxent);
+ pxent = xent;
+ key_read(c, &xent->key, &key);
+ }
+
+ kfree(pxent);
+ if (err != -ENOENT) {
+ ubifs_err(c, "cannot find next direntry, error %d", err);
+ return err;
+ }
+
+ ubifs_assert(c, written <= size);
+ return written;
+}
+
+static int remove_xattr(struct ubifs_info *c, struct inode *host,
+ struct inode *inode, const struct fscrypt_name *nm)
+{
+ int err;
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1,
+ .dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
+
+ ubifs_assert(c, ui->data_len == inode->i_size);
+
+ err = ubifs_budget_space(c, &req);
+ if (err)
+ return err;
+
+ mutex_lock(&host_ui->ui_mutex);
+ host->i_ctime = current_time(host);
+ host_ui->xattr_cnt -= 1;
+ host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
+ host_ui->xattr_names -= fname_len(nm);
+
+ err = ubifs_jnl_delete_xattr(c, host, inode, nm);
+ if (err)
+ goto out_cancel;
+ mutex_unlock(&host_ui->ui_mutex);
+
+ ubifs_release_budget(c, &req);
+ return 0;
+
+out_cancel:
+ host_ui->xattr_cnt += 1;
+ host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
+ host_ui->xattr_names += fname_len(nm);
+ mutex_unlock(&host_ui->ui_mutex);
+ ubifs_release_budget(c, &req);
+ make_bad_inode(inode);
+ return err;
+}
+
+/**
+ * ubifs_evict_xattr_inode - Evict an xattr inode.
+ * @c: UBIFS file-system description object
+ * @xattr_inum: xattr inode number
+ *
+ * When an inode that hosts xattrs is being removed we have to make sure
+ * that cached inodes of the xattrs also get removed from the inode cache
+ * otherwise we'd waste memory. This function looks up an inode from the
+ * inode cache and clears the link counter such that iput() will evict
+ * the inode.
+ */
+void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum)
+{
+ struct inode *inode;
+
+ inode = ilookup(c->vfs_sb, xattr_inum);
+ if (inode) {
+ clear_nlink(inode);
+ iput(inode);
+ }
+}
+
+static int ubifs_xattr_remove(struct inode *host, const char *name)
+{
+ struct inode *inode;
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+ struct ubifs_dent_node *xent;
+ union ubifs_key key;
+ int err;
+
+ ubifs_assert(c, inode_is_locked(host));
+
+ if (fname_len(&nm) > UBIFS_MAX_NLEN)
+ return -ENAMETOOLONG;
+
+ xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+ if (!xent)
+ return -ENOMEM;
+
+ xent_key_init(c, &key, host->i_ino, &nm);
+ err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+ if (err) {
+ if (err == -ENOENT)
+ err = -ENODATA;
+ goto out_free;
+ }
+
+ inode = iget_xattr(c, le64_to_cpu(xent->inum));
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_free;
+ }
+
+ ubifs_assert(c, inode->i_nlink == 1);
+ clear_nlink(inode);
+ err = remove_xattr(c, host, inode, &nm);
+ if (err)
+ set_nlink(inode, 1);
+
+ /* If @i_nlink is 0, 'iput()' will delete the inode */
+ iput(inode);
+
+out_free:
+ kfree(xent);
+ return err;
+}
+
+#ifdef CONFIG_UBIFS_FS_SECURITY
+static int init_xattrs(struct inode *inode, const struct xattr *xattr_array,
+ void *fs_info)
+{
+ const struct xattr *xattr;
+ char *name;
+ int err = 0;
+
+ for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+ name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
+ strlen(xattr->name) + 1, GFP_NOFS);
+ if (!name) {
+ err = -ENOMEM;
+ break;
+ }
+ strcpy(name, XATTR_SECURITY_PREFIX);
+ strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
+ /*
+ * creating a new inode without holding the inode rwsem,
+ * no need to check whether inode is locked.
+ */
+ err = ubifs_xattr_set(inode, name, xattr->value,
+ xattr->value_len, 0, false);
+ kfree(name);
+ if (err < 0)
+ break;
+ }
+
+ return err;
+}
+
+int ubifs_init_security(struct inode *dentry, struct inode *inode,
+ const struct qstr *qstr)
+{
+ int err;
+
+ err = security_inode_init_security(inode, dentry, qstr,
+ &init_xattrs, 0);
+ if (err) {
+ struct ubifs_info *c = dentry->i_sb->s_fs_info;
+ ubifs_err(c, "cannot initialize security for inode %lu, error %d",
+ inode->i_ino, err);
+ }
+ return err;
+}
+#endif
+
+static int xattr_get(const struct xattr_handler *handler,
+ struct dentry *dentry, struct inode *inode,
+ const char *name, void *buffer, size_t size)
+{
+ dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name,
+ inode->i_ino, dentry, size);
+
+ name = xattr_full_name(handler, name);
+ return ubifs_xattr_get(inode, name, buffer, size);
+}
+
+static int xattr_set(const struct xattr_handler *handler,
+ struct dentry *dentry, struct inode *inode,
+ const char *name, const void *value,
+ size_t size, int flags)
+{
+ dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd",
+ name, inode->i_ino, dentry, size);
+
+ name = xattr_full_name(handler, name);
+
+ if (value)
+ return ubifs_xattr_set(inode, name, value, size, flags, true);
+ else
+ return ubifs_xattr_remove(inode, name);
+}
+
+static const struct xattr_handler ubifs_user_xattr_handler = {
+ .prefix = XATTR_USER_PREFIX,
+ .get = xattr_get,
+ .set = xattr_set,
+};
+
+static const struct xattr_handler ubifs_trusted_xattr_handler = {
+ .prefix = XATTR_TRUSTED_PREFIX,
+ .get = xattr_get,
+ .set = xattr_set,
+};
+
+#ifdef CONFIG_UBIFS_FS_SECURITY
+static const struct xattr_handler ubifs_security_xattr_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .get = xattr_get,
+ .set = xattr_set,
+};
+#endif
+
+const struct xattr_handler *ubifs_xattr_handlers[] = {
+ &ubifs_user_xattr_handler,
+ &ubifs_trusted_xattr_handler,
+#ifdef CONFIG_UBIFS_FS_SECURITY
+ &ubifs_security_xattr_handler,
+#endif
+ NULL
+};