f2fs: add xattr and acl functionalities

This implements xattr and acl functionalities.

- F2FS uses a node page to contain use extended attributes.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 389 insertions, 0 deletions

diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
new file mode 100644
index 000000000000..aca50fe163f6
--- /dev/null
+++ b/fs/f2fs/xattr.c
@@ -0,0 +1,389 @@
+/**
+ * fs/f2fs/xattr.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/xattr.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Extended attributes for symlinks and special files added per
+ *  suggestion of Luka Renko <luka.renko@hermes.si>.
+ * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
+ *  Red Hat Inc.
+ *
+ * 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.
+ */
+#include <linux/rwsem.h>
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "xattr.h"
+
+static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
+                size_t list_size, const char *name, size_t name_len, int type)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+        int total_len, prefix_len = 0;
+        const char *prefix = NULL;
+
+        switch (type) {
+        case F2FS_XATTR_INDEX_USER:
+                if (!test_opt(sbi, XATTR_USER))
+                        return -EOPNOTSUPP;
+                prefix = XATTR_USER_PREFIX;
+                prefix_len = XATTR_USER_PREFIX_LEN;
+                break;
+        case F2FS_XATTR_INDEX_TRUSTED:
+                if (!capable(CAP_SYS_ADMIN))
+                        return -EPERM;
+                prefix = XATTR_TRUSTED_PREFIX;
+                prefix_len = XATTR_TRUSTED_PREFIX_LEN;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        total_len = prefix_len + name_len + 1;
+        if (list && total_len <= list_size) {
+                memcpy(list, prefix, prefix_len);
+                memcpy(list+prefix_len, name, name_len);
+                list[prefix_len + name_len] = '\0';
+        }
+        return total_len;
+}
+
+static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
+                void *buffer, size_t size, int type)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+
+        switch (type) {
+        case F2FS_XATTR_INDEX_USER:
+                if (!test_opt(sbi, XATTR_USER))
+                        return -EOPNOTSUPP;
+                break;
+        case F2FS_XATTR_INDEX_TRUSTED:
+                if (!capable(CAP_SYS_ADMIN))
+                        return -EPERM;
+                break;
+        default:
+                return -EINVAL;
+        }
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return f2fs_getxattr(dentry->d_inode, type, name,
+                        buffer, size);
+}
+
+static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
+                const void *value, size_t size, int flags, int type)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+
+        switch (type) {
+        case F2FS_XATTR_INDEX_USER:
+                if (!test_opt(sbi, XATTR_USER))
+                        return -EOPNOTSUPP;
+                break;
+        case F2FS_XATTR_INDEX_TRUSTED:
+                if (!capable(CAP_SYS_ADMIN))
+                        return -EPERM;
+                break;
+        default:
+                return -EINVAL;
+        }
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+
+        return f2fs_setxattr(dentry->d_inode, type, name, value, size);
+}
+
+const struct xattr_handler f2fs_xattr_user_handler = {
+        .prefix = XATTR_USER_PREFIX,
+        .flags  = F2FS_XATTR_INDEX_USER,
+        .list   = f2fs_xattr_generic_list,
+        .get    = f2fs_xattr_generic_get,
+        .set    = f2fs_xattr_generic_set,
+};
+
+const struct xattr_handler f2fs_xattr_trusted_handler = {
+        .prefix = XATTR_TRUSTED_PREFIX,
+        .flags  = F2FS_XATTR_INDEX_TRUSTED,
+        .list   = f2fs_xattr_generic_list,
+        .get    = f2fs_xattr_generic_get,
+        .set    = f2fs_xattr_generic_set,
+};
+
+static const struct xattr_handler *f2fs_xattr_handler_map[] = {
+        [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+        [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &f2fs_xattr_acl_access_handler,
+        [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &f2fs_xattr_acl_default_handler,
+#endif
+        [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
+        [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
+};
+
+const struct xattr_handler *f2fs_xattr_handlers[] = {
+        &f2fs_xattr_user_handler,
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+        &f2fs_xattr_acl_access_handler,
+        &f2fs_xattr_acl_default_handler,
+#endif
+        &f2fs_xattr_trusted_handler,
+        &f2fs_xattr_advise_handler,
+        NULL,
+};
+
+static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
+{
+        const struct xattr_handler *handler = NULL;
+
+        if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
+                handler = f2fs_xattr_handler_map[name_index];
+        return handler;
+}
+
+int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
+                void *buffer, size_t buffer_size)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+        struct f2fs_inode_info *fi = F2FS_I(inode);
+        struct f2fs_xattr_entry *entry;
+        struct page *page;
+        void *base_addr;
+        int error = 0, found = 0;
+        int value_len, name_len;
+
+        if (name == NULL)
+                return -EINVAL;
+        name_len = strlen(name);
+
+        if (!fi->i_xattr_nid)
+                return -ENODATA;
+
+        page = get_node_page(sbi, fi->i_xattr_nid);
+        base_addr = page_address(page);
+
+        list_for_each_xattr(entry, base_addr) {
+                if (entry->e_name_index != name_index)
+                        continue;
+                if (entry->e_name_len != name_len)
+                        continue;
+                if (!memcmp(entry->e_name, name, name_len)) {
+                        found = 1;
+                        break;
+                }
+        }
+        if (!found) {
+                error = -ENODATA;
+                goto cleanup;
+        }
+
+        value_len = le16_to_cpu(entry->e_value_size);
+
+        if (buffer && value_len > buffer_size) {
+                error = -ERANGE;
+                goto cleanup;
+        }
+
+        if (buffer) {
+                char *pval = entry->e_name + entry->e_name_len;
+                memcpy(buffer, pval, value_len);
+        }
+        error = value_len;
+
+cleanup:
+        f2fs_put_page(page, 1);
+        return error;
+}
+
+ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+        struct inode *inode = dentry->d_inode;
+        struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+        struct f2fs_inode_info *fi = F2FS_I(inode);
+        struct f2fs_xattr_entry *entry;
+        struct page *page;
+        void *base_addr;
+        int error = 0;
+        size_t rest = buffer_size;
+
+        if (!fi->i_xattr_nid)
+                return 0;
+
+        page = get_node_page(sbi, fi->i_xattr_nid);
+        base_addr = page_address(page);
+
+        list_for_each_xattr(entry, base_addr) {
+                const struct xattr_handler *handler =
+                        f2fs_xattr_handler(entry->e_name_index);
+                size_t size;
+
+                if (!handler)
+                        continue;
+
+                size = handler->list(dentry, buffer, rest, entry->e_name,
+                                entry->e_name_len, handler->flags);
+                if (buffer && size > rest) {
+                        error = -ERANGE;
+                        goto cleanup;
+                }
+
+                if (buffer)
+                        buffer += size;
+                rest -= size;
+        }
+        error = buffer_size - rest;
+cleanup:
+        f2fs_put_page(page, 1);
+        return error;
+}
+
+int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
+                                        const void *value, size_t value_len)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+        struct f2fs_inode_info *fi = F2FS_I(inode);
+        struct f2fs_xattr_header *header = NULL;
+        struct f2fs_xattr_entry *here, *last;
+        struct page *page;
+        void *base_addr;
+        int error, found, free, name_len, newsize;
+        char *pval;
+
+        if (name == NULL)
+                return -EINVAL;
+        name_len = strlen(name);
+
+        if (value == NULL)
+                value_len = 0;
+
+        if (name_len > 255 || value_len > MAX_VALUE_LEN)
+                return -ERANGE;
+
+        mutex_lock_op(sbi, NODE_NEW);
+        if (!fi->i_xattr_nid) {
+                /* Allocate new attribute block */
+                struct dnode_of_data dn;
+
+                if (!alloc_nid(sbi, &fi->i_xattr_nid)) {
+                        mutex_unlock_op(sbi, NODE_NEW);
+                        return -ENOSPC;
+                }
+                set_new_dnode(&dn, inode, NULL, NULL, fi->i_xattr_nid);
+                mark_inode_dirty(inode);
+
+                page = new_node_page(&dn, XATTR_NODE_OFFSET);
+                if (IS_ERR(page)) {
+                        alloc_nid_failed(sbi, fi->i_xattr_nid);
+                        fi->i_xattr_nid = 0;
+                        mutex_unlock_op(sbi, NODE_NEW);
+                        return PTR_ERR(page);
+                }
+
+                alloc_nid_done(sbi, fi->i_xattr_nid);
+                base_addr = page_address(page);
+                header = XATTR_HDR(base_addr);
+                header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
+                header->h_refcount = cpu_to_le32(1);
+        } else {
+                /* The inode already has an extended attribute block. */
+                page = get_node_page(sbi, fi->i_xattr_nid);
+                if (IS_ERR(page)) {
+                        mutex_unlock_op(sbi, NODE_NEW);
+                        return PTR_ERR(page);
+                }
+
+                base_addr = page_address(page);
+                header = XATTR_HDR(base_addr);
+        }
+
+        if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
+                error = -EIO;
+                goto cleanup;
+        }
+
+        /* find entry with wanted name. */
+        found = 0;
+        list_for_each_xattr(here, base_addr) {
+                if (here->e_name_index != name_index)
+                        continue;
+                if (here->e_name_len != name_len)
+                        continue;
+                if (!memcmp(here->e_name, name, name_len)) {
+                        found = 1;
+                        break;
+                }
+        }
+
+        last = here;
+
+        while (!IS_XATTR_LAST_ENTRY(last))
+                last = XATTR_NEXT_ENTRY(last);
+
+        newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
+                        name_len + value_len);
+
+        /* 1. Check space */
+        if (value) {
+                /* If value is NULL, it is remove operation.
+                 * In case of update operation, we caculate free.
+                 */
+                free = MIN_OFFSET - ((char *)last - (char *)header);
+                if (found)
+                        free = free - ENTRY_SIZE(here);
+
+                if (free < newsize) {
+                        error = -ENOSPC;
+                        goto cleanup;
+                }
+        }
+
+        /* 2. Remove old entry */
+        if (found) {
+                /* If entry is found, remove old entry.
+                 * If not found, remove operation is not needed.
+                 */
+                struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
+                int oldsize = ENTRY_SIZE(here);
+
+                memmove(here, next, (char *)last - (char *)next);
+                last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
+                memset(last, 0, oldsize);
+        }
+
+        /* 3. Write new entry */
+        if (value) {
+                /* Before we come here, old entry is removed.
+                 * We just write new entry. */
+                memset(last, 0, newsize);
+                last->e_name_index = name_index;
+                last->e_name_len = name_len;
+                memcpy(last->e_name, name, name_len);
+                pval = last->e_name + name_len;
+                memcpy(pval, value, value_len);
+                last->e_value_size = cpu_to_le16(value_len);
+        }
+
+        set_page_dirty(page);
+        f2fs_put_page(page, 1);
+
+        if (is_inode_flag_set(fi, FI_ACL_MODE)) {
+                inode->i_mode = fi->i_acl_mode;
+                inode->i_ctime = CURRENT_TIME;
+                clear_inode_flag(fi, FI_ACL_MODE);
+        }
+        f2fs_write_inode(inode, NULL);
+        mutex_unlock_op(sbi, NODE_NEW);
+
+        return 0;
+cleanup:
+        f2fs_put_page(page, 1);
+        mutex_unlock_op(sbi, NODE_NEW);
+        return error;
+}