Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / f2fs / xattr.c
diff --git a/kernel/fs/f2fs/xattr.c b/kernel/fs/f2fs/xattr.c
new file mode 100644 (file)
index 0000000..9757f65
--- /dev/null
@@ -0,0 +1,618 @@
+/*
+ * 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 <linux/security.h>
+#include <linux/posix_acl_xattr.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 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;
+       case F2FS_XATTR_INDEX_SECURITY:
+               prefix = XATTR_SECURITY_PREFIX;
+               prefix_len = XATTR_SECURITY_PREFIX_LEN;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       total_len = prefix_len + len + 1;
+       if (list && total_len <= list_size) {
+               memcpy(list, prefix, prefix_len);
+               memcpy(list + prefix_len, name, len);
+               list[prefix_len + 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;
+       case F2FS_XATTR_INDEX_SECURITY:
+               break;
+       default:
+               return -EINVAL;
+       }
+       if (strcmp(name, "") == 0)
+               return -EINVAL;
+       return f2fs_getxattr(d_inode(dentry), type, name, buffer, size, NULL);
+}
+
+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;
+       case F2FS_XATTR_INDEX_SECURITY:
+               break;
+       default:
+               return -EINVAL;
+       }
+       if (strcmp(name, "") == 0)
+               return -EINVAL;
+
+       return f2fs_setxattr(d_inode(dentry), type, name,
+                                       value, size, NULL, flags);
+}
+
+static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
+               size_t list_size, const char *name, size_t len, int type)
+{
+       const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
+       size_t size;
+
+       if (type != F2FS_XATTR_INDEX_ADVISE)
+               return 0;
+
+       size = strlen(xname) + 1;
+       if (list && size <= list_size)
+               memcpy(list, xname, size);
+       return size;
+}
+
+static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
+               void *buffer, size_t size, int type)
+{
+       struct inode *inode = d_inode(dentry);
+
+       if (strcmp(name, "") != 0)
+               return -EINVAL;
+
+       if (buffer)
+               *((char *)buffer) = F2FS_I(inode)->i_advise;
+       return sizeof(char);
+}
+
+static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
+               const void *value, size_t size, int flags, int type)
+{
+       struct inode *inode = d_inode(dentry);
+
+       if (strcmp(name, "") != 0)
+               return -EINVAL;
+       if (!inode_owner_or_capable(inode))
+               return -EPERM;
+       if (value == NULL)
+               return -EINVAL;
+
+       F2FS_I(inode)->i_advise |= *(char *)value;
+       mark_inode_dirty(inode);
+       return 0;
+}
+
+#ifdef CONFIG_F2FS_FS_SECURITY
+static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+               void *page)
+{
+       const struct xattr *xattr;
+       int err = 0;
+
+       for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+               err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
+                               xattr->name, xattr->value,
+                               xattr->value_len, (struct page *)page, 0);
+               if (err < 0)
+                       break;
+       }
+       return err;
+}
+
+int f2fs_init_security(struct inode *inode, struct inode *dir,
+                               const struct qstr *qstr, struct page *ipage)
+{
+       return security_inode_init_security(inode, dir, qstr,
+                               &f2fs_initxattrs, ipage);
+}
+#endif
+
+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,
+};
+
+const struct xattr_handler f2fs_xattr_advise_handler = {
+       .prefix = F2FS_SYSTEM_ADVISE_PREFIX,
+       .flags  = F2FS_XATTR_INDEX_ADVISE,
+       .list   = f2fs_xattr_advise_list,
+       .get    = f2fs_xattr_advise_get,
+       .set    = f2fs_xattr_advise_set,
+};
+
+const struct xattr_handler f2fs_xattr_security_handler = {
+       .prefix = XATTR_SECURITY_PREFIX,
+       .flags  = F2FS_XATTR_INDEX_SECURITY,
+       .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] = &posix_acl_access_xattr_handler,
+       [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+#endif
+       [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
+#ifdef CONFIG_F2FS_FS_SECURITY
+       [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
+#endif
+       [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
+       &posix_acl_access_xattr_handler,
+       &posix_acl_default_xattr_handler,
+#endif
+       &f2fs_xattr_trusted_handler,
+#ifdef CONFIG_F2FS_FS_SECURITY
+       &f2fs_xattr_security_handler,
+#endif
+       &f2fs_xattr_advise_handler,
+       NULL,
+};
+
+static inline const struct xattr_handler *f2fs_xattr_handler(int index)
+{
+       const struct xattr_handler *handler = NULL;
+
+       if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map))
+               handler = f2fs_xattr_handler_map[index];
+       return handler;
+}
+
+static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int index,
+                                       size_t len, const char *name)
+{
+       struct f2fs_xattr_entry *entry;
+
+       list_for_each_xattr(entry, base_addr) {
+               if (entry->e_name_index != index)
+                       continue;
+               if (entry->e_name_len != len)
+                       continue;
+               if (!memcmp(entry->e_name, name, len))
+                       break;
+       }
+       return entry;
+}
+
+static void *read_all_xattrs(struct inode *inode, struct page *ipage)
+{
+       struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+       struct f2fs_xattr_header *header;
+       size_t size = PAGE_SIZE, inline_size = 0;
+       void *txattr_addr;
+
+       inline_size = inline_xattr_size(inode);
+
+       txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
+       if (!txattr_addr)
+               return NULL;
+
+       /* read from inline xattr */
+       if (inline_size) {
+               struct page *page = NULL;
+               void *inline_addr;
+
+               if (ipage) {
+                       inline_addr = inline_xattr_addr(ipage);
+               } else {
+                       page = get_node_page(sbi, inode->i_ino);
+                       if (IS_ERR(page))
+                               goto fail;
+                       inline_addr = inline_xattr_addr(page);
+               }
+               memcpy(txattr_addr, inline_addr, inline_size);
+               f2fs_put_page(page, 1);
+       }
+
+       /* read from xattr node block */
+       if (F2FS_I(inode)->i_xattr_nid) {
+               struct page *xpage;
+               void *xattr_addr;
+
+               /* The inode already has an extended attribute block. */
+               xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
+               if (IS_ERR(xpage))
+                       goto fail;
+
+               xattr_addr = page_address(xpage);
+               memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
+               f2fs_put_page(xpage, 1);
+       }
+
+       header = XATTR_HDR(txattr_addr);
+
+       /* never been allocated xattrs */
+       if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
+               header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
+               header->h_refcount = cpu_to_le32(1);
+       }
+       return txattr_addr;
+fail:
+       kzfree(txattr_addr);
+       return NULL;
+}
+
+static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
+                               void *txattr_addr, struct page *ipage)
+{
+       struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+       size_t inline_size = 0;
+       void *xattr_addr;
+       struct page *xpage;
+       nid_t new_nid = 0;
+       int err;
+
+       inline_size = inline_xattr_size(inode);
+
+       if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
+               if (!alloc_nid(sbi, &new_nid))
+                       return -ENOSPC;
+
+       /* write to inline xattr */
+       if (inline_size) {
+               struct page *page = NULL;
+               void *inline_addr;
+
+               if (ipage) {
+                       inline_addr = inline_xattr_addr(ipage);
+                       f2fs_wait_on_page_writeback(ipage, NODE);
+               } else {
+                       page = get_node_page(sbi, inode->i_ino);
+                       if (IS_ERR(page)) {
+                               alloc_nid_failed(sbi, new_nid);
+                               return PTR_ERR(page);
+                       }
+                       inline_addr = inline_xattr_addr(page);
+                       f2fs_wait_on_page_writeback(page, NODE);
+               }
+               memcpy(inline_addr, txattr_addr, inline_size);
+               f2fs_put_page(page, 1);
+
+               /* no need to use xattr node block */
+               if (hsize <= inline_size) {
+                       err = truncate_xattr_node(inode, ipage);
+                       alloc_nid_failed(sbi, new_nid);
+                       return err;
+               }
+       }
+
+       /* write to xattr node block */
+       if (F2FS_I(inode)->i_xattr_nid) {
+               xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
+               if (IS_ERR(xpage)) {
+                       alloc_nid_failed(sbi, new_nid);
+                       return PTR_ERR(xpage);
+               }
+               f2fs_bug_on(sbi, new_nid);
+               f2fs_wait_on_page_writeback(xpage, NODE);
+       } else {
+               struct dnode_of_data dn;
+               set_new_dnode(&dn, inode, NULL, NULL, new_nid);
+               xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
+               if (IS_ERR(xpage)) {
+                       alloc_nid_failed(sbi, new_nid);
+                       return PTR_ERR(xpage);
+               }
+               alloc_nid_done(sbi, new_nid);
+       }
+
+       xattr_addr = page_address(xpage);
+       memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
+                                               sizeof(struct node_footer));
+       set_page_dirty(xpage);
+       f2fs_put_page(xpage, 1);
+
+       /* need to checkpoint during fsync */
+       F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
+       return 0;
+}
+
+int f2fs_getxattr(struct inode *inode, int index, const char *name,
+               void *buffer, size_t buffer_size, struct page *ipage)
+{
+       struct f2fs_xattr_entry *entry;
+       void *base_addr;
+       int error = 0;
+       size_t size, len;
+
+       if (name == NULL)
+               return -EINVAL;
+
+       len = strlen(name);
+       if (len > F2FS_NAME_LEN)
+               return -ERANGE;
+
+       base_addr = read_all_xattrs(inode, ipage);
+       if (!base_addr)
+               return -ENOMEM;
+
+       entry = __find_xattr(base_addr, index, len, name);
+       if (IS_XATTR_LAST_ENTRY(entry)) {
+               error = -ENODATA;
+               goto cleanup;
+       }
+
+       size = le16_to_cpu(entry->e_value_size);
+
+       if (buffer && size > buffer_size) {
+               error = -ERANGE;
+               goto cleanup;
+       }
+
+       if (buffer) {
+               char *pval = entry->e_name + entry->e_name_len;
+               memcpy(buffer, pval, size);
+       }
+       error = size;
+
+cleanup:
+       kzfree(base_addr);
+       return error;
+}
+
+ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+       struct inode *inode = d_inode(dentry);
+       struct f2fs_xattr_entry *entry;
+       void *base_addr;
+       int error = 0;
+       size_t rest = buffer_size;
+
+       base_addr = read_all_xattrs(inode, NULL);
+       if (!base_addr)
+               return -ENOMEM;
+
+       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:
+       kzfree(base_addr);
+       return error;
+}
+
+static int __f2fs_setxattr(struct inode *inode, int index,
+                       const char *name, const void *value, size_t size,
+                       struct page *ipage, int flags)
+{
+       struct f2fs_inode_info *fi = F2FS_I(inode);
+       struct f2fs_xattr_entry *here, *last;
+       void *base_addr;
+       int found, newsize;
+       size_t len;
+       __u32 new_hsize;
+       int error = -ENOMEM;
+
+       if (name == NULL)
+               return -EINVAL;
+
+       if (value == NULL)
+               size = 0;
+
+       len = strlen(name);
+
+       if (len > F2FS_NAME_LEN || size > MAX_VALUE_LEN(inode))
+               return -ERANGE;
+
+       base_addr = read_all_xattrs(inode, ipage);
+       if (!base_addr)
+               goto exit;
+
+       /* find entry with wanted name. */
+       here = __find_xattr(base_addr, index, len, name);
+
+       found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
+
+       if ((flags & XATTR_REPLACE) && !found) {
+               error = -ENODATA;
+               goto exit;
+       } else if ((flags & XATTR_CREATE) && found) {
+               error = -EEXIST;
+               goto exit;
+       }
+
+       last = here;
+       while (!IS_XATTR_LAST_ENTRY(last))
+               last = XATTR_NEXT_ENTRY(last);
+
+       newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);
+
+       /* 1. Check space */
+       if (value) {
+               int free;
+               /*
+                * If value is NULL, it is remove operation.
+                * In case of update operation, we calculate free.
+                */
+               free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
+               if (found)
+                       free = free + ENTRY_SIZE(here);
+
+               if (unlikely(free < newsize)) {
+                       error = -ENOSPC;
+                       goto exit;
+               }
+       }
+
+       /* 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);
+       }
+
+       new_hsize = (char *)last - (char *)base_addr;
+
+       /* 3. Write new entry */
+       if (value) {
+               char *pval;
+               /*
+                * Before we come here, old entry is removed.
+                * We just write new entry.
+                */
+               memset(last, 0, newsize);
+               last->e_name_index = index;
+               last->e_name_len = len;
+               memcpy(last->e_name, name, len);
+               pval = last->e_name + len;
+               memcpy(pval, value, size);
+               last->e_value_size = cpu_to_le16(size);
+               new_hsize += newsize;
+       }
+
+       error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
+       if (error)
+               goto exit;
+
+       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);
+       }
+
+       if (ipage)
+               update_inode(inode, ipage);
+       else
+               update_inode_page(inode);
+exit:
+       kzfree(base_addr);
+       return error;
+}
+
+int f2fs_setxattr(struct inode *inode, int index, const char *name,
+                               const void *value, size_t size,
+                               struct page *ipage, int flags)
+{
+       struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+       int err;
+
+       /* this case is only from init_inode_metadata */
+       if (ipage)
+               return __f2fs_setxattr(inode, index, name, value,
+                                               size, ipage, flags);
+       f2fs_balance_fs(sbi);
+
+       f2fs_lock_op(sbi);
+       /* protect xattr_ver */
+       down_write(&F2FS_I(inode)->i_sem);
+       err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags);
+       up_write(&F2FS_I(inode)->i_sem);
+       f2fs_unlock_op(sbi);
+
+       return err;
+}