f2fs: add xattr and acl functionalities
authorJaegeuk Kim <jaegeuk.kim@samsung.com>
Fri, 2 Nov 2012 08:12:17 +0000 (17:12 +0900)
committerJaegeuk Kim <jaegeuk.kim@samsung.com>
Tue, 11 Dec 2012 04:43:41 +0000 (13:43 +0900)
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>
fs/f2fs/acl.c [new file with mode: 0644]
fs/f2fs/acl.h [new file with mode: 0644]
fs/f2fs/xattr.c [new file with mode: 0644]
fs/f2fs/xattr.h [new file with mode: 0644]

diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
new file mode 100644 (file)
index 0000000..dff2a2b
--- /dev/null
@@ -0,0 +1,465 @@
+/**
+ * fs/f2fs/acl.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * 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/f2fs_fs.h>
+#include "f2fs.h"
+#include "xattr.h"
+#include "acl.h"
+
+#define get_inode_mode(i)      ((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
+                                       (F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
+
+static inline size_t f2fs_acl_size(int count)
+{
+       if (count <= 4) {
+               return sizeof(struct f2fs_acl_header) +
+                       count * sizeof(struct f2fs_acl_entry_short);
+       } else {
+               return sizeof(struct f2fs_acl_header) +
+                       4 * sizeof(struct f2fs_acl_entry_short) +
+                       (count - 4) * sizeof(struct f2fs_acl_entry);
+       }
+}
+
+static inline int f2fs_acl_count(size_t size)
+{
+       ssize_t s;
+       size -= sizeof(struct f2fs_acl_header);
+       s = size - 4 * sizeof(struct f2fs_acl_entry_short);
+       if (s < 0) {
+               if (size % sizeof(struct f2fs_acl_entry_short))
+                       return -1;
+               return size / sizeof(struct f2fs_acl_entry_short);
+       } else {
+               if (s % sizeof(struct f2fs_acl_entry))
+                       return -1;
+               return s / sizeof(struct f2fs_acl_entry) + 4;
+       }
+}
+
+static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
+{
+       int i, count;
+       struct posix_acl *acl;
+       struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
+       struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
+       const char *end = value + size;
+
+       if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
+               return ERR_PTR(-EINVAL);
+
+       count = f2fs_acl_count(size);
+       if (count < 0)
+               return ERR_PTR(-EINVAL);
+       if (count == 0)
+               return NULL;
+
+       acl = posix_acl_alloc(count, GFP_KERNEL);
+       if (!acl)
+               return ERR_PTR(-ENOMEM);
+
+       for (i = 0; i < count; i++) {
+
+               if ((char *)entry > end)
+                       goto fail;
+
+               acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag);
+               acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
+
+               switch (acl->a_entries[i].e_tag) {
+               case ACL_USER_OBJ:
+               case ACL_GROUP_OBJ:
+               case ACL_MASK:
+               case ACL_OTHER:
+                       acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
+                       entry = (struct f2fs_acl_entry *)((char *)entry +
+                                       sizeof(struct f2fs_acl_entry_short));
+                       break;
+
+               case ACL_USER:
+                       acl->a_entries[i].e_uid =
+                               make_kuid(&init_user_ns,
+                                               le32_to_cpu(entry->e_id));
+                       entry = (struct f2fs_acl_entry *)((char *)entry +
+                                       sizeof(struct f2fs_acl_entry));
+                       break;
+               case ACL_GROUP:
+                       acl->a_entries[i].e_gid =
+                               make_kgid(&init_user_ns,
+                                               le32_to_cpu(entry->e_id));
+                       entry = (struct f2fs_acl_entry *)((char *)entry +
+                                       sizeof(struct f2fs_acl_entry));
+                       break;
+               default:
+                       goto fail;
+               }
+       }
+       if ((char *)entry != end)
+               goto fail;
+       return acl;
+fail:
+       posix_acl_release(acl);
+       return ERR_PTR(-EINVAL);
+}
+
+static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+       struct f2fs_acl_header *f2fs_acl;
+       struct f2fs_acl_entry *entry;
+       int i;
+
+       f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
+                       sizeof(struct f2fs_acl_entry), GFP_KERNEL);
+       if (!f2fs_acl)
+               return ERR_PTR(-ENOMEM);
+
+       f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
+       entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
+
+       for (i = 0; i < acl->a_count; i++) {
+
+               entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag);
+               entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
+
+               switch (acl->a_entries[i].e_tag) {
+               case ACL_USER:
+                       entry->e_id = cpu_to_le32(
+                                       from_kuid(&init_user_ns,
+                                               acl->a_entries[i].e_uid));
+                       entry = (struct f2fs_acl_entry *)((char *)entry +
+                                       sizeof(struct f2fs_acl_entry));
+                       break;
+               case ACL_GROUP:
+                       entry->e_id = cpu_to_le32(
+                                       from_kgid(&init_user_ns,
+                                               acl->a_entries[i].e_gid));
+                       entry = (struct f2fs_acl_entry *)((char *)entry +
+                                       sizeof(struct f2fs_acl_entry));
+                       break;
+               case ACL_USER_OBJ:
+               case ACL_GROUP_OBJ:
+               case ACL_MASK:
+               case ACL_OTHER:
+                       entry = (struct f2fs_acl_entry *)((char *)entry +
+                                       sizeof(struct f2fs_acl_entry_short));
+                       break;
+               default:
+                       goto fail;
+               }
+       }
+       *size = f2fs_acl_size(acl->a_count);
+       return (void *)f2fs_acl;
+
+fail:
+       kfree(f2fs_acl);
+       return ERR_PTR(-EINVAL);
+}
+
+struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
+{
+       struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+       int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+       void *value = NULL;
+       struct posix_acl *acl;
+       int retval;
+
+       if (!test_opt(sbi, POSIX_ACL))
+               return NULL;
+
+       acl = get_cached_acl(inode, type);
+       if (acl != ACL_NOT_CACHED)
+               return acl;
+
+       if (type == ACL_TYPE_ACCESS)
+               name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+
+       retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
+       if (retval > 0) {
+               value = kmalloc(retval, GFP_KERNEL);
+               if (!value)
+                       return ERR_PTR(-ENOMEM);
+               retval = f2fs_getxattr(inode, name_index, "", value, retval);
+       }
+
+       if (retval < 0) {
+               if (retval == -ENODATA)
+                       acl = NULL;
+               else
+                       acl = ERR_PTR(retval);
+       } else {
+               acl = f2fs_acl_from_disk(value, retval);
+       }
+       kfree(value);
+       if (!IS_ERR(acl))
+               set_cached_acl(inode, type, acl);
+
+       return acl;
+}
+
+static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+       struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+       struct f2fs_inode_info *fi = F2FS_I(inode);
+       int name_index;
+       void *value = NULL;
+       size_t size = 0;
+       int error;
+
+       if (!test_opt(sbi, POSIX_ACL))
+               return 0;
+       if (S_ISLNK(inode->i_mode))
+               return -EOPNOTSUPP;
+
+       switch (type) {
+       case ACL_TYPE_ACCESS:
+               name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+               if (acl) {
+                       error = posix_acl_equiv_mode(acl, &inode->i_mode);
+                       if (error < 0)
+                               return error;
+                       set_acl_inode(fi, inode->i_mode);
+                       if (error == 0)
+                               acl = NULL;
+               }
+               break;
+
+       case ACL_TYPE_DEFAULT:
+               name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+               if (!S_ISDIR(inode->i_mode))
+                       return acl ? -EACCES : 0;
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       if (acl) {
+               value = f2fs_acl_to_disk(acl, &size);
+               if (IS_ERR(value)) {
+                       cond_clear_inode_flag(fi, FI_ACL_MODE);
+                       return (int)PTR_ERR(value);
+               }
+       }
+
+       error = f2fs_setxattr(inode, name_index, "", value, size);
+
+       kfree(value);
+       if (!error)
+               set_cached_acl(inode, type, acl);
+
+       cond_clear_inode_flag(fi, FI_ACL_MODE);
+       return error;
+}
+
+int f2fs_init_acl(struct inode *inode, struct inode *dir)
+{
+       struct posix_acl *acl = NULL;
+       struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
+       int error = 0;
+
+       if (!S_ISLNK(inode->i_mode)) {
+               if (test_opt(sbi, POSIX_ACL)) {
+                       acl = f2fs_get_acl(dir, ACL_TYPE_DEFAULT);
+                       if (IS_ERR(acl))
+                               return PTR_ERR(acl);
+               }
+               if (!acl)
+                       inode->i_mode &= ~current_umask();
+       }
+
+       if (test_opt(sbi, POSIX_ACL) && acl) {
+
+               if (S_ISDIR(inode->i_mode)) {
+                       error = f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
+                       if (error)
+                               goto cleanup;
+               }
+               error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
+               if (error < 0)
+                       return error;
+               if (error > 0)
+                       error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
+       }
+cleanup:
+       posix_acl_release(acl);
+       return error;
+}
+
+int f2fs_acl_chmod(struct inode *inode)
+{
+       struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+       struct posix_acl *acl;
+       int error;
+       mode_t mode = get_inode_mode(inode);
+
+       if (!test_opt(sbi, POSIX_ACL))
+               return 0;
+       if (S_ISLNK(mode))
+               return -EOPNOTSUPP;
+
+       acl = f2fs_get_acl(inode, ACL_TYPE_ACCESS);
+       if (IS_ERR(acl) || !acl)
+               return PTR_ERR(acl);
+
+       error = posix_acl_chmod(&acl, GFP_KERNEL, mode);
+       if (error)
+               return error;
+       error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
+       posix_acl_release(acl);
+       return error;
+}
+
+static size_t f2fs_xattr_list_acl(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);
+       const char *xname = POSIX_ACL_XATTR_DEFAULT;
+       size_t size;
+
+       if (!test_opt(sbi, POSIX_ACL))
+               return 0;
+
+       if (type == ACL_TYPE_ACCESS)
+               xname = POSIX_ACL_XATTR_ACCESS;
+
+       size = strlen(xname) + 1;
+       if (list && size <= list_size)
+               memcpy(list, xname, size);
+       return size;
+}
+
+static int f2fs_xattr_get_acl(struct dentry *dentry, const char *name,
+               void *buffer, size_t size, int type)
+{
+       struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+       struct posix_acl *acl;
+       int error;
+
+       if (strcmp(name, "") != 0)
+               return -EINVAL;
+       if (!test_opt(sbi, POSIX_ACL))
+               return -EOPNOTSUPP;
+
+       acl = f2fs_get_acl(dentry->d_inode, type);
+       if (IS_ERR(acl))
+               return PTR_ERR(acl);
+       if (!acl)
+               return -ENODATA;
+       error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
+       posix_acl_release(acl);
+
+       return error;
+}
+
+static int f2fs_xattr_set_acl(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);
+       struct inode *inode = dentry->d_inode;
+       struct posix_acl *acl = NULL;
+       int error;
+
+       if (strcmp(name, "") != 0)
+               return -EINVAL;
+       if (!test_opt(sbi, POSIX_ACL))
+               return -EOPNOTSUPP;
+       if (!inode_owner_or_capable(inode))
+               return -EPERM;
+
+       if (value) {
+               acl = posix_acl_from_xattr(&init_user_ns, value, size);
+               if (IS_ERR(acl))
+                       return PTR_ERR(acl);
+               if (acl) {
+                       error = posix_acl_valid(acl);
+                       if (error)
+                               goto release_and_out;
+               }
+       } else {
+               acl = NULL;
+       }
+
+       error = f2fs_set_acl(inode, type, acl);
+
+release_and_out:
+       posix_acl_release(acl);
+       return error;
+}
+
+const struct xattr_handler f2fs_xattr_acl_default_handler = {
+       .prefix = POSIX_ACL_XATTR_DEFAULT,
+       .flags = ACL_TYPE_DEFAULT,
+       .list = f2fs_xattr_list_acl,
+       .get = f2fs_xattr_get_acl,
+       .set = f2fs_xattr_set_acl,
+};
+
+const struct xattr_handler f2fs_xattr_acl_access_handler = {
+       .prefix = POSIX_ACL_XATTR_ACCESS,
+       .flags = ACL_TYPE_ACCESS,
+       .list = f2fs_xattr_list_acl,
+       .get = f2fs_xattr_get_acl,
+       .set = f2fs_xattr_set_acl,
+};
+
+static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
+               size_t list_size, const char *name, size_t name_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 = dentry->d_inode;
+
+       if (strcmp(name, "") != 0)
+               return -EINVAL;
+
+       *((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 = dentry->d_inode;
+
+       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;
+       return 0;
+}
+
+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,
+};
diff --git a/fs/f2fs/acl.h b/fs/f2fs/acl.h
new file mode 100644 (file)
index 0000000..c97675e
--- /dev/null
@@ -0,0 +1,57 @@
+/**
+ * fs/f2fs/acl.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.h
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * 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.
+ */
+#ifndef __F2FS_ACL_H__
+#define __F2FS_ACL_H__
+
+#include <linux/posix_acl_xattr.h>
+
+#define F2FS_ACL_VERSION       0x0001
+
+struct f2fs_acl_entry {
+       __le16 e_tag;
+       __le16 e_perm;
+       __le32 e_id;
+};
+
+struct f2fs_acl_entry_short {
+       __le16 e_tag;
+       __le16 e_perm;
+};
+
+struct f2fs_acl_header {
+       __le32 a_version;
+};
+
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+
+extern struct posix_acl *f2fs_get_acl(struct inode *inode, int type);
+extern int f2fs_acl_chmod(struct inode *inode);
+extern int f2fs_init_acl(struct inode *inode, struct inode *dir);
+#else
+#define f2fs_check_acl NULL
+#define f2fs_get_acl   NULL
+#define f2fs_set_acl   NULL
+
+static inline int f2fs_acl_chmod(struct inode *inode)
+{
+       return 0;
+}
+
+static inline int f2fs_init_acl(struct inode *inode, struct inode *dir)
+{
+       return 0;
+}
+#endif
+#endif /* __F2FS_ACL_H__ */
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
new file mode 100644 (file)
index 0000000..aca50fe
--- /dev/null
@@ -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;
+}
diff --git a/fs/f2fs/xattr.h b/fs/f2fs/xattr.h
new file mode 100644 (file)
index 0000000..29b0a08
--- /dev/null
@@ -0,0 +1,145 @@
+/**
+ * fs/f2fs/xattr.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/xattr.h
+ *
+ * On-disk format of extended attributes for the ext2 filesystem.
+ *
+ * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ *
+ * 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.
+ */
+#ifndef __F2FS_XATTR_H__
+#define __F2FS_XATTR_H__
+
+#include <linux/init.h>
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define F2FS_XATTR_MAGIC                0xF2F52011
+
+/* Maximum number of references to one attribute block */
+#define F2FS_XATTR_REFCOUNT_MAX         1024
+
+/* Name indexes */
+#define F2FS_SYSTEM_ADVISE_PREFIX              "system.advise"
+#define F2FS_XATTR_INDEX_USER                  1
+#define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS      2
+#define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT     3
+#define F2FS_XATTR_INDEX_TRUSTED               4
+#define F2FS_XATTR_INDEX_LUSTRE                        5
+#define F2FS_XATTR_INDEX_SECURITY              6
+#define F2FS_XATTR_INDEX_ADVISE                        7
+
+struct f2fs_xattr_header {
+       __le32  h_magic;        /* magic number for identification */
+       __le32  h_refcount;     /* reference count */
+       __u32   h_reserved[4];  /* zero right now */
+};
+
+struct f2fs_xattr_entry {
+       __u8    e_name_index;
+       __u8    e_name_len;
+       __le16  e_value_size;   /* size of attribute value */
+       char    e_name[0];      /* attribute name */
+};
+
+#define XATTR_HDR(ptr)         ((struct f2fs_xattr_header *)(ptr))
+#define XATTR_ENTRY(ptr)       ((struct f2fs_xattr_entry *)(ptr))
+#define XATTR_FIRST_ENTRY(ptr) (XATTR_ENTRY(XATTR_HDR(ptr)+1))
+#define XATTR_ROUND            (3)
+
+#define XATTR_ALIGN(size)      ((size + XATTR_ROUND) & ~XATTR_ROUND)
+
+#define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
+                       entry->e_name_len + le16_to_cpu(entry->e_value_size)))
+
+#define XATTR_NEXT_ENTRY(entry)        ((struct f2fs_xattr_entry *)((char *)(entry) +\
+                       ENTRY_SIZE(entry)))
+
+#define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+
+#define list_for_each_xattr(entry, addr) \
+               for (entry = XATTR_FIRST_ENTRY(addr);\
+                               !IS_XATTR_LAST_ENTRY(entry);\
+                               entry = XATTR_NEXT_ENTRY(entry))
+
+
+#define MIN_OFFSET     XATTR_ALIGN(PAGE_SIZE - \
+                       sizeof(struct node_footer) - \
+                       sizeof(__u32))
+
+#define MAX_VALUE_LEN  (MIN_OFFSET - sizeof(struct f2fs_xattr_header) - \
+                       sizeof(struct f2fs_xattr_entry))
+
+/**
+ * On-disk structure of f2fs_xattr
+ * We use only 1 block for xattr.
+ *
+ * +--------------------+
+ * | f2fs_xattr_header  |
+ * |                    |
+ * +--------------------+
+ * | f2fs_xattr_entry   |
+ * | .e_name_index = 1  |
+ * | .e_name_len = 3    |
+ * | .e_value_size = 14 |
+ * | .e_name = "foo"    |
+ * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
+ * +--------------------+
+ * | f2fs_xattr_entry   |
+ * | .e_name_index = 4  |
+ * | .e_name = "bar"    |
+ * +--------------------+
+ * |                    |
+ * |        Free        |
+ * |                    |
+ * +--------------------+<- MIN_OFFSET
+ * |   node_footer      |
+ * | (nid, ino, offset) |
+ * +--------------------+
+ *
+ **/
+
+#ifdef CONFIG_F2FS_FS_XATTR
+extern const struct xattr_handler f2fs_xattr_user_handler;
+extern const struct xattr_handler f2fs_xattr_trusted_handler;
+extern const struct xattr_handler f2fs_xattr_acl_access_handler;
+extern const struct xattr_handler f2fs_xattr_acl_default_handler;
+extern const struct xattr_handler f2fs_xattr_advise_handler;
+
+extern const struct xattr_handler *f2fs_xattr_handlers[];
+
+extern int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
+               const void *value, size_t value_len);
+extern int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
+               void *buffer, size_t buffer_size);
+extern ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
+               size_t buffer_size);
+
+#else
+
+#define f2fs_xattr_handlers    NULL
+static inline int f2fs_setxattr(struct inode *inode, int name_index,
+       const char *name, const void *value, size_t value_len)
+{
+       return -EOPNOTSUPP;
+}
+static inline int f2fs_getxattr(struct inode *inode, int name_index,
+               const char *name, void *buffer, size_t buffer_size)
+{
+       return -EOPNOTSUPP;
+}
+static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
+               size_t buffer_size)
+{
+       return -EOPNOTSUPP;
+}
+#endif
+
+#endif /* __F2FS_XATTR_H__ */