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, 465 insertions, 0 deletions

diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
new file mode 100644
index 000000000000..dff2a2bfa755
--- /dev/null
+++ b/fs/f2fs/acl.c
@@ -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,
+};