nilfs2: pathname operations

This adds pathname operations, most of which comes from the ext2 file
system.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 446 insertions, 0 deletions

diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
new file mode 100644
index 000000000000..95d1b29bff3c
--- /dev/null
+++ b/fs/nilfs2/namei.c
@@ -0,0 +1,446 @@
+/*
+ * namei.c - NILFS pathname lookup operations.
+ *
+ * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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
+ *
+ * Modified for NILFS by Amagai Yoshiji <amagai@osrg.net>,
+ *                       Ryusuke Konishi <ryusuke@osrg.net>
+ */
+/*
+ *  linux/fs/ext2/namei.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/namei.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/pagemap.h>
+#include "nilfs.h"
+
+
+static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode)
+{
+        int err = nilfs_add_link(dentry, inode);
+        if (!err) {
+                d_instantiate(dentry, inode);
+                return 0;
+        }
+        inode_dec_link_count(inode);
+        iput(inode);
+        return err;
+}
+
+/*
+ * Methods themselves.
+ */
+
+static struct dentry *
+nilfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+        struct inode *inode;
+        ino_t ino;
+
+        if (dentry->d_name.len > NILFS_NAME_LEN)
+                return ERR_PTR(-ENAMETOOLONG);
+
+        ino = nilfs_inode_by_name(dir, dentry);
+        inode = NULL;
+        if (ino) {
+                inode = nilfs_iget(dir->i_sb, ino);
+                if (IS_ERR(inode))
+                        return ERR_CAST(inode);
+        }
+        return d_splice_alias(inode, dentry);
+}
+
+struct dentry *nilfs_get_parent(struct dentry *child)
+{
+        unsigned long ino;
+        struct inode *inode;
+        struct dentry dotdot;
+
+        dotdot.d_name.name = "..";
+        dotdot.d_name.len = 2;
+
+        ino = nilfs_inode_by_name(child->d_inode, &dotdot);
+        if (!ino)
+                return ERR_PTR(-ENOENT);
+
+        inode = nilfs_iget(child->d_inode->i_sb, ino);
+        if (IS_ERR(inode))
+                return ERR_CAST(inode);
+        return d_obtain_alias(inode);
+}
+
+/*
+ * By the time this is called, we already have created
+ * the directory cache entry for the new file, but it
+ * is so far negative - it has no inode.
+ *
+ * If the create succeeds, we fill in the inode information
+ * with d_instantiate().
+ */
+static int nilfs_create(struct inode *dir, struct dentry *dentry, int mode,
+                        struct nameidata *nd)
+{
+        struct inode *inode;
+        struct nilfs_transaction_info ti;
+        int err, err2;
+
+        err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
+        if (err)
+                return err;
+        inode = nilfs_new_inode(dir, mode);
+        err = PTR_ERR(inode);
+        if (!IS_ERR(inode)) {
+                inode->i_op = &nilfs_file_inode_operations;
+                inode->i_fop = &nilfs_file_operations;
+                inode->i_mapping->a_ops = &nilfs_aops;
+                mark_inode_dirty(inode);
+                err = nilfs_add_nondir(dentry, inode);
+        }
+        err2 = nilfs_transaction_end(dir->i_sb, !err);
+        return err ? : err2;
+}
+
+static int
+nilfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
+{
+        struct inode *inode;
+        struct nilfs_transaction_info ti;
+        int err, err2;
+
+        if (!new_valid_dev(rdev))
+                return -EINVAL;
+
+        err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
+        if (err)
+                return err;
+        inode = nilfs_new_inode(dir, mode);
+        err = PTR_ERR(inode);
+        if (!IS_ERR(inode)) {
+                init_special_inode(inode, inode->i_mode, rdev);
+                mark_inode_dirty(inode);
+                err = nilfs_add_nondir(dentry, inode);
+        }
+        err2 = nilfs_transaction_end(dir->i_sb, !err);
+        return err ? : err2;
+}
+
+static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
+                         const char *symname)
+{
+        struct nilfs_transaction_info ti;
+        struct super_block *sb = dir->i_sb;
+        unsigned l = strlen(symname)+1;
+        struct inode *inode;
+        int err, err2;
+
+        if (l > sb->s_blocksize)
+                return -ENAMETOOLONG;
+
+        err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
+        if (err)
+                return err;
+
+        inode = nilfs_new_inode(dir, S_IFLNK | S_IRWXUGO);
+        err = PTR_ERR(inode);
+        if (IS_ERR(inode))
+                goto out;
+
+        /* slow symlink */
+        inode->i_op = &nilfs_symlink_inode_operations;
+        inode->i_mapping->a_ops = &nilfs_aops;
+        err = page_symlink(inode, symname, l);
+        if (err)
+                goto out_fail;
+
+        /* mark_inode_dirty(inode); */
+        /* nilfs_new_inode() and page_symlink() do this */
+
+        err = nilfs_add_nondir(dentry, inode);
+out:
+        err2 = nilfs_transaction_end(dir->i_sb, !err);
+        return err ? : err2;
+
+out_fail:
+        inode_dec_link_count(inode);
+        iput(inode);
+        goto out;
+}
+
+static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
+                      struct dentry *dentry)
+{
+        struct inode *inode = old_dentry->d_inode;
+        struct nilfs_transaction_info ti;
+        int err, err2;
+
+        if (inode->i_nlink >= NILFS_LINK_MAX)
+                return -EMLINK;
+
+        err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
+        if (err)
+                return err;
+
+        inode->i_ctime = CURRENT_TIME;
+        inode_inc_link_count(inode);
+        atomic_inc(&inode->i_count);
+
+        err = nilfs_add_nondir(dentry, inode);
+        err2 = nilfs_transaction_end(dir->i_sb, !err);
+        return err ? : err2;
+}
+
+static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+        struct inode *inode;
+        struct nilfs_transaction_info ti;
+        int err, err2;
+
+        if (dir->i_nlink >= NILFS_LINK_MAX)
+                return -EMLINK;
+
+        err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
+        if (err)
+                return err;
+
+        inode_inc_link_count(dir);
+
+        inode = nilfs_new_inode(dir, S_IFDIR | mode);
+        err = PTR_ERR(inode);
+        if (IS_ERR(inode))
+                goto out_dir;
+
+        inode->i_op = &nilfs_dir_inode_operations;
+        inode->i_fop = &nilfs_dir_operations;
+        inode->i_mapping->a_ops = &nilfs_aops;
+
+        inode_inc_link_count(inode);
+
+        err = nilfs_make_empty(inode, dir);
+        if (err)
+                goto out_fail;
+
+        err = nilfs_add_link(dentry, inode);
+        if (err)
+                goto out_fail;
+
+        d_instantiate(dentry, inode);
+out:
+        err2 = nilfs_transaction_end(dir->i_sb, !err);
+        return err ? : err2;
+
+out_fail:
+        inode_dec_link_count(inode);
+        inode_dec_link_count(inode);
+        iput(inode);
+out_dir:
+        inode_dec_link_count(dir);
+        goto out;
+}
+
+static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+        struct inode *inode;
+        struct nilfs_dir_entry *de;
+        struct page *page;
+        struct nilfs_transaction_info ti;
+        int err, err2;
+
+        err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
+        if (err)
+                return err;
+
+        err = -ENOENT;
+        de = nilfs_find_entry(dir, dentry, &page);
+        if (!de)
+                goto out;
+
+        inode = dentry->d_inode;
+        err = -EIO;
+        if (le64_to_cpu(de->inode) != inode->i_ino)
+                goto out;
+
+        if (!inode->i_nlink) {
+                nilfs_warning(inode->i_sb, __func__,
+                              "deleting nonexistent file (%lu), %d\n",
+                              inode->i_ino, inode->i_nlink);
+                inode->i_nlink = 1;
+        }
+        err = nilfs_delete_entry(de, page);
+        if (err)
+                goto out;
+
+        inode->i_ctime = dir->i_ctime;
+        inode_dec_link_count(inode);
+        err = 0;
+out:
+        err2 = nilfs_transaction_end(dir->i_sb, !err);
+        return err ? : err2;
+}
+
+static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+        struct inode *inode = dentry->d_inode;
+        struct nilfs_transaction_info ti;
+        int err, err2;
+
+        err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
+        if (err)
+                return err;
+
+        err = -ENOTEMPTY;
+        if (nilfs_empty_dir(inode)) {
+                err = nilfs_unlink(dir, dentry);
+                if (!err) {
+                        inode->i_size = 0;
+                        inode_dec_link_count(inode);
+                        inode_dec_link_count(dir);
+                }
+        }
+        err2 = nilfs_transaction_end(dir->i_sb, !err);
+        return err ? : err2;
+}
+
+static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+                        struct inode *new_dir,  struct dentry *new_dentry)
+{
+        struct inode *old_inode = old_dentry->d_inode;
+        struct inode *new_inode = new_dentry->d_inode;
+        struct page *dir_page = NULL;
+        struct nilfs_dir_entry *dir_de = NULL;
+        struct page *old_page;
+        struct nilfs_dir_entry *old_de;
+        struct nilfs_transaction_info ti;
+        int err;
+
+        err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
+        if (unlikely(err))
+                return err;
+
+        err = -ENOENT;
+        old_de = nilfs_find_entry(old_dir, old_dentry, &old_page);
+        if (!old_de)
+                goto out;
+
+        if (S_ISDIR(old_inode->i_mode)) {
+                err = -EIO;
+                dir_de = nilfs_dotdot(old_inode, &dir_page);
+                if (!dir_de)
+                        goto out_old;
+        }
+
+        if (new_inode) {
+                struct page *new_page;
+                struct nilfs_dir_entry *new_de;
+
+                err = -ENOTEMPTY;
+                if (dir_de && !nilfs_empty_dir(new_inode))
+                        goto out_dir;
+
+                err = -ENOENT;
+                new_de = nilfs_find_entry(new_dir, new_dentry, &new_page);
+                if (!new_de)
+                        goto out_dir;
+                inode_inc_link_count(old_inode);
+                nilfs_set_link(new_dir, new_de, new_page, old_inode);
+                new_inode->i_ctime = CURRENT_TIME;
+                if (dir_de)
+                        drop_nlink(new_inode);
+                inode_dec_link_count(new_inode);
+        } else {
+                if (dir_de) {
+                        err = -EMLINK;
+                        if (new_dir->i_nlink >= NILFS_LINK_MAX)
+                                goto out_dir;
+                }
+                inode_inc_link_count(old_inode);
+                err = nilfs_add_link(new_dentry, old_inode);
+                if (err) {
+                        inode_dec_link_count(old_inode);
+                        goto out_dir;
+                }
+                if (dir_de)
+                        inode_inc_link_count(new_dir);
+        }
+
+        /*
+         * Like most other Unix systems, set the ctime for inodes on a
+         * rename.
+         * inode_dec_link_count() will mark the inode dirty.
+         */
+        old_inode->i_ctime = CURRENT_TIME;
+
+        nilfs_delete_entry(old_de, old_page);
+        inode_dec_link_count(old_inode);
+
+        if (dir_de) {
+                nilfs_set_link(old_inode, dir_de, dir_page, new_dir);
+                inode_dec_link_count(old_dir);
+        }
+
+        err = nilfs_transaction_end(old_dir->i_sb, 1);
+        return err;
+
+out_dir:
+        if (dir_de) {
+                kunmap(dir_page);
+                page_cache_release(dir_page);
+        }
+out_old:
+        kunmap(old_page);
+        page_cache_release(old_page);
+out:
+        nilfs_transaction_end(old_dir->i_sb, 0);
+        return err;
+}
+
+struct inode_operations nilfs_dir_inode_operations = {
+        .create         = nilfs_create,
+        .lookup         = nilfs_lookup,
+        .link           = nilfs_link,
+        .unlink         = nilfs_unlink,
+        .symlink        = nilfs_symlink,
+        .mkdir          = nilfs_mkdir,
+        .rmdir          = nilfs_rmdir,
+        .mknod          = nilfs_mknod,
+        .rename         = nilfs_rename,
+        .setattr        = nilfs_setattr,
+        .permission     = nilfs_permission,
+};
+
+struct inode_operations nilfs_special_inode_operations = {
+        .setattr        = nilfs_setattr,
+        .permission     = nilfs_permission,
+};
+
+struct inode_operations nilfs_symlink_inode_operations = {
+        .readlink       = generic_readlink,
+        .follow_link    = page_follow_link_light,
+        .put_link       = page_put_link,
+};