/* * 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" #include "export.h" #define NILFS_FID_SIZE_NON_CONNECTABLE \ (offsetof(struct nilfs_fid, parent_gen) / 4) #define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4) 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, unsigned int flags) { 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->d_name); inode = ino ? nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino) : NULL; return d_splice_alias(inode, dentry); } /* * 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, umode_t mode, bool excl) { struct inode *inode; struct nilfs_transaction_info ti; int err; 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; nilfs_mark_inode_dirty(inode); err = nilfs_add_nondir(dentry, inode); } if (!err) err = nilfs_transaction_commit(dir->i_sb); else nilfs_transaction_abort(dir->i_sb); return err; } static int nilfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) { struct inode *inode; struct nilfs_transaction_info ti; int err; 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); nilfs_mark_inode_dirty(inode); err = nilfs_add_nondir(dentry, inode); } if (!err) err = nilfs_transaction_commit(dir->i_sb); else nilfs_transaction_abort(dir->i_sb); return err; } 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; 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); */ /* page_symlink() do this */ err = nilfs_add_nondir(dentry, inode); out: if (!err) err = nilfs_transaction_commit(dir->i_sb); else nilfs_transaction_abort(dir->i_sb); return err; out_fail: drop_nlink(inode); nilfs_mark_inode_dirty(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; err = nilfs_transaction_begin(dir->i_sb, &ti, 1); if (err) return err; inode->i_ctime = CURRENT_TIME; inode_inc_link_count(inode); ihold(inode); err = nilfs_add_nondir(dentry, inode); if (!err) err = nilfs_transaction_commit(dir->i_sb); else nilfs_transaction_abort(dir->i_sb); return err; } static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct inode *inode; struct nilfs_transaction_info ti; int err; err = nilfs_transaction_begin(dir->i_sb, &ti, 1); if (err) return err; inc_nlink(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; inc_nlink(inode); err = nilfs_make_empty(inode, dir); if (err) goto out_fail; err = nilfs_add_link(dentry, inode); if (err) goto out_fail; nilfs_mark_inode_dirty(inode); d_instantiate(dentry, inode); out: if (!err) err = nilfs_transaction_commit(dir->i_sb); else nilfs_transaction_abort(dir->i_sb); return err; out_fail: drop_nlink(inode); drop_nlink(inode); nilfs_mark_inode_dirty(inode); iput(inode); out_dir: drop_nlink(dir); nilfs_mark_inode_dirty(dir); goto out; } static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry) { struct inode *inode; struct nilfs_dir_entry *de; struct page *page; int err; err = -ENOENT; de = nilfs_find_entry(dir, &dentry->d_name, &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); set_nlink(inode, 1); } err = nilfs_delete_entry(de, page); if (err) goto out; inode->i_ctime = dir->i_ctime; drop_nlink(inode); err = 0; out: return err; } static int nilfs_unlink(struct inode *dir, struct dentry *dentry) { struct nilfs_transaction_info ti; int err; err = nilfs_transaction_begin(dir->i_sb, &ti, 0); if (err) return err; err = nilfs_do_unlink(dir, dentry); if (!err) { nilfs_mark_inode_dirty(dir); nilfs_mark_inode_dirty(dentry->d_inode); err = nilfs_transaction_commit(dir->i_sb); } else nilfs_transaction_abort(dir->i_sb); return err; } static int nilfs_rmdir(struct inode *dir, struct dentry *dentry) { struct inode *inode = dentry->d_inode; struct nilfs_transaction_info ti; int err; err = nilfs_transaction_begin(dir->i_sb, &ti, 0); if (err) return err; err = -ENOTEMPTY; if (nilfs_empty_dir(inode)) { err = nilfs_do_unlink(dir, dentry); if (!err) { inode->i_size = 0; drop_nlink(inode); nilfs_mark_inode_dirty(inode); drop_nlink(dir); nilfs_mark_inode_dirty(dir); } } if (!err) err = nilfs_transaction_commit(dir->i_sb); else nilfs_transaction_abort(dir->i_sb); return err; } 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->d_name, &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->d_name, &new_page); if (!new_de) goto out_dir; nilfs_set_link(new_dir, new_de, new_page, old_inode); nilfs_mark_inode_dirty(new_dir); new_inode->i_ctime = CURRENT_TIME; if (dir_de) drop_nlink(new_inode); drop_nlink(new_inode); nilfs_mark_inode_dirty(new_inode); } else { err = nilfs_add_link(new_dentry, old_inode); if (err) goto out_dir; if (dir_de) { inc_nlink(new_dir); nilfs_mark_inode_dirty(new_dir); } } /* * Like most other Unix systems, set the ctime for inodes on a * rename. */ old_inode->i_ctime = CURRENT_TIME; nilfs_delete_entry(old_de, old_page); if (dir_de) { nilfs_set_link(old_inode, dir_de, dir_page, new_dir); drop_nlink(old_dir); } nilfs_mark_inode_dirty(old_dir); nilfs_mark_inode_dirty(old_inode); err = nilfs_transaction_commit(old_dir->i_sb); 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_abort(old_dir->i_sb); return err; } /* * Export operations */ static struct dentry *nilfs_get_parent(struct dentry *child) { unsigned long ino; struct inode *inode; struct qstr dotdot = QSTR_INIT("..", 2); struct nilfs_root *root; ino = nilfs_inode_by_name(child->d_inode, &dotdot); if (!ino) return ERR_PTR(-ENOENT); root = NILFS_I(child->d_inode)->i_root; inode = nilfs_iget(child->d_inode->i_sb, root, ino); if (IS_ERR(inode)) return ERR_CAST(inode); return d_obtain_alias(inode); } static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno, u64 ino, u32 gen) { struct nilfs_root *root; struct inode *inode; if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO) return ERR_PTR(-ESTALE); root = nilfs_lookup_root(sb->s_fs_info, cno); if (!root) return ERR_PTR(-ESTALE); inode = nilfs_iget(sb, root, ino); nilfs_put_root(root); if (IS_ERR(inode)) return ERR_CAST(inode); if (gen && inode->i_generation != gen) { iput(inode); return ERR_PTR(-ESTALE); } return d_obtain_alias(inode); } static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh, int fh_len, int fh_type) { struct nilfs_fid *fid = (struct nilfs_fid *)fh; if ((fh_len != NILFS_FID_SIZE_NON_CONNECTABLE && fh_len != NILFS_FID_SIZE_CONNECTABLE) || (fh_type != FILEID_NILFS_WITH_PARENT && fh_type != FILEID_NILFS_WITHOUT_PARENT)) return NULL; return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen); } static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh, int fh_len, int fh_type) { struct nilfs_fid *fid = (struct nilfs_fid *)fh; if (fh_len != NILFS_FID_SIZE_CONNECTABLE || fh_type != FILEID_NILFS_WITH_PARENT) return NULL; return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen); } static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp, struct inode *parent) { struct nilfs_fid *fid = (struct nilfs_fid *)fh; struct nilfs_root *root = NILFS_I(inode)->i_root; int type; if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) { *lenp = NILFS_FID_SIZE_CONNECTABLE; return 255; } if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) { *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; return 255; } fid->cno = root->cno; fid->ino = inode->i_ino; fid->gen = inode->i_generation; if (parent) { fid->parent_ino = parent->i_ino; fid->parent_gen = parent->i_generation; type = FILEID_NILFS_WITH_PARENT; *lenp = NILFS_FID_SIZE_CONNECTABLE; } else { type = FILEID_NILFS_WITHOUT_PARENT; *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; } return type; } const 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, .fiemap = nilfs_fiemap, }; const struct inode_operations nilfs_special_inode_operations = { .setattr = nilfs_setattr, .permission = nilfs_permission, }; const struct inode_operations nilfs_symlink_inode_operations = { .readlink = generic_readlink, .follow_link = page_follow_link_light, .put_link = page_put_link, .permission = nilfs_permission, }; const struct export_operations nilfs_export_ops = { .encode_fh = nilfs_encode_fh, .fh_to_dentry = nilfs_fh_to_dentry, .fh_to_parent = nilfs_fh_to_parent, .get_parent = nilfs_get_parent, };