mirror of https://gitee.com/openkylin/linux.git
ubifs: Implement RENAME_EXCHANGE
Adds RENAME_EXCHANGE to UBIFS, the operation itself is completely disjunct from a regular rename() that's why we dispatch very early in ubifs_reaname(). RENAME_EXCHANGE used by the renameat2() system call allows the caller to exchange two paths atomically. Both paths have to exist and have to be on the same filesystem. Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Richard Weinberger
parent
9e0a1fff8d
commit
9ec64962af
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@ -1095,11 +1095,6 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
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old_dentry, old_inode->i_ino, old_dir->i_ino,
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new_dentry, new_dir->i_ino, flags);
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if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT))
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return -EINVAL;
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ubifs_assert(inode_is_locked(old_dir));
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ubifs_assert(inode_is_locked(new_dir));
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if (unlink)
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ubifs_assert(inode_is_locked(new_inode));
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@ -1283,6 +1278,64 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
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return err;
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}
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static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry)
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{
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struct ubifs_info *c = old_dir->i_sb->s_fs_info;
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struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
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.dirtied_ino = 2 };
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int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
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struct inode *fst_inode = d_inode(old_dentry);
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struct inode *snd_inode = d_inode(new_dentry);
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struct timespec time;
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int err;
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ubifs_assert(fst_inode && snd_inode);
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lock_4_inodes(old_dir, new_dir, NULL, NULL);
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time = ubifs_current_time(old_dir);
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fst_inode->i_ctime = time;
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snd_inode->i_ctime = time;
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old_dir->i_mtime = old_dir->i_ctime = time;
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new_dir->i_mtime = new_dir->i_ctime = time;
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if (old_dir != new_dir) {
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if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
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inc_nlink(new_dir);
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drop_nlink(old_dir);
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}
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else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
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drop_nlink(new_dir);
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inc_nlink(old_dir);
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}
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}
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err = ubifs_jnl_xrename(c, old_dir, old_dentry, new_dir, new_dentry,
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sync);
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unlock_4_inodes(old_dir, new_dir, NULL, NULL);
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ubifs_release_budget(c, &req);
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return err;
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}
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static int ubifs_rename2(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry,
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unsigned int flags)
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{
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if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
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return -EINVAL;
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ubifs_assert(inode_is_locked(old_dir));
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ubifs_assert(inode_is_locked(new_dir));
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if (flags & RENAME_EXCHANGE)
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return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
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return ubifs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
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}
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int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
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struct kstat *stat)
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{
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@ -1331,7 +1384,7 @@ const struct inode_operations ubifs_dir_inode_operations = {
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.mkdir = ubifs_mkdir,
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.rmdir = ubifs_rmdir,
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.mknod = ubifs_mknod,
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.rename2 = ubifs_rename,
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.rename2 = ubifs_rename2,
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.setattr = ubifs_setattr,
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.getattr = ubifs_getattr,
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.setxattr = generic_setxattr,
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@ -907,6 +907,147 @@ int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode)
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return err;
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}
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/**
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* ubifs_jnl_xrename - cross rename two directory entries.
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* @c: UBIFS file-system description object
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* @fst_dir: parent inode of 1st directory entry to exchange
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* @fst_dentry: 1st directory entry to exchange
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* @snd_dir: parent inode of 2nd directory entry to exchange
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* @snd_dentry: 2nd directory entry to exchange
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* @sync: non-zero if the write-buffer has to be synchronized
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*
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* This function implements the cross rename operation which may involve
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* writing 2 inodes and 2 directory entries. It marks the written inodes as clean
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* and returns zero on success. In case of failure, a negative error code is
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* returned.
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*/
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int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir,
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const struct dentry *fst_dentry,
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const struct inode *snd_dir,
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const struct dentry *snd_dentry, int sync)
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{
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union ubifs_key key;
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struct ubifs_dent_node *dent1, *dent2;
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int err, dlen1, dlen2, lnum, offs, len, plen = UBIFS_INO_NODE_SZ;
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int aligned_dlen1, aligned_dlen2;
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int twoparents = (fst_dir != snd_dir);
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const struct inode *fst_inode = d_inode(fst_dentry);
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const struct inode *snd_inode = d_inode(snd_dentry);
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void *p;
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dbg_jnl("dent '%pd' in dir ino %lu between dent '%pd' in dir ino %lu",
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fst_dentry, fst_dir->i_ino, snd_dentry, snd_dir->i_ino);
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ubifs_assert(ubifs_inode(fst_dir)->data_len == 0);
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ubifs_assert(ubifs_inode(snd_dir)->data_len == 0);
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ubifs_assert(mutex_is_locked(&ubifs_inode(fst_dir)->ui_mutex));
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ubifs_assert(mutex_is_locked(&ubifs_inode(snd_dir)->ui_mutex));
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dlen1 = UBIFS_DENT_NODE_SZ + snd_dentry->d_name.len + 1;
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dlen2 = UBIFS_DENT_NODE_SZ + fst_dentry->d_name.len + 1;
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aligned_dlen1 = ALIGN(dlen1, 8);
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aligned_dlen2 = ALIGN(dlen2, 8);
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len = aligned_dlen1 + aligned_dlen2 + ALIGN(plen, 8);
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if (twoparents)
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len += plen;
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dent1 = kmalloc(len, GFP_NOFS);
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if (!dent1)
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return -ENOMEM;
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/* Make reservation before allocating sequence numbers */
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err = make_reservation(c, BASEHD, len);
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if (err)
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goto out_free;
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/* Make new dent for 1st entry */
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dent1->ch.node_type = UBIFS_DENT_NODE;
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dent_key_init_flash(c, &dent1->key, snd_dir->i_ino, &snd_dentry->d_name);
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dent1->inum = cpu_to_le64(fst_inode->i_ino);
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dent1->type = get_dent_type(fst_inode->i_mode);
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dent1->nlen = cpu_to_le16(snd_dentry->d_name.len);
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memcpy(dent1->name, snd_dentry->d_name.name, snd_dentry->d_name.len);
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dent1->name[snd_dentry->d_name.len] = '\0';
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zero_dent_node_unused(dent1);
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ubifs_prep_grp_node(c, dent1, dlen1, 0);
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/* Make new dent for 2nd entry */
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dent2 = (void *)dent1 + aligned_dlen1;
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dent2->ch.node_type = UBIFS_DENT_NODE;
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dent_key_init_flash(c, &dent2->key, fst_dir->i_ino, &fst_dentry->d_name);
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dent2->inum = cpu_to_le64(snd_inode->i_ino);
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dent2->type = get_dent_type(snd_inode->i_mode);
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dent2->nlen = cpu_to_le16(fst_dentry->d_name.len);
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memcpy(dent2->name, fst_dentry->d_name.name, fst_dentry->d_name.len);
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dent2->name[fst_dentry->d_name.len] = '\0';
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zero_dent_node_unused(dent2);
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ubifs_prep_grp_node(c, dent2, dlen2, 0);
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p = (void *)dent2 + aligned_dlen2;
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if (!twoparents)
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pack_inode(c, p, fst_dir, 1);
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else {
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pack_inode(c, p, fst_dir, 0);
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p += ALIGN(plen, 8);
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pack_inode(c, p, snd_dir, 1);
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}
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err = write_head(c, BASEHD, dent1, len, &lnum, &offs, sync);
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if (err)
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goto out_release;
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if (!sync) {
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struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
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ubifs_wbuf_add_ino_nolock(wbuf, fst_dir->i_ino);
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ubifs_wbuf_add_ino_nolock(wbuf, snd_dir->i_ino);
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}
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release_head(c, BASEHD);
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dent_key_init(c, &key, snd_dir->i_ino, &snd_dentry->d_name);
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err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, &snd_dentry->d_name);
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if (err)
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goto out_ro;
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offs += aligned_dlen1;
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dent_key_init(c, &key, fst_dir->i_ino, &fst_dentry->d_name);
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err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, &fst_dentry->d_name);
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if (err)
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goto out_ro;
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offs += aligned_dlen2;
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ino_key_init(c, &key, fst_dir->i_ino);
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err = ubifs_tnc_add(c, &key, lnum, offs, plen);
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if (err)
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goto out_ro;
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if (twoparents) {
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offs += ALIGN(plen, 8);
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ino_key_init(c, &key, snd_dir->i_ino);
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err = ubifs_tnc_add(c, &key, lnum, offs, plen);
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if (err)
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goto out_ro;
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}
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finish_reservation(c);
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mark_inode_clean(c, ubifs_inode(fst_dir));
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if (twoparents)
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mark_inode_clean(c, ubifs_inode(snd_dir));
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kfree(dent1);
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return 0;
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out_release:
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release_head(c, BASEHD);
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out_ro:
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ubifs_ro_mode(c, err);
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finish_reservation(c);
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out_free:
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kfree(dent1);
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return err;
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}
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/**
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* ubifs_jnl_rename - rename a directory entry.
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* @c: UBIFS file-system description object
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@ -1521,6 +1521,10 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
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const union ubifs_key *key, const void *buf, int len);
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int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode);
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int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode);
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int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir,
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const struct dentry *fst_dentry,
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const struct inode *snd_dir,
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const struct dentry *snd_dentry, int sync);
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int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
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const struct dentry *old_dentry,
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const struct inode *new_dir,
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