diff --git a/fs/libfs.c b/fs/libfs.c index b913ab238cc15..3d34393a5a797 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -344,22 +344,22 @@ void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry) * User space expects the directory offset value of the replaced * (new) directory entry to be unchanged after a rename. * - * Returns zero on success, a negative errno value on failure. + * Caller must have grabbed a slot for new_dentry in the maple_tree + * associated with new_dir, even if dentry is negative. */ -int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) +void simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) { struct offset_ctx *old_ctx = old_dir->i_op->get_offset_ctx(old_dir); struct offset_ctx *new_ctx = new_dir->i_op->get_offset_ctx(new_dir); long new_offset = dentry2offset(new_dentry); - simple_offset_remove(old_ctx, old_dentry); + if (WARN_ON(!new_offset)) + return; - if (new_offset) { - offset_set(new_dentry, 0); - return simple_offset_replace(new_ctx, old_dentry, new_offset); - } - return simple_offset_add(new_ctx, old_dentry); + simple_offset_remove(old_ctx, old_dentry); + offset_set(new_dentry, 0); + WARN_ON(simple_offset_replace(new_ctx, old_dentry, new_offset)); } /** @@ -386,31 +386,21 @@ int simple_offset_rename_exchange(struct inode *old_dir, u32 new_index = dentry2offset(new_dentry); int ret; - simple_offset_remove(old_ctx, old_dentry); - simple_offset_remove(new_ctx, new_dentry); + if (WARN_ON(!old_index || !new_index)) + return -EINVAL; ret = simple_offset_replace(new_ctx, old_dentry, new_index); if (ret) - goto out_restore; + return ret; ret = simple_offset_replace(old_ctx, new_dentry, old_index); if (ret) { - simple_offset_remove(new_ctx, old_dentry); - goto out_restore; + simple_offset_replace(new_ctx, new_dentry, new_index); + return ret; } - ret = simple_rename_exchange(old_dir, old_dentry, new_dir, new_dentry); - if (ret) { - simple_offset_remove(new_ctx, old_dentry); - simple_offset_remove(old_ctx, new_dentry); - goto out_restore; - } + simple_rename_exchange(old_dir, old_dentry, new_dir, new_dentry); return 0; - -out_restore: - (void)simple_offset_replace(old_ctx, old_dentry, old_index); - (void)simple_offset_replace(new_ctx, new_dentry, new_index); - return ret; } /** diff --git a/include/linux/fs.h b/include/linux/fs.h index 971e49d473e8c..9d903573358e3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3306,7 +3306,7 @@ struct offset_ctx { void simple_offset_init(struct offset_ctx *octx); int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry); void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry); -int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, +void simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry); int simple_offset_rename_exchange(struct inode *old_dir, struct dentry *old_dentry, diff --git a/mm/shmem.c b/mm/shmem.c index b69d845dff091..9c0796b425cdb 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -3415,6 +3415,7 @@ static int shmem_rename2(struct mnt_idmap *idmap, { struct inode *inode = d_inode(old_dentry); int they_are_dirs = S_ISDIR(inode->i_mode); + bool had_offset = false; int error; if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) @@ -3427,16 +3428,23 @@ static int shmem_rename2(struct mnt_idmap *idmap, if (!simple_empty(new_dentry)) return -ENOTEMPTY; + error = simple_offset_add(shmem_get_offset_ctx(new_dir), new_dentry); + if (error == -EBUSY) + had_offset = true; + else if (unlikely(error)) + return error; + if (flags & RENAME_WHITEOUT) { error = shmem_whiteout(idmap, old_dir, old_dentry); - if (error) + if (error) { + if (!had_offset) + simple_offset_remove(shmem_get_offset_ctx(new_dir), + new_dentry); return error; + } } - error = simple_offset_rename(old_dir, old_dentry, new_dir, new_dentry); - if (error) - return error; - + simple_offset_rename(old_dir, old_dentry, new_dir, new_dentry); if (d_really_is_positive(new_dentry)) { (void) shmem_unlink(new_dir, new_dentry); if (they_are_dirs) {