diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 747 |
1 files changed, 639 insertions, 108 deletions
diff --git a/fs/namei.c b/fs/namei.c index 13041756d941..bf0f66f0e9b9 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2835,6 +2835,62 @@ static int filename_parentat(int dfd, struct filename *name, return __filename_parentat(dfd, name, flags, parent, last, type, NULL); } +/** + * start_dirop - begin a create or remove dirop, performing locking and lookup + * @parent: the dentry of the parent in which the operation will occur + * @name: a qstr holding the name within that parent + * @lookup_flags: intent and other lookup flags. + * + * The lookup is performed and necessary locks are taken so that, on success, + * the returned dentry can be operated on safely. + * The qstr must already have the hash value calculated. + * + * Returns: a locked dentry, or an error. + * + */ +static struct dentry *__start_dirop(struct dentry *parent, struct qstr *name, + unsigned int lookup_flags, + unsigned int state) +{ + struct dentry *dentry; + struct inode *dir = d_inode(parent); + + if (state == TASK_KILLABLE) { + int ret = down_write_killable_nested(&dir->i_rwsem, + I_MUTEX_PARENT); + if (ret) + return ERR_PTR(ret); + } else { + inode_lock_nested(dir, I_MUTEX_PARENT); + } + dentry = lookup_one_qstr_excl(name, parent, lookup_flags); + if (IS_ERR(dentry)) + inode_unlock(dir); + return dentry; +} + +struct dentry *start_dirop(struct dentry *parent, struct qstr *name, + unsigned int lookup_flags) +{ + return __start_dirop(parent, name, lookup_flags, TASK_NORMAL); +} + +/** + * end_dirop - signal completion of a dirop + * @de: the dentry which was returned by start_dirop or similar. + * + * If the de is an error, nothing happens. Otherwise any lock taken to + * protect the dentry is dropped and the dentry itself is release (dput()). + */ +void end_dirop(struct dentry *de) +{ + if (!IS_ERR(de)) { + inode_unlock(de->d_parent->d_inode); + dput(de); + } +} +EXPORT_SYMBOL(end_dirop); + /* does lookup, returns the object with parent locked */ static struct dentry *__start_removing_path(int dfd, struct filename *name, struct path *path) @@ -2851,10 +2907,9 @@ static struct dentry *__start_removing_path(int dfd, struct filename *name, return ERR_PTR(-EINVAL); /* don't fail immediately if it's r/o, at least try to report other errors */ error = mnt_want_write(parent_path.mnt); - inode_lock_nested(parent_path.dentry->d_inode, I_MUTEX_PARENT); - d = lookup_one_qstr_excl(&last, parent_path.dentry, 0); + d = start_dirop(parent_path.dentry, &last, 0); if (IS_ERR(d)) - goto unlock; + goto drop; if (error) goto fail; path->dentry = no_free_ptr(parent_path.dentry); @@ -2862,10 +2917,9 @@ static struct dentry *__start_removing_path(int dfd, struct filename *name, return d; fail: - dput(d); + end_dirop(d); d = ERR_PTR(error); -unlock: - inode_unlock(parent_path.dentry->d_inode); +drop: if (!error) mnt_drop_write(parent_path.mnt); return d; @@ -2980,7 +3034,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, } EXPORT_SYMBOL(vfs_path_lookup); -static int lookup_noperm_common(struct qstr *qname, struct dentry *base) +int lookup_noperm_common(struct qstr *qname, struct dentry *base) { const char *name = qname->name; u32 len = qname->len; @@ -3251,6 +3305,234 @@ struct dentry *lookup_noperm_positive_unlocked(struct qstr *name, } EXPORT_SYMBOL(lookup_noperm_positive_unlocked); +/** + * start_creating - prepare to create a given name with permission checking + * @idmap: idmap of the mount + * @parent: directory in which to prepare to create the name + * @name: the name to be created + * + * Locks are taken and a lookup is performed prior to creating + * an object in a directory. Permission checking (MAY_EXEC) is performed + * against @idmap. + * + * If the name already exists, a positive dentry is returned, so + * behaviour is similar to O_CREAT without O_EXCL, which doesn't fail + * with -EEXIST. + * + * Returns: a negative or positive dentry, or an error. + */ +struct dentry *start_creating(struct mnt_idmap *idmap, struct dentry *parent, + struct qstr *name) +{ + int err = lookup_one_common(idmap, name, parent); + + if (err) + return ERR_PTR(err); + return start_dirop(parent, name, LOOKUP_CREATE); +} +EXPORT_SYMBOL(start_creating); + +/** + * start_removing - prepare to remove a given name with permission checking + * @idmap: idmap of the mount + * @parent: directory in which to find the name + * @name: the name to be removed + * + * Locks are taken and a lookup in performed prior to removing + * an object from a directory. Permission checking (MAY_EXEC) is performed + * against @idmap. + * + * If the name doesn't exist, an error is returned. + * + * end_removing() should be called when removal is complete, or aborted. + * + * Returns: a positive dentry, or an error. + */ +struct dentry *start_removing(struct mnt_idmap *idmap, struct dentry *parent, + struct qstr *name) +{ + int err = lookup_one_common(idmap, name, parent); + + if (err) + return ERR_PTR(err); + return start_dirop(parent, name, 0); +} +EXPORT_SYMBOL(start_removing); + +/** + * start_creating_killable - prepare to create a given name with permission checking + * @idmap: idmap of the mount + * @parent: directory in which to prepare to create the name + * @name: the name to be created + * + * Locks are taken and a lookup in performed prior to creating + * an object in a directory. Permission checking (MAY_EXEC) is performed + * against @idmap. + * + * If the name already exists, a positive dentry is returned. + * + * If a signal is received or was already pending, the function aborts + * with -EINTR; + * + * Returns: a negative or positive dentry, or an error. + */ +struct dentry *start_creating_killable(struct mnt_idmap *idmap, + struct dentry *parent, + struct qstr *name) +{ + int err = lookup_one_common(idmap, name, parent); + + if (err) + return ERR_PTR(err); + return __start_dirop(parent, name, LOOKUP_CREATE, TASK_KILLABLE); +} +EXPORT_SYMBOL(start_creating_killable); + +/** + * start_removing_killable - prepare to remove a given name with permission checking + * @idmap: idmap of the mount + * @parent: directory in which to find the name + * @name: the name to be removed + * + * Locks are taken and a lookup in performed prior to removing + * an object from a directory. Permission checking (MAY_EXEC) is performed + * against @idmap. + * + * If the name doesn't exist, an error is returned. + * + * end_removing() should be called when removal is complete, or aborted. + * + * If a signal is received or was already pending, the function aborts + * with -EINTR; + * + * Returns: a positive dentry, or an error. + */ +struct dentry *start_removing_killable(struct mnt_idmap *idmap, + struct dentry *parent, + struct qstr *name) +{ + int err = lookup_one_common(idmap, name, parent); + + if (err) + return ERR_PTR(err); + return __start_dirop(parent, name, 0, TASK_KILLABLE); +} +EXPORT_SYMBOL(start_removing_killable); + +/** + * start_creating_noperm - prepare to create a given name without permission checking + * @parent: directory in which to prepare to create the name + * @name: the name to be created + * + * Locks are taken and a lookup in performed prior to creating + * an object in a directory. + * + * If the name already exists, a positive dentry is returned. + * + * Returns: a negative or positive dentry, or an error. + */ +struct dentry *start_creating_noperm(struct dentry *parent, + struct qstr *name) +{ + int err = lookup_noperm_common(name, parent); + + if (err) + return ERR_PTR(err); + return start_dirop(parent, name, LOOKUP_CREATE); +} +EXPORT_SYMBOL(start_creating_noperm); + +/** + * start_removing_noperm - prepare to remove a given name without permission checking + * @parent: directory in which to find the name + * @name: the name to be removed + * + * Locks are taken and a lookup in performed prior to removing + * an object from a directory. + * + * If the name doesn't exist, an error is returned. + * + * end_removing() should be called when removal is complete, or aborted. + * + * Returns: a positive dentry, or an error. + */ +struct dentry *start_removing_noperm(struct dentry *parent, + struct qstr *name) +{ + int err = lookup_noperm_common(name, parent); + + if (err) + return ERR_PTR(err); + return start_dirop(parent, name, 0); +} +EXPORT_SYMBOL(start_removing_noperm); + +/** + * start_creating_dentry - prepare to create a given dentry + * @parent: directory from which dentry should be removed + * @child: the dentry to be removed + * + * A lock is taken to protect the dentry again other dirops and + * the validity of the dentry is checked: correct parent and still hashed. + * + * If the dentry is valid and negative a reference is taken and + * returned. If not an error is returned. + * + * end_creating() should be called when creation is complete, or aborted. + * + * Returns: the valid dentry, or an error. + */ +struct dentry *start_creating_dentry(struct dentry *parent, + struct dentry *child) +{ + inode_lock_nested(parent->d_inode, I_MUTEX_PARENT); + if (unlikely(IS_DEADDIR(parent->d_inode) || + child->d_parent != parent || + d_unhashed(child))) { + inode_unlock(parent->d_inode); + return ERR_PTR(-EINVAL); + } + if (d_is_positive(child)) { + inode_unlock(parent->d_inode); + return ERR_PTR(-EEXIST); + } + return dget(child); +} +EXPORT_SYMBOL(start_creating_dentry); + +/** + * start_removing_dentry - prepare to remove a given dentry + * @parent: directory from which dentry should be removed + * @child: the dentry to be removed + * + * A lock is taken to protect the dentry again other dirops and + * the validity of the dentry is checked: correct parent and still hashed. + * + * If the dentry is valid and positive, a reference is taken and + * returned. If not an error is returned. + * + * end_removing() should be called when removal is complete, or aborted. + * + * Returns: the valid dentry, or an error. + */ +struct dentry *start_removing_dentry(struct dentry *parent, + struct dentry *child) +{ + inode_lock_nested(parent->d_inode, I_MUTEX_PARENT); + if (unlikely(IS_DEADDIR(parent->d_inode) || + child->d_parent != parent || + d_unhashed(child))) { + inode_unlock(parent->d_inode); + return ERR_PTR(-EINVAL); + } + if (d_is_negative(child)) { + inode_unlock(parent->d_inode); + return ERR_PTR(-ENOENT); + } + return dget(child); +} +EXPORT_SYMBOL(start_removing_dentry); + #ifdef CONFIG_UNIX98_PTYS int path_pts(struct path *path) { @@ -3489,6 +3771,290 @@ void unlock_rename(struct dentry *p1, struct dentry *p2) EXPORT_SYMBOL(unlock_rename); /** + * __start_renaming - lookup and lock names for rename + * @rd: rename data containing parents and flags, and + * for receiving found dentries + * @lookup_flags: extra flags to pass to ->lookup (e.g. LOOKUP_REVAL, + * LOOKUP_NO_SYMLINKS etc). + * @old_last: name of object in @rd.old_parent + * @new_last: name of object in @rd.new_parent + * + * Look up two names and ensure locks are in place for + * rename. + * + * On success the found dentries are stored in @rd.old_dentry, + * @rd.new_dentry and an extra ref is taken on @rd.old_parent. + * These references and the lock are dropped by end_renaming(). + * + * The passed in qstrs must have the hash calculated, and no permission + * checking is performed. + * + * Returns: zero or an error. + */ +static int +__start_renaming(struct renamedata *rd, int lookup_flags, + struct qstr *old_last, struct qstr *new_last) +{ + struct dentry *trap; + struct dentry *d1, *d2; + int target_flags = LOOKUP_RENAME_TARGET | LOOKUP_CREATE; + int err; + + if (rd->flags & RENAME_EXCHANGE) + target_flags = 0; + if (rd->flags & RENAME_NOREPLACE) + target_flags |= LOOKUP_EXCL; + + trap = lock_rename(rd->old_parent, rd->new_parent); + if (IS_ERR(trap)) + return PTR_ERR(trap); + + d1 = lookup_one_qstr_excl(old_last, rd->old_parent, + lookup_flags); + err = PTR_ERR(d1); + if (IS_ERR(d1)) + goto out_unlock; + + d2 = lookup_one_qstr_excl(new_last, rd->new_parent, + lookup_flags | target_flags); + err = PTR_ERR(d2); + if (IS_ERR(d2)) + goto out_dput_d1; + + if (d1 == trap) { + /* source is an ancestor of target */ + err = -EINVAL; + goto out_dput_d2; + } + + if (d2 == trap) { + /* target is an ancestor of source */ + if (rd->flags & RENAME_EXCHANGE) + err = -EINVAL; + else + err = -ENOTEMPTY; + goto out_dput_d2; + } + + rd->old_dentry = d1; + rd->new_dentry = d2; + dget(rd->old_parent); + return 0; + +out_dput_d2: + dput(d2); +out_dput_d1: + dput(d1); +out_unlock: + unlock_rename(rd->old_parent, rd->new_parent); + return err; +} + +/** + * start_renaming - lookup and lock names for rename with permission checking + * @rd: rename data containing parents and flags, and + * for receiving found dentries + * @lookup_flags: extra flags to pass to ->lookup (e.g. LOOKUP_REVAL, + * LOOKUP_NO_SYMLINKS etc). + * @old_last: name of object in @rd.old_parent + * @new_last: name of object in @rd.new_parent + * + * Look up two names and ensure locks are in place for + * rename. + * + * On success the found dentries are stored in @rd.old_dentry, + * @rd.new_dentry. Also the refcount on @rd->old_parent is increased. + * These references and the lock are dropped by end_renaming(). + * + * The passed in qstrs need not have the hash calculated, and basic + * eXecute permission checking is performed against @rd.mnt_idmap. + * + * Returns: zero or an error. + */ +int start_renaming(struct renamedata *rd, int lookup_flags, + struct qstr *old_last, struct qstr *new_last) +{ + int err; + + err = lookup_one_common(rd->mnt_idmap, old_last, rd->old_parent); + if (err) + return err; + err = lookup_one_common(rd->mnt_idmap, new_last, rd->new_parent); + if (err) + return err; + return __start_renaming(rd, lookup_flags, old_last, new_last); +} +EXPORT_SYMBOL(start_renaming); + +static int +__start_renaming_dentry(struct renamedata *rd, int lookup_flags, + struct dentry *old_dentry, struct qstr *new_last) +{ + struct dentry *trap; + struct dentry *d2; + int target_flags = LOOKUP_RENAME_TARGET | LOOKUP_CREATE; + int err; + + if (rd->flags & RENAME_EXCHANGE) + target_flags = 0; + if (rd->flags & RENAME_NOREPLACE) + target_flags |= LOOKUP_EXCL; + + /* Already have the dentry - need to be sure to lock the correct parent */ + trap = lock_rename_child(old_dentry, rd->new_parent); + if (IS_ERR(trap)) + return PTR_ERR(trap); + if (d_unhashed(old_dentry) || + (rd->old_parent && rd->old_parent != old_dentry->d_parent)) { + /* dentry was removed, or moved and explicit parent requested */ + err = -EINVAL; + goto out_unlock; + } + + d2 = lookup_one_qstr_excl(new_last, rd->new_parent, + lookup_flags | target_flags); + err = PTR_ERR(d2); + if (IS_ERR(d2)) + goto out_unlock; + + if (old_dentry == trap) { + /* source is an ancestor of target */ + err = -EINVAL; + goto out_dput_d2; + } + + if (d2 == trap) { + /* target is an ancestor of source */ + if (rd->flags & RENAME_EXCHANGE) + err = -EINVAL; + else + err = -ENOTEMPTY; + goto out_dput_d2; + } + + rd->old_dentry = dget(old_dentry); + rd->new_dentry = d2; + rd->old_parent = dget(old_dentry->d_parent); + return 0; + +out_dput_d2: + dput(d2); +out_unlock: + unlock_rename(old_dentry->d_parent, rd->new_parent); + return err; +} + +/** + * start_renaming_dentry - lookup and lock name for rename with permission checking + * @rd: rename data containing parents and flags, and + * for receiving found dentries + * @lookup_flags: extra flags to pass to ->lookup (e.g. LOOKUP_REVAL, + * LOOKUP_NO_SYMLINKS etc). + * @old_dentry: dentry of name to move + * @new_last: name of target in @rd.new_parent + * + * Look up target name and ensure locks are in place for + * rename. + * + * On success the found dentry is stored in @rd.new_dentry and + * @rd.old_parent is confirmed to be the parent of @old_dentry. If it + * was originally %NULL, it is set. In either case a reference is taken + * so that end_renaming() can have a stable reference to unlock. + * + * References and the lock can be dropped with end_renaming() + * + * The passed in qstr need not have the hash calculated, and basic + * eXecute permission checking is performed against @rd.mnt_idmap. + * + * Returns: zero or an error. + */ +int start_renaming_dentry(struct renamedata *rd, int lookup_flags, + struct dentry *old_dentry, struct qstr *new_last) +{ + int err; + + err = lookup_one_common(rd->mnt_idmap, new_last, rd->new_parent); + if (err) + return err; + return __start_renaming_dentry(rd, lookup_flags, old_dentry, new_last); +} +EXPORT_SYMBOL(start_renaming_dentry); + +/** + * start_renaming_two_dentries - Lock to dentries in given parents for rename + * @rd: rename data containing parent + * @old_dentry: dentry of name to move + * @new_dentry: dentry to move to + * + * Ensure locks are in place for rename and check parentage is still correct. + * + * On success the two dentries are stored in @rd.old_dentry and + * @rd.new_dentry and @rd.old_parent and @rd.new_parent are confirmed to + * be the parents of the dentries. + * + * References and the lock can be dropped with end_renaming() + * + * Returns: zero or an error. + */ +int +start_renaming_two_dentries(struct renamedata *rd, + struct dentry *old_dentry, struct dentry *new_dentry) +{ + struct dentry *trap; + int err; + + /* Already have the dentry - need to be sure to lock the correct parent */ + trap = lock_rename_child(old_dentry, rd->new_parent); + if (IS_ERR(trap)) + return PTR_ERR(trap); + err = -EINVAL; + if (d_unhashed(old_dentry) || + (rd->old_parent && rd->old_parent != old_dentry->d_parent)) + /* old_dentry was removed, or moved and explicit parent requested */ + goto out_unlock; + if (d_unhashed(new_dentry) || + rd->new_parent != new_dentry->d_parent) + /* new_dentry was removed or moved */ + goto out_unlock; + + if (old_dentry == trap) + /* source is an ancestor of target */ + goto out_unlock; + + if (new_dentry == trap) { + /* target is an ancestor of source */ + if (rd->flags & RENAME_EXCHANGE) + err = -EINVAL; + else + err = -ENOTEMPTY; + goto out_unlock; + } + + err = -EEXIST; + if (d_is_positive(new_dentry) && (rd->flags & RENAME_NOREPLACE)) + goto out_unlock; + + rd->old_dentry = dget(old_dentry); + rd->new_dentry = dget(new_dentry); + rd->old_parent = dget(old_dentry->d_parent); + return 0; + +out_unlock: + unlock_rename(old_dentry->d_parent, rd->new_parent); + return err; +} +EXPORT_SYMBOL(start_renaming_two_dentries); + +void end_renaming(struct renamedata *rd) +{ + unlock_rename(rd->old_parent, rd->new_parent); + dput(rd->old_dentry); + dput(rd->new_dentry); + dput(rd->old_parent); +} +EXPORT_SYMBOL(end_renaming); + +/** * vfs_prepare_mode - prepare the mode to be used for a new inode * @idmap: idmap of the mount the inode was found from * @dir: parent directory of the new inode @@ -4310,21 +4876,18 @@ static struct dentry *filename_create(int dfd, struct filename *name, */ if (last.name[last.len] && !want_dir) create_flags &= ~LOOKUP_CREATE; - inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT); - dentry = lookup_one_qstr_excl(&last, path->dentry, - reval_flag | create_flags); + dentry = start_dirop(path->dentry, &last, reval_flag | create_flags); if (IS_ERR(dentry)) - goto unlock; + goto out_drop_write; if (unlikely(error)) goto fail; return dentry; fail: - dput(dentry); + end_dirop(dentry); dentry = ERR_PTR(error); -unlock: - inode_unlock(path->dentry->d_inode); +out_drop_write: if (!error) mnt_drop_write(path->mnt); out: @@ -4343,11 +4906,20 @@ struct dentry *start_creating_path(int dfd, const char *pathname, } EXPORT_SYMBOL(start_creating_path); +/** + * end_creating_path - finish a code section started by start_creating_path() + * @path: the path instantiated by start_creating_path() + * @dentry: the dentry returned by start_creating_path() + * + * end_creating_path() will unlock and locks taken by start_creating_path() + * and drop an references that were taken. It should only be called + * if start_creating_path() returned a non-error. + * If vfs_mkdir() was called and it returned an error, that error *should* + * be passed to end_creating_path() together with the path. + */ void end_creating_path(const struct path *path, struct dentry *dentry) { - if (!IS_ERR(dentry)) - dput(dentry); - inode_unlock(path->dentry->d_inode); + end_creating(dentry); mnt_drop_write(path->mnt); path_put(path); } @@ -4567,7 +5139,7 @@ struct dentry *vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir, return dentry; err: - dput(dentry); + end_creating(dentry); return ERR_PTR(error); } EXPORT_SYMBOL(vfs_mkdir); @@ -4709,8 +5281,7 @@ retry: if (error) goto exit2; - inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT); - dentry = lookup_one_qstr_excl(&last, path.dentry, lookup_flags); + dentry = start_dirop(path.dentry, &last, lookup_flags); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto exit3; @@ -4720,9 +5291,8 @@ retry: error = vfs_rmdir(mnt_idmap(path.mnt), path.dentry->d_inode, dentry, &delegated_inode); exit4: - dput(dentry); + end_dirop(dentry); exit3: - inode_unlock(path.dentry->d_inode); mnt_drop_write(path.mnt); exit2: path_put(&path); @@ -4831,67 +5401,62 @@ int do_unlinkat(int dfd, struct filename *name) struct path path; struct qstr last; int type; - struct inode *inode = NULL; + struct inode *inode; struct delegated_inode delegated_inode = { }; unsigned int lookup_flags = 0; retry: error = filename_parentat(dfd, name, lookup_flags, &path, &last, &type); if (error) - goto exit1; + goto exit_putname; error = -EISDIR; if (type != LAST_NORM) - goto exit2; + goto exit_path_put; error = mnt_want_write(path.mnt); if (error) - goto exit2; + goto exit_path_put; retry_deleg: - inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT); - dentry = lookup_one_qstr_excl(&last, path.dentry, lookup_flags); + dentry = start_dirop(path.dentry, &last, lookup_flags); error = PTR_ERR(dentry); - if (!IS_ERR(dentry)) { + if (IS_ERR(dentry)) + goto exit_drop_write; - /* Why not before? Because we want correct error value */ - if (last.name[last.len]) - goto slashes; - inode = dentry->d_inode; - ihold(inode); - error = security_path_unlink(&path, dentry); - if (error) - goto exit3; - error = vfs_unlink(mnt_idmap(path.mnt), path.dentry->d_inode, - dentry, &delegated_inode); -exit3: - dput(dentry); + /* Why not before? Because we want correct error value */ + if (unlikely(last.name[last.len])) { + if (d_is_dir(dentry)) + error = -EISDIR; + else + error = -ENOTDIR; + end_dirop(dentry); + goto exit_drop_write; } - inode_unlock(path.dentry->d_inode); - if (inode) - iput(inode); /* truncate the inode here */ - inode = NULL; + inode = dentry->d_inode; + ihold(inode); + error = security_path_unlink(&path, dentry); + if (error) + goto exit_end_dirop; + error = vfs_unlink(mnt_idmap(path.mnt), path.dentry->d_inode, + dentry, &delegated_inode); +exit_end_dirop: + end_dirop(dentry); + iput(inode); /* truncate the inode here */ if (is_delegated(&delegated_inode)) { error = break_deleg_wait(&delegated_inode); if (!error) goto retry_deleg; } +exit_drop_write: mnt_drop_write(path.mnt); -exit2: +exit_path_put: path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; - inode = NULL; goto retry; } -exit1: +exit_putname: putname(name); return error; - -slashes: - if (d_is_dir(dentry)) - error = -EISDIR; - else - error = -ENOTDIR; - goto exit3; } SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag) @@ -5404,14 +5969,11 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd, struct filename *to, unsigned int flags) { struct renamedata rd; - struct dentry *old_dentry, *new_dentry; - struct dentry *trap; struct path old_path, new_path; struct qstr old_last, new_last; int old_type, new_type; struct delegated_inode delegated_inode = { }; - unsigned int lookup_flags = 0, target_flags = - LOOKUP_RENAME_TARGET | LOOKUP_CREATE; + unsigned int lookup_flags = 0; bool should_retry = false; int error = -EINVAL; @@ -5422,11 +5984,6 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd, (flags & RENAME_EXCHANGE)) goto put_names; - if (flags & RENAME_EXCHANGE) - target_flags = 0; - if (flags & RENAME_NOREPLACE) - target_flags |= LOOKUP_EXCL; - retry: error = filename_parentat(olddfd, from, lookup_flags, &old_path, &old_last, &old_type); @@ -5456,66 +6013,40 @@ retry: goto exit2; retry_deleg: - trap = lock_rename(new_path.dentry, old_path.dentry); - if (IS_ERR(trap)) { - error = PTR_ERR(trap); + rd.old_parent = old_path.dentry; + rd.mnt_idmap = mnt_idmap(old_path.mnt); + rd.new_parent = new_path.dentry; + rd.delegated_inode = &delegated_inode; + rd.flags = flags; + + error = __start_renaming(&rd, lookup_flags, &old_last, &new_last); + if (error) goto exit_lock_rename; - } - old_dentry = lookup_one_qstr_excl(&old_last, old_path.dentry, - lookup_flags); - error = PTR_ERR(old_dentry); - if (IS_ERR(old_dentry)) - goto exit3; - new_dentry = lookup_one_qstr_excl(&new_last, new_path.dentry, - lookup_flags | target_flags); - error = PTR_ERR(new_dentry); - if (IS_ERR(new_dentry)) - goto exit4; if (flags & RENAME_EXCHANGE) { - if (!d_is_dir(new_dentry)) { + if (!d_is_dir(rd.new_dentry)) { error = -ENOTDIR; if (new_last.name[new_last.len]) - goto exit5; + goto exit_unlock; } } /* unless the source is a directory trailing slashes give -ENOTDIR */ - if (!d_is_dir(old_dentry)) { + if (!d_is_dir(rd.old_dentry)) { error = -ENOTDIR; if (old_last.name[old_last.len]) - goto exit5; + goto exit_unlock; if (!(flags & RENAME_EXCHANGE) && new_last.name[new_last.len]) - goto exit5; + goto exit_unlock; } - /* source should not be ancestor of target */ - error = -EINVAL; - if (old_dentry == trap) - goto exit5; - /* target should not be an ancestor of source */ - if (!(flags & RENAME_EXCHANGE)) - error = -ENOTEMPTY; - if (new_dentry == trap) - goto exit5; - error = security_path_rename(&old_path, old_dentry, - &new_path, new_dentry, flags); + error = security_path_rename(&old_path, rd.old_dentry, + &new_path, rd.new_dentry, flags); if (error) - goto exit5; + goto exit_unlock; - rd.old_parent = old_path.dentry; - rd.old_dentry = old_dentry; - rd.mnt_idmap = mnt_idmap(old_path.mnt); - rd.new_parent = new_path.dentry; - rd.new_dentry = new_dentry; - rd.delegated_inode = &delegated_inode; - rd.flags = flags; error = vfs_rename(&rd); -exit5: - dput(new_dentry); -exit4: - dput(old_dentry); -exit3: - unlock_rename(new_path.dentry, old_path.dentry); +exit_unlock: + end_renaming(&rd); exit_lock_rename: if (is_delegated(&delegated_inode)) { error = break_deleg_wait(&delegated_inode); |