diff options
| -rw-r--r-- | fs/ubifs/dir.c | 92 |
1 files changed, 36 insertions, 56 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index d29b771..f55d523 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -482,30 +482,29 @@ static int ubifs_dir_release(struct inode *dir, struct file *file) } /** - * lock_2_inodes - lock two UBIFS inodes. + * lock_2_inodes - a wrapper for locking two UBIFS inodes. * @inode1: first inode * @inode2: second inode + * + * We do not implement any tricks to guarantee strict lock ordering, because + * VFS has already done it for us on the @i_mutex. So this is just a simple + * wrapper function. */ static void lock_2_inodes(struct inode *inode1, struct inode *inode2) { - if (inode1->i_ino < inode2->i_ino) { - mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_2); - mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_3); - } else { - mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); - mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_3); - } + mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); + mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); } /** - * unlock_2_inodes - unlock two UBIFS inodes inodes. + * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. * @inode1: first inode * @inode2: second inode */ static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) { - mutex_unlock(&ubifs_inode(inode1)->ui_mutex); mutex_unlock(&ubifs_inode(inode2)->ui_mutex); + mutex_unlock(&ubifs_inode(inode1)->ui_mutex); } static int ubifs_link(struct dentry *old_dentry, struct inode *dir, @@ -527,6 +526,8 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu", dentry->d_name.len, dentry->d_name.name, inode->i_ino, inode->i_nlink, dir->i_ino); + ubifs_assert(mutex_is_locked(&dir->i_mutex)); + ubifs_assert(mutex_is_locked(&inode->i_mutex)); err = dbg_check_synced_i_size(inode); if (err) return err; @@ -580,6 +581,8 @@ static int ubifs_unlink(struct inode *dir, struct dentry *dentry) dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu", dentry->d_name.len, dentry->d_name.name, inode->i_ino, inode->i_nlink, dir->i_ino); + ubifs_assert(mutex_is_locked(&dir->i_mutex)); + ubifs_assert(mutex_is_locked(&inode->i_mutex)); err = dbg_check_synced_i_size(inode); if (err) return err; @@ -667,7 +670,8 @@ static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len, dentry->d_name.name, inode->i_ino, dir->i_ino); - + ubifs_assert(mutex_is_locked(&dir->i_mutex)); + ubifs_assert(mutex_is_locked(&inode->i_mutex)); err = check_dir_empty(c, dentry->d_inode); if (err) return err; @@ -922,59 +926,30 @@ out_budg: } /** - * lock_3_inodes - lock three UBIFS inodes for rename. + * lock_3_inodes - a wrapper for locking three UBIFS inodes. * @inode1: first inode * @inode2: second inode * @inode3: third inode * - * For 'ubifs_rename()', @inode1 may be the same as @inode2 whereas @inode3 may - * be null. + * This function is used for 'ubifs_rename()' and @inode1 may be the same as + * @inode2 whereas @inode3 may be %NULL. + * + * We do not implement any tricks to guarantee strict lock ordering, because + * VFS has already done it for us on the @i_mutex. So this is just a simple + * wrapper function. */ static void lock_3_inodes(struct inode *inode1, struct inode *inode2, struct inode *inode3) { - struct inode *i1, *i2, *i3; - - if (!inode3) { - if (inode1 != inode2) { - lock_2_inodes(inode1, inode2); - return; - } - mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); - return; - } - - if (inode1 == inode2) { - lock_2_inodes(inode1, inode3); - return; - } - - /* 3 different inodes */ - if (inode1 < inode2) { - i3 = inode2; - if (inode1 < inode3) { - i1 = inode1; - i2 = inode3; - } else { - i1 = inode3; - i2 = inode1; - } - } else { - i3 = inode1; - if (inode2 < inode3) { - i1 = inode2; - i2 = inode3; - } else { - i1 = inode3; - i2 = inode2; - } - } - mutex_lock_nested(&ubifs_inode(i1)->ui_mutex, WB_MUTEX_1); - lock_2_inodes(i2, i3); + mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); + if (inode2 != inode1) + mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); + if (inode3) + mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3); } /** - * unlock_3_inodes - unlock three UBIFS inodes for rename. + * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename. * @inode1: first inode * @inode2: second inode * @inode3: third inode @@ -982,11 +957,11 @@ static void lock_3_inodes(struct inode *inode1, struct inode *inode2, static void unlock_3_inodes(struct inode *inode1, struct inode *inode2, struct inode *inode3) { - mutex_unlock(&ubifs_inode(inode1)->ui_mutex); - if (inode1 != inode2) - mutex_unlock(&ubifs_inode(inode2)->ui_mutex); if (inode3) mutex_unlock(&ubifs_inode(inode3)->ui_mutex); + if (inode1 != inode2) + mutex_unlock(&ubifs_inode(inode2)->ui_mutex); + mutex_unlock(&ubifs_inode(inode1)->ui_mutex); } static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, @@ -1020,6 +995,11 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name, old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len, new_dentry->d_name.name, new_dir->i_ino); + ubifs_assert(mutex_is_locked(&old_dir->i_mutex)); + ubifs_assert(mutex_is_locked(&new_dir->i_mutex)); + if (unlink) + ubifs_assert(mutex_is_locked(&new_inode->i_mutex)); + if (unlink && is_dir) { err = check_dir_empty(c, new_inode); |
