Reorganize classes so that it is easier to read. Before number 4 was written in one lenghty paragraph. It is as long as number 6 and it is basically same kind of class (rename()). Also old number 5 was list and it is as short as 1, 2, 3 so it can be converted non list. This makes file now much readible. Signed-off-by: Kari Argillander <kari.argillander@xxxxxxxxx> --- .../filesystems/directory-locking.rst | 31 +++++++++---------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/Documentation/filesystems/directory-locking.rst b/Documentation/filesystems/directory-locking.rst index 504ba940c36c..33921dff7af4 100644 --- a/Documentation/filesystems/directory-locking.rst +++ b/Documentation/filesystems/directory-locking.rst @@ -11,7 +11,7 @@ When taking the i_rwsem on multiple non-directory objects, we always acquire the locks in order by increasing address. We'll call that "inode pointer" order in the following. -For our purposes all operations fall in 5 classes: +For our purposes all operations fall in 6 classes: 1) read access. Locking rules: caller locks directory we are accessing. The lock is taken shared. @@ -22,26 +22,25 @@ exclusive. 3) object removal. Locking rules: caller locks parent, finds victim, locks victim and calls the method. Locks are exclusive. -4) rename() that is _not_ cross-directory. Locking rules: caller locks -the parent and finds source and target. In case of exchange (with -RENAME_EXCHANGE in flags argument) lock both. In any case, -if the target already exists, lock it. If the source is a non-directory, -lock it. If we need to lock both, lock them in inode pointer order. -Then call the method. All locks are exclusive. -NB: we might get away with locking the source (and target in exchange -case) shared. +4) link creation. Locking rules: lock parent, check that source is not +a directory, lock source and call the method. Locks are exclusive. -5) link creation. Locking rules: +5) rename() that is _not_ cross-directory. +Locking rules: - * lock parent - * check that source is not a directory - * lock source - * call the method. + * Caller locks the parent and finds source and target. + * In case of exchange (with RENAME_EXCHANGE in flags argument) + lock both the source and the target. + * If the target exists, lock it, If the source is a non-directory, + lock it. If we need to lock both, do so in inode pointer order. + * Call the method. All locks are exclusive. +NB: we might get away with locking the source (and target in exchange +case) shared. -6) cross-directory rename. The trickiest in the whole bunch. Locking -rules: +6) rename() that _is_ cross-directory. The trickiest in the whole bunch. +Locking rules: * lock the filesystem * lock parents in "ancestors first" order. -- 2.30.2
