Lines Matching +full:lock +full:- +full:state

1 .. SPDX-License-Identifier: GPL-2.0
78    1. Obtain a space mapping via ``->iomap_begin``
80    2. For each sub-unit of work...
89    4. Release the mapping via ``->iomap_end``, if necessary
105 -----------
112    Processes hold this in shared mode to read file state and contents.
114    Processes often hold this in exclusive mode to change file state and
120    Processes wishing to insert folios must hold this lock in shared
122    Processes wishing to remove folios must hold this lock in exclusive
126  * ``dax_read_lock``: The RCU read lock that dax takes to prevent a
127    device pre-shutdown hook from returning before other threads have
130  * **filesystem mapping lock**: This synchronization primitive is
134    happen; it does not need to be an actual lock.
136  * **iomap internal operation lock**: This is a general term for
139    A specific example would be taking the folio lock while reading or
152 ----------------
158 .. code-block:: c
193      ``->iomap_end`` function must delete the reservation.
212      For write operation, the ``->iomap_end`` function presumably
217    These flags should be set by the filesystem in ``->iomap_begin``:
250    The filesystem should supply an ``->iomap_end`` function if it needs
257      iomap will call ``->iomap_end`` on this mapping and then
258      ``->iomap_begin`` to obtain a new mapping.
275  * ``private`` is a pointer to `filesystem-private information
276    <https://lore.kernel.org/all/20180619164137.13720-7-hch@lst.de/>`_.
277    This value will be passed unchanged to ``->iomap_end``.
285    should not be held between ``->iomap_begin`` and ``->iomap_end``.
291 --------------------
296 .. code-block:: c
308 ``->iomap_begin``
311 iomap operations call ``->iomap_begin`` to obtain one file mapping for
321 operation-specific sections below.
329    memory-like storage.
334    This is similar in intent to ``O_NONBLOCK`` for network APIs - it is
350    then they should return ``-EAGAIN`` as early as possible rather than
356 <https://lore.kernel.org/all/20191008071527.29304-9-hch@lst.de/>`_
362 ``->iomap_end``
365 After the operation completes, the ``->iomap_end`` function, if present,
368 context that were set up in ``->iomap_begin``.
373 ``flags`` will contain the same value passed to ``->iomap_begin``.
384 and file state before initiating an I/O operation.
398    but is often a VFS inode, pagecache invalidation, or folio lock.
402    Pagecache writeback may lock a folio to prevent other threads from
406      ``->iomap_begin`` and ``->iomap_end`` functions to coordinate
424      then grab and lock a folio to copy new contents.
425      It may also lock an internal folio state object to update metadata.
439  * Does iomap *actually* work for non-regular file data?