Merge tag 'tegra-for-5.20-dt-bindings' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-microblaze.git] / Documentation / filesystems / locking.rst

diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index 515bc48..c0fe711 100644 (file)
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -258,8 +258,9 @@ prototypes::
        int (*launder_folio)(struct folio *);
        bool (*is_partially_uptodate)(struct folio *, size_t from, size_t count);
        int (*error_remove_page)(struct address_space *, struct page *);
-       int (*swap_activate)(struct file *);
+       int (*swap_activate)(struct swap_info_struct *sis, struct file *f, sector_t *span)
        int (*swap_deactivate)(struct file *);
+       int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter);
 
 locking rules:
        All except dirty_folio and free_folio may block
@@ -287,6 +288,7 @@ is_partially_uptodate:      yes
 error_remove_page:     yes
 swap_activate:         no
 swap_deactivate:       no
+swap_rw:               yes, unlocks
 ====================== ======================== =========      ===============
 
 ->write_begin(), ->write_end() and ->read_folio() may be called from
@@ -386,15 +388,19 @@ cleaned, or an error value if not. Note that in order to prevent the folio
 getting mapped back in and redirtied, it needs to be kept locked
 across the entire operation.
 
-->swap_activate will be called with a non-zero argument on
-files backing (non block device backed) swapfiles. A return value
-of zero indicates success, in which case this file can be used for
-backing swapspace. The swapspace operations will be proxied to the
-address space operations.
+->swap_activate() will be called to prepare the given file for swap.  It
+should perform any validation and preparation necessary to ensure that
+writes can be performed with minimal memory allocation.  It should call
+add_swap_extent(), or the helper iomap_swapfile_activate(), and return
+the number of extents added.  If IO should be submitted through
+->swap_rw(), it should set SWP_FS_OPS, otherwise IO will be submitted
+directly to the block device ``sis->bdev``.
 
 ->swap_deactivate() will be called in the sys_swapoff()
 path after ->swap_activate() returned success.
 
+->swap_rw will be called for swap IO if SWP_FS_OPS was set by ->swap_activate().
+
 file_lock_operations
 ====================
 
@@ -428,6 +434,8 @@ prototypes::
        void (*lm_break)(struct file_lock *); /* break_lease callback */
        int (*lm_change)(struct file_lock **, int);
        bool (*lm_breaker_owns_lease)(struct file_lock *);
+        bool (*lm_lock_expirable)(struct file_lock *);
+        void (*lm_expire_lock)(void);
 
 locking rules:
 
@@ -439,6 +447,8 @@ lm_grant:           no              no                      no
 lm_break:              yes             no                      no
 lm_change              yes             no                      no
 lm_breaker_owns_lease: yes             no                      no
+lm_lock_expirable      yes             no                      no
+lm_expire_lock         no              no                      yes
 ====================== =============   =================       =========
 
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