diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/filesystems/Locking | 13 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 12 |
2 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index e0cce2a5f820..2db1900d7538 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -206,6 +206,8 @@ prototypes: int (*launder_page)(struct page *); int (*is_partially_uptodate)(struct page *, read_descriptor_t *, unsigned long); int (*error_remove_page)(struct address_space *, struct page *); + int (*swap_activate)(struct file *); + int (*swap_deactivate)(struct file *); locking rules: All except set_page_dirty and freepage may block @@ -229,6 +231,8 @@ migratepage: yes (both) launder_page: yes is_partially_uptodate: yes error_remove_page: yes +swap_activate: no +swap_deactivate: no ->write_begin(), ->write_end(), ->sync_page() and ->readpage() may be called from the request handler (/dev/loop). @@ -330,6 +334,15 @@ cleaned, or an error value if not. Note that in order to prevent the page 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_deactivate() will be called in the sys_swapoff() +path after ->swap_activate() returned success. + ----------------------- file_lock_operations ------------------------------ prototypes: void (*fl_copy_lock)(struct file_lock *, struct file_lock *); diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index aa754e01464e..065aa2dc0835 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -592,6 +592,8 @@ struct address_space_operations { int (*migratepage) (struct page *, struct page *); int (*launder_page) (struct page *); int (*error_remove_page) (struct mapping *mapping, struct page *page); + int (*swap_activate)(struct file *); + int (*swap_deactivate)(struct file *); }; writepage: called by the VM to write a dirty page to backing store. @@ -760,6 +762,16 @@ struct address_space_operations { Setting this implies you deal with pages going away under you, unless you have them locked or reference counts increased. + swap_activate: Called when swapon is used on a file to allocate + space if necessary and pin the block lookup information in + memory. A return value of zero indicates success, + in which case this file can be used to back swapspace. The + swapspace operations will be proxied to this address space's + ->swap_{out,in} methods. + + swap_deactivate: Called during swapoff on files where swap_activate + was successful. + The File Object =============== |