diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/Locking | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 790ef6fbe495..28bfea75bcf2 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -171,6 +171,7 @@ prototypes: int (*releasepage) (struct page *, int); int (*direct_IO)(int, struct kiocb *, const struct iovec *iov, loff_t offset, unsigned long nr_segs); + int (*launder_page) (struct page *); locking rules: All except set_page_dirty may block @@ -188,6 +189,7 @@ bmap: yes invalidatepage: no yes releasepage: no yes direct_IO: no +launder_page: no yes ->prepare_write(), ->commit_write(), ->sync_page() and ->readpage() may be called from the request handler (/dev/loop). @@ -281,6 +283,12 @@ buffers from the page in preparation for freeing it. It returns zero to indicate that the buffers are (or may be) freeable. If ->releasepage is zero, the kernel assumes that the fs has no private interest in the buffers. + ->launder_page() may be called prior to releasing a page if +it is still found to be dirty. It returns zero if the page was successfully +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. + Note: currently almost all instances of address_space methods are using BKL for internal serialization and that's one of the worst sources of contention. Normally they are calling library functions (in fs/buffer.c) |