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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-23 04:26:56 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-23 04:26:56 +0300
commit6b1f86f8e9c7f9de7ca1cb987b2cf25e99b1ae3a (patch)
treeaf9dd0afd9ae6f044db13f8b6f7688d9b1fd1402 /Documentation/filesystems/locking.rst
parent9030fb0bb9d607908d51f9ee02efdbe01da355ee (diff)
parent3a3bae50af5d73fab5da20484029de77ca67bb2e (diff)
downloadlinux-6b1f86f8e9c7f9de7ca1cb987b2cf25e99b1ae3a.tar.xz
Merge tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache
Pull filesystem folio updates from Matthew Wilcox: "Primarily this series converts some of the address_space operations to take a folio instead of a page. Notably: - a_ops->is_partially_uptodate() takes a folio instead of a page and changes the type of the 'from' and 'count' arguments to make it obvious they're bytes. - a_ops->invalidatepage() becomes ->invalidate_folio() and has a similar type change. - a_ops->launder_page() becomes ->launder_folio() - a_ops->set_page_dirty() becomes ->dirty_folio() and adds the address_space as an argument. There are a couple of other misc changes up front that weren't worth separating into their own pull request" * tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits) fs: Remove aops ->set_page_dirty fb_defio: Use noop_dirty_folio() fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio fs: Convert __set_page_dirty_buffers to block_dirty_folio nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio() mm: Convert swap_set_page_dirty() to swap_dirty_folio() ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio() btrfs: Convert extent_range_redirty_for_io() to use folios fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio btrfs: Convert from set_page_dirty to dirty_folio fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio() fs: Add aops->dirty_folio fs: Remove aops->launder_page orangefs: Convert launder_page to launder_folio nfs: Convert from launder_page to launder_folio fuse: Convert from launder_page to launder_folio ...
Diffstat (limited to 'Documentation/filesystems/locking.rst')
-rw-r--r--Documentation/filesystems/locking.rst42
1 files changed, 21 insertions, 21 deletions
diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index aaca0b601819..2998cec9af4b 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -239,7 +239,7 @@ prototypes::
int (*writepage)(struct page *page, struct writeback_control *wbc);
int (*readpage)(struct file *, struct page *);
int (*writepages)(struct address_space *, struct writeback_control *);
- int (*set_page_dirty)(struct page *page);
+ bool (*dirty_folio)(struct address_space *, struct folio *folio);
void (*readahead)(struct readahead_control *);
int (*readpages)(struct file *filp, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages);
@@ -250,21 +250,21 @@ prototypes::
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
sector_t (*bmap)(struct address_space *, sector_t);
- void (*invalidatepage) (struct page *, unsigned int, unsigned int);
+ void (*invalidate_folio) (struct folio *, size_t start, size_t len);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
int (*direct_IO)(struct kiocb *, struct iov_iter *iter);
bool (*isolate_page) (struct page *, isolate_mode_t);
int (*migratepage)(struct address_space *, struct page *, struct page *);
void (*putback_page) (struct page *);
- int (*launder_page)(struct page *);
- int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long);
+ 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_deactivate)(struct file *);
locking rules:
- All except set_page_dirty and freepage may block
+ All except dirty_folio and freepage may block
====================== ======================== ========= ===============
ops PageLocked(page) i_rwsem invalidate_lock
@@ -272,20 +272,20 @@ ops PageLocked(page) i_rwsem invalidate_lock
writepage: yes, unlocks (see below)
readpage: yes, unlocks shared
writepages:
-set_page_dirty no
+dirty_folio maybe
readahead: yes, unlocks shared
readpages: no shared
write_begin: locks the page exclusive
write_end: yes, unlocks exclusive
bmap:
-invalidatepage: yes exclusive
+invalidate_folio: yes exclusive
releasepage: yes
freepage: yes
direct_IO:
isolate_page: yes
migratepage: yes (both)
putback_page: yes
-launder_page: yes
+launder_folio: yes
is_partially_uptodate: yes
error_remove_page: yes
swap_activate: no
@@ -361,22 +361,22 @@ If nr_to_write is NULL, all dirty pages must be written.
writepages should _only_ write pages which are present on
mapping->io_pages.
-->set_page_dirty() is called from various places in the kernel
-when the target page is marked as needing writeback. It may be called
-under spinlock (it cannot block) and is sometimes called with the page
-not locked.
+->dirty_folio() is called from various places in the kernel when
+the target folio is marked as needing writeback. The folio cannot be
+truncated because either the caller holds the folio lock, or the caller
+has found the folio while holding the page table lock which will block
+truncation.
->bmap() is currently used by legacy ioctl() (FIBMAP) provided by some
filesystems and by the swapper. The latter will eventually go away. Please,
keep it that way and don't breed new callers.
-->invalidatepage() is called when the filesystem must attempt to drop
+->invalidate_folio() is called when the filesystem must attempt to drop
some or all of the buffers from the page when it is being truncated. It
-returns zero on success. If ->invalidatepage is zero, the kernel uses
-block_invalidatepage() instead. The filesystem must exclusively acquire
-invalidate_lock before invalidating page cache in truncate / hole punch path
-(and thus calling into ->invalidatepage) to block races between page cache
-invalidation and page cache filling functions (fault, read, ...).
+returns zero on success. The filesystem must exclusively acquire
+invalidate_lock before invalidating page cache in truncate / hole punch
+path (and thus calling into ->invalidate_folio) to block races between page
+cache invalidation and page cache filling functions (fault, read, ...).
->releasepage() is called when the kernel is about to try to drop the
buffers from the page in preparation for freeing it. It returns zero to
@@ -386,9 +386,9 @@ the kernel assumes that the fs has no private interest in the buffers.
->freepage() is called when the kernel is done dropping the page
from the page cache.
-->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
+->launder_folio() may be called prior to releasing a folio if
+it is still found to be dirty. It returns zero if the folio was successfully
+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.