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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-02-09 23:21:32 +0300
committerMatthew Wilcox (Oracle) <willy@infradead.org>2022-03-15 15:23:29 +0300
commit128d1f8241d62ab014eef6dd4ef9bb977dbeadb2 (patch)
tree993afed4947fda2a865573f47a7d19c4022519f6 /Documentation/filesystems
parent020df9baeac50ed911501e1950de9ddab58652b6 (diff)
downloadlinux-128d1f8241d62ab014eef6dd4ef9bb977dbeadb2.tar.xz
fs: Add invalidate_folio() aops method
This is used in preference to invalidatepage, if defined. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/locking.rst13
-rw-r--r--Documentation/filesystems/vfs.rst11
2 files changed, 13 insertions, 11 deletions
diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index 88b33524687f..29a045fd3860 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -250,6 +250,7 @@ prototypes::
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
sector_t (*bmap)(struct address_space *, sector_t);
+ void (*invalidate_folio) (struct folio *, size_t start, size_t len);
void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
@@ -278,6 +279,7 @@ readpages: no shared
write_begin: locks the page exclusive
write_end: yes, unlocks exclusive
bmap:
+invalidate_folio: yes exclusive
invalidatepage: yes exclusive
releasepage: yes
freepage: yes
@@ -370,13 +372,12 @@ not locked.
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
diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
index da3e7b470f0a..26c090cd8cf5 100644
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -735,6 +735,7 @@ cache in your filesystem. The following members are defined:
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
sector_t (*bmap)(struct address_space *, sector_t);
+ void (*invalidate_folio) (struct folio *, size_t start, size_t len);
void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
@@ -868,15 +869,15 @@ cache in your filesystem. The following members are defined:
to find out where the blocks in the file are and uses those
addresses directly.
-``invalidatepage``
- If a page has PagePrivate set, then invalidatepage will be
- called when part or all of the page is to be removed from the
+``invalidate_folio``
+ If a folio has private data, then invalidate_folio will be
+ called when part or all of the folio is to be removed from the
address space. This generally corresponds to either a
truncation, punch hole or a complete invalidation of the address
space (in the latter case 'offset' will always be 0 and 'length'
- will be PAGE_SIZE). Any private data associated with the page
+ will be folio_size()). Any private data associated with the page
should be updated to reflect this truncation. If offset is 0
- and length is PAGE_SIZE, then the private data should be
+ and length is folio_size(), then the private data should be
released, because the page must be able to be completely
discarded. This may be done by calling the ->releasepage
function, but in this case the release MUST succeed.