diff options
| -rw-r--r-- | Documentation/filesystems/locking.rst | 13 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.rst | 11 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 | ||||
| -rw-r--r-- | mm/truncate.c | 8 |
4 files changed, 21 insertions, 12 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. diff --git a/include/linux/fs.h b/include/linux/fs.h index 5939e6694ada..bcdb613cd652 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -387,6 +387,7 @@ struct address_space_operations { /* Unfortunately this kludge is needed for FIBMAP. Don't use it */ sector_t (*bmap)(struct address_space *, sector_t); + void (*invalidate_folio) (struct folio *, size_t offset, size_t len); void (*invalidatepage) (struct page *, unsigned int, unsigned int); int (*releasepage) (struct page *, gfp_t); void (*freepage)(struct page *); diff --git a/mm/truncate.c b/mm/truncate.c index aa0ed373789d..b9ad298e6ce7 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -154,9 +154,15 @@ static int invalidate_exceptional_entry2(struct address_space *mapping, */ void folio_invalidate(struct folio *folio, size_t offset, size_t length) { + const struct address_space_operations *aops = folio->mapping->a_ops; void (*invalidatepage)(struct page *, unsigned int, unsigned int); - invalidatepage = folio->mapping->a_ops->invalidatepage; + if (aops->invalidate_folio) { + aops->invalidate_folio(folio, offset, length); + return; + } + + invalidatepage = aops->invalidatepage; #ifdef CONFIG_BLOCK if (!invalidatepage) invalidatepage = block_invalidatepage; |