From f86726a69dec5df6ba051baf9265584419478b64 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 22 Oct 2020 14:08:23 +0100 Subject: afs: Fix afs_invalidatepage to adjust the dirty region Fix afs_invalidatepage() to adjust the dirty region recorded in page->private when truncating a page. If the dirty region is entirely removed, then the private data is cleared and the page dirty state is cleared. Without this, if the page is truncated and then expanded again by truncate, zeros from the expanded, but no-longer dirty region may get written back to the server if the page gets laundered due to a conflicting 3rd-party write. It mustn't, however, shorten the dirty region of the page if that page is still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is stored in page->private to record this. Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Signed-off-by: David Howells --- fs/afs/internal.h | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'fs/afs/internal.h') diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 344c545f934c..b0fce1f75397 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -864,11 +864,13 @@ struct afs_vnode_cache_aux { * 0...PAGE_SIZE inclusive, so we can't support 64K pages on a 32-bit system. */ #ifdef CONFIG_64BIT -#define __AFS_PAGE_PRIV_MASK 0xffffffffUL +#define __AFS_PAGE_PRIV_MASK 0x7fffffffUL #define __AFS_PAGE_PRIV_SHIFT 32 +#define __AFS_PAGE_PRIV_MMAPPED 0x80000000UL #else -#define __AFS_PAGE_PRIV_MASK 0xffffUL +#define __AFS_PAGE_PRIV_MASK 0x7fffUL #define __AFS_PAGE_PRIV_SHIFT 16 +#define __AFS_PAGE_PRIV_MMAPPED 0x8000UL #endif static inline size_t afs_page_dirty_from(unsigned long priv) @@ -886,6 +888,16 @@ static inline unsigned long afs_page_dirty(size_t from, size_t to) return ((unsigned long)(to - 1) << __AFS_PAGE_PRIV_SHIFT) | from; } +static inline unsigned long afs_page_dirty_mmapped(unsigned long priv) +{ + return priv | __AFS_PAGE_PRIV_MMAPPED; +} + +static inline bool afs_is_page_dirty_mmapped(unsigned long priv) +{ + return priv & __AFS_PAGE_PRIV_MMAPPED; +} + #include /*****************************************************************************/ -- cgit v1.2.3-58-ga151