xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

afs: Fix afs_invalidatepage to adjust the dirty region

Browse Source 
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: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
David Howells
2020-10-22 14:08:23 +01:00
parent 65dd2d6072
commit f86726a69d
4 changed files with 79 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
fs/afs/internal.h
View File

@@ -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 <trace/events/afs.h>
/*****************************************************************************/