diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index a57c909a15e4..c56b39890a41 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -73,6 +73,7 @@ */ enum pageflags { PG_locked, /* Page is locked. Don't touch. */ + PG_waiters, /* Page has waiters, check its waitqueue */ PG_error, PG_referenced, PG_uptodate, @@ -169,6 +170,9 @@ static __always_inline int PageCompound(struct page *page) * for compound page all operations related to the page flag applied to * head page. * + * PF_ONLY_HEAD: + * for compound page, callers only ever operate on the head page. + * * PF_NO_TAIL: * modifications of the page flag must be done on small or head pages, * checks can be done on tail pages too. @@ -178,6 +182,9 @@ static __always_inline int PageCompound(struct page *page) */ #define PF_ANY(page, enforce) page #define PF_HEAD(page, enforce) compound_head(page) +#define PF_ONLY_HEAD(page, enforce) ({ \ + VM_BUG_ON_PGFLAGS(PageTail(page), page); \ + page;}) #define PF_NO_TAIL(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ compound_head(page);}) @@ -255,6 +262,7 @@ static inline int TestClearPage##uname(struct page *page) { return 0; } TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) __PAGEFLAG(Locked, locked, PF_NO_TAIL) +PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) PAGEFLAG(Referenced, referenced, PF_HEAD) TESTCLEARFLAG(Referenced, referenced, PF_HEAD) @@ -743,6 +751,7 @@ static inline int page_has_private(struct page *page) #undef PF_ANY #undef PF_HEAD +#undef PF_ONLY_HEAD #undef PF_NO_TAIL #undef PF_NO_COMPOUND #endif /* !__GENERATING_BOUNDS_H */ |