[PATCH 12/18] mm: Define MAP_SYNC and VM_SYNC flags
From: Jan Kara <hidden>
Date: 2017-11-01 15:36:41
Also in:
linux-ext4, linux-fsdevel, linux-mm, linux-xfs, nvdimm
Subsystem:
filesystems (vfs and infrastructure), generic include/asm header files, memory management - core, memory mapping, proc filesystem, the rest · Maintainers:
Alexander Viro, Christian Brauner, Arnd Bergmann, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
Define new MAP_SYNC flag and corresponding VMA VM_SYNC flag. As the MAP_SYNC flag is not part of LEGACY_MAP_MASK, currently it will be refused by all MAP_SHARED_VALIDATE map attempts and silently ignored for everything else. Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> Reviewed-by: Christoph Hellwig <redacted> Signed-off-by: Jan Kara <redacted> --- fs/proc/task_mmu.c | 1 + include/linux/mm.h | 1 + include/linux/mman.h | 8 ++++++-- include/uapi/asm-generic/mman.h | 1 + 4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5589b4bd4b85..ea78b37deeaa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c@@ -664,6 +664,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_ACCOUNT)] = "ac", [ilog2(VM_NORESERVE)] = "nr", [ilog2(VM_HUGETLB)] = "ht", + [ilog2(VM_SYNC)] = "sf", [ilog2(VM_ARCH_1)] = "ar", [ilog2(VM_WIPEONFORK)] = "wf", [ilog2(VM_DONTDUMP)] = "dd",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ca72b67153d5..5411cb7442de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -189,6 +189,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */ #define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */ #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */ +#define VM_SYNC 0x00800000 /* Synchronous page faults */ #define VM_ARCH_1 0x01000000 /* Architecture-specific flag */ #define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */ #define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 94b63b4d71ff..8f7cc87828e6 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h@@ -9,7 +9,7 @@ /* * Arrange for legacy / undefined architecture specific flags to be - * ignored by default in LEGACY_MAP_MASK. + * ignored by mmap handling code. */ #ifndef MAP_32BIT #define MAP_32BIT 0
@@ -23,6 +23,9 @@ #ifndef MAP_UNINITIALIZED #define MAP_UNINITIALIZED 0 #endif +#ifndef MAP_SYNC +#define MAP_SYNC 0 +#endif /* * The historical set of flags that all mmap implementations implicitly
@@ -125,7 +128,8 @@ calc_vm_flag_bits(unsigned long flags) { return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) | - _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ); + _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | + _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ); } unsigned long vm_commit_limit(void);
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 7162cd4cca73..00e55627d2df 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h@@ -12,6 +12,7 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ +#define MAP_SYNC 0x80000 /* perform synchronous page faults for the mapping */ /* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
--
2.12.3