statx: Include a mask for stx_attributes in struct statx
Include a mask in struct stat to indicate which bits of stx_attributes the
filesystem actually supports.
This would also be useful if we add another system call that allows you to
do a 'bulk attribute set' and pass in a statx struct with the masks
appropriately set to say what you want to set.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/stat.h b/include/linux/stat.h
index c76e524..64b6b3a 100644
--- a/include/linux/stat.h
+++ b/include/linux/stat.h
@@ -26,6 +26,7 @@ struct kstat {
unsigned int nlink;
uint32_t blksize; /* Preferred I/O size */
u64 attributes;
+ u64 attributes_mask;
#define KSTAT_ATTR_FS_IOC_FLAGS \
(STATX_ATTR_COMPRESSED | \
STATX_ATTR_IMMUTABLE | \
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 0869b9e..d538897 100644
--- a/include/uapi/linux/stat.h
+++ b/include/uapi/linux/stat.h
@@ -114,7 +114,7 @@ struct statx {
__u64 stx_ino; /* Inode number */
__u64 stx_size; /* File size */
__u64 stx_blocks; /* Number of 512-byte blocks allocated */
- __u64 __spare1[1];
+ __u64 stx_attributes_mask; /* Mask to show what's supported in stx_attributes */
/* 0x40 */
struct statx_timestamp stx_atime; /* Last access time */
struct statx_timestamp stx_btime; /* File creation time */
@@ -155,7 +155,7 @@ struct statx {
#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */
/*
- * Attributes to be found in stx_attributes
+ * Attributes to be found in stx_attributes and masked in stx_attributes_mask.
*
* These give information about the features or the state of a file that might
* be of use to ordinary userspace programs such as GUIs or ls rather than