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@xxxxxxxxxx>
---
fs/ext4/inode.c | 6 ++++++
fs/stat.c | 1 +
include/linux/stat.h | 1 +
include/uapi/linux/stat.h | 4 ++--
samples/statx/test-statx.c | 12 ++++++++----
5 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5d02b922afa3..349f97ae3c87 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5413,6 +5413,12 @@ int ext4_getattr(const struct path *path, struct kstat *stat,
if (flags & EXT4_NODUMP_FL)
stat->attributes |= STATX_ATTR_NODUMP;
+ stat->attributes_mask |= (STATX_ATTR_APPEND |
+ STATX_ATTR_COMPRESSED |
+ STATX_ATTR_ENCRYPTED |
+ STATX_ATTR_IMMUTABLE |
+ STATX_ATTR_NODUMP);
+
generic_fillattr(inode, stat);
return 0;
}
diff --git a/fs/stat.c b/fs/stat.c
index 0c7e6cdc435c..c6c963b2546b 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -527,6 +527,7 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer)
tmp.stx_ino = stat->ino;
tmp.stx_size = stat->size;
tmp.stx_blocks = stat->blocks;
+ tmp.stx_attributes_mask = stat->attributes_mask;
tmp.stx_atime.tv_sec = stat->atime.tv_sec;
tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
tmp.stx_btime.tv_sec = stat->btime.tv_sec;
diff --git a/include/linux/stat.h b/include/linux/stat.h
index c76e524fb34b..64b6b3aece21 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 0869b9eaa8ce..d538897b8e08 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
diff --git a/samples/statx/test-statx.c b/samples/statx/test-statx.c
index 8571d766331d..d4d77b09412c 100644
--- a/samples/statx/test-statx.c
+++ b/samples/statx/test-statx.c
@@ -141,8 +141,8 @@ static void dump_statx(struct statx *stx)
if (stx->stx_mask & STATX_BTIME)
print_time(" Birth: ", &stx->stx_btime);
- if (stx->stx_attributes) {
- unsigned char bits;
+ if (stx->stx_attributes_mask) {
+ unsigned char bits, mbits;
int loop, byte;
static char attr_representation[64 + 1] =
@@ -160,14 +160,18 @@ static void dump_statx(struct statx *stx)
printf("Attributes: %016llx (", stx->stx_attributes);
for (byte = 64 - 8; byte >= 0; byte -= 8) {
bits = stx->stx_attributes >> byte;
+ mbits = stx->stx_attributes_mask >> byte;
for (loop = 7; loop >= 0; loop--) {
int bit = byte + loop;
- if (bits & 0x80)
+ if (!(mbits & 0x80))
+ putchar('.'); /* Not supported */
+ else if (bits & 0x80)
putchar(attr_representation[63 - bit]);
else
- putchar('-');
+ putchar('-'); /* Not set */
bits <<= 1;
+ mbits <<= 1;
}
if (byte)
putchar(' ');
