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Merge pull request #16928 from poettering/statx-fallback

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stat-util: provide single statx() fallback on top of fstatat()
This commit is contained in:
Zbigniew Jędrzejewski-Szmek
2020-09-05 22:04:18 +02:00
committed by GitHub
parent e813a74ae8 ca194a2a0c
commit 6743a1caf4
6 changed files with 185 additions and 163 deletions
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src/basic/missing_stat.h
+30
View File
@@ -49,6 +49,16 @@ struct statx STATX_DEFINITION;
* defines an older definition */
struct new_statx STATX_DEFINITION;
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef AT_STATX_SYNC_AS_STAT
#define AT_STATX_SYNC_AS_STAT 0x0000
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef AT_STATX_FORCE_SYNC
#define AT_STATX_FORCE_SYNC 0x2000
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef AT_STATX_DONT_SYNC
#define AT_STATX_DONT_SYNC 0x4000
@@ -64,11 +74,21 @@ struct new_statx STATX_DEFINITION;
#define STATX_MODE 0x00000002U
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef STATX_NLINK
#define STATX_NLINK 0x00000004U
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef STATX_UID
#define STATX_UID 0x00000008U
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef STATX_GID
#define STATX_GID 0x00000010U
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef STATX_ATIME
#define STATX_ATIME 0x00000020U
@@ -89,6 +109,16 @@ struct new_statx STATX_DEFINITION;
#define STATX_INO 0x00000100U
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef STATX_SIZE
#define STATX_SIZE 0x00000200U
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef STATX_BLOCKS
#define STATX_BLOCKS 0x00000400U
#endif
/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
#ifndef STATX_BTIME
#define STATX_BTIME 0x00000800U
src/basic/mountpoint-util.c
+3 -15
View File
@@ -13,6 +13,7 @@
#include "mountpoint-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "stat-util.h"
#include "stdio-util.h"
#include "strv.h"
@@ -135,13 +136,8 @@ int fd_is_mount_point(int fd, const char *filename, int flags) {
_cleanup_free_ struct file_handle *h = NULL, *h_parent = NULL;
int mount_id = -1, mount_id_parent = -1;
bool nosupp = false, check_st_dev = true;
STRUCT_STATX_DEFINE(sx);
struct stat a, b;
struct statx sx
#if HAS_FEATURE_MEMORY_SANITIZER
= {}
# warning "Explicitly initializing struct statx, to work around msan limitation. Please remove as soon as msan has been updated to not require this."
#endif
;
int r;
assert(fd >= 0);
@@ -298,15 +294,7 @@ int path_is_mount_point(const char *t, const char *root, int flags) {
}
int path_get_mnt_id(const char *path, int *ret) {
union {
struct statx sx;
struct new_statx nsx;
} buf
#if HAS_FEATURE_MEMORY_SANITIZER
= {}
# warning "Explicitly initializing struct statx, to work around msan limitation. Please remove as soon as msan has been updated to not require this."
#endif
;
STRUCT_NEW_STATX_DEFINE(buf);
int r;
if (statx(AT_FDCWD, path, AT_SYMLINK_NOFOLLOW|AT_NO_AUTOMOUNT, STATX_MNT_ID, &buf.sx) < 0) {
src/basic/stat-util.c
+57
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@@ -15,6 +15,7 @@
#include "macro.h"
#include "missing_fs.h"
#include "missing_magic.h"
#include "missing_syscall.h"
#include "parse-util.h"
#include "stat-util.h"
#include "string-util.h"
@@ -413,3 +414,59 @@ bool stat_inode_unmodified(const struct stat *a, const struct stat *b) {
a->st_ino == b->st_ino &&
(!(S_ISCHR(a->st_mode) || S_ISBLK(a->st_mode)) || a->st_rdev == b->st_rdev); /* if device node, also compare major/minor, because we can */
}
int statx_fallback(int dfd, const char *path, int flags, unsigned mask, struct statx *sx) {
static bool avoid_statx = false;
struct stat st;
if (!avoid_statx) {
if (statx(dfd, path, flags, mask, sx) < 0) {
if (!ERRNO_IS_NOT_SUPPORTED(errno) && errno != EPERM)
return -errno;
/* If statx() is not supported or if we see EPERM (which might indicate seccomp
* filtering or so), let's do a fallback. Not that on EACCES we'll not fall back,
* since that is likely an indication of fs access issues, which we should
* propagate */
} else
return 0;
avoid_statx = true;
}
/* Only do fallback if fstatat() supports the flag too, or if it's one of the sync flags, which are
* OK to ignore */
if ((flags & ~(AT_EMPTY_PATH|AT_NO_AUTOMOUNT|AT_SYMLINK_NOFOLLOW|
AT_STATX_SYNC_AS_STAT|AT_STATX_FORCE_SYNC|AT_STATX_DONT_SYNC)) != 0)
return -EOPNOTSUPP;
if (fstatat(dfd, path, &st, flags & (AT_EMPTY_PATH|AT_NO_AUTOMOUNT|AT_SYMLINK_NOFOLLOW)) < 0)
return -errno;
*sx = (struct statx) {
.stx_mask = STATX_TYPE|STATX_MODE|
STATX_NLINK|STATX_UID|STATX_GID|
STATX_ATIME|STATX_MTIME|STATX_CTIME|
STATX_INO|STATX_SIZE|STATX_BLOCKS,
.stx_blksize = st.st_blksize,
.stx_nlink = st.st_nlink,
.stx_uid = st.st_uid,
.stx_gid = st.st_gid,
.stx_mode = st.st_mode,
.stx_ino = st.st_ino,
.stx_size = st.st_size,
.stx_blocks = st.st_blocks,
.stx_rdev_major = major(st.st_rdev),
.stx_rdev_minor = minor(st.st_rdev),
.stx_dev_major = major(st.st_dev),
.stx_dev_minor = minor(st.st_dev),
.stx_atime.tv_sec = st.st_atim.tv_sec,
.stx_atime.tv_nsec = st.st_atim.tv_nsec,
.stx_mtime.tv_sec = st.st_mtim.tv_sec,
.stx_mtime.tv_nsec = st.st_mtim.tv_nsec,
.stx_ctime.tv_sec = st.st_ctim.tv_sec,
.stx_ctime.tv_nsec = st.st_ctim.tv_nsec,
};
return 0;
}
src/basic/stat-util.h
+22
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@@ -10,6 +10,7 @@
#include <sys/vfs.h>
#include "macro.h"
#include "missing_stat.h"
int is_symlink(const char *path);
int is_dir(const char *path, bool follow);
@@ -91,3 +92,24 @@ int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret
int proc_mounted(void);
bool stat_inode_unmodified(const struct stat *a, const struct stat *b);
int statx_fallback(int dfd, const char *path, int flags, unsigned mask, struct statx *sx);
#if HAS_FEATURE_MEMORY_SANITIZER
# warning "Explicitly initializing struct statx, to work around msan limitation. Please remove as soon as msan has been updated to not require this."
# define STRUCT_STATX_DEFINE(var) \
struct statx var = {}
# define STRUCT_NEW_STATX_DEFINE(var) \
union { \
struct statx sx; \
struct new_statx nsx; \
} var = {}
#else
# define STRUCT_STATX_DEFINE(var) \
struct statx var
# define STRUCT_NEW_STATX_DEFINE(var) \
union { \
struct statx sx; \
struct new_statx nsx; \
} var
#endif
src/basic/xattr-util.c
+2 -6
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@@ -12,6 +12,7 @@
#include "macro.h"
#include "missing_syscall.h"
#include "sparse-endian.h"
#include "stat-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "time-util.h"
@@ -154,12 +155,7 @@ static int parse_crtime(le64_t le, usec_t *usec) {
}
int fd_getcrtime_at(int dirfd, const char *name, usec_t *ret, int flags) {
struct_statx sx
#if HAS_FEATURE_MEMORY_SANITIZER
= {}
# warning "Explicitly initializing struct statx, to work around msan limitation. Please remove as soon as msan has been updated to not require this."
#endif
;
STRUCT_STATX_DEFINE(sx);
usec_t a, b;
le64_t le;
size_t n;