From 19d8eb0c92fda8931b14d2daac71a0644ebe4695 Mon Sep 17 00:00:00 2001 From: Ben Noordhuis Date: Sat, 9 Feb 2019 23:17:05 +0100 Subject: [PATCH] linux: use statx() to obtain file birth time MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Kernels > 4.11 support the statx() system call that lets one retrieve the birth time of a file. Teach libuv about it. Fixes: https://github.com/libuv/libuv/issues/2152 PR-URL: https://github.com/libuv/libuv/pull/2184 Reviewed-By: Anna Henningsen Reviewed-By: Colin Ihrig Reviewed-By: Santiago Gimeno Reviewed-By: Saúl Ibarra Corretgé --- src/unix/fs.c | 80 +++++++++++++++++++++++++++++++++++++++ src/unix/linux-syscalls.c | 28 ++++++++++++++ src/unix/linux-syscalls.h | 35 +++++++++++++++++ test/test-fs.c | 10 +++++ 4 files changed, 153 insertions(+) diff --git a/src/unix/fs.c b/src/unix/fs.c index 91bb82f7..596e69da 100644 --- a/src/unix/fs.c +++ b/src/unix/fs.c @@ -1053,10 +1053,82 @@ static void uv__to_stat(struct stat* src, uv_stat_t* dst) { } +static int uv__fs_statx(int fd, + const char* path, + int is_fstat, + int is_lstat, + uv_stat_t* buf) { + STATIC_ASSERT(UV_ENOSYS != -1); +#ifdef __linux__ + static int no_statx; + struct uv__statx statxbuf; + int dirfd; + int flags; + int mode; + int rc; + + if (no_statx) + return UV_ENOSYS; + + dirfd = AT_FDCWD; + flags = 0; /* AT_STATX_SYNC_AS_STAT */ + mode = 0xFFF; /* STATX_BASIC_STATS + STATX_BTIME */ + + if (is_fstat) { + dirfd = fd; + flags |= 0x1000; /* AT_EMPTY_PATH */ + } + + if (is_lstat) + flags |= AT_SYMLINK_NOFOLLOW; + + rc = uv__statx(dirfd, path, flags, mode, &statxbuf); + + if (rc == -1) { + /* EPERM happens when a seccomp filter rejects the system call. + * Has been observed with libseccomp < 2.3.3 and docker < 18.04. + */ + if (errno != EINVAL && errno != EPERM && errno != ENOSYS) + return -1; + + no_statx = 1; + return UV_ENOSYS; + } + + buf->st_dev = 256 * statxbuf.stx_dev_major + statxbuf.stx_dev_minor; + buf->st_mode = statxbuf.stx_mode; + buf->st_nlink = statxbuf.stx_nlink; + buf->st_uid = statxbuf.stx_uid; + buf->st_gid = statxbuf.stx_gid; + buf->st_rdev = statxbuf.stx_rdev_major; + buf->st_ino = statxbuf.stx_ino; + buf->st_size = statxbuf.stx_size; + buf->st_blksize = statxbuf.stx_blksize; + buf->st_blocks = statxbuf.stx_blocks; + buf->st_atim.tv_sec = statxbuf.stx_atime.tv_sec; + buf->st_atim.tv_nsec = statxbuf.stx_atime.tv_nsec; + buf->st_mtim.tv_sec = statxbuf.stx_mtime.tv_sec; + buf->st_mtim.tv_nsec = statxbuf.stx_mtime.tv_nsec; + buf->st_ctim.tv_sec = statxbuf.stx_ctime.tv_sec; + buf->st_ctim.tv_nsec = statxbuf.stx_ctime.tv_nsec; + buf->st_birthtim.tv_sec = statxbuf.stx_btime.tv_sec; + buf->st_birthtim.tv_nsec = statxbuf.stx_btime.tv_nsec; + + return 0; +#else + return UV_ENOSYS; +#endif /* __linux__ */ +} + + static int uv__fs_stat(const char *path, uv_stat_t *buf) { struct stat pbuf; int ret; + ret = uv__fs_statx(-1, path, /* is_fstat */ 0, /* is_lstat */ 0, buf); + if (ret != UV_ENOSYS) + return ret; + ret = stat(path, &pbuf); if (ret == 0) uv__to_stat(&pbuf, buf); @@ -1069,6 +1141,10 @@ static int uv__fs_lstat(const char *path, uv_stat_t *buf) { struct stat pbuf; int ret; + ret = uv__fs_statx(-1, path, /* is_fstat */ 0, /* is_lstat */ 1, buf); + if (ret != UV_ENOSYS) + return ret; + ret = lstat(path, &pbuf); if (ret == 0) uv__to_stat(&pbuf, buf); @@ -1081,6 +1157,10 @@ static int uv__fs_fstat(int fd, uv_stat_t *buf) { struct stat pbuf; int ret; + ret = uv__fs_statx(fd, "", /* is_fstat */ 1, /* is_lstat */ 0, buf); + if (ret != UV_ENOSYS) + return ret; + ret = fstat(fd, &pbuf); if (ret == 0) uv__to_stat(&pbuf, buf); diff --git a/src/unix/linux-syscalls.c b/src/unix/linux-syscalls.c index bfd75448..beaba4ed 100644 --- a/src/unix/linux-syscalls.c +++ b/src/unix/linux-syscalls.c @@ -187,6 +187,21 @@ # endif #endif /* __NR_pwritev */ +#ifndef __NR_statx +# if defined(__x86_64__) +# define __NR_statx 332 +# elif defined(__i386__) +# define __NR_statx 383 +# elif defined(__aarch64__) +# define __NR_statx 397 +# elif defined(__arm__) +# define __NR_statx (UV_SYSCALL_BASE + 397) +# elif defined(__ppc__) +# define __NR_statx 383 +# elif defined(__s390__) +# define __NR_statx 379 +# endif +#endif /* __NR_statx */ int uv__accept4(int fd, struct sockaddr* addr, socklen_t* addrlen, int flags) { #if defined(__i386__) @@ -336,3 +351,16 @@ int uv__dup3(int oldfd, int newfd, int flags) { return errno = ENOSYS, -1; #endif } + + +int uv__statx(int dirfd, + const char* path, + int flags, + unsigned int mask, + struct uv__statx* statxbuf) { +#if defined(__NR_statx) + return syscall(__NR_statx, dirfd, path, flags, mask, statxbuf); +#else + return errno = ENOSYS, -1; +#endif +} diff --git a/src/unix/linux-syscalls.h b/src/unix/linux-syscalls.h index 3dfd329d..7e58bfa2 100644 --- a/src/unix/linux-syscalls.h +++ b/src/unix/linux-syscalls.h @@ -80,6 +80,36 @@ #define UV__IN_DELETE_SELF 0x400 #define UV__IN_MOVE_SELF 0x800 +struct uv__statx_timestamp { + int64_t tv_sec; + uint32_t tv_nsec; + int32_t unused0; +}; + +struct uv__statx { + uint32_t stx_mask; + uint32_t stx_blksize; + uint64_t stx_attributes; + uint32_t stx_nlink; + uint32_t stx_uid; + uint32_t stx_gid; + uint16_t stx_mode; + uint16_t unused0; + uint64_t stx_ino; + uint64_t stx_size; + uint64_t stx_blocks; + uint64_t stx_attributes_mask; + struct uv__statx_timestamp stx_atime; + struct uv__statx_timestamp stx_btime; + struct uv__statx_timestamp stx_ctime; + struct uv__statx_timestamp stx_mtime; + uint32_t stx_rdev_major; + uint32_t stx_rdev_minor; + uint32_t stx_dev_major; + uint32_t stx_dev_minor; + uint64_t unused1[14]; +}; + struct uv__inotify_event { int32_t wd; uint32_t mask; @@ -113,5 +143,10 @@ int uv__sendmmsg(int fd, ssize_t uv__preadv(int fd, const struct iovec *iov, int iovcnt, int64_t offset); ssize_t uv__pwritev(int fd, const struct iovec *iov, int iovcnt, int64_t offset); int uv__dup3(int oldfd, int newfd, int flags); +int uv__statx(int dirfd, + const char* path, + int flags, + unsigned int mask, + struct uv__statx* statxbuf); #endif /* UV_LINUX_SYSCALL_H_ */ diff --git a/test/test-fs.c b/test/test-fs.c index 5eed160d..e3f11373 100644 --- a/test/test-fs.c +++ b/test/test-fs.c @@ -1248,6 +1248,16 @@ TEST_IMPL(fs_fstat) { #endif #endif +#if defined(__linux__) + /* If statx() is supported, the birth time should be equal to the change time + * because we just created the file. On older kernels, it's set to zero. + */ + ASSERT(s->st_birthtim.tv_sec == 0 || + s->st_birthtim.tv_sec == t.st_ctim.tv_sec); + ASSERT(s->st_birthtim.tv_nsec == 0 || + s->st_birthtim.tv_nsec == t.st_ctim.tv_nsec); +#endif + uv_fs_req_cleanup(&req); /* Now do the uv_fs_fstat call asynchronously */