From e7ba8f306fcfc8566f09cc8f64b6f318aeae96a1 Mon Sep 17 00:00:00 2001
From: Theodore Dubois <tblodt@icloud.com>
Date: Sun, 20 Oct 2024 18:24:04 -0700
Subject: [PATCH] Add real implementation of statx

Fixes #2418
---
 fs/stat.c      | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/stat.h      | 35 +++++++++++++++++++++++++++++++++
 kernel/calls.c |  2 +-
 kernel/calls.h |  1 +
 kernel/fs.h    |  1 +
 5 files changed, 90 insertions(+), 1 deletion(-)

diff --git a/fs/stat.c b/fs/stat.c
index d277bae4f5..c509b41d1b 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -93,3 +93,55 @@ dword_t sys_fstat64(fd_t fd_no, addr_t statbuf_addr) {
         return _EFAULT;
     return 0;
 }
+
+dword_t sys_statx(fd_t at_f, addr_t path_addr, int_t flags, uint_t mask, addr_t statx_addr) {
+    int err;
+    char path[MAX_PATH];
+    if (user_read_string(path_addr, path, sizeof(path)))
+        return _EFAULT;
+    struct fd *at = at_fd(at_f);
+    if (at == NULL)
+        return _EBADF;
+
+    STRACE("statx(at=%d, path=\"%s\", flags=%d, mask=%d, statx=0x%x)", at_f, path, flags, mask, statx_addr);
+
+    struct statbuf stat = {};
+
+    if ((flags & AT_EMPTY_PATH_) && strcmp(path, "") == 0) {
+        struct fd *fd = at;
+        int err = fd->mount->fs->fstat(fd, &stat);
+        if (err < 0)
+            return err;
+    } else {
+        bool follow_links = !(flags & AT_SYMLINK_NOFOLLOW_);
+        int err = generic_statat(at, path, &stat, follow_links);
+        if (err < 0)
+            return err;
+    }
+
+    // for now, ignore the requested mask and just fill in the same fields as stat returns
+    struct statx_ statx = {};
+    statx.mask = STATX_BASIC_STATS_;
+    statx.blksize = stat.blksize;
+    statx.nlink = stat.nlink;
+    statx.uid = stat.uid;
+    statx.gid = stat.gid;
+    statx.mode = stat.mode;
+    statx.ino = stat.inode;
+    statx.size = stat.size;
+    statx.blocks = stat.blocks;
+    statx.atime.sec = stat.atime;
+    statx.atime.nsec = stat.atime_nsec;
+    statx.mtime.sec = stat.mtime;
+    statx.mtime.nsec = stat.mtime_nsec;
+    statx.ctime.sec = stat.ctime;
+    statx.ctime.nsec = stat.ctime_nsec;
+    statx.rdev_major = dev_major(stat.rdev);
+    statx.rdev_minor = dev_minor(stat.rdev);
+    statx.dev_major = dev_major(stat.dev);
+    statx.dev_minor = dev_minor(stat.dev);
+
+    if (user_put(statx_addr, statx))
+        return _EFAULT;
+    return 0;
+}
diff --git a/fs/stat.h b/fs/stat.h
index 632c172bdb..51557c4681 100644
--- a/fs/stat.h
+++ b/fs/stat.h
@@ -123,4 +123,39 @@ struct statfs64_ {
     uint_t pad[4];
 } __attribute__((packed));
 
+struct statx_timestamp_ {
+    int64_t sec;
+    uint32_t nsec;
+    uint32_t _pad;
+};
+
+struct statx_ {
+    uint32_t mask;
+    uint32_t blksize;
+    uint64_t attributes;
+    uint32_t nlink;
+    uint32_t uid;
+    uint32_t gid;
+    uint16_t mode;
+    uint16_t _pad1;
+    uint64_t ino;
+    uint64_t size;
+    uint64_t blocks;
+    uint64_t attributes_mask;
+    struct statx_timestamp_ atime;
+    struct statx_timestamp_ btime;
+    struct statx_timestamp_ ctime;
+    struct statx_timestamp_ mtime;
+    uint32_t rdev_major;
+    uint32_t rdev_minor;
+    uint32_t dev_major;
+    uint32_t dev_minor;
+    uint64_t mnt_id;
+    uint32_t dio_mem_align;
+    uint32_t dio_offset_align;
+    uint32_t _pad2[24];
+} __attribute__((packed));
+
+#define STATX_BASIC_STATS_ 0x7ff
+
 #endif
diff --git a/kernel/calls.c b/kernel/calls.c
index 88d214b1c6..10f06e6b96 100644
--- a/kernel/calls.c
+++ b/kernel/calls.c
@@ -246,7 +246,7 @@ syscall_t syscall_table[] = {
     [373] = (syscall_t) sys_shutdown,
     [375] = (syscall_t) syscall_silent_stub, // membarrier
     [377] = (syscall_t) sys_copy_file_range,
-    [383] = (syscall_t) syscall_silent_stub, // statx
+    [383] = (syscall_t) sys_statx,
     [384] = (syscall_t) sys_arch_prctl,
     [422] = (syscall_t) syscall_silent_stub, // futex_time64
     [439] = (syscall_t) syscall_silent_stub, // faccessat2
diff --git a/kernel/calls.h b/kernel/calls.h
index 9fd7c4d962..5a661102d3 100644
--- a/kernel/calls.h
+++ b/kernel/calls.h
@@ -158,6 +158,7 @@ dword_t sys_statfs(addr_t path_addr, addr_t buf_addr);
 dword_t sys_statfs64(addr_t path_addr, dword_t buf_size, addr_t buf_addr);
 dword_t sys_fstatfs(fd_t f, addr_t buf_addr);
 dword_t sys_fstatfs64(fd_t f, addr_t buf_addr);
+dword_t sys_statx(fd_t at_f, addr_t path_addr, int_t flags, uint_t mask, addr_t statx_addr);
 
 #define MS_READONLY_ (1 << 0)
 #define MS_NOSUID_ (1 << 1)
diff --git a/kernel/fs.h b/kernel/fs.h
index 5a8154ccb4..5a0becc7f0 100644
--- a/kernel/fs.h
+++ b/kernel/fs.h
@@ -45,6 +45,7 @@ struct attr {
     ((struct attr) {.type = attr_##_type, ._type = thing})
 
 #define AT_SYMLINK_NOFOLLOW_ 0x100
+#define AT_EMPTY_PATH_ 0x1000
 
 struct fd *generic_open(const char *path, int flags, int mode);
 struct fd *generic_openat(struct fd *at, const char *path, int flags, int mode);