TapTap/FastSync
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 2 Wiki Activity

feat(xattr): --fake-super for directories (#319)

Browse Source
This commit is contained in:
TapTap
2026-09-24 02:30:02 +02:00
parent a14fbb2c10
commit cc931790e9
7 changed files with 279 additions and 50 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/shared/xattr.h
+10 -6
View File
@@ -140,21 +140,25 @@ bool xattr_apply_path_nofollow(int parent_fd, const char* leaf, const FileXattrL
/* --fake-super: write the source uid/gid/mode/rdev record into the reserved
* FAKESUPER_XATTR on `fd`, using rsync 3.4.1's exact grammar (see the key
* comment above). `mode` is the full st_mode including its S_IFMT bits.
* Best-effort (logged, never fatal). Only meaningful when metadata was
* transmitted so the values exist. */
* `fd` may be a regular file, a faked char/block device (written as a regular
* file), or a DIRECTORY: rsync stores a directory's faked mode/uid/gid in the
* reserved xattr on the directory itself. Best-effort (logged, never fatal).
* Only meaningful when metadata was transmitted so the values exist. */
void fake_super_store_fd(int fd, uint32_t uid, uint32_t gid, uint32_t mode, uint32_t rdev_major,
uint32_t rdev_minor);
/* --fake-super replay: parse the FAKESUPER_XATTR record previously written on
* `fd` by fake_super_store_fd and re-apply the recorded permission bits
* fd-relative. The recorded uid/gid are deliberately NOT chowned for real:
* --fake-super only RECORDS ownership (the caller stores the resolved mapping
* via identity_resolve_storage_ids), it never performs a real chown. The
* fd-relative. `fd` may be a regular file, a faked device, or a DIRECTORY;
* fgetxattr/fchmod work identically on a directory descriptor. The recorded
* uid/gid are deliberately NOT chowned for real: --fake-super only RECORDS
* ownership (the caller stores the resolved mapping via
* identity_resolve_storage_ids), it never performs a real chown. The
* recorded rdev is retained for a later privileged restore but is not acted on
* here. Best-effort: absence of the xattr or a malformed record is a silent
* no-op that never fails the transfer. The MODE leg is applied only when
* policy.perms||policy.executability, and the recorded special bits
* (setuid/setgid/sticky) are NOT applied to the real file -- exactly like
* (setuid/setgid/sticky) are NOT applied to the real entry -- exactly like
* rsync's fake-super receiver, which stores the full mode in the xattr but
* strips the special bits on disk. mtime is not part of the record; the normal
* metadata path carries it (policy.times) exactly as rsync sets the file's own