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| author | Amir Goldstein <amir73il@gmail.com> | 2026-01-08 10:45:22 +0300 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-01-12 12:57:34 +0300 |
| commit | c644bce62b9c6b441143a03c910f986109c47001 (patch) | |
| tree | 6a604afe0fdade458369e60c3c6533b86ffd02a3 /include/linux | |
| parent | 7d42f2b1cc3a60a71784967384ddcf29fe3f35ed (diff) | |
| download | linux-c644bce62b9c6b441143a03c910f986109c47001.tar.xz | |
readdir: require opt-in for d_type flags
Commit c31f91c6af96 ("fuse: don't allow signals to interrupt getdents
copying") introduced the use of high bits in d_type as flags. However,
overlayfs was not adapted to handle this change.
In ovl_cache_entry_new(), the code checks if d_type == DT_CHR to
determine if an entry might be a whiteout. When fuse is used as the
lower layer and sets high bits in d_type, this comparison fails,
causing whiteout files to not be recognized properly and resulting in
incorrect overlayfs behavior.
Fix this by requiring callers of iterate_dir() to opt-in for getting
flag bits in d_type outside of S_DT_MASK.
Fixes: c31f91c6af96 ("fuse: don't allow signals to interrupt getdents copying")
Link: https://lore.kernel.org/all/20260107034551.439-1-luochunsheng@ustc.edu/
Link: https://github.com/containerd/stargz-snapshotter/issues/2214
Reported-by: Chunsheng Luo <luochunsheng@ustc.edu>
Reviewed-by: Chunsheng Luo <luochunsheng@ustc.edu>
Tested-by: Chunsheng Luo <luochunsheng@ustc.edu>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20260108074522.3400998-1-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/fs.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index f5c9cf28c4dc..a01621fa636a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1855,6 +1855,8 @@ struct dir_context { * INT_MAX unlimited */ int count; + /* @actor supports these flags in d_type high bits */ + unsigned int dt_flags_mask; }; /* If OR-ed with d_type, pending signals are not checked */ @@ -3524,7 +3526,9 @@ static inline bool dir_emit(struct dir_context *ctx, const char *name, int namelen, u64 ino, unsigned type) { - return ctx->actor(ctx, name, namelen, ctx->pos, ino, type); + unsigned int dt_mask = S_DT_MASK | ctx->dt_flags_mask; + + return ctx->actor(ctx, name, namelen, ctx->pos, ino, type & dt_mask); } static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx) { |