fs-util: add new CHASE_NOFOLLOW flag to chase_symlinks()

This flag mimics what "O_NOFOLLOW|O_PATH" does for open(2) that is
chase_symlinks() will not resolve the final pathname component if it's a
symlink and instead will return a file descriptor referring to the symlink
itself.

Note: if CHASE_SAFE is also passed, no safety checking is performed on the
transition done if the symlink would have been followed.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/basic/fs-util.h b/src/basic/fs-util.h
index b1a366ae49..4b65625861 100644
--- a/src/basic/fs-util.h
+++ b/src/basic/fs-util.h
@@ -73,6 +73,7 @@ enum {
         CHASE_OPEN        = 1 << 4, /* If set, return an O_PATH object to the final component */
         CHASE_TRAIL_SLASH = 1 << 5, /* If set, any trailing slash will be preserved */
         CHASE_STEP        = 1 << 6, /* If set, just execute a single step of the normalization */
+        CHASE_NOFOLLOW    = 1 << 7, /* Only valid with CHASE_OPEN: when the path's right-most component refers to symlink return O_PATH fd of the symlink, rather than following it. */
 };
 
 /* How many iterations to execute before returning -ELOOP */