From 4215f4dd2c73b4e709a40099116d32dc2f3fa9bc Mon Sep 17 00:00:00 2001
From: Darryl Nixon <git@nixon.mozmail.com>
Date: Sun, 16 Jul 2023 14:40:46 -0700
Subject: [PATCH] proc is a cruel mistress

---
 melamine/shred.py | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/melamine/shred.py b/melamine/shred.py
index 370f0d3..0bf3ce5 100644
--- a/melamine/shred.py
+++ b/melamine/shred.py
@@ -33,7 +33,8 @@ async def main(job: argparse.Namespace) -> bool:
     job.paths = await get_all_hardlinks(new_paths)
 
     tasks = [path.absolute() for path in job.ignoredir]
-    tasks.append(AsyncPath("/proc").absolute())
+    for path in ["/proc", "/dev", "/sys"]:
+        tasks.append(AsyncPath(path).absolute())
     job.ignoredir = set(await asyncio.gather(*tasks))
 
     # Shred all physical files including hardlinks
@@ -72,10 +73,25 @@ async def main(job: argparse.Namespace) -> bool:
     for mount_point, inodes in inodes_in_mount_points.items():
         # checking for . and .. should not be neccessary w/ rglob
         tasks = []
-        async for item in mount_point.rglob("*"):
-            if any(str(item).startswith(str(path)) for path in job.ignoredir):
-                continue
-            tasks.append(check_inode_and_unlink(item, inodes))
+        # scandir/glob/rglob doesn't play nice with FileNotFound errors,
+        # so let's avoid them entirely for now in /proc, /dev, and /sys
+        if any((mount_point / path).exists() for path in ("/proc", "/dev", "/sys")):
+            # Traverse every directory in mount_point recursively except /proc, /dev, and /sys
+            async for item in mount_point.glob("*"):
+                if await item.is_dir():
+                    if str(item) in ("proc", "dev", "sys"):
+                        continue
+                    async for subitem in item.rglob("*"):
+                        if any(str(subitem).startswith(str(path)) for path in job.ignoredir):
+                            continue
+                        tasks.append(check_inode_and_unlink(subitem, inodes))
+                else:
+                    tasks.append(check_inode_and_unlink(item, inodes))
+        else:
+            async for item in mount_point.rglob("*"):
+                if any(str(item).startswith(str(path)) for path in job.ignoredir):
+                    continue
+                tasks.append(check_inode_and_unlink(item, inodes))
         done, _ = await asyncio.wait(tasks)
         for task in done:
             e = task.exception()