Avoid remounting already mounted /run and /tmp directories #408
+19
−2
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
troglobit
requested changes
Aug 5, 2024
src/util.c
Outdated
Comment on lines
580
to
586
| struct statfs info; | ||
|
|
||
| statfs(dir, &info); | ||
| if (info.f_type == TMPFS_MAGIC || info.f_type == OVERLAYFS_SUPER_MAGIC) | ||
| return 1; |
There was a problem hiding this comment.
Either initialize the stack variable with { 0 }, and/or check the return value of statfs(), e.g., on error return 0;
Adds the function fistmpfs to determine if a new tmpfs mount should be performed on /run and /tmp. The function supports cases where more complex mount hierarchies are in use, including overlayfs backed mounts. Signed-off-by: Mathias Thore <[email protected]>
troglobit
approved these changes
Aug 5, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is a patch for finit 4.8 beta 1.
It adds the function fistmpfs to determine if a new tmpfs mount should be performed on /run and /tmp. The function supports cases where more complex mount hierarchies are in use, including overlayfs backed mounts.
In our system, /tmp is a symbolic link to a subdirectory in an overlayfs mount. This means that /tmp does not explicitly show up in /proc/mounts, so in fs_finalize, finit decides to mount a new tmpfs on top of it.
This turns out to be problematic for our smallest systems where the new tmpfs on /tmp is not large enough.
I do realize this may be a bit particular to our specific setup, but the patch works on our system. Any comments are welcome.