Fix "No such file or directory" when launched with empty fd 0. #55
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
If any of the first three file descriptors are closed when squashfuse is launched, it will get a fd <= 2 when it opens the squashfs image file. Unfortunately fuse_daemonize() from libfuse unconditionally clobbers fds 0-2 by dup2-ing /dev/null over them. This made the squashfuse image inaccessible and things went very poorly. Fix by simply making sure fds 0-2 are open before calling sqfs_ll_open() so it is guaranteed to get a safe fd. Reproduction (previously failed with "No such file or directory", now succeeds): 0<&- squashfuse_ll fs.image /tmp/crap ls /tmp/crap
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Outdated suggestions cannot be applied.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.
If any of the first three file descriptors are closed when squashfuse is
launched, it will get a fd <= 2 when it opens the squashfs image file.
Unfortunately fuse_daemonize() from libfuse unconditionally clobbers fds 0-2
by dup2-ing /dev/null over them. This made the squashfuse image inaccessible
and things went very poorly.
Fix by simply making sure fds 0-2 are open before calling sqfs_ll_open() so
it is guaranteed to get a safe fd.
Reproduction (previously failed with "No such file or directory", now
succeeds):
0<&- squashfuse_ll fs.image /tmp/crap
ls /tmp/crap