- With the usage of simple_recursive_remove() recommended by Al Viro,
the code should not be calling "d_invalidate()" itself. Doing so
is causing crashes. The code was calling d_invalidate() on the race
of trying to look up a file while the parent was being deleted.
This was detected, and the added dentry was having d_invalidate() called
on it, but the deletion of the directory was also calling d_invalidate()
on that same dentry.
- A fix to not free the eventfs_inode (ei) until the last dput() was called
on its ei->dentry made the ei->dentry exist even after it was marked
for free by setting the ei->is_freed. But code elsewhere still was
checking if ei->dentry was NULL if ei->is_freed is set and would
trigger WARN_ON if that was the case. That's no longer true and there
should not be any warnings when it is true.
- Use GFP_NOFS for allocations done under eventfs_mutex.
The eventfs_mutex can be taken on file system reclaim, make sure
that allocations done under that mutex do not trigger file system
reclaim.
- Clean up code by moving the taking of inode_lock out of the helper
functions and into where they are needed, and not use the
parameter to know to take it or not. It must always be held but
some callers of the helper function have it taken when they were
called.
- Warn if the inode_lock is not held in the helper functions.
- Warn if eventfs_start_creating() is called without a parent.
As eventfs is underneath tracefs, all files created will have
a parent (the top one will have a tracefs parent).
Tracing update;
- Add Mathieu Desnoyers as an official reviewer of the tracing sub system.
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Merge tag 'trace-v6.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt::
"Eventfs fixes:
- With the usage of simple_recursive_remove() recommended by Al Viro,
the code should not be calling "d_invalidate()" itself. Doing so is
causing crashes. The code was calling d_invalidate() on the race of
trying to look up a file while the parent was being deleted. This
was detected, and the added dentry was having d_invalidate() called
on it, but the deletion of the directory was also calling
d_invalidate() on that same dentry.
- A fix to not free the eventfs_inode (ei) until the last dput() was
called on its ei->dentry made the ei->dentry exist even after it
was marked for free by setting the ei->is_freed. But code elsewhere
still was checking if ei->dentry was NULL if ei->is_freed is set
and would trigger WARN_ON if that was the case. That's no longer
true and there should not be any warnings when it is true.
- Use GFP_NOFS for allocations done under eventfs_mutex. The
eventfs_mutex can be taken on file system reclaim, make sure that
allocations done under that mutex do not trigger file system
reclaim.
- Clean up code by moving the taking of inode_lock out of the helper
functions and into where they are needed, and not use the parameter
to know to take it or not. It must always be held but some callers
of the helper function have it taken when they were called.
- Warn if the inode_lock is not held in the helper functions.
- Warn if eventfs_start_creating() is called without a parent. As
eventfs is underneath tracefs, all files created will have a parent
(the top one will have a tracefs parent).
Tracing update:
- Add Mathieu Desnoyers as an official reviewer of the tracing subsystem"
* tag 'trace-v6.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
MAINTAINERS: TRACING: Add Mathieu Desnoyers as Reviewer
eventfs: Make sure that parent->d_inode is locked in creating files/dirs
eventfs: Do not allow NULL parent to eventfs_start_creating()
eventfs: Move taking of inode_lock into dcache_dir_open_wrapper()
eventfs: Use GFP_NOFS for allocation when eventfs_mutex is held
eventfs: Do not invalidate dentry in create_file/dir_dentry()
eventfs: Remove expectation that ei->is_freed means ei->dentry == NULL
5b2b1173a9