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| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-11-05 10:56:32 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-08 11:56:21 +0100 |
| commit | fa18a8a0539b02cc621938091691f0b73f0b1288 (patch) | |
| tree | 5b067731368e74d8c701d9f98939eef7d68eda24 | |
| parent | 9034c87d61be8cff989017740a91701ac8195a1d (diff) | |
| download | linux-fa18a8a0539b02cc621938091691f0b73f0b1288.tar.gz linux-fa18a8a0539b02cc621938091691f0b73f0b1288.tar.bz2 linux-fa18a8a0539b02cc621938091691f0b73f0b1288.zip | |
eventfs: Remove "is_freed" union with rcu head
commit f2f496370afcbc5227d7002da28c74b91fed12ff upstream
The eventfs_inode->is_freed was a union with the rcu_head with the
assumption that when it was on the srcu list the head would contain a
pointer which would make "is_freed" true. But that was a wrong assumption
as the rcu head is a single link list where the last element is NULL.
Instead, split the nr_entries integer so that "is_freed" is one bit and
the nr_entries is the next 31 bits. As there shouldn't be more than 10
(currently there's at most 5 to 7 depending on the config), this should
not be a problem.
Link: https://lkml.kernel.org/r/20231101172649.049758712@goodmis.org
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Fixes: 63940449555e7 ("eventfs: Implement eventfs lookup, read, open functions")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/tracefs/event_inode.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 8c8d64e76103..a64d8fa39e54 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -38,6 +38,7 @@ struct eventfs_inode { * @fop: file_operations for file or directory * @iop: inode_operations for file or directory * @data: something that the caller will want to get to later on + * @is_freed: Flag set if the eventfs is on its way to be freed * @mode: the permission that the file or directory should have */ struct eventfs_file { @@ -52,15 +53,14 @@ struct eventfs_file { * Union - used for deletion * @del_list: list of eventfs_file to delete * @rcu: eventfs_file to delete in RCU - * @is_freed: node is freed if one of the above is set */ union { struct list_head del_list; struct rcu_head rcu; - unsigned long is_freed; }; void *data; - umode_t mode; + unsigned int is_freed:1; + unsigned int mode:31; }; static DEFINE_MUTEX(eventfs_mutex); @@ -814,6 +814,8 @@ static void eventfs_remove_rec(struct eventfs_file *ef, struct list_head *head, } } + ef->is_freed = 1; + list_del_rcu(&ef->list); list_add_tail(&ef->del_list, head); } |