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| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-11-01 13:25:42 -0400 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-11-01 23:49:32 -0400 |
| commit | f2f496370afcbc5227d7002da28c74b91fed12ff (patch) | |
| tree | 0f695fce17211e783d42ec37a1d80eca2edc7108 /fs/tracefs | |
| parent | 9037caa09ed345b35325200f0e4acf5a94ae0a65 (diff) | |
| download | linux-f2f496370afcbc5227d7002da28c74b91fed12ff.tar.gz linux-f2f496370afcbc5227d7002da28c74b91fed12ff.tar.bz2 linux-f2f496370afcbc5227d7002da28c74b91fed12ff.zip | |
eventfs: Remove "is_freed" union with rcu head
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>
Diffstat (limited to 'fs/tracefs')
| -rw-r--r-- | fs/tracefs/event_inode.c | 2 | ||||
| -rw-r--r-- | fs/tracefs/internal.h | 6 |
2 files changed, 5 insertions, 3 deletions
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 9f612a8f009d..1ce73acf3df0 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -824,6 +824,8 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, struct list_head *head, eventfs_remove_rec(ei_child, head, level + 1); } + ei->is_freed = 1; + list_del_rcu(&ei->list); list_add_tail(&ei->del_list, head); } diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 64fde9490f52..c7d88aaa949f 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -23,6 +23,7 @@ struct tracefs_inode { * @d_parent: pointer to the parent's dentry * @d_children: The array of dentries to represent the files when created * @data: The private data to pass to the callbacks + * @is_freed: Flag set if the eventfs is on its way to be freed * @nr_entries: The number of items in @entries */ struct eventfs_inode { @@ -38,14 +39,13 @@ struct eventfs_inode { * Union - used for deletion * @del_list: list of eventfs_inode to delete * @rcu: eventfs_inode 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; }; - int nr_entries; + unsigned int is_freed:1; + unsigned int nr_entries:31; }; static inline struct tracefs_inode *get_tracefs(const struct inode *inode) |