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| author | Kent Overstreet <kent.overstreet@linux.dev> | 2023-08-13 00:10:42 +0300 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-23 00:10:10 +0300 |
| commit | f854ce4d0a3f7281b5b99b28dd028abe21c1b0c8 (patch) | |
| tree | ef25cdde9b57eef88a45a068534358db4df6b8a7 /fs/bcachefs/six.c | |
| parent | 93ee2c4b211b6fcfa0d796801372732a8214617c (diff) | |
| download | linux-f854ce4d0a3f7281b5b99b28dd028abe21c1b0c8.tar.xz | |
bcachefs: six locks: Guard against wakee exiting in __six_lock_wakeup()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/six.c')
| -rw-r--r-- | fs/bcachefs/six.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/bcachefs/six.c b/fs/bcachefs/six.c index 0473aa4dd18a..7faa27310de4 100644 --- a/fs/bcachefs/six.c +++ b/fs/bcachefs/six.c @@ -8,6 +8,7 @@ #include <linux/sched.h> #include <linux/sched/clock.h> #include <linux/sched/rt.h> +#include <linux/sched/task.h> #include <linux/slab.h> #include "six.h" @@ -221,7 +222,12 @@ again: if (ret <= 0) goto unlock; - task = w->task; + /* + * Similar to percpu_rwsem_wake_function(), we need to guard + * against the wakee noticing w->lock_acquired, returning, and + * then exiting before we do the wakeup: + */ + task = get_task_struct(w->task); __list_del(w->list.prev, w->list.next); /* * The release barrier here ensures the ordering of the @@ -232,6 +238,7 @@ again: */ smp_store_release(&w->lock_acquired, true); wake_up_process(task); + put_task_struct(task); } six_clear_bitmask(lock, SIX_LOCK_WAITING_read << lock_type); |