Messages in this thread Patch in this message | | | From | Al Viro <> | Subject | [PATCH v3 11/21] __dentry_kill(): get consistent rules for victim's refcount | Date | Fri, 24 Nov 2023 06:04:12 +0000 |
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Currently we call it with refcount equal to 1 when called from dentry_kill(); all other callers have it equal to 0.
Make it always be called with zero refcount; on this step we just decrement it before the calls in dentry_kill(). That is safe, since all places that care about the value of refcount either do that under ->d_lock or hold a reference to dentry in question. Either is sufficient to prevent observing a dentry immediately prior to __dentry_kill() getting called from dentry_kill().
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- fs/dcache.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/dcache.c b/fs/dcache.c index 2e74f3f2ce2e..b527db8e5901 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -729,6 +729,7 @@ static struct dentry *dentry_kill(struct dentry *dentry) goto slow_positive; } } + dentry->d_lockref.count--; __dentry_kill(dentry); return parent; @@ -741,6 +742,7 @@ static struct dentry *dentry_kill(struct dentry *dentry) if (unlikely(dentry->d_lockref.count != 1)) { dentry->d_lockref.count--; } else if (likely(!retain_dentry(dentry))) { + dentry->d_lockref.count--; __dentry_kill(dentry); return parent; } else { -- 2.39.2
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