diff options
| author |   Al Viro <viro@zeniv.linux.org.uk> | 2023-10-29 18:38:27 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2023-11-25 02:33:42 -0500 |
| commit | ee0c82503dcd0d14cc1ad53da18d32a04f612c4c (patch) | |
| tree | 2d49579d0132aa562488be0fceffc940a3dcaf15 /fs/dcache.c | |
| parent | make retain_dentry() neutral with respect to refcounting (diff) | |
| download | wireguard-linux-ee0c82503dcd0d14cc1ad53da18d32a04f612c4c.tar.xz wireguard-linux-ee0c82503dcd0d14cc1ad53da18d32a04f612c4c.zip | |
__dentry_kill(): get consistent rules for victim's refcount
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>
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 2 |
1 files changed, 2 insertions, 0 deletions
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 @@ got_locks: 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 { |