From: Jeff Layton <jlayton@kernel.org>
Date: Thu, 2 Sep 2021 12:34:21 -0400
Subject: ceph: drop private list from remove_session_caps_cb
Git-commit: c35cac610a24f8b2e2d6f6535b7300d3bb2e5c29
Patch-mainline: v5.16-rc1
References: jsc#SES-1880
This function does a lot of list-shuffling with cap flushes, all to
avoid possibly freeing a slab allocation under spinlock (which is
totally ok). Simplify the code by just detaching and freeing the cap
flushes in place.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
fs/ceph/mds_client.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index d64413adc0fd..9967824ad9c3 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1619,7 +1619,6 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_inode_info *ci = ceph_inode(inode);
- LIST_HEAD(to_remove);
bool dirty_dropped = false;
bool invalidate = false;
int capsnap_release = 0;
@@ -1638,16 +1637,17 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
mapping_set_error(&inode->i_data, -EIO);
}
+ spin_lock(&mdsc->cap_dirty_lock);
+
+ /* trash all of the cap flushes for this inode */
while (!list_empty(&ci->i_cap_flush_list)) {
cf = list_first_entry(&ci->i_cap_flush_list,
struct ceph_cap_flush, i_list);
- list_move(&cf->i_list, &to_remove);
- }
-
- spin_lock(&mdsc->cap_dirty_lock);
-
- list_for_each_entry(cf, &to_remove, i_list)
list_del_init(&cf->g_list);
+ list_del_init(&cf->i_list);
+ if (!cf->is_capsnap)
+ ceph_free_cap_flush(cf);
+ }
if (!list_empty(&ci->i_dirty_item)) {
pr_warn_ratelimited(
@@ -1690,22 +1690,16 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
}
if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
- list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
+ cf = ci->i_prealloc_cap_flush;
ci->i_prealloc_cap_flush = NULL;
+ if (!cf->is_capsnap)
+ ceph_free_cap_flush(cf);
}
if (!list_empty(&ci->i_cap_snaps))
capsnap_release = remove_capsnaps(mdsc, inode);
}
spin_unlock(&ci->i_ceph_lock);
- while (!list_empty(&to_remove)) {
- struct ceph_cap_flush *cf;
- cf = list_first_entry(&to_remove,
- struct ceph_cap_flush, i_list);
- list_del_init(&cf->i_list);
- if (!cf->is_capsnap)
- ceph_free_cap_flush(cf);
- }
wake_up_all(&ci->i_cap_wq);
if (invalidate)