path: root/fs/proc/proc_sysctl.c
diff options
authorEric W. Biederman <>2020-02-21 08:43:23 -0600
committerEric W. Biederman <>2020-02-24 09:50:04 -0600
commitf90f3cafe8d56d593fc509a4185da1d5800efea4 (patch)
tree9222e57f17f8716d8345fadea251ff1e83bce8c9 /fs/proc/proc_sysctl.c
parent080f6276fccfb3923691e57c1b44a627eabd1a25 (diff)
proc: Use d_invalidate in proc_prune_siblings_dcache
The function d_prune_aliases has the problem that it will only prune aliases thare are completely unused. It will not remove aliases for the dcache or even think of removing mounts from the dcache. For that behavior d_invalidate is needed. To use d_invalidate replace d_prune_aliases with d_find_alias followed by d_invalidate and dput. For completeness the directory and the non-directory cases are separated because in theory (although not in currently in practice for proc) directories can only ever have a single dentry while non-directories can have hardlinks and thus multiple dentries. As part of this separation use d_find_any_alias for directories to spare d_find_alias the extra work of doing that. Plus the differences between d_find_any_alias and d_find_alias makes it clear why the directory and non-directory code and not share code. To make it clear these routines now invalidate dentries rename proc_prune_siblings_dache to proc_invalidate_siblings_dcache, and rename proc_sys_prune_dcache proc_sys_invalidate_dcache. V2: Split the directory and non-directory cases. To make this code robust to future changes in proc. Signed-off-by: "Eric W. Biederman" <>
Diffstat (limited to 'fs/proc/proc_sysctl.c')
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 5da9d7f7ae34..b6f5d459b087 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -267,9 +267,9 @@ static void unuse_table(struct ctl_table_header *p)
-static void proc_sys_prune_dcache(struct ctl_table_header *head)
+static void proc_sys_invalidate_dcache(struct ctl_table_header *head)
- proc_prune_siblings_dcache(&head->inodes, &sysctl_lock);
+ proc_invalidate_siblings_dcache(&head->inodes, &sysctl_lock);
/* called under sysctl_lock, will reacquire if has to wait */
@@ -291,10 +291,10 @@ static void start_unregistering(struct ctl_table_header *p)
- * Prune dentries for unregistered sysctls: namespaced sysctls
+ * Invalidate dentries for unregistered sysctls: namespaced sysctls
* can have duplicate names and contaminate dcache very badly.
- proc_sys_prune_dcache(p);
+ proc_sys_invalidate_dcache(p);
* do not remove from the list until nobody holds it; walking the
* list in do_sysctl() relies on that.