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authorBaokun Li <libaokun1@huawei.com>2024-07-19 21:40:02 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-07-25 09:50:57 +0200
commit5c5a577a2cc62969450650a076be7183339c0857 (patch)
tree91e24607386fc6111079c199ac8ebab2d8ebd3f3
parent6f1fc7fea4b21bc13cc981224bd8bf3d3bfc0d68 (diff)
netfs, fscache: export fscache_put_volume() and add fscache_try_get_volume()
[ Upstream commit 85b08b31a22b481ec6528130daf94eee4452e23f ] Export fscache_put_volume() and add fscache_try_get_volume() helper function to allow cachefiles to get/put fscache_volume via linux/fscache-cache.h. Signed-off-by: Baokun Li <libaokun1@huawei.com> Link: https://lore.kernel.org/r/20240628062930.2467993-2-libaokun@huaweicloud.com Signed-off-by: Christian Brauner <brauner@kernel.org> Stable-dep-of: 522018a0de6b ("cachefiles: fix slab-use-after-free in fscache_withdraw_volume()") Stable-dep-of: 5d8f80578907 ("cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()") Signed-off-by: Baokun Li <libaokun1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/fscache/internal.h2
-rw-r--r--fs/fscache/volume.c14
-rw-r--r--include/linux/fscache-cache.h6
3 files changed, 20 insertions, 2 deletions
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 1336f517e9b1..4799a722bc28 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -145,8 +145,6 @@ extern const struct seq_operations fscache_volumes_seq_ops;
struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
enum fscache_volume_trace where);
-void fscache_put_volume(struct fscache_volume *volume,
- enum fscache_volume_trace where);
bool fscache_begin_volume_access(struct fscache_volume *volume,
struct fscache_cookie *cookie,
enum fscache_access_trace why);
diff --git a/fs/fscache/volume.c b/fs/fscache/volume.c
index cdf991bdd9de..cb75c07b5281 100644
--- a/fs/fscache/volume.c
+++ b/fs/fscache/volume.c
@@ -27,6 +27,19 @@ struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
return volume;
}
+struct fscache_volume *fscache_try_get_volume(struct fscache_volume *volume,
+ enum fscache_volume_trace where)
+{
+ int ref;
+
+ if (!__refcount_inc_not_zero(&volume->ref, &ref))
+ return NULL;
+
+ trace_fscache_volume(volume->debug_id, ref + 1, where);
+ return volume;
+}
+EXPORT_SYMBOL(fscache_try_get_volume);
+
static void fscache_see_volume(struct fscache_volume *volume,
enum fscache_volume_trace where)
{
@@ -420,6 +433,7 @@ void fscache_put_volume(struct fscache_volume *volume,
fscache_free_volume(volume);
}
}
+EXPORT_SYMBOL(fscache_put_volume);
/*
* Relinquish a volume representation cookie.
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index a174cedf4d90..35e86d2f2887 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -19,6 +19,7 @@
enum fscache_cache_trace;
enum fscache_cookie_trace;
enum fscache_access_trace;
+enum fscache_volume_trace;
enum fscache_cache_state {
FSCACHE_CACHE_IS_NOT_PRESENT, /* No cache is present for this name */
@@ -97,6 +98,11 @@ extern void fscache_withdraw_cookie(struct fscache_cookie *cookie);
extern void fscache_io_error(struct fscache_cache *cache);
+extern struct fscache_volume *
+fscache_try_get_volume(struct fscache_volume *volume,
+ enum fscache_volume_trace where);
+extern void fscache_put_volume(struct fscache_volume *volume,
+ enum fscache_volume_trace where);
extern void fscache_end_volume_access(struct fscache_volume *volume,
struct fscache_cookie *cookie,
enum fscache_access_trace why);