jbd2,ext4: dynamically allocate the jbd2-journal shrinker

In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the jbd2-journal shrinker, so that it can be freed
asynchronously via RCU. Then it doesn't need to wait for RCU read-side
critical section when releasing the struct journal_s.

Link: https://lkml.kernel.org/r/20230911094444.68966-32-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Chuck Lever <cel@kernel.org>
Cc: Coly Li <colyli@suse.de>
Cc: Dai Ngo <Dai.Ngo@oracle.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Kirill Tkhai <tkhai@ya.ru>
Cc: Marijn Suijten <marijn.suijten@somainline.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Olga Kornievskaia <kolga@netapp.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sean Paul <sean@poorly.run>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Song Liu <song@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 30dec2bd2ecc26abb8d67a66b0d04f84e08dc718..ed53188472f9aa9949d1c3c6338cba01f725b79a 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1290,7 +1290,7 @@ static int jbd2_min_tag_size(void)
 static unsigned long jbd2_journal_shrink_scan(struct shrinker *shrink,
                                              struct shrink_control *sc)
 {
-       journal_t *journal = container_of(shrink, journal_t, j_shrinker);
+       journal_t *journal = shrink->private_data;
        unsigned long nr_to_scan = sc->nr_to_scan;
        unsigned long nr_shrunk;
        unsigned long count;
@@ -1316,7 +1316,7 @@ static unsigned long jbd2_journal_shrink_scan(struct shrinker *shrink,
 static unsigned long jbd2_journal_shrink_count(struct shrinker *shrink,
                                               struct shrink_control *sc)
 {
-       journal_t *journal = container_of(shrink, journal_t, j_shrinker);
+       journal_t *journal = shrink->private_data;
        unsigned long count;
 
        count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count);
@@ -1588,14 +1588,21 @@ static journal_t *journal_init_common(struct block_device *bdev,
                goto err_cleanup;
 
        journal->j_shrink_transaction = NULL;
-       journal->j_shrinker.scan_objects = jbd2_journal_shrink_scan;
-       journal->j_shrinker.count_objects = jbd2_journal_shrink_count;
-       journal->j_shrinker.seeks = DEFAULT_SEEKS;
-       journal->j_shrinker.batch = journal->j_max_transaction_buffers;
-       err = register_shrinker(&journal->j_shrinker, "jbd2-journal:(%u:%u)",
-                               MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
-       if (err)
+
+       journal->j_shrinker = shrinker_alloc(0, "jbd2-journal:(%u:%u)",
+                                            MAJOR(bdev->bd_dev),
+                                            MINOR(bdev->bd_dev));
+       if (!journal->j_shrinker) {
+               err = -ENOMEM;
                goto err_cleanup;
+       }
+
+       journal->j_shrinker->scan_objects = jbd2_journal_shrink_scan;
+       journal->j_shrinker->count_objects = jbd2_journal_shrink_count;
+       journal->j_shrinker->batch = journal->j_max_transaction_buffers;
+       journal->j_shrinker->private_data = journal;
+
+       shrinker_register(journal->j_shrinker);
 
        return journal;
 
@@ -2172,9 +2179,9 @@ int jbd2_journal_destroy(journal_t *journal)
                brelse(journal->j_sb_buffer);
        }
 
-       if (journal->j_shrinker.flags & SHRINKER_REGISTERED) {
+       if (journal->j_shrinker) {
                percpu_counter_destroy(&journal->j_checkpoint_jh_count);
-               unregister_shrinker(&journal->j_shrinker);
+               shrinker_free(journal->j_shrinker);
        }
        if (journal->j_proc_entry)
                jbd2_stats_proc_exit(journal);

diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 52772c826c8682086a15d4dced31d34cc5ceeb04..6dcbb4eb80fb2085c578ef4c8fd40bfeba9d6db3 100644 (file)
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -886,7 +886,7 @@ struct journal_s
         * Journal head shrinker, reclaim buffer's journal head which
         * has been written back.
         */
-       struct shrinker         j_shrinker;
+       struct shrinker         *j_shrinker;
 
        /**
         * @j_checkpoint_jh_count: