From b839dadae8721eaf7245fcef3d67d82b95d00c77 Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Wed, 17 Apr 2019 12:04:27 -0600 Subject: gfs2: new slab for transactions This patch adds a new slab for gfs2 transactions. That allows us to reduce kernel memory fragmentation, have better organization of data for analysis of vmcore dumps. A new centralized function is added to free the slab objects, and it exposes use-after-free by giving warnings if a transaction is freed while it still has bd elements attached to its buffers or ail lists. We make sure to initialize those transaction ail lists so we can check their integrity when freeing. At a later time, we should add a slab initialization function to make it more efficient, but for this initial patch I wanted to minimize the impact. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher --- fs/gfs2/trans.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'fs/gfs2/trans.c') diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c index 62a65ed9a9f5..a3dfa3aa87ad 100644 --- a/fs/gfs2/trans.c +++ b/fs/gfs2/trans.c @@ -37,7 +37,7 @@ int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks, if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) return -EROFS; - tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS); + tr = kmem_cache_zalloc(gfs2_trans_cachep, GFP_NOFS); if (!tr) return -ENOMEM; @@ -67,7 +67,7 @@ int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks, fail: sb_end_intwrite(sdp->sd_vfs); - kfree(tr); + kmem_cache_free(gfs2_trans_cachep, tr); return error; } @@ -95,7 +95,7 @@ void gfs2_trans_end(struct gfs2_sbd *sdp) if (!test_bit(TR_TOUCHED, &tr->tr_flags)) { gfs2_log_release(sdp, tr->tr_reserved); if (alloced) { - kfree(tr); + gfs2_trans_free(sdp, tr); sb_end_intwrite(sdp->sd_vfs); } return; @@ -111,7 +111,7 @@ void gfs2_trans_end(struct gfs2_sbd *sdp) gfs2_log_commit(sdp, tr); if (alloced && !test_bit(TR_ATTACHED, &tr->tr_flags)) - kfree(tr); + gfs2_trans_free(sdp, tr); up_read(&sdp->sd_log_flush_lock); if (sdp->sd_vfs->s_flags & SB_SYNCHRONOUS) @@ -278,3 +278,14 @@ void gfs2_trans_remove_revoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len) gfs2_log_unlock(sdp); } +void gfs2_trans_free(struct gfs2_sbd *sdp, struct gfs2_trans *tr) +{ + if (tr == NULL) + return; + + gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list)); + gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list)); + gfs2_assert_warn(sdp, list_empty(&tr->tr_databuf)); + gfs2_assert_warn(sdp, list_empty(&tr->tr_buf)); + kmem_cache_free(gfs2_trans_cachep, tr); +} -- cgit v1.2.3