On Thu, Dec 14, 2017 at 02:24:52AM -0600, Bruno Wolff III wrote: > On Wed, Dec 13, 2017 at 16:54:17 -0800, > Laura Abbott <labbott@xxxxxxxxxx> wrote: > >Hi, > > > >Fedora got a bug report https://bugzilla.redhat.com/show_bug.cgi?id=1520982 > >of a boot failure/bug on Linus' master (full bootlog at the bugzilla) > > I'm available for testing. The problem happens on my x86_64 Dell > Workstation, but not an old i386 server or an x86_64 mac hardware > based laptop. Hi, It seems something wrong with bdi debugfs register, could you help test the forllowing debug patch, I add some debug log, no function change, thanks. >From d2728c07589e8b83115a51e0c629451bff7308db Mon Sep 17 00:00:00 2001 From: weiping zhang <zhangweiping@xxxxxxxxxxxxxxx> Date: Thu, 14 Dec 2017 17:56:22 +0800 Subject: [PATCH] bdi debugfs Signed-off-by: weiping zhang <zhangweiping@xxxxxxxxxxxxxxx> --- mm/backing-dev.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 84b2dc7..fbbb9a6 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -39,6 +39,10 @@ static struct dentry *bdi_debug_root; static void bdi_debug_init(void) { bdi_debug_root = debugfs_create_dir("bdi", NULL); + if (!bdi_debug_root) + pr_err("DEBUG:bdi_debug_root fail\n"); + else + pr_err("DEBUG:bdi_debug_root success\n"); } static int bdi_debug_stats_show(struct seq_file *m, void *v) @@ -115,18 +119,29 @@ static const struct file_operations bdi_debug_stats_fops = { static int bdi_debug_register(struct backing_dev_info *bdi, const char *name) { - if (!bdi_debug_root) + if (!bdi_debug_root) { + pr_err("DEBUG:dev:%s, bdi_debug_root fail\n", name); return -ENOMEM; + } else { + pr_err("DEBUG:dev:%s, bdi_debug_root success\n", name); + } bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root); - if (!bdi->debug_dir) + if (!bdi->debug_dir) { + pr_err("DEBUG:dev:%s, debug_dir fail\n", name); return -ENOMEM; + } else { + pr_err("DEBUG:dev:%s, debug_dir success\n", name); + } bdi->debug_stats = debugfs_create_file("stats", 0444, bdi->debug_dir, bdi, &bdi_debug_stats_fops); if (!bdi->debug_stats) { debugfs_remove(bdi->debug_dir); + pr_err("DEBUG:dev:%s, debug_stats fail\n", name); return -ENOMEM; + } else { + pr_err("DEBUG:dev:%s, debug_stats success\n", name); } return 0; @@ -879,13 +894,20 @@ int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args) return 0; dev = device_create_vargs(bdi_class, NULL, MKDEV(0, 0), bdi, fmt, args); - if (IS_ERR(dev)) + if (IS_ERR(dev)) { + pr_err("DEBUG: bdi device_create_vargs fail\n"); return PTR_ERR(dev); + } + pr_err("DEBUG: bdi(0x%p) device_create_vargs sucess\n", bdi); if (bdi_debug_register(bdi, dev_name(dev))) { + pr_err("DEBUG: dev:%s, bdi(0x%p) bdi_debug_register fail\n", + dev_name(dev), bdi); device_destroy(bdi_class, dev->devt); return -ENOMEM; } + pr_err("DEBUG: dev:%s, bdi(0x%p) bdi_debug_register success\n", + dev_name(dev), bdi); cgwb_bdi_register(bdi); bdi->dev = dev; -- 2.9.4
