ok, so if you don't have any idea where this bug is after those debug patches, I'll try to find some time to bisect it as a last resort. Stay tuned. --Ilkka On Wed, Jun 12, 2024 at 6:56 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > On Wed, 12 Jun 2024 15:36:22 +0200 > "Linux regression tracking (Thorsten Leemhuis)" <regressions@xxxxxxxxxxxxx> wrote: > > > Hi, Thorsten here, the Linux kernel's regression tracker. Top-posting > > for once, to make this easily accessible to everyone. > > > > Ilkka or Steven, what happened to this? This thread looks stalled. I > > also was unsuccessful when looking for other threads related to this > > report or the culprit. Did it fall through the cracks or am I missing > > something here? > > Honesty, I have no idea where the bug is. I can't reproduce it. These > patches I sent would check all the places that add to the list to make > sure the proper trace_inode was being added, and the output shows that > they are all correct. Then suddenly, something that came from the > inode cache is calling the tracefs inode cache to free it, and that's > where the bug is happening. > > This really looks like another bug that the recent changes have made > more predominate. > > -- Steve > > > > > > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) > > -- > > Everything you wanna know about Linux kernel regression tracking: > > https://linux-regtracking.leemhuis.info/about/#tldr > > If I did something stupid, please tell me, as explained on that page. > > > > #regzbot poke > > > > On 02.06.24 09:32, Ilkka Naulapää wrote: > > > sorry longer delay, been a bit busy but here is the result from that > > > new patch. Only applied this patch so if the previous one is needed > > > also, let me know and I'll rerun it. > > > > > > --Ilkka > > > > > > On Thu, May 30, 2024 at 5:00 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > >> > > >> On Thu, 30 May 2024 16:02:37 +0300 > > >> Ilkka Naulapää <digirigawa@xxxxxxxxx> wrote: > > >> > > >>> applied your patch and here's the output. > > >>> > > >> > > >> Unfortunately, it doesn't give me any new information. I added one more > > >> BUG on, want to try this? Otherwise, I'm pretty much at a lost. :-/ > > >> > > >> -- Steve > > >> > > >> diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c > > >> index de5b72216b1a..a090495e78c9 100644 > > >> --- a/fs/tracefs/inode.c > > >> +++ b/fs/tracefs/inode.c > > >> @@ -39,13 +39,17 @@ static struct inode *tracefs_alloc_inode(struct super_block *sb) > > >> return NULL; > > >> > > >> ti->flags = 0; > > >> + ti->magic = 20240823; > > >> > > >> return &ti->vfs_inode; > > >> } > > >> > > >> static void tracefs_free_inode(struct inode *inode) > > >> { > > >> - kmem_cache_free(tracefs_inode_cachep, get_tracefs(inode)); > > >> + struct tracefs_inode *ti = get_tracefs(inode); > > >> + > > >> + BUG_ON(ti->magic != 20240823); > > >> + kmem_cache_free(tracefs_inode_cachep, ti); > > >> } > > >> > > >> static ssize_t default_read_file(struct file *file, char __user *buf, > > >> @@ -147,16 +151,6 @@ static const struct inode_operations tracefs_dir_inode_operations = { > > >> .rmdir = tracefs_syscall_rmdir, > > >> }; > > >> > > >> -struct inode *tracefs_get_inode(struct super_block *sb) > > >> -{ > > >> - struct inode *inode = new_inode(sb); > > >> - if (inode) { > > >> - inode->i_ino = get_next_ino(); > > >> - inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode); > > >> - } > > >> - return inode; > > >> -} > > >> - > > >> struct tracefs_mount_opts { > > >> kuid_t uid; > > >> kgid_t gid; > > >> @@ -384,6 +378,7 @@ static void tracefs_dentry_iput(struct dentry *dentry, struct inode *inode) > > >> return; > > >> > > >> ti = get_tracefs(inode); > > >> + BUG_ON(ti->magic != 20240823); > > >> if (ti && ti->flags & TRACEFS_EVENT_INODE) > > >> eventfs_set_ef_status_free(dentry); > > >> iput(inode); > > >> @@ -568,6 +563,18 @@ struct dentry *eventfs_end_creating(struct dentry *dentry) > > >> return dentry; > > >> } > > >> > > >> +struct inode *tracefs_get_inode(struct super_block *sb) > > >> +{ > > >> + struct inode *inode = new_inode(sb); > > >> + > > >> + BUG_ON(sb->s_op != &tracefs_super_operations); > > >> + if (inode) { > > >> + inode->i_ino = get_next_ino(); > > >> + inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode); > > >> + } > > >> + return inode; > > >> +} > > >> + > > >> /** > > >> * tracefs_create_file - create a file in the tracefs filesystem > > >> * @name: a pointer to a string containing the name of the file to create. > > >> diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h > > >> index 69c2b1d87c46..9059b8b11bb6 100644 > > >> --- a/fs/tracefs/internal.h > > >> +++ b/fs/tracefs/internal.h > > >> @@ -9,12 +9,15 @@ enum { > > >> struct tracefs_inode { > > >> unsigned long flags; > > >> void *private; > > >> + unsigned long magic; > > >> struct inode vfs_inode; > > >> }; > > >> > > >> static inline struct tracefs_inode *get_tracefs(const struct inode *inode) > > >> { > > >> - return container_of(inode, struct tracefs_inode, vfs_inode); > > >> + struct tracefs_inode *ti = container_of(inode, struct tracefs_inode, vfs_inode); > > >> + BUG_ON(ti->magic != 20240823); > > >> + return ti; > > >> } > > >> > > >> struct dentry *tracefs_start_creating(const char *name, struct dentry *parent); >
