From dd70edbde2627f47df118d899de6bbb55abcfdbf Mon Sep 17 00:00:00 2001 From: Vyacheslav Dubeyko Date: Fri, 8 Aug 2014 14:20:55 -0700 Subject: nilfs2: integrate sysfs support into driver This patch integrates creation of sysfs groups and attributes into NILFS file system driver. It was found the issue with nilfs_sysfs_{create/delete}_snapshot_group functions by Michael L Semon in the first version of the patch: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:579 in_atomic(): 1, irqs_disabled(): 0, pid: 32676, name: umount.nilfs2 2 locks held by umount.nilfs2/32676: #0: (&type->s_umount_key#21){++++..}, at: [<790c18e2>] deactivate_super+0x37/0x58 #1: (&(&nilfs->ns_cptree_lock)->rlock){+.+...}, at: [<791bf659>] nilfs_put_root+0x23/0x5a Preemption disabled at:[<791bf659>] nilfs_put_root+0x23/0x5a CPU: 0 PID: 32676 Comm: umount.nilfs2 Not tainted 3.14.0+ #2 Hardware name: Dell Computer Corporation Dimension 2350/07W080, BIOS A01 12/17/2002 Call Trace: dump_stack+0x4b/0x75 __might_sleep+0x111/0x16f mutex_lock_nested+0x1e/0x3ad kernfs_remove+0x12/0x26 sysfs_remove_dir+0x3d/0x62 kobject_del+0x13/0x38 nilfs_sysfs_delete_snapshot_group+0xb/0xd nilfs_put_root+0x2a/0x5a nilfs_detach_log_writer+0x1ab/0x2c1 nilfs_put_super+0x13/0x68 generic_shutdown_super+0x60/0xd1 kill_block_super+0x1d/0x60 deactivate_locked_super+0x22/0x3f deactivate_super+0x3e/0x58 mntput_no_expire+0xe2/0x141 SyS_oldumount+0x70/0xa5 syscall_call+0x7/0xb The reason of the issue was placement of nilfs_sysfs_{create/delete}_snapshot_group() call under nilfs->ns_cptree_lock protection. But this protection is unnecessary and wrong solution. The second version of the patch fixes this issue. [fengguang.wu@intel.com: nilfs_sysfs_create_mounted_snapshots_group can be static] Reported-by: Michael L. Semon Signed-off-by: Vyacheslav Dubeyko Cc: Vyacheslav Dubeyko Cc: Ryusuke Konishi Tested-by: Michael L. Semon Signed-off-by: Fengguang Wu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/super.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'fs/nilfs2/super.c') diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 8c532b2ca3ab..c519927b7b5e 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -1452,13 +1452,19 @@ static int __init init_nilfs_fs(void) if (err) goto fail; - err = register_filesystem(&nilfs_fs_type); + err = nilfs_sysfs_init(); if (err) goto free_cachep; + err = register_filesystem(&nilfs_fs_type); + if (err) + goto deinit_sysfs_entry; + printk(KERN_INFO "NILFS version 2 loaded\n"); return 0; +deinit_sysfs_entry: + nilfs_sysfs_exit(); free_cachep: nilfs_destroy_cachep(); fail: @@ -1468,6 +1474,7 @@ fail: static void __exit exit_nilfs_fs(void) { nilfs_destroy_cachep(); + nilfs_sysfs_exit(); unregister_filesystem(&nilfs_fs_type); } -- cgit v1.2.3