Ryusuke Konishi a924586036 nilfs2: fix oopses with doubly mounted snapshots ... will fix kernel oopses like the following: # mount -t nilfs2 -r -o cp=20 /dev/sdb1 /test1 # mount -t nilfs2 -r -o cp=20 /dev/sdb1 /test2 # umount /test1 # umount /test2 BUG: sleeping function called from invalid context at arch/x86/mm/fault.c:1069 in_atomic(): 0, irqs_disabled(): 1, pid: 3886, name: umount.nilfs2 1 lock held by umount.nilfs2/3886: #0: (&type->s_umount_key#31){+.+...}, at: [<c10b398a>] deactivate_super+0x52/0x6c irq event stamp: 1219 hardirqs last enabled at (1219): [<c135c774>] __mutex_unlock_slowpath+0xf8/0x119 hardirqs last disabled at (1218): [<c135c6d5>] __mutex_unlock_slowpath+0x59/0x119 softirqs last enabled at (1214): [<c1033316>] __do_softirq+0x1a5/0x1ad softirqs last disabled at (1205): [<c1033354>] do_softirq+0x36/0x5a Pid: 3886, comm: umount.nilfs2 Not tainted 2.6.31-rc6 #55 Call Trace: [<c1023549>] __might_sleep+0x107/0x10e [<c13603c0>] do_page_fault+0x246/0x397 [<c136017a>] ? do_page_fault+0x0/0x397 [<c135e753>] error_code+0x6b/0x70 [<c136017a>] ? do_page_fault+0x0/0x397 [<c104f805>] ? __lock_acquire+0x91/0x12fd [<c1050a62>] ? __lock_acquire+0x12ee/0x12fd [<c1050a62>] ? __lock_acquire+0x12ee/0x12fd [<c1050b2b>] lock_acquire+0xba/0xdd [<d0d17d3f>] ? nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2] [<c135d4fe>] down_write+0x2a/0x46 [<d0d17d3f>] ? nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2] [<d0d17d3f>] nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2] [<c104ea2c>] ? mark_held_locks+0x43/0x5b [<c104ecb1>] ? trace_hardirqs_on_caller+0x10b/0x133 [<c104ece4>] ? trace_hardirqs_on+0xb/0xd [<d0d09ac1>] nilfs_put_super+0x2f/0xca [nilfs2] [<c10b3352>] generic_shutdown_super+0x49/0xb8 [<c10b33de>] kill_block_super+0x1d/0x31 [<c10e6599>] ? vfs_quota_off+0x0/0x12 [<c10b398f>] deactivate_super+0x57/0x6c [<c10c4bc3>] mntput_no_expire+0x8c/0xb4 [<c10c5094>] sys_umount+0x27f/0x2a4 [<c10c50c6>] sys_oldumount+0xd/0xf [<c10031a4>] sysenter_do_call+0x12/0x38 ... This turns out to be a bug brought by an -rc1 patch ("nilfs2: simplify remaining sget() use"). In the patch, a new "put resource" function, nilfs_put_sbinfo() was introduced to delay freeing nilfs_sb_info struct. But the nilfs_put_sbinfo() mistakenly used atomic_dec_and_test() function to check the reference count, and it caused the nilfs_sb_info was freed when user mounted a snapshot twice. This bug also suggests there was unseen memory leak in usual mount /umount operations for nilfs. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>		2009-08-19 02:10:13 +09:00
..
alloc.c
alloc.h
bmap_union.h
bmap.c	nilfs2: fix lockdep warning between regular file and inode file	2009-07-05 10:44:20 +09:00
bmap.h
btnode.c
btnode.h
btree.c
btree.h
cpfile.c	nilfs2: fix disorder in cp count on error during deleting checkpoints	2009-07-05 10:44:20 +09:00
cpfile.h
dat.c	nilfs2: fix incorrect KERN_CRIT messages in case of write failures	2009-07-05 10:44:20 +09:00
dat.h
dir.c	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
direct.c
direct.h
file.c
gcdat.c
gcinode.c
ifile.c
ifile.h
inode.c	switch nilfs2 to inode->i_acl	2009-06-24 08:17:05 -04:00
ioctl.c
Kconfig	fs/Kconfig: move nilfs2 out	2009-07-14 12:34:17 +09:00
Makefile
mdt.c	nilfs2: fix missing unlock in error path of nilfs_mdt_write_page	2009-08-02 22:24:15 +09:00
mdt.h
namei.c
nilfs.h	switch nilfs2 to inode->i_acl	2009-06-24 08:17:05 -04:00
page.c
page.h
recovery.c
sb.h	nilfs2: simplify remaining sget() use	2009-06-11 21:36:18 -04:00
segbuf.c
segbuf.h
segment.c	nilfs2: fix oops due to inconsistent state in page with discrete b-tree nodes	2009-08-01 22:48:32 +09:00
segment.h
sufile.c
sufile.h
super.c	nilfs2: missing a read lock for segment writer in nilfs_attach_checkpoint()	2009-08-18 17:32:27 +09:00
the_nilfs.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2	2009-06-15 09:13:49 -07:00
the_nilfs.h	nilfs2: fix oopses with doubly mounted snapshots	2009-08-19 02:10:13 +09:00