* [patch] fs,reiserfs: unlock superblock before callling reiserfs_quota_on_mount() [not found] ` <20120814151539.GA19716@somewhere> @ 2012-08-16 12:44 ` Mike Galbraith 2012-08-16 13:05 ` Frederic Weisbecker 0 siblings, 1 reply; 3+ messages in thread From: Mike Galbraith @ 2012-08-16 12:44 UTC (permalink / raw) To: Frederic Weisbecker; +Cc: Thomas Gleixner, Steven Rostedt, reiserfs-devel, RT On Tue, 2012-08-14 at 17:15 +0200, Frederic Weisbecker wrote: > Looks ok. Thanks. > > Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Thanks. Slightly reworded patchlet below. If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can deadlock our own worker - mount blocks kworker/3:2, sleeps forever more. crash> ps|grep UN 715 2 3 ffff880220734d30 UN 0.0 0 0 [kworker/3:2] 9369 9341 2 ffff88021ffb7560 UN 1.3 493404 123184 Xorg 9665 9664 3 ffff880225b92ab0 UN 0.0 47368 812 udisks-daemon 10635 10403 3 ffff880222f22c70 UN 0.0 14904 936 mount crash> bt ffff880220734d30 PID: 715 TASK: ffff880220734d30 CPU: 3 COMMAND: "kworker/3:2" #0 [ffff8802244c3c20] schedule at ffffffff8144584b #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3 #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5 #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs] #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs] #5 [ffff8802244c3e08] process_one_work at ffffffff81073726 #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba #7 [ffff8802244c3ec8] kthread at ffffffff810782e0 #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064 crash> rd ffff8802244c3cc8 10 ffff8802244c3cc8: ffffffff814472b3 ffff880222f23250 .rD.....P2.".... ffff8802244c3cd8: 0000000000000000 0000000000000286 ................ ffff8802244c3ce8: ffff8802244c3d30 ffff880220734d80 0=L$.....Ms .... ffff8802244c3cf8: ffff880222e8f628 0000000000000000 (.."............ ffff8802244c3d08: 0000000000000000 0000000000000002 ................ crash> struct rt_mutex ffff880222e8f628 struct rt_mutex { wait_lock = { raw_lock = { slock = 65537 } }, wait_list = { node_list = { next = 0xffff8802244c3d48, prev = 0xffff8802244c3d48 } }, owner = 0xffff880222f22c71, save_state = 0 } crash> bt 0xffff880222f22c70 PID: 10635 TASK: ffff880222f22c70 CPU: 3 COMMAND: "mount" #0 [ffff8802216a9868] schedule at ffffffff8144584b #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865 #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74 #3 [ffff8802216a9a30] flush_work at ffffffff810712d3 #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463 #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632 #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs] #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs] #10 [ffff8802216a9d90] mount_bdev at ffffffff8114c93f #11 [ffff8802216a9e00] mount_fs at ffffffff8114d035 #12 [ffff8802216a9e50] vfs_kern_mount at ffffffff81167d36 #13 [ffff8802216a9e90] do_kern_mount at ffffffff811692c3 #14 [ffff8802216a9ed0] do_mount at ffffffff8116adb5 #15 [ffff8802216a9f30] sys_mount at ffffffff8116b25a #16 [ffff8802216a9f80] system_call_fastpath at ffffffff8144ef12 RIP: 00007f7b9303997a RSP: 00007ffff443c7a8 RFLAGS: 00010202 RAX: 00000000000000a5 RBX: ffffffff8144ef12 RCX: 00007f7b932e9ee0 RDX: 00007f7b93d9a400 RSI: 00007f7b93d9a3e0 RDI: 00007f7b93d9a3c0 RBP: 00007f7b93d9a2c0 R8: 00007f7b93d9a550 R9: 0000000000000001 R10: ffffffffc0ed040e R11: 0000000000000202 R12: 000000000000040e R13: 0000000000000000 R14: 00000000c0ed040e R15: 00007ffff443ca20 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: stable <stable@vger.kernel.org> --- fs/reiserfs/super.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -184,7 +184,13 @@ static int remove_save_link_only(struct static int reiserfs_quota_on_mount(struct super_block *, int); #endif -/* look for uncompleted unlinks and truncates and complete them */ +/* + *look for uncompleted unlinks and truncates and complete them + * + * Called with super_block write locked. If quotas are enabled, + * we have to release/retake lest we call dquot_quota_on_mount(), + * proceed to schedule_on_each_cpu() and deadlock our own worker. + */ static int finish_unfinished(struct super_block *s) { INITIALIZE_PATH(path); @@ -231,7 +237,9 @@ static int finish_unfinished(struct supe quota_enabled[i] = 0; continue; } + reiserfs_write_unlock(s); ret = reiserfs_quota_on_mount(s, i); + reiserfs_write_lock(s); if (ret < 0) reiserfs_warning(s, "reiserfs-2500", "cannot turn on journaled " ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [patch] fs,reiserfs: unlock superblock before callling reiserfs_quota_on_mount() 2012-08-16 12:44 ` [patch] fs,reiserfs: unlock superblock before callling reiserfs_quota_on_mount() Mike Galbraith @ 2012-08-16 13:05 ` Frederic Weisbecker 2012-08-16 13:49 ` Mike Galbraith 0 siblings, 1 reply; 3+ messages in thread From: Frederic Weisbecker @ 2012-08-16 13:05 UTC (permalink / raw) To: Mike Galbraith; +Cc: Thomas Gleixner, Steven Rostedt, reiserfs-devel, RT On Thu, Aug 16, 2012 at 02:44:34PM +0200, Mike Galbraith wrote: > On Tue, 2012-08-14 at 17:15 +0200, Frederic Weisbecker wrote: > > > Looks ok. Thanks. > > > > Acked-by: Frederic Weisbecker <fweisbec@gmail.com> > > Thanks. Slightly reworded patchlet below. > > > If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can > deadlock our own worker - mount blocks kworker/3:2, sleeps forever more. > > crash> ps|grep UN > 715 2 3 ffff880220734d30 UN 0.0 0 0 [kworker/3:2] > 9369 9341 2 ffff88021ffb7560 UN 1.3 493404 123184 Xorg > 9665 9664 3 ffff880225b92ab0 UN 0.0 47368 812 udisks-daemon > 10635 10403 3 ffff880222f22c70 UN 0.0 14904 936 mount > crash> bt ffff880220734d30 > PID: 715 TASK: ffff880220734d30 CPU: 3 COMMAND: "kworker/3:2" > #0 [ffff8802244c3c20] schedule at ffffffff8144584b > #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3 > #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5 > #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs] > #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs] > #5 [ffff8802244c3e08] process_one_work at ffffffff81073726 > #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba > #7 [ffff8802244c3ec8] kthread at ffffffff810782e0 > #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064 > crash> rd ffff8802244c3cc8 10 > ffff8802244c3cc8: ffffffff814472b3 ffff880222f23250 .rD.....P2.".... > ffff8802244c3cd8: 0000000000000000 0000000000000286 ................ > ffff8802244c3ce8: ffff8802244c3d30 ffff880220734d80 0=L$.....Ms .... > ffff8802244c3cf8: ffff880222e8f628 0000000000000000 (.."............ > ffff8802244c3d08: 0000000000000000 0000000000000002 ................ > crash> struct rt_mutex ffff880222e8f628 > struct rt_mutex { > wait_lock = { > raw_lock = { > slock = 65537 > } > }, > wait_list = { > node_list = { > next = 0xffff8802244c3d48, > prev = 0xffff8802244c3d48 > } > }, > owner = 0xffff880222f22c71, > save_state = 0 > } > crash> bt 0xffff880222f22c70 > PID: 10635 TASK: ffff880222f22c70 CPU: 3 COMMAND: "mount" > #0 [ffff8802216a9868] schedule at ffffffff8144584b > #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865 > #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74 > #3 [ffff8802216a9a30] flush_work at ffffffff810712d3 > #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463 > #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba > #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632 > #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c > #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs] > #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs] > #10 [ffff8802216a9d90] mount_bdev at ffffffff8114c93f > #11 [ffff8802216a9e00] mount_fs at ffffffff8114d035 > #12 [ffff8802216a9e50] vfs_kern_mount at ffffffff81167d36 > #13 [ffff8802216a9e90] do_kern_mount at ffffffff811692c3 > #14 [ffff8802216a9ed0] do_mount at ffffffff8116adb5 > #15 [ffff8802216a9f30] sys_mount at ffffffff8116b25a > #16 [ffff8802216a9f80] system_call_fastpath at ffffffff8144ef12 > RIP: 00007f7b9303997a RSP: 00007ffff443c7a8 RFLAGS: 00010202 > RAX: 00000000000000a5 RBX: ffffffff8144ef12 RCX: 00007f7b932e9ee0 > RDX: 00007f7b93d9a400 RSI: 00007f7b93d9a3e0 RDI: 00007f7b93d9a3c0 > RBP: 00007f7b93d9a2c0 R8: 00007f7b93d9a550 R9: 0000000000000001 > R10: ffffffffc0ed040e R11: 0000000000000202 R12: 000000000000040e > R13: 0000000000000000 R14: 00000000c0ed040e R15: 00007ffff443ca20 > ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b > > Signed-off-by: Mike Galbraith <efault@gmx.de> > Acked-by: Frederic Weisbecker <fweisbec@gmail.com> > Cc: stable <stable@vger.kernel.org> > --- > fs/reiserfs/super.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > --- a/fs/reiserfs/super.c > +++ b/fs/reiserfs/super.c > @@ -184,7 +184,13 @@ static int remove_save_link_only(struct > static int reiserfs_quota_on_mount(struct super_block *, int); > #endif > > -/* look for uncompleted unlinks and truncates and complete them */ > +/* > + *look for uncompleted unlinks and truncates and complete them > + * > + * Called with super_block write locked. If quotas are enabled, > + * we have to release/retake lest we call dquot_quota_on_mount(), > + * proceed to schedule_on_each_cpu() and deadlock our own worker. Could you please mention in the comment that the real issue is that we wait for the per cpu worklets to complete flush_async_commits() that in turn wait for the superblock write lock? schedule_on_each_cpu() in itself is not the problem. Otherwise it might sound confusing. Thanks. > + */ > static int finish_unfinished(struct super_block *s) > { > INITIALIZE_PATH(path); > @@ -231,7 +237,9 @@ static int finish_unfinished(struct supe > quota_enabled[i] = 0; > continue; > } > + reiserfs_write_unlock(s); > ret = reiserfs_quota_on_mount(s, i); > + reiserfs_write_lock(s); > if (ret < 0) > reiserfs_warning(s, "reiserfs-2500", > "cannot turn on journaled " > > ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [patch] fs,reiserfs: unlock superblock before callling reiserfs_quota_on_mount() 2012-08-16 13:05 ` Frederic Weisbecker @ 2012-08-16 13:49 ` Mike Galbraith 0 siblings, 0 replies; 3+ messages in thread From: Mike Galbraith @ 2012-08-16 13:49 UTC (permalink / raw) To: Frederic Weisbecker; +Cc: Thomas Gleixner, Steven Rostedt, reiserfs-devel, RT On Thu, 2012-08-16 at 15:05 +0200, Frederic Weisbecker wrote: > On Thu, Aug 16, 2012 at 02:44:34PM +0200, Mike Galbraith wrote: > > --- a/fs/reiserfs/super.c > > +++ b/fs/reiserfs/super.c > > @@ -184,7 +184,13 @@ static int remove_save_link_only(struct > > static int reiserfs_quota_on_mount(struct super_block *, int); > > #endif > > > > -/* look for uncompleted unlinks and truncates and complete them */ > > +/* > > + *look for uncompleted unlinks and truncates and complete them > > + * > > + * Called with super_block write locked. If quotas are enabled, > > + * we have to release/retake lest we call dquot_quota_on_mount(), > > + * proceed to schedule_on_each_cpu() and deadlock our own worker. > > Could you please mention in the comment that the real issue is that we wait for > the per cpu worklets to complete flush_async_commits() that in turn wait for > the superblock write lock? schedule_on_each_cpu() in itself is not the problem. > Otherwise it might sound confusing. > > Thanks. Done (stealing your text). If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can deadlock our own worker - mount blocks kworker/3:2, sleeps forever more. crash> ps|grep UN 715 2 3 ffff880220734d30 UN 0.0 0 0 [kworker/3:2] 9369 9341 2 ffff88021ffb7560 UN 1.3 493404 123184 Xorg 9665 9664 3 ffff880225b92ab0 UN 0.0 47368 812 udisks-daemon 10635 10403 3 ffff880222f22c70 UN 0.0 14904 936 mount crash> bt ffff880220734d30 PID: 715 TASK: ffff880220734d30 CPU: 3 COMMAND: "kworker/3:2" #0 [ffff8802244c3c20] schedule at ffffffff8144584b #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3 #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5 #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs] #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs] #5 [ffff8802244c3e08] process_one_work at ffffffff81073726 #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba #7 [ffff8802244c3ec8] kthread at ffffffff810782e0 #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064 crash> rd ffff8802244c3cc8 10 ffff8802244c3cc8: ffffffff814472b3 ffff880222f23250 .rD.....P2.".... ffff8802244c3cd8: 0000000000000000 0000000000000286 ................ ffff8802244c3ce8: ffff8802244c3d30 ffff880220734d80 0=L$.....Ms .... ffff8802244c3cf8: ffff880222e8f628 0000000000000000 (.."............ ffff8802244c3d08: 0000000000000000 0000000000000002 ................ crash> struct rt_mutex ffff880222e8f628 struct rt_mutex { wait_lock = { raw_lock = { slock = 65537 } }, wait_list = { node_list = { next = 0xffff8802244c3d48, prev = 0xffff8802244c3d48 } }, owner = 0xffff880222f22c71, save_state = 0 } crash> bt 0xffff880222f22c70 PID: 10635 TASK: ffff880222f22c70 CPU: 3 COMMAND: "mount" #0 [ffff8802216a9868] schedule at ffffffff8144584b #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865 #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74 #3 [ffff8802216a9a30] flush_work at ffffffff810712d3 #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463 #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632 #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs] #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs] #10 [ffff8802216a9d90] mount_bdev at ffffffff8114c93f #11 [ffff8802216a9e00] mount_fs at ffffffff8114d035 #12 [ffff8802216a9e50] vfs_kern_mount at ffffffff81167d36 #13 [ffff8802216a9e90] do_kern_mount at ffffffff811692c3 #14 [ffff8802216a9ed0] do_mount at ffffffff8116adb5 #15 [ffff8802216a9f30] sys_mount at ffffffff8116b25a #16 [ffff8802216a9f80] system_call_fastpath at ffffffff8144ef12 RIP: 00007f7b9303997a RSP: 00007ffff443c7a8 RFLAGS: 00010202 RAX: 00000000000000a5 RBX: ffffffff8144ef12 RCX: 00007f7b932e9ee0 RDX: 00007f7b93d9a400 RSI: 00007f7b93d9a3e0 RDI: 00007f7b93d9a3c0 RBP: 00007f7b93d9a2c0 R8: 00007f7b93d9a550 R9: 0000000000000001 R10: ffffffffc0ed040e R11: 0000000000000202 R12: 000000000000040e R13: 0000000000000000 R14: 00000000c0ed040e R15: 00007ffff443ca20 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@vger.kernel.org> --- fs/reiserfs/super.c | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-) diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index 7a37dab..50635a9 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -184,7 +184,15 @@ static int remove_save_link_only(struct super_block *s, static int reiserfs_quota_on_mount(struct super_block *, int); #endif -/* look for uncompleted unlinks and truncates and complete them */ +/* + *look for uncompleted unlinks and truncates and complete them + * + * Called with superblock write locked. If quotas are enabled, + * we have to release/retake lest we call dquot_quota_on_mount(), + * proceed to schedule_on_each_cpu() and deadlock waiting for + * the per cpu worklets to complete flush_async_commits() that + * in turn wait for the superblock write lock. + */ static int finish_unfinished(struct super_block *s) { INITIALIZE_PATH(path); @@ -231,7 +239,9 @@ static int finish_unfinished(struct super_block *s) quota_enabled[i] = 0; continue; } + reiserfs_write_unlock(s); ret = reiserfs_quota_on_mount(s, i); + reiserfs_write_lock(s); if (ret < 0) reiserfs_warning(s, "reiserfs-2500", "cannot turn on journaled " ^ permalink raw reply related [flat|nested] 3+ messages in thread
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[not found] <1344949583.14924.36.camel@marge.simpson.net>
[not found] ` <20120814151539.GA19716@somewhere>
2012-08-16 12:44 ` [patch] fs,reiserfs: unlock superblock before callling reiserfs_quota_on_mount() Mike Galbraith
2012-08-16 13:05 ` Frederic Weisbecker
2012-08-16 13:49 ` Mike Galbraith
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