Re: Umount failing due to a file leak on 3.18 Android
On Tue, Apr 19, 2016 at 06:26:27PM -0700, Nikhilesh Reddy wrote: > Hi > > I am looking into a bug that results in umount failures ( since there is a > mount ref from the leaked file that is never freed on the mount ) > > The issue seems to be a result of the following callstack > > 39.958104: <6> Call trace: > 39.958108: <2> [] fput+0x1e0/0x1f8 > 39.958113: <2> [] filp_close+0xa0/0xb8 > 39.958119: <2> [] put_files_struct+0x88/0xf0 > 39.958123: <2> [] binder_deferred_func+0x6a8/0x704 > 39.958129: <2> [] process_one_work+0x238/0x3f0 > 39.958133: <2> [] worker_thread+0x2f8/0x418 > > What seems to occur is that once in a while a file ( say a.txt) is fput in > the above stack > right as the task is being killed > > And then we see that the fput schedules a delayed_fput_work on this file > > But when the function delayed_fput() is actually run : > the file that was put i.e this a.txt is not in the delayed_fput_list > > Any chance you can help me get to the bottom of this leak? > I dont understand why the delayed_fput_list is missing the file. 3.18 is very old, can you duplicate this on 4.5 or newer? thanks, greg k-h
Re: Umount failing due to a file leak on 3.18 Android
Adding Arve Hjønnevåg and Riley Andrews I am looking into a bug that results in umount failures ( since there is a mount ref from the leaked file that is never freed on the mount ) The issue seems to be a result of the following callstack 39.958104: <6> Call trace: 39.958108: <2> [] fput+0x1e0/0x1f8 39.958113: <2> [] filp_close+0xa0/0xb8 39.958119: <2> [] put_files_struct+0x88/0xf0 39.958123: <2> [] binder_deferred_func+0x6a8/0x704 39.958129: <2> [] process_one_work+0x238/0x3f0 39.958133: <2> [] worker_thread+0x2f8/0x418 What seems to occur is that once in a while a file ( say a.txt) is fput in the above stack right as the task is being killed And then we see that the fput schedules a delayed_fput_work on this file But when the function delayed_fput() is actually run : the file that was put i.e this a.txt is not in the delayed_fput_list Any chance you can help me get to the bottom of this leak? I dont understand why the delayed_fput_list is missing the file. Is there some sort of race condition? I will appreciate any pointers you can give me to debug this issue Thanks so much in advance for your help. -- Thanks Nikhilesh Reddy Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
Re: Umount failing due to a file leak on 3.18 Android
On Tue 19 Apr 2016 06:26:27 PM PDT, Nikhilesh Reddy wrote: Hi I am looking into a bug that results in umount failures ( since there is a mount ref from the leaked file that is never freed on the mount ) The issue seems to be a result of the following callstack 39.958104: <6> Call trace: 39.958108: <2> [] fput+0x1e0/0x1f8 39.958113: <2> [] filp_close+0xa0/0xb8 39.958119: <2> [] put_files_struct+0x88/0xf0 39.958123: <2> [] binder_deferred_func+0x6a8/0x704 39.958129: <2> [] process_one_work+0x238/0x3f0 39.958133: <2> [] worker_thread+0x2f8/0x418 What seems to occur is that once in a while a file ( say a.txt) is fput in the above stack right as the task is being killed And then we see that the fput schedules a delayed_fput_work on this file But when the function delayed_fput() is actually run : the file that was put i.e this a.txt is not in the delayed_fput_list Any chance you can help me get to the bottom of this leak? I dont understand why the delayed_fput_list is missing the file. Is there some sort of race condition? I will appreciate any pointers you can give me to debug this issue Thanks so much in advance for your help. -- Thanks Nikhilesh Reddy Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
