Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-21 Thread Nilesh More
Just to keep the thread updated with latest findngs : (Let me know if anybody has any inputs) Skipping the measureExactStorage and measureApproximateStorage calls seems to help. These are called as a part of auto-mount sequence when USB is hotplugged. I will dig-in further to understand if it

Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-21 Thread Nilesh More
Just to keep the thread updated with latest findngs : (Let me know if anybody has any inputs) Skipping the measureExactStorage and measureApproximateStorage calls seems to help. These are called as a part of auto-mount sequence when USB is hotplugged. I will dig-in further to understand if it

Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-20 Thread Nilesh More
I now know the source of page allocations between add_disk call and mount call. The auto mount service triggers disk check operation which eventually calls checkfilesys(). This function does open and close calls which results into page allocations and de-allocations. If I do an early return from

Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-20 Thread Nilesh More
I now know the source of page allocations between add_disk call and mount call. The auto mount service triggers disk check operation which eventually calls checkfilesys(). This function does open and close calls which results into page allocations and de-allocations. If I do an early return from

Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-19 Thread Nilesh More
Hi Ted, >And I'll repeat the comments I made a few weeks ago. Last time you >reported this, you included a dmesg output which included this: > [ 413.607849] usb 2-1.1: USB disconnect, device number 12 > [ 414.022630] EXT4-fs error (device mmcblk0p20): ext4_readdir:227: inode > #81827: block

Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-19 Thread tytso
On Thu, Mar 20, 2014 at 12:05:44AM +0530, Nilesh More wrote: > Hi all, > > First of all sorry for the lengthy mail but I did not want to miss out > on any details. > > The following issue that I am reporting occurs when I plugin the USB > drive on android tablet with USB mount support. Please

Page cache corruption with mount/unmount of USB with Fat file system

2014-03-19 Thread Nilesh More
Hi all, First of all sorry for the lengthy mail but I did not want to miss out on any details. The following issue that I am reporting occurs when I plugin the USB drive on android tablet with USB mount support. Please note that this issue may or may not occur the first time I hotplug the USB

Page cache corruption with mount/unmount of USB with Fat file system

2014-03-19 Thread Nilesh More
Hi all, First of all sorry for the lengthy mail but I did not want to miss out on any details. The following issue that I am reporting occurs when I plugin the USB drive on android tablet with USB mount support. Please note that this issue may or may not occur the first time I hotplug the USB

Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-19 Thread tytso
On Thu, Mar 20, 2014 at 12:05:44AM +0530, Nilesh More wrote: Hi all, First of all sorry for the lengthy mail but I did not want to miss out on any details. The following issue that I am reporting occurs when I plugin the USB drive on android tablet with USB mount support. Please note that

Re: Page cache corruption with mount/unmount of USB with Fat file system

2014-03-19 Thread Nilesh More
Hi Ted, And I'll repeat the comments I made a few weeks ago. Last time you reported this, you included a dmesg output which included this: [ 413.607849] usb 2-1.1: USB disconnect, device number 12 [ 414.022630] EXT4-fs error (device mmcblk0p20): ext4_readdir:227: inode #81827: block 328308: