linux-toradex.git/fs/block_dev.c, branch v3.4.34

fs/block_dev.c: page cache wrongly left invalidated after revalidate_disk()

2013-02-28T14:59:01+00:00

commit 7630b661da330b35dd57b6f5d6d62b386f2dd751 upstream.

We found that bdev->bd_invalidated was left set once revalidate_disk()
is called, which results in page cache flush every time that device is
open.

Specifically, we found this problem in MD block device.  Once we resize
a MD device, mdadm --monitor periodically flush all page cache for that
device every 60 or 1000 seconds when it opens the device.

This bug lies since at least 3.2.0 till the latest kernel(3.6.2).  Patch
is attached.

The following steps will reproduce the problem.

1. prepair a block device (eg /dev/sdb).

2. create two partitions:

   sudo parted /dev/sdb
   mklabel gpt
   mkpart primary 0% 50%
   mkpart primary 50% 100%

3. create a md device.

   sudo mdadm -C /dev/md/hoge -l 1 -n 2 -e 1.2 --assume-clean --auto=md --symlink=no /dev/sdb1 /dev/sdb2

4. create file system and mount it

   sudo mkfs.ext3 /dev/md/hoge
   sudo mkdir /mnt/test
   sudo mount /dev/md/hoge /mnt/test

5. try to resize the device

   sudo mdadm -G /dev/md/hoge --size=max

6. create a file to fill file cache.

  sudo dd if=/dev/urandom of=/mnt/test/data bs=1M count=10

and verify the current status of file by free command.

7. mdadm monitor will open the md device every 1000 seconds and you
   will find all file cache on the device are cleared.

The timing can be reduced by the following steps.

a) kill mdadm and restart it with --delay option

   /sbin/mdadm --monitor --delay=30 --pid-file /var/run/mdadm/monitor.pid --daemonise --scan --syslog

or open the md device directly.

   sudo dd if=/dev/md/hoge of=/dev/null bs=4096 count=1

Signed-off-by: MITSUNARI Shigeo 
Cc: Al Viro 
Cc: Jeff Moyer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

block: don't mark buffers beyond end of disk as mapped

2012-05-11T14:42:14+00:00

Hi,

We have a bug report open where a squashfs image mounted on ppc64 would
exhibit errors due to trying to read beyond the end of the disk.  It can
easily be reproduced by doing the following:

[root@ibm-p750e-02-lp3 ~]# ls -l install.img
-rw-r--r-- 1 root root 142032896 Apr 30 16:46 install.img
[root@ibm-p750e-02-lp3 ~]# mount -o loop ./install.img /mnt/test
[root@ibm-p750e-02-lp3 ~]# dd if=/dev/loop0 of=/dev/null
dd: reading `/dev/loop0': Input/output error
277376+0 records in
277376+0 records out
142016512 bytes (142 MB) copied, 0.9465 s, 150 MB/s

In dmesg, you'll find the following:

squashfs: version 4.0 (2009/01/31) Phillip Lougher
[   43.106012] attempt to access beyond end of device
[   43.106029] loop0: rw=0, want=277410, limit=277408
[   43.106039] Buffer I/O error on device loop0, logical block 138704
[   43.106053] attempt to access beyond end of device
[   43.106057] loop0: rw=0, want=277412, limit=277408
[   43.106061] Buffer I/O error on device loop0, logical block 138705
[   43.106066] attempt to access beyond end of device
[   43.106070] loop0: rw=0, want=277414, limit=277408
[   43.106073] Buffer I/O error on device loop0, logical block 138706
[   43.106078] attempt to access beyond end of device
[   43.106081] loop0: rw=0, want=277416, limit=277408
[   43.106085] Buffer I/O error on device loop0, logical block 138707
[   43.106089] attempt to access beyond end of device
[   43.106093] loop0: rw=0, want=277418, limit=277408
[   43.106096] Buffer I/O error on device loop0, logical block 138708
[   43.106101] attempt to access beyond end of device
[   43.106104] loop0: rw=0, want=277420, limit=277408
[   43.106108] Buffer I/O error on device loop0, logical block 138709
[   43.106112] attempt to access beyond end of device
[   43.106116] loop0: rw=0, want=277422, limit=277408
[   43.106120] Buffer I/O error on device loop0, logical block 138710
[   43.106124] attempt to access beyond end of device
[   43.106128] loop0: rw=0, want=277424, limit=277408
[   43.106131] Buffer I/O error on device loop0, logical block 138711
[   43.106135] attempt to access beyond end of device
[   43.106139] loop0: rw=0, want=277426, limit=277408
[   43.106143] Buffer I/O error on device loop0, logical block 138712
[   43.106147] attempt to access beyond end of device
[   43.106151] loop0: rw=0, want=277428, limit=277408
[   43.106154] Buffer I/O error on device loop0, logical block 138713
[   43.106158] attempt to access beyond end of device
[   43.106162] loop0: rw=0, want=277430, limit=277408
[   43.106166] attempt to access beyond end of device
[   43.106169] loop0: rw=0, want=277432, limit=277408
...
[   43.106307] attempt to access beyond end of device
[   43.106311] loop0: rw=0, want=277470, limit=2774

Squashfs manages to read in the end block(s) of the disk during the
mount operation.  Then, when dd reads the block device, it leads to
block_read_full_page being called with buffers that are beyond end of
disk, but are marked as mapped.  Thus, it would end up submitting read
I/O against them, resulting in the errors mentioned above.  I fixed the
problem by modifying init_page_buffers to only set the buffer mapped if
it fell inside of i_size.

Cheers,
Jeff

Signed-off-by: Jeff Moyer 
Acked-by: Nick Piggin 

--

Changes from v1->v2: re-used max_block, as suggested by Nick Piggin.
Signed-off-by: Jens Axboe

magic.h: move some FS magic numbers into magic.h

2012-03-23T23:58:31+00:00

- Move open-coded filesystem magic numbers into magic.h

- Rearrange magic.h so that the filesystem-related constants are grouped
  together.

Signed-off-by: Muthukumar R 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'stable/cleancache.v13' into linux-next

2012-03-19T16:12:19+00:00

* stable/cleancache.v13:
  mm: cleancache: Use __read_mostly as appropiate.
  mm: cleancache: report statistics via debugfs instead of sysfs.
  mm: zcache/tmem/cleancache: s/flush/invalidate/
  mm: cleancache: s/flush/invalidate/

block: Fix NULL pointer dereference in sd_revalidate_disk

2012-03-02T09:38:33+00:00

Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(),
__blkdev_get() calls rescan_partitions() to remove
in-kernel partition structures and raise KOBJ_CHANGE uevent.

However it ends up calling driver's revalidate_disk without open
and could cause oops.

In the case of SCSI:

  process A                  process B
  ----------------------------------------------
  sys_open
    __blkdev_get
      sd_open
        returns -ENOMEDIUM
                             scsi_remove_device
                               
      rescan_partitions
        sd_revalidate_disk
          
Oopses are reported here:
http://marc.info/?l=linux-scsi&m=132388619710052

This patch separates the partition invalidation from rescan_partitions()
and use it for -ENOMEDIUM case.

Reported-by: Huajun Li 
Signed-off-by: Jun'ichi Nomura 
Acked-by: Tejun Heo 
Cc: stable@kernel.org
Signed-off-by: Jens Axboe

mm: cleancache: s/flush/invalidate/

2012-01-23T21:06:24+00:00

Per akpm suggestions alter the use of the term flush to be
invalidate. The next patch will do this across all MM.

This change is completely cosmetic.

[v9: akpm@linux-foundation.org: change "flush" to "invalidate", part 3]

Signed-off-by: Dan Magenheimer 
Cc: Kamezawa Hiroyuki 
Cc: Jan Beulich 
Reviewed-by: Seth Jennings 
Cc: Jeremy Fitzhardinge 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Nitin Gupta 
Cc: Matthew Wilcox 
Cc: Chris Mason 
Cc: Rik Riel 
Cc: Andrew Morton 
[v10: Fixed  fs: move code out of buffer.c conflict change]
Signed-off-by: Konrad Rzeszutek Wilk

vfs: cache request_queue in struct block_device

2012-01-13T04:13:12+00:00

This makes it possible to get from the inode to the request_queue with one
less cache miss.  Used in followon optimization.

The livetime of the pointer is the same as the gendisk.

This assumes that the queue will always stay the same in the gendisk while
it's visible to block_devices.  I think that's safe correct?

Signed-off-by: Andi Kleen 
Acked-by: Jeff Moyer 
Cc: Jens Axboe 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block_dev: Suppress bdev_cache_init() kmemleak warninig

2012-01-10T18:08:55+00:00

Kmemleak reports the following warning in bdev_cache_init()
[    0.003738] kmemleak: Object 0xffff880153035200 (size 256):
[    0.003823] kmemleak:   comm "swapper/0", pid 0, jiffies 4294667299
[    0.003909] kmemleak:   min_count = 1
[    0.003988] kmemleak:   count = 0
[    0.004066] kmemleak:   flags = 0x1
[    0.004144] kmemleak:   checksum = 0
[    0.004224] kmemleak:   backtrace:
[    0.004303]      [] kmemleak_alloc+0x21/0x3e
[    0.004446]      [] kmem_cache_alloc+0xca/0x1dc
[    0.004592]      [] alloc_vfsmnt+0x1f/0x198
[    0.004736]      [] vfs_kern_mount+0x36/0xd2
[    0.004879]      [] kern_mount_data+0x18/0x32
[    0.005025]      [] bdev_cache_init+0x51/0x81
[    0.005169]      [] vfs_caches_init+0x101/0x10d
[    0.005313]      [] start_kernel+0x344/0x383
[    0.005456]      [] x86_64_start_reservations+0xae/0xb2
[    0.005602]      [] x86_64_start_kernel+0x102/0x111
[    0.005747]      [] 0xffffffffffffffff
[    0.008653] kmemleak: Trying to color unknown object at 0xffff880153035220 as Grey
[    0.008754] Pid: 0, comm: swapper/0 Not tainted 3.3.0-rc0-dbg-04200-g8180888-dirty #888
[    0.008856] Call Trace:
[    0.008934]  [] ? find_and_get_object+0x44/0x118
[    0.009023]  [] paint_ptr+0x57/0x8f
[    0.009109]  [] kmemleak_not_leak+0x23/0x42
[    0.009195]  [] bdev_cache_init+0x72/0x81
[    0.009282]  [] vfs_caches_init+0x101/0x10d
[    0.009368]  [] start_kernel+0x344/0x383
[    0.009466]  [] x86_64_start_reservations+0xae/0xb2
[    0.009555]  [] ? early_idt_handlers+0x140/0x140
[    0.009643]  [] x86_64_start_kernel+0x102/0x111

due to attempt to mark pointer to `struct vfsmount' as a gray object, which
is embedded into `struct mount' returned from alloc_vfsmnt().

Make `bd_mnt' static, avoiding need to tell kmemleak to mark it gray, as
suggested by Al Viro.

Signed-off-by: Sergey Senozhatsky 
Signed-off-by: Al Viro

fs: move code out of buffer.c

2012-01-04T03:54:07+00:00

Move invalidate_bdev, block_sync_page into fs/block_dev.c.  Export
kill_bdev as well, so brd doesn't have to open code it.  Reduce
buffer_head.h requirement accordingly.

Removed a rather large comment from invalidate_bdev, as it looked a bit
obsolete to bother moving.  The small comment replacing it says enough.

Signed-off-by: Nick Piggin 
Cc: Al Viro 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Al Viro

vfs: fix the stupidity with i_dentry in inode destructors

2012-01-04T03:52:40+00:00

Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else.  Not to mention the removal of
boilerplate code from ->destroy_inode() instances...

Signed-off-by: Al Viro