linux.git/drivers/md/bcache/super.c, branch v4.5

bcache: allows use of register in udev to avoid "device_busy" error.

2015-12-31T03:23:13+00:00

Allows to use register, not register_quiet in udev to avoid "device_busy" error.
The initial patch proposed at https://lkml.org/lkml/2013/8/26/549 by Gabriel de Perthuis
 does not unlock the mutex and hangs the kernel.

See http://thread.gmane.org/gmane.linux.kernel.bcache.devel/2594 for the discussion.

Cc: Denis Bychkov 
Cc: Kent Overstreet 
Cc: Eric Wheeler 
Cc: Gabriel de Perthuis 
Cc: stable@vger.kernel.org

Signed-off-by: Jens Axboe

bcache: unregister reboot notifier if bcache fails to unregister device

2015-12-31T03:23:11+00:00

In bcache_init() function it forgot to unregister reboot notifier if
bcache fails to unregister a block device.  This commit fixes this.

Signed-off-by: Zheng Liu 
Tested-by: Joshua Schmid 
Tested-by: Eric Wheeler 
Cc: Kent Overstreet 
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe

bcache: fix a leak in bch_cached_dev_run()

2015-12-31T03:23:10+00:00

Signed-off-by: Al Viro 
Tested-by: Joshua Schmid 
Tested-by: Eric Wheeler 
Cc: Kent Overstreet 
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe

bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing device

2015-12-31T03:23:08+00:00

This bug can be reproduced by the following script:

  #!/bin/bash

  bcache_sysfs="/sys/fs/bcache"

  function clear_cache()
  {
  	if [ ! -e $bcache_sysfs ]; then
  		echo "no bcache sysfs"
  		exit
  	fi

  	cset_uuid=$(ls -l $bcache_sysfs|head -n 2|tail -n 1|awk '{print $9}')
  	sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/detach"
  	sleep 5
  	sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/attach"
  }

  for ((i=0;i<10;i++)); do
  	clear_cache
  done

The warning messages look like below:
[  275.948611] ------------[ cut here ]------------
[  275.963840] WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xb8/0xd0() (Tainted: P        W
---------------   )
[  275.979253] Hardware name: Tecal RH2285
[  275.994106] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:09.0/0000:08:00.0/host4/target4:2:1/4:2:1:0/block/sdb/sdb1/bcache/cache'
[  276.024105] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler
bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801
i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas
pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan]
[  276.072643] Pid: 2765, comm: sh Tainted: P        W  ---------------    2.6.32 #1
[  276.089315] Call Trace:
[  276.105801]  [] ? warn_slowpath_common+0x87/0xc0
[  276.122650]  [] ? warn_slowpath_fmt+0x46/0x50
[  276.139361]  [] ? sysfs_add_one+0xb8/0xd0
[  276.156012]  [] ? sysfs_do_create_link+0x12b/0x170
[  276.172682]  [] ? sysfs_create_link+0x13/0x20
[  276.189282]  [] ? bcache_device_link+0xc1/0x110 [bcache]
[  276.205993]  [] ? bch_cached_dev_attach+0x478/0x4f0 [bcache]
[  276.222794]  [] ? bch_cached_dev_store+0x627/0x780 [bcache]
[  276.239680]  [] ? alloc_pages_current+0xaa/0x110
[  276.256594]  [] ? sysfs_write_file+0xe5/0x170
[  276.273364]  [] ? vfs_write+0xb8/0x1a0
[  276.290133]  [] ? sys_write+0x51/0x90
[  276.306368]  [] ? system_call_fastpath+0x16/0x1b
[  276.322301] ---[ end trace 9f5d4fcdd0c3edfb ]---
[  276.338241] ------------[ cut here ]------------
[  276.354109] WARNING: at /home/wenqing.lz/bcache/bcache/super.c:720
bcache_device_link+0xdf/0x110 [bcache]() (Tainted: P        W  ---------------   )
[  276.386017] Hardware name: Tecal RH2285
[  276.401430] Couldn't create device <-> cache set symlinks
[  276.401759] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler
bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801
i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas
pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan]
[  276.465477] Pid: 2765, comm: sh Tainted: P        W  ---------------    2.6.32 #1
[  276.482169] Call Trace:
[  276.498610]  [] ? warn_slowpath_common+0x87/0xc0
[  276.515405]  [] ? warn_slowpath_fmt+0x46/0x50
[  276.532059]  [] ? bcache_device_link+0xdf/0x110 [bcache]
[  276.548808]  [] ? bch_cached_dev_attach+0x478/0x4f0 [bcache]
[  276.565569]  [] ? bch_cached_dev_store+0x627/0x780 [bcache]
[  276.582418]  [] ? alloc_pages_current+0xaa/0x110
[  276.599341]  [] ? sysfs_write_file+0xe5/0x170
[  276.616142]  [] ? vfs_write+0xb8/0x1a0
[  276.632607]  [] ? sys_write+0x51/0x90
[  276.648671]  [] ? system_call_fastpath+0x16/0x1b
[  276.664756] ---[ end trace 9f5d4fcdd0c3edfc ]---

We forget to clear BCACHE_DEV_UNLINK_DONE flag in bcache_device_attach()
function when we attach a backing device first time.  After detaching this
backing device, this flag will be true and sysfs_remove_link() isn't called in
bcache_device_unlink().  Then when we attach this backing device again,
sysfs_create_link() will return EEXIST error in bcache_device_link().

So the fix is trival and we clear this flag in bcache_device_link().

Signed-off-by: Zheng Liu 
Tested-by: Joshua Schmid 
Tested-by: Eric Wheeler 
Cc: Kent Overstreet 
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe

bcache: remove driver private bio splitting code

2015-08-13T18:31:40+00:00

The bcache driver has always accepted arbitrarily large bios and split
them internally.  Now that every driver must accept arbitrarily large
bios this code isn't nessecary anymore.

Cc: linux-bcache@vger.kernel.org
Signed-off-by: Kent Overstreet 
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park 
Signed-off-by: Ming Lin 
Signed-off-by: Jens Axboe

block: add a bi_error field to struct bio

2015-07-29T14:55:15+00:00

Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: NeilBrown 
Signed-off-by: Jens Axboe

block: have drivers use blk_queue_max_discard_sectors()

2015-07-17T14:41:53+00:00

Some drivers use it now, others just set the limits field manually.
But in preparation for splitting this into a hard and soft limit,
ensure that they all call the proper function for setting the hw
limit for discards.

Reviewed-by: Jeff Moyer 
Signed-off-by: Jens Axboe

bcache: use kvfree() in various places

2015-07-01T02:45:00+00:00

Use kvfree() instead of open-coding it.

Signed-off-by: Pekka Enberg 
Cc: Kent Overstreet 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: disable entropy contributions for nonrot devices

2014-10-04T16:55:32+00:00

Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set
QUEUE_FLAG_NONROT.

Historically, all block devices have automatically made entropy
contributions.  But as previously stated in commit e2e1a148 ("block: add
sysfs knob for turning off disk entropy contributions"):
    - On SSD disks, the completion times aren't as random as they
      are for rotational drives. So it's questionable whether they
      should contribute to the random pool in the first place.
    - Calling add_disk_randomness() has a lot of overhead.

There are more reliable sources for randomness than non-rotational block
devices.  From a security perspective it is better to err on the side of
caution than to allow entropy contributions from unreliable "random"
sources.

Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe

bcache: Drop unneeded blk_sync_queue() calls

2014-08-04T22:23:04+00:00

this is needed for the queue/block device we created (it's done by
blk_cleanup_queue() which we do call) - but calling it for the block devices we
only opened is pointless.

Change-Id: I53dfded14ed15b9581d10ca8399d5e1b3abbf9f2