linux.git/fs/btrfs/dev-replace.c, branch v4.12

Btrfs: switch to div64_u64 if with a u64 divisor

2017-04-18T12:07:26+00:00

This is fixing code pieces where we use div_u64 when passing a u64 divisor.

Cc: David Sterba 
Signed-off-by: Liu Bo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: Wait for in-flight bios before freeing target device for raid56

2017-04-18T12:07:26+00:00

When raid56 dev-replace is cancelled by running scrub, we will free
target device without waiting for in-flight bios, causing the following
NULL pointer deference or general protection failure.

 BUG: unable to handle kernel NULL pointer dereference at 00000000000005e0
 IP: generic_make_request_checks+0x4d/0x610
 CPU: 1 PID: 11676 Comm: kworker/u4:14 Tainted: G  O    4.11.0-rc2 #72
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
 Workqueue: btrfs-endio-raid56 btrfs_endio_raid56_helper [btrfs]
 task: ffff88002875b4c0 task.stack: ffffc90001334000
 RIP: 0010:generic_make_request_checks+0x4d/0x610
 Call Trace:
  ? generic_make_request+0xc7/0x360
  generic_make_request+0x24/0x360
  ? generic_make_request+0xc7/0x360
  submit_bio+0x64/0x120
  ? page_in_rbio+0x4d/0x80 [btrfs]
  ? rbio_orig_end_io+0x80/0x80 [btrfs]
  finish_rmw+0x3f4/0x540 [btrfs]
  validate_rbio_for_rmw+0x36/0x40 [btrfs]
  raid_rmw_end_io+0x7a/0x90 [btrfs]
  bio_endio+0x56/0x60
  end_workqueue_fn+0x3c/0x40 [btrfs]
  btrfs_scrubparity_helper+0xef/0x620 [btrfs]
  btrfs_endio_raid56_helper+0xe/0x10 [btrfs]
  process_one_work+0x2af/0x720
  ? process_one_work+0x22b/0x720
  worker_thread+0x4b/0x4f0
  kthread+0x10f/0x150
  ? process_one_work+0x720/0x720
  ? kthread_create_on_node+0x40/0x40
  ret_from_fork+0x2e/0x40
 RIP: generic_make_request_checks+0x4d/0x610 RSP: ffffc90001337bb8

In btrfs_dev_replace_finishing(), we will call
btrfs_rm_dev_replace_blocked() to wait bios before destroying the target
device when scrub is finished normally.

However when dev-replace is aborted, either due to error or cancelled by
scrub, we didn't wait for bios, this can lead to use-after-free if there
are bios holding the target device.

Furthermore, for raid56 scrub, at least 2 places are calling
btrfs_map_sblock() without protection of bio_counter, leading to the
problem.

This patch fixes the problem:
1) Wait for bio_counter before freeing target device when canceling
   replace
2) When calling btrfs_map_sblock() for raid56, use bio_counter to
   protect the call.

Cc: Liu Bo 
Signed-off-by: Qu Wenruo 
Reviewed-by: Liu Bo 
Signed-off-by: David Sterba

btrfs: track exclusive filesystem operation in flags

2017-04-18T12:07:25+00:00

There are several operations, usually started from ioctls, that cannot
run concurrently. The status is tracked in
mutually_exclusive_operation_running as an atomic_t. We can easily track
the status as one of the per-filesystem flag bits with same
synchronization guarantees.

The conversion replaces:

* atomic_xchg(..., 1)    ->   test_and_set_bit(FLAG, ...)
* atomic_set(..., 0)     ->   clear_bit(FLAG, ...)

Reviewed-by: Anand Jain 
Signed-off-by: David Sterba

btrfs: constify device path passed to relevant helpers

2017-02-28T13:26:07+00:00

Signed-off-by: David Sterba

btrfs: remove root parameter from transaction commit/end routines

2016-12-06T15:07:00+00:00

Now we only use the root parameter to print the root objectid in
a tracepoint.  We can use the root parameter from the transaction
handle for that.  It's also used to join the transaction with
async commits, so we remove the comment that it's just for checking.

Signed-off-by: Jeff Mahoney 
Signed-off-by: David Sterba

btrfs: take an fs_info directly when the root is not used otherwise

2016-12-06T15:06:59+00:00

There are loads of functions in btrfs that accept a root parameter
but only use it to obtain an fs_info pointer.  Let's convert those to
just accept an fs_info pointer directly.

Signed-off-by: Jeff Mahoney 
Signed-off-by: David Sterba

btrfs: root->fs_info cleanup, add fs_info convenience variables

2016-12-06T15:06:59+00:00

In routines where someptr->fs_info is referenced multiple times, we
introduce a convenience variable.  This makes the code considerably
more readable.

Signed-off-by: Jeff Mahoney 
Signed-off-by: David Sterba

btrfs: convert pr_* to btrfs_* where possible

2016-09-26T17:37:04+00:00

For many printks, we want to know which file system issued the message.

This patch converts most pr_* calls to use the btrfs_* versions instead.
In some cases, this means adding plumbing to allow call sites access to
an fs_info pointer.

fs/btrfs/check-integrity.c is left alone for another day.

Signed-off-by: Jeff Mahoney 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: unsplit printed strings

2016-09-26T16:08:44+00:00

CodingStyle chapter 2:
"[...] never break user-visible strings such as printk messages,
because that breaks the ability to grep for them."

This patch unsplits user-visible strings.

Signed-off-by: Jeff Mahoney 
Signed-off-by: David Sterba

btrfs: btrfs_test_opt and friends should take a btrfs_fs_info

2016-07-26T11:53:16+00:00

btrfs_test_opt and friends only use the root pointer to access
the fs_info.  Let's pass the fs_info directly in preparation to
eliminate similar patterns all over btrfs.

Signed-off-by: Jeff Mahoney 
Signed-off-by: David Sterba