linux-stable.git/drivers/md/raid1.c, branch v4.9.76

md: don't use flush_signals in userspace processes

2017-07-27T22:08:01+00:00

commit f9c79bc05a2a91f4fba8bfd653579e066714b1ec upstream.

The function flush_signals clears all pending signals for the process. It
may be used by kernel threads when we need to prepare a kernel thread for
responding to signals. However using this function for an userspaces
processes is incorrect - clearing signals without the program expecting it
can cause misbehavior.

The raid1 and raid5 code uses flush_signals in its request routine because
it wants to prepare for an interruptible wait. This patch drops
flush_signals and uses sigprocmask instead to block all signals (including
SIGKILL) around the schedule() call. The signals are not lost, but the
schedule() call won't respond to them.

Signed-off-by: Mikulas Patocka 
Acked-by: NeilBrown 
Signed-off-by: Shaohua Li 
Signed-off-by: Greg Kroah-Hartman

raid1: handle read error also in readonly mode

2016-10-29T05:04:04+00:00

If write is the first operation on a disk and it happens not to be
aligned to page size, block layer sends read request first. If read
operation fails, the disk is set as failed as no attempt to fix the
error is made because array is in auto-readonly mode. Similarily, the
disk is set as failed for read-only array.

Take the same approach as in raid10. Don't fail the disk if array is in
readonly or auto-readonly mode. Try to redirect the request first and if
unsuccessful, return a read error.

Signed-off-by: Tomasz Majchrzak 
Signed-off-by: Shaohua Li

RAID1: ignore discard error

2016-10-24T22:28:17+00:00

If a write error occurs, raid1 will try to rewrite the bio in small
chunk size. If the rewrite fails, raid1 will record the error in bad
block. narrow_write_error will always use WRITE for the bio, but
actually it could be a discard. Since discard bio hasn't payload, write
the bio will cause different issues. But discard error isn't fatal, we
can safely ignore it. This is what this patch does.

This issue should exist since discard is added, but only exposed with
recent arbitrary bio size feature.

Reported-and-tested-by: Sitsofe Wheeler 
Cc: stable@vger.kernel.org (v3.6)
Signed-off-by: Shaohua Li

block: export bio_free_pages to other modules

2016-09-22T13:48:03+00:00

bio_free_pages is introduced in commit 1dfa0f68c040
("block: add a helper to free bio bounce buffer pages"),
we can reuse the func in other modules after it was
imported.

Cc: Christoph Hellwig 
Cc: Jens Axboe 
Cc: Mike Snitzer 
Cc: Shaohua Li 
Signed-off-by: Guoqing Jiang 
Acked-by: Kent Overstreet 
Signed-off-by: Jens Axboe

block: rename bio bi_rw to bi_opf

2016-08-07T20:41:02+00:00

Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.

No intended functional changes in this commit.

Signed-off-by: Jens Axboe

Merge branch 'mymd/for-next' into mymd/for-linus

2016-07-28T16:34:14+00:00

block: get rid of bio_rw and READA

2016-07-20T23:37:01+00:00

These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces.  For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense.  Any check for READA is replaced with an
explicit check for REQ_RAHEAD.  Also remove the READA alias for
REQ_RAHEAD.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Mike Christie 
Signed-off-by: Jens Axboe

md: reduce the number of synchronize_rcu() calls when multiple devices fail.

2016-06-13T18:54:22+00:00

Every time a device is removed with ->hot_remove_disk() a synchronize_rcu() call is made
which can delay several milliseconds in some case.
If lots of devices fail at once - as could happen with a large RAID10 where one set
of devices are removed all at once - these delays can add up to be very inconcenient.

As failure is not reversible we can check for that first, setting a
separate flag if it is found, and then all synchronize_rcu() once for
all the flagged devices.  Then ->hot_remove_disk() function can skip the
synchronize_rcu() step if the flag is set.

fix build error(Shaohua)
Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li

md/raid1: add rcu protection to rdev in fix_read_error

2016-06-13T18:54:18+00:00

Since remove_and_add_spares() was added to hot_remove_disk() it has
been possible for an rdev to be hot-removed while fix_read_error()
was running, so we need to be more careful, and take a reference to
the rdev while performing IO.

Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li

md/raid1: small code cleanup in end_sync_write

2016-06-13T18:54:17+00:00

'mirror' is only used to find 'rdev', several times.
So just find 'rdev' once, and use it instead.

Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li