This patch adds some code to disallow operations on the device that
is used as the target for the device replace operation.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Btrfs admin operations that are manually started from user mode
and that cannot be executed at the same time return -EINPROGRESS.
A common way to enter and leave this locked section is introduced
since it used to be specific to the balance operation.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

A small number of functions that are used in a device replace
procedure when the operation is resumed at mount time are unable
to pass the same root pointer that would be used in the regular
(ioctl) context. And since the root pointer is not required, only
the fs_info is, the root pointer argument is replaced with the
fs_info pointer argument.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This new function is used by the device replace procedure in
a later patch.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This is required for the device replace procedure in a later step.
Two calling functions also had to be changed to have the fs_info
pointer: repair_io_failure() and scrub_setup_recheck_block().
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This is required for the device replace procedure in a later step.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

The new function btrfs_find_device_missing_or_by_path() will be
used for the device replace procedure. This function itself calls
the second new function btrfs_find_device_by_path().
Unfortunately, it is not possible to currently make the rest of the
code use these functions as well, since all functions that look
similar at first view are all a little bit different in what they
are doing. But in the future, new code could benefit from these
two new functions, and currently, device replace uses them.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Some code to open block devices, to read the superblock and to
handle errors was repeated multiple times in 3 places, and the
following patch makes use of it as well. This code is now moved
into a subfunction.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Since we've kill the bigger one volume_mutex, we need to add devices
list mutex back.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Someone who is root or capable(CAP_SYS_ADMIN) could corrupt the
superblock and make Btrfs printk("%s") crash while holding the
uuid_mutex since nobody forces a limit on the string. Since the
uuid_mutex is significant, the system would be unusable
afterwards.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Use WARN rather than printk followed by WARN_ON(1), for conciseness.

A simplified version of the semantic patch that makes this transformation
is as follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression list es;
@@

-printk(
+WARN(1,
  es);
-WARN_ON(1);
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Correct spelling typo in btrfs.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Remove an invalid size check up from btrfs_shrink_dev().

The new size should not larger than the device->total_bytes as it was
already verified before coming to here(i.e. new_size < old_size).

Remove invalid check up for btrfs_shrink_dev().
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Alex reported a problem where we were writing between chunks on a rbd
device.  The thing is we do bio_add_page using logical offsets, but the
physical offset may be different.  So when we map the bio now check to see
if the bio is still ok with the physical offset, and if it is not split the
bio up and redo the bio_add_page with the physical sector.  This fixes the
problem for Alex and doesn't affect performance in the normal case.  Thanks,
Reported-and-tested-by: NAlex Elder <elder@inktank.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

div_factor{_fine} has been implemented for two times, cleanup it.
And I move them into a independent file named math.h because they are
common math functions.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Steps to reproduce:
 # mkfs.btrfs -m raid1 <disk1> <disk2>
 # btrfstune -S 1 <disk1>
 # mount <disk1> <mnt>
 # btrfs device add <disk3> <disk4> <mnt>
 # mount -o remount,rw <mnt>
 # dd if=/dev/zero of=<mnt>/tmpfile bs=1M count=1
 Deadlock happened.

It is because of the nested chunk allocation. When we wrote the data
into the filesystem, we would allocate the data chunk because there was
no data chunk in the filesystem. At the end of the data chunk allocation,
we should insert the metadata of the data chunk into the extent tree, but
there was no raid1 chunk, so we tried to lock the chunk allocation mutex to
allocate the new chunk, but we had held the mutex, the deadlock happened.

By rights, we would allocate the raid1 chunk when we added the second device
because the profile of the seed filesystem is raid1 and we had two devices.
But we didn't do that in fact. It is because the last step of the first device
insertion didn't commit the transaction. So when we added the second device,
we didn't cow the tree, and just inserted the relative metadata into the leaves
which were generated by the first device insertion, and its profile was dup.

So, I fix this problem by commiting the transaction at the end of the first
device insertion.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>

So far the return code of barrier_all_devices() is ignored, which
means that errors are ignored. The result can be a corrupt
filesystem which is not consistent.
This commit adds code to evaluate the return code of
barrier_all_devices(). The normal btrfs_error() mechanism is used to
switch the filesystem into read-only mode when errors are detected.

In order to decide whether barrier_all_devices() should return
error or success, the number of disks that are allowed to fail the
barrier submission is calculated. This calculation accounts for the
worst RAID level of metadata, system and data. If single, dup or
RAID0 is in use, a single disk error is already considered to be
fatal. Otherwise a single disk error is tolerated.

The calculation of the number of disks that are tolerated to fail
the barrier operation is performed when the filesystem gets mounted,
when a balance operation is started and finished, and when devices
are added or removed.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

Fix various messages to include newline and module prefix.
Signed-off-by: NDaniel J Blueman <daniel@quora.org>

Call btrfs_abort_transaction as early as possible when an error
condition is detected, that way the line number reported is useful
and we're not clueless anymore which error path led to the abort.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Commit 442a4f63 added btrfs device
statistic counters for detected IO and checksum errors to Linux 3.5.
The statistic part that counts checksum errors in
end_bio_extent_readpage() can cause a BUG() in a subfunction:
"kernel BUG at fs/btrfs/volumes.c:3762!"
That part is reverted with the current patch.
However, the counting of checksum errors in the scrub context remains
active, and the counting of detected IO errors (read, write or flush
errors) in all contexts remains active.

Cc: stable <stable@vger.kernel.org> # 3.5
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We need a barrir before calling waitqueue_active otherwise we will miss
wakeups.  So in places that do atomic_dec(); then atomic_read() use
atomic_dec_return() which imply a memory barrier (see memory-barriers.txt)
and then add an explicit memory barrier everywhere else that need them.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

When we close devices we add back empty devices for some reason that escapes
me.  In the case of a missing dev we don't allocate an rcu_string for it's
name, so check to see if the device has a name and if it doesn't don't
bother strdup()'ing it.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from btrfs.

Cc: Chris Mason <chris.mason@fusionio.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Code is added to suppress the I/O stats printing at mount time if all
statistic values are zero.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

People complained about the annoying kernel log message
"btrfs: no dev_stats entry found ... (OK on first mount after mkfs)"
everytime a filesystem is mounted for the first time after running
mkfs. Since the distribution of the btrfs-progs is not synchronized
to the kernel version, mkfs like it is now will be used also in the
future. Then this message is not useful to find errors, it is just
annoying. This commit removes the printk().
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

This will be used in conjunction with btrfs device ready <dev>.  This is
needed for initrd's to have a nice and lightweight way to tell if all of the
devices needed for a file system are in the cache currently.  This keeps
them from having to do mount+sleep loops waiting for devices to show up.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Commit c11d2c23 (Btrfs: add ioctl to get and reset the device
stats) introduced two ioctls doing almost the same thing distinguished
by just the ioctl number which encodes "do reset after read". I have
suggested

http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg16604.html

to implement it via the ioctl args. This hasn't happen, and I think we
should use a more clean way to pass flags and should not waste ioctl
numbers.

CC: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

This introduces btrfs_resume_balance_async(), which, given that
restriper state was recovered earlier by btrfs_recover_balance(),
resumes balance in btrfs-balance kthread.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Fix a bug that triggered asserts in btrfs_balance() in both normal and
resume modes -- restriper state was not properly restored on read-only
mounts.  This factors out resuming code from btrfs_restore_balance(),
which is now also called earlier in the mount sequence to avoid the
problem of some early writes getting the old profile.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

It is normal behaviour of the low level btrfs function btrfs_map_bio()
to complete a bio with -EIO if the device is missing, instead of just
preventing the bio creation in an earlier step.
This used to cause I/O statistic read error increments and annoying
printk_ratelimited messages. This commit fixes the issue.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Reported-by: NCarey Underwood <cwillu@cwillu.com>

Al pointed out that we can just toss out the old name on a device and add a
new one arbitrarily, so anybody who uses device->name in printk could
possibly use free'd memory.  Instead of adding locking around all of this he
suggested doing it with RCU, so I've introduced a struct rcu_string that
does just that and have gone through and protected all accesses to
device->name that aren't under the uuid_mutex with rcu_read_lock().  This
protects us and I will use it for dealing with removing the device that we
used to mount the file system in a later patch.  Thanks,
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <josef@redhat.com>

The device statistics are written into the device tree with each
transaction commit. Only modified statistics are written.
When a filesystem is mounted, the device statistics for each involved
device are read from the device tree and used to initialize the
counters.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

An ioctl interface is added to get the device statistic counters.
A second ioctl is added to atomically get and reset these counters.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

The goal is to detect when drives start to get an increased error rate,
when drives should be replaced soon. Therefore statistic counters are
added that count IO errors (read, write and flush). Additionally, the
software detected errors like checksum errors and corrupted blocks are
counted.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

Reproduce:
$ mkfs.btrfs /dev/sdb7
$ mount /dev/sdb7 /mnt/btrfs -o ro
$ btrfs dev add /dev/sdb8 /mnt/btrfs
ERROR: error adding the device '/dev/sdb8' - Invalid argument

Since we mount with readonly options, and /dev/sdb7 is not a seeding one,
a readonly notification is preferred.
Signed-off-by: NLiu Bo <liubo2009@cn.fujitsu.com>
Reviewed-by: NJosef Bacik <josef@redhat.com>

btrfs_map_block sets mirror_num, so that the repair code knows eventually
which device gave us the read error. For RAID10, mirror_num must be 1 or 2.
Before this fix mirror_num was incorrectly related to our stripe index.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Free fs_devices as done in the error-handling code just below.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>

Fix a bug, where in case we need to adjust stripe_size so that the
length of the resulting chunk is less than or equal to max_chunk_size,
DUP chunks turn out to be only half as big as they could be.

Cc: Arne Jansen <sensille@gmx.net>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

We miscalculate the length of extents we're discarding, and it leads to
an eof of device.
Reported-by: NDaniel Blueman <daniel@quora.org>
Signed-off-by: NLiu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Btrfs puts the filesystem metadata into its own address space, and
somehow the block device address space isn't getting onto disk properly
before a mount.  The end result is that a loop of mkfs and mounting the
filesystem will sometimes find stale or incorrect data.

This commit should fix it by sprinkling fdatawrites and invalidate_bdev
calls around.  This is a short term measure to make sure it is fixed.
The block devices really should be flushed and cleaned up higher in the
stack.
Signed-off-by: NChris Mason <chris.mason@oracle.com>