Currently udev does not know about the device being removed from the
file system. This may result in the situation where we're unable to
mount the file system by UUID or by LABEL because the by-uuid and
by-label links may still point to the device which is no longer part of
the btrfs file system and hence does not have any btrfs super block.

It can be easily reproduced by the following:

mkfs.btrfs -L bugfs /dev/loop[0-6]
mount /dev/loop0 /mnt/test
btrfs device delete /dev/loop0 /mnt/test
umount /mnt/test

mount LABEL=bugfs /mnt/test <---- this fails

then see:

ls -l /dev/disk/by-label/bugfs

which will still point to the /dev/loop0

We did not noticed this before because libblkid would send the udev
event for us when it notice that the link does not fit the reality,
however it does not do that anymore and completely relies on udev
information.

Fix this by sending the KOBJ_CHANGE event to the bdev kobject after
successful device removal.

Note that this does not affect device addition, because we will open the
device prior the addition from userspace and udev will notice that and
reread the device afterwards.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

ret variant may be set to 0 if we read page successfully, but it might be
released before we lock it again. On this case, if we fail to allocate a
new page, we will return 0, it is wrong, fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Since we can pre-allocate the space past EOF, we should be able to reclaim
that space if we need. This patch implements it by removing the EOF check.

Though the manual of fallocate command says we can use truncate command to
reclaim the pre-allocated space which past EOF, but because truncate command
changes the file size, we must run several commands to reclaim the space if we
don't want to change the file size, so it is not a good choice.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Steps to reproduce:
 # mkfs.btrfs <disk>
 # mount <disk> <mnt>
 # dd if=/dev/zero of=<mnt>/<file> bs=512 seek=5 count=8
 # fallocate -p -o 2048 -l 16384 <mnt>/<file>
 # dd if=/dev/zero of=<mnt>/<file> bs=4096 seek=3 count=8 conv=notrunc,nocreat
 # umount <mnt>
 # dmesg
 WARNING: at fs/btrfs/inode.c:7140 btrfs_destroy_inode+0x2eb/0x330

The reason is that we inputed a range which is beyond the end of the file. And
because the end of this range was not page-aligned, we had to truncate the last
page in this range, this operation is similar to a buffered file write. In other
words, we reserved enough space and clear the data which was in the hole range
on that page. But when we expanded that test file, write the data into the same
page, we forgot that we have reserved enough space for the buffered write of
that page because in most cases there is no page that is beyond the end of
the file. As a result, we reserved the space twice.

In fact, we needn't truncate the page if it is beyond the end of the file, just
release the allocated space in that range. Fix the above problem by this way.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

(start + len) is the start of the adjacent extent, not the end of the current
extent, so we should not use it to check the hole is on the same page or not.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We forget to release the reserved space in the error path of delalloc
reservatiom, fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If we runt the direct IO, we should not run auto defrag, because it may
introduce buffered IO vs direcIO problem, and make direct IO slow down.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Value 0 is not a tree id, so besides an upper limit, a lower limit is
necessary as well while parsing root types of tracepoint.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We should use ctl->unit for free space calculation instead of block_group->sectorsize
even though for free space use_bitmap or free space cluster we only have sectorsize assigned to ctl->unit currently. Also, we can keep it consisten in code style.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Refactor it by checking whether the inode has been created and needs to be
dropped (drop_inode_on_err) and also if the err variable is set. That way the
variable doesn't need to be set on each and every error handling block.
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

When a new file is created with btrfs_create(), the inode will initially be
created with permissions 0666 and later on in btrfs_init_acl() it will be
adapted to mask out the umask bits. The problem is that this change won't make
it into the btrfs_inode unless there's another change to the inode (e.g. writing
content changing the size or touching the file changing the mtime.)

This fix adds a call to btrfs_update_inode() to btrfs_create() to make sure that
the change will not get lost if the in-memory inode is flushed before other
changes are made to the file.
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

When the flag not supported is specified, it is necessary to return the error
to the caller.
So, we add the validity check of the fiemap's flag.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Passing a null extended attribute value means to remove the attribute,
but we don't have to add a new NULL extended attribute.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If the acl can be exactly represented in the traditional file
mode permission bits, we don't set another acl attribute.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

alloc_end is not the real end of the current extent, it is the start of the
next adjoining extent. So we needn't +1 when calculating the size the space
that is about to be reserved.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

The kernel developers have implemented some often-used align macros, we should
use them instead of the complex code.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This regression was introduced by the device-replace patches.
Scrub immediately stops checking those disks that have write errors.
This is nothing that happens in the real world, but it is wrong
since scrub is the tool to detect and repair defects. Fix it.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This issue was detected by the "0-DAY kernel build testing".

fs/btrfs/volumes.c: In function 'btrfs_rm_device':
fs/btrfs/volumes.c:1505:1: warning: label 'error_close' defined but not used [-Wunused-label]
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

The structure member mirror_num is modified concurrently to the
structure member is_iodone. This doesn't require any locking by
design, unless everything is stored in the same 32 bits of a
bit field. This was the case and xfstest 284 was able to
trigger false warnings from the checker code. This patch
seperates the bits and fixes the race.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If we freeze the fs, the auto defragment should not run. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This patch restructure btrfs_run_defrag_inodes() and make the code of the auto
defragment more readable.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We forget to get the defrag lock when we re-add the defragable inode,
Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

The auto defrag allocation is in the fast path of the IO, so use slabs
to improve the speed of the allocation.

And besides that, it can do check for leaked objects when the module is removed.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We need get write access for qgroup operations, or we will modify the R/O fs.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

We need get write access for scrub, or we will modify the R/O fs.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Steps to reproduce:
 # mkfs.btrfs -d single -m single <disk0> <disk1>
 # mount -o ro <disk0> <mnt0>
 # mount -o ro <disk0> <mnt1>
 # mount -o remount,rw <mnt0>
 # umount <mnt0>
 # btrfs device delete <disk1> <mnt1>

We can remove a device from a R/O filesystem. The reason is that we just check
the R/O flag of the super block object. It is not enough, because the kernel
may set the R/O flag only for the mount point. We need invoke

	mnt_want_write_file()

to do a full check.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Steps to reproduce:
 # mkfs.btrfs <partition>
 # mount -o ro <partition> <mnt0>
 # mount -o ro <partition> <mnt1>
 # mount -o remount,rw <mnt0>
 # umount <mnt0>
 # btrfs fi resize 10g <mnt1>

We re-sized a R/O filesystem. The reason is that we just check the R/O flag
of the super block object. It is not enough, because the kernel may set the
R/O flag only for the mount point. We need invoke mnt_want_write_file() to
do a full check.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

When wen want to set the default subvolume, we must get write access, or
we will change the R/O file system.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If the id of the existed transaction is more than the one we specified, it
means the specified transaction was commited, so we should return 0, not
EINVAL.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If there is no running transaction in the fs, we needn't start a new one when
we want to start sync.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Since we have gotten the root in the caller, just pass it into
btrfs_ioctl_{start, wait}_sync() directly.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

If we found an invalid xattr dir item, we'd better try the next one instead.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

io_ctl_map_page is called by many functions in free-space-cache.
In most scenarios, the ->cur is not null, e.g. io_ctl_add_entry.
I think we'd better remove the warn_on here.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This is the commit that allows to start the device replace
procedure.

An ioctl() interface is added that supports starting and
canceling the device replace procedure, and to retrieve
the status and progress.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Make the target disk of a running device replace operation
available for reading. This is only used as a last ressort for
the defect repair procedure. And it is dependent on the location
of the data block to read, because during an ongoing device
replace operation, the target drive is only partially filled
with the filesystem data.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This change of the define is effective in all modes, it
is required and used only in the case when a device replace
procedure is running. The reason is that during an active
device replace procedure, the target device of the copy
operation is a mirror for the filesystem data as well that
can be used to read data in order to repair read errors on
other disks.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

It is desirable to be able to configure the device replace
procedure to avoid reading the source drive (the one to be
copied) whenever possible. This is useful when the number of
read errors on this disk is high, because it would delay the
copy procedure alot. Therefore there is an option to avoid
reading from the source disk unless the repair procedure
really needs to access it. The regular read req asks for
mapping the block with mirror_num == 0, in this case the
source disk is avoided whenever possible. The repair code
selects the mirror_num explicitly (mirror_num != 0), this
case is not changed by this commit.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

During a running dev replace operation, all write requests to
the live filesystem are duplicated to also write to the target
drive. Therefore btrfs_map_block() is changed to duplicate
stripes that are written to the source disk of a device replace
procedure to be written to the target disk as well.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

Before this commit, btrfs_map_block() was called with REQ_WRITE
in order to retrieve the list of mirrors for a disk block.
This needs to be changed for the device replace procedure since
it makes a difference whether you are asking for read mirrors
or for locations to write to.
GET_READ_MIRRORS is introduced as a new interface to call
btrfs_map_block().
In the current commit, the functionality is not yet changed,
only the interface for GET_READ_MIRRORS is introduced and all
the places that should use this new interface are adapted.

The reason that REQ_WRITE cannot be abused anymore to retrieve
a list of read mirrors is that during a running dev replace
operation all write requests to the live filesystem are
duplicated to also write to the target drive.
Keep in mind that the target disk is only partially a valid
copy of the source disk while the operation is ongoing. All
writes go to the target disk, but not all reads would return
valid data on the target disk. Therefore it is not possible
anymore to abuse a REQ_WRITE interface to find valid mirrors
for a REQ_READ.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This commit contains all the essential changes to the core code
of Btrfs for support of the device replace procedure.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>