Liu Bo [Mon, 7 Jan 2013 10:10:12 +0000 (10:10 +0000)]
Btrfs: fix a bug when llseek for delalloc bytes behind prealloc extents
xfstests case 285 complains.
It it because btrfs did not try to find unwritten delalloc
bytes(only dirty pages, not yet writeback) behind prealloc
extents, it ends up finding nothing while we're with SEEK_DATA.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Liu Bo [Thu, 27 Dec 2012 09:01:24 +0000 (09:01 +0000)]
Btrfs: let allocation start from the right raid type
This'd avoid us empty looping.
Say we have only one disk and the metadata raid type will be defaultly DUP,
and we do not need to start from index=0(RAID10) and get over two empty
loops to index=2(DUP).
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Josef Bacik [Mon, 7 Jan 2013 22:03:21 +0000 (17:03 -0500)]
Btrfs: add orphan before truncating pagecache
Running xfstests 83 in a loop would sometimes fail the fsck. This happens
because if we invalidate a page that already has an ordered extent setup for
it we will complete the ordered extent ourselves, assuming that the truncate
will clean everything up. The problem with this is there is plenty of time
for the truncate to fail after we've done this work. So to fix this we need
to add the orphan item first to make sure the cleanup gets done properly,
and then we can truncate the pagecache and all that stuff and be safe. This
fixes the btrfsck failures I was seeing while running 83 in a loop. Thanks,
Miao Xie [Mon, 22 Oct 2012 11:39:53 +0000 (11:39 +0000)]
Btrfs: do not delete a subvolume which is in a R/O subvolume
Step to reproduce:
# mkfs.btrfs <disk>
# mount <disk> <mnt>
# btrfs sub create <mnt>/subv0
# btrfs sub snap <mnt> <mnt>/subv0/snap0
# change <mnt>/subv0 from R/W to R/O
# btrfs sub del <mnt>/subv0/snap0
We deleted the snapshot successfully. I think we should not be able to delete
the snapshot since the parent subvolume is R/O.
Lukas Czerner [Fri, 7 Dec 2012 10:09:19 +0000 (10:09 +0000)]
btrfs: get the device in write mode when deleting it
When we're deleting the device we should get it in write mode since
we're going to re-write the super block magic on that device. And it
should fail if the device is read-only.
Chris Mason [Mon, 17 Dec 2012 19:26:57 +0000 (14:26 -0500)]
Btrfs: fix hash overflow handling
The handling for directory crc hash overflows was fairly obscure,
split_leaf returns EOVERFLOW when we try to extend the item and that is
supposed to bubble up to userland. For a while it did so, but along the
way we added better handling of errors and forced the FS readonly if we
hit IO errors during the directory insertion.
Along the way, we started testing only for EEXIST and the EOVERFLOW case
was dropped. The end result is that we may force the FS readonly if we
catch a directory hash bucket overflow.
This fixes a few problem spots. First I add tests for EOVERFLOW in the
places where we can safely just return the error up the chain.
btrfs_rename is harder though, because it tries to insert the new
directory item only after it has already unlinked anything the rename
was going to overwrite. Rather than adding very complex logic, I added
a helper to test for the hash overflow case early while it is still safe
to bail out.
Snapshot and subvolume creation had a similar problem, so they are using
the new helper now too.
Signed-off-by: Chris Mason <chris.mason@fusionio.com> Reported-by: Pascal Junod <pascal@junod.info>
Josef Bacik [Fri, 14 Dec 2012 18:48:14 +0000 (13:48 -0500)]
Btrfs: don't take inode delalloc mutex if we're a free space inode
This confuses and angers lockdep even though it's ok. We don't really need
the lock for free space inodes since only the transaction committer will be
reserving space. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 14 Dec 2012 18:46:43 +0000 (13:46 -0500)]
Btrfs: fix autodefrag and umount lockup
This happens because writeback_inodes_sb_nr_if_idle does down_read. This
doesn't work for us and it has not been fixed upstream yet, so do it
ourselves and use that instead so we can stop having this stupid long
standing lockup. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix permissions of empty files not affected by umask
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>
Stefan Behrens [Wed, 14 Nov 2012 18:57:29 +0000 (18:57 +0000)]
Btrfs: fix BUG() in scrub when first superblock reading gives EIO
This fixes a very special case that can be reproduced by just
disconnecting a disk at runtime, and without unmounting the
filesystem first, start scrub on the filesystem with the
disconnected disk. All read and write EIOs are handled
correctly, only the first superblock is an exception and gives
a BUG() in a subfunction. The BUG() is correct, it would crash
later otherwise. The subfunction must not be called for
superblocks and this is what the fix changes.
Reported-by: Joeri Vanthienen <mail@joerivanthienen.be> Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 9 Nov 2012 15:53:21 +0000 (10:53 -0500)]
Btrfs: do not call file_update_time in aio_write
This starts a transaction and dirties the inode everytime we call it, which
is super expensive if you have a write heavy workload. We will be updating
the inode when the IO completes and we reserve the space for the inode
update when we reserve space for the write, so there is no chance of loss of
information or enospc issues. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Wed, 7 Nov 2012 18:44:13 +0000 (13:44 -0500)]
Btrfs: only unlock and relock if we have to
I noticed while doing fsync tests that we were always dropping the path and
re-searching when we first cow the log root even though we've already gotten
the write lock on the root. That's because we don't take into account that
there might not be a parent node, so fix the check to make sure there is
actually a parent node before we undo all of this work for nothing. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Tue, 23 Oct 2012 20:03:44 +0000 (16:03 -0400)]
Btrfs: use tokens where we can in the tree log
If we are syncing over and over the overhead of doing all those maps in
fill_inode_item and log_changed_extents really starts to hurt, so use map
tokens so we can avoid all the extra mapping. Since the token maps from our
offset to the end of the page make sure to set the first thing in the item
first so we really only do one map. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 15 Oct 2012 17:43:18 +0000 (13:43 -0400)]
Btrfs: optimize leaf_space_used
This gets called at least 4 times for every level while adding an object,
and it involves 3 kmapping calls, which on my box take about 5us a piece.
So instead use a token, which brings us down to 1 kmap call and makes this
function take 1/3 of the time per call. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 15 Oct 2012 17:39:33 +0000 (13:39 -0400)]
Btrfs: don't memset new tokens
Our token logic depends on token->kaddr being set, and if it is not it sets
everything properly as needed. So instead of memsetting just set
token->kaddr to NULL. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Thu, 11 Oct 2012 20:54:30 +0000 (16:54 -0400)]
Btrfs: log changed inodes based on the extent map tree
We don't really need to copy extents from the source tree since we have all
of the information already available to us in the extent_map tree. So
instead just write the extents straight to the log tree and don't bother to
copy the extent items from the source tree.
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Wed, 12 Dec 2012 22:00:01 +0000 (17:00 -0500)]
Btrfs: add path->really_keep_locks
You'd think path->keep_locks would keep all the locks wouldn't you? You'd
be wrong. It only keeps them if the slot is pointing to the last item in
the node. This is for use with btrfs_next_leaf, which needs this sort of
thing. But the horrible horrible things I'm going to do to the tree log
means I really need everything held from root to leaf so I can add and
delete items in the same search. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 3 Dec 2012 15:58:15 +0000 (10:58 -0500)]
Btrfs: do not mark ems as prealloc if we are writing to them
We are going to use EM's to log extents in the future, so we need to not
mark them as prealloc if they aren't actually prealloc extents. Instead
mark them with FILLING so we know to ammend mod_start/mod_len and that way
we don't confuse the extent logging code. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 3 Dec 2012 15:31:19 +0000 (10:31 -0500)]
Btrfs: keep track of the extents original block length
If we've written to a prealloc extent we need to know the original block len
for the extent. We can't figure this out currently since ->block_len is
just set to the extent length. So introduce ->orig_block_len so that we
know how many bytes were in the original extent for proper extent logging
that future patches will need. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 16 Nov 2012 18:56:32 +0000 (13:56 -0500)]
Btrfs: inline csums if we're fsyncing
The tree logging stuff needs the csums to be on the ordered extents in order
to log them properly, so mark that we're sync and inline the csum creation
so we don't have to wait on the csumming to be done when logging extents
that are still in flight. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Thu, 11 Oct 2012 20:17:34 +0000 (16:17 -0400)]
Btrfs: don't bother copying if we're only logging the inode
We don't copy inode items anwyay, we just copy them straight into the log
from the in memory inode. So if we know we're only logging the inode, don't
bother dropping anything, just try to insert it and either if it succeeds or
we get EEXIST we can update the inode item in the log and carry on. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Thu, 11 Oct 2012 19:53:56 +0000 (15:53 -0400)]
Btrfs: only log the inode item if we can get away with it
Currently we copy all the file information into the log, inode item, the
refs, xattrs etc. Except most of this doesn't change from fsync to fsync,
just the inode item changes. So set a flag if an xattr changes or a link is
added, and otherwise only log the inode item. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Anand Jain [Fri, 7 Dec 2012 09:28:54 +0000 (09:28 +0000)]
Btrfs: rename root_times_lock to root_item_lock
Originally root_times_lock was introduced as part of send/receive
code however newly developed patch to label the subvol reused
the same lock, so renaming it for a meaningful name.
Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Lukas Czerner [Thu, 6 Dec 2012 19:25:48 +0000 (19:25 +0000)]
btrfs: Notify udev when removing device
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.
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>
Miao Xie [Wed, 5 Dec 2012 10:56:13 +0000 (10:56 +0000)]
Btrfs: fix wrong return value of btrfs_truncate_page()
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>
Miao Xie [Wed, 5 Dec 2012 10:54:52 +0000 (10:54 +0000)]
Btrfs: punch hole past the end of the file
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>
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>
Miao Xie [Wed, 5 Dec 2012 10:53:45 +0000 (10:53 +0000)]
Btrfs: fix off-by-one error of the same page check in btrfs_punch_hole()
(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>
Wang Sheng-Hui [Fri, 30 Nov 2012 06:30:14 +0000 (06:30 +0000)]
Btrfs: use ctl->unit for free space calculation instead of block_group->sectorsize
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>
Btrfs: refactor error handling to drop inode in btrfs_create()
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>
Btrfs: fix permissions of empty files not affected by umask
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>
Miao Xie [Wed, 28 Nov 2012 10:28:54 +0000 (10:28 +0000)]
Btrfs: fix off-by-one error of the reserved size of btrfs_allocate()
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>
Stefan Behrens [Tue, 27 Nov 2012 17:39:51 +0000 (17:39 +0000)]
Btrfs: fix a scrub regression in case of write errors
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>
Stefan Behrens [Tue, 27 Nov 2012 16:10:21 +0000 (16:10 +0000)]
Btrfs: fix race in check-integrity caused by usage of bitfield
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>
Miao Xie [Mon, 26 Nov 2012 08:44:50 +0000 (08:44 +0000)]
Btrfs: get write access when removing a device
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>
Miao Xie [Mon, 26 Nov 2012 08:43:45 +0000 (08:43 +0000)]
Btrfs: get write access when doing resize fs
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>
Miao Xie [Mon, 26 Nov 2012 08:42:07 +0000 (08:42 +0000)]
Btrfs: fix wrong return value of btrfs_wait_for_commit()
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>
Wang Sheng-Hui [Fri, 23 Nov 2012 03:03:14 +0000 (03:03 +0000)]
Btrfs: do not warn_on io_ctl->cur in io_ctl_map_page
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>
Stefan Behrens [Tue, 6 Nov 2012 14:06:47 +0000 (15:06 +0100)]
Btrfs: allow repair code to include target disk when searching mirrors
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>
Stefan Behrens [Tue, 6 Nov 2012 13:57:46 +0000 (14:57 +0100)]
Btrfs: increase BTRFS_MAX_MIRRORS by one for dev replace
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>
Stefan Behrens [Tue, 6 Nov 2012 13:52:18 +0000 (14:52 +0100)]
Btrfs: optionally avoid reads from device replace source drive
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>
Stefan Behrens [Tue, 6 Nov 2012 13:43:46 +0000 (14:43 +0100)]
Btrfs: changes to live filesystem are also written to replacement disk
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>
Stefan Behrens [Tue, 6 Nov 2012 13:16:24 +0000 (14:16 +0100)]
Btrfs: introduce GET_READ_MIRRORS functionality for btrfs_map_block()
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>
Stefan Behrens [Mon, 5 Nov 2012 16:33:06 +0000 (17:33 +0100)]
Btrfs: add new sources for device replace code
This adds a new file to the sources together with the header file
and the changes to ioctl.h and ctree.h that are required by the
new C source file. Additionally, 4 new functions are added to
volume.c that deal with device creation and destruction.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Tue, 6 Nov 2012 10:43:11 +0000 (11:43 +0100)]
Btrfs: add code to scrub to copy read data to another disk
The device replace procedure makes use of the scrub code. The scrub
code is the most efficient code to read the allocated data of a disk,
i.e. it reads sequentially in order to avoid disk head movements, it
skips unallocated blocks, it uses read ahead mechanisms, and it
contains all the code to detect and repair defects.
This commit adds code to scrub to allow the scrub code to copy read
data to another disk.
One goal is to be able to perform as fast as possible. Therefore the
write requests are collected until huge bios are built, and the
write process is decoupled from the read process with some kind of
flow control, of course, in order to limit the allocated memory.
The best performance on spinning disks could by reached when the
head movements are avoided as much as possible. Therefore a single
worker is used to interface the read process with the write process.
The regular scrub operation works as fast as before, it is not
negatively influenced and actually it is more or less unchanged.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 5 Nov 2012 17:51:52 +0000 (18:51 +0100)]
Btrfs: handle errors from btrfs_map_bio() everywhere
With the addition of the device replace procedure, it is possible
for btrfs_map_bio(READ) to report an error. This happens when the
specific mirror is requested which is located on the target disk,
and the copy operation has not yet copied this block. Hence the
block cannot be read and this error state is indicated by
returning EIO.
Some background information follows now. A new mirror is added
while the device replace procedure is running.
btrfs_get_num_copies() returns one more, and
btrfs_map_bio(GET_READ_MIRROR) adds one more mirror if a disk
location is involved that was already handled by the device
replace copy operation. The assigned mirror num is the highest
mirror number, e.g. the value 3 in case of RAID1.
If btrfs_map_bio() is invoked with mirror_num == 0 (i.e., select
any mirror), the copy on the target drive is never selected
because that disk shall be able to perform the write requests as
quickly as possible. The parallel execution of read requests would
only slow down the disk copy procedure. Second case is that
btrfs_map_bio() is called with mirror_num > 0. This is done from
the repair code only. In this case, the highest mirror num is
assigned to the target disk, since it is used last. And when this
mirror is not available because the copy procedure has not yet
handled this area, an error is returned. Everywhere in the code
the handling of such errors is added now.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 5 Nov 2012 16:54:08 +0000 (17:54 +0100)]
Btrfs: disallow mutually exclusive admin operations from user mode
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: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 5 Nov 2012 16:11:06 +0000 (17:11 +0100)]
Btrfs: avoid risk of a deadlock in btrfs_handle_error
Remove the attempt to cancel a running scrub or device replace
operation in btrfs_handle_error() because it adds the risk of
a deadlock. The only penalty of not canceling the operation is
that some I/O remains active until the procedure completes.
This is basically the same thing that happens to other tasks
that are running in user mode context, they are not affected
or stopped in btrfs_handle_error(), these tasks just need to
handle write errors correctly.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 5 Nov 2012 16:03:39 +0000 (17:03 +0100)]
Btrfs: pass fs_info instead of root
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: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 5 Nov 2012 14:46:42 +0000 (15:46 +0100)]
Btrfs: pass fs_info to btrfs_map_block() instead of mapping_tree
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: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 5 Nov 2012 13:42:30 +0000 (14:42 +0100)]
Btrfs: add two more find_device() methods
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: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 12 Nov 2012 13:03:45 +0000 (14:03 +0100)]
Btrfs: move some common code into a subfunction
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: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Fri, 2 Nov 2012 15:16:26 +0000 (16:16 +0100)]
Btrfs: in scrub repair code, simplify alloc error handling
In the scrub repair code, the code is changed to handle memory
allocation errors a little bit smarter. The change is to handle
it just like a read error. This simplifies the code and removes
a couple of lines of code, since the code to handle read errors
is there anyway.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Fri, 2 Nov 2012 15:14:21 +0000 (16:14 +0100)]
Btrfs: in scrub repair code, optimize the reading of mirrors
In case that disk blocks need to be repaired (rewritten), the
current code at first (for simplicity reasons) reads all alternate
mirrors in the first step, afterwards selects the best one in a
second step. This is now changed to read one alternate mirror
after the other and to leave the loop early when a perfect mirror
is found.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Fri, 2 Nov 2012 13:58:04 +0000 (14:58 +0100)]
Btrfs: make the scrub page array dynamically allocated
With the modified design (in order to support the devive replace
procedure) it is necessary to alloc the page array dynamically.
The reason is that pages are reused. At first a page is used for
the bio to read the data from the filesystem, then the same page
is reused for the bio that writes the data to the target disk.
Since the read process and the write process are completely
decoupled, this requires a new concept of refcounts and get/put
functions for pages, and it requires to use newly created pages
for each read bio which are freed after the write operation
is finished.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Fri, 2 Nov 2012 12:26:57 +0000 (13:26 +0100)]
Btrfs: remove the block device pointer from the scrub context struct
The block device is removed from the scrub context state structure.
The scrub code as it is used for the device replace procedure reads
the source data from whereever it is optimal. The source device might
even be gone (disconnected, for instance due to a hardware failure).
Or the drive can be so faulty so that the device replace procedure
tries to avoid access to the faulty source drive as much as possible,
and only if all other mirrors are damaged, as a last resort, the
source disk is accessed.
The modified scrub code operates as if it would handle the source
drive and thereby generates an exact copy of the source disk on the
target disk, even if the source disk is not present at all. Therefore
the block device pointer to the source disk is removed in the scrub
context struct and moved into the lower level scope of scrub_bio,
fixup and page structures where the block device context is known.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Fri, 2 Nov 2012 08:58:09 +0000 (09:58 +0100)]
Btrfs: rename the scrub context structure
The device replace procedure makes use of the scrub code. The scrub
code is the most efficient code to read the allocated data of a disk,
i.e. it reads sequentially in order to avoid disk head movements, it
skips unallocated blocks, it uses read ahead mechanisms, and it
contains all the code to detect and repair defects.
This commit is a first preparation step to adapt the scrub code to
be shareable for the device replace procedure.
The block device will be removed from the scrub context state
structure in a later step. It used to be the source block device.
The scrub code as it is used for the device replace procedure reads
the source data from whereever it is optimal. The source device might
even be gone (disconnected, for instance due to a hardware failure).
Or the drive can be so faulty so that the device replace procedure
tries to avoid access to the faulty source drive as much as possible,
and only if all other mirrors are damaged, as a last resort, the
source disk is accessed.
The modified scrub code operates as if it would handle the source
drive and thereby generates an exact copy of the source disk on the
target disk, even if the source disk is not present at all. Therefore
the block device pointer to the source disk is removed in a later
patch, and therefore the context structure is renamed (this is the
goal of the current patch) to reflect that no source block device
scope is there anymore.
Summary:
This first preparation step consists of a textual substitution of the
term "dev" to the term "ctx" whereever the scrub context is used.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Alexander Block [Thu, 8 Nov 2012 21:27:24 +0000 (21:27 +0000)]
Btrfs: merge inode_list in __merge_refs
When __merge_refs merges two refs, it is also needed to merge the
inode_list of both refs. Otherwise we have missed backrefs and memory
leaks. This happens for example if two inodes share an extent and
both lie in the same leaf and thus also have the same parent.
Signed-off-by: Alexander Block <ablock84@googlemail.com> Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
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