Commit Graph

487 Commits

Author SHA1 Message Date
Filipe Manana
a96295965b Btrfs: fix racy system chunk allocation when setting block group ro
If while setting a block group read-only we end up allocating a system
chunk, through check_system_chunk(), we were not doing it while holding
the chunk mutex which is a problem if a concurrent chunk allocation is
happening, through do_chunk_alloc(), as it means both block groups can
end up using the same logical addresses and physical regions in the
device(s). So make sure we hold the chunk mutex.

Cc: stable@vger.kernel.org  # 4.0+
Fixes: 2f0810880f ("btrfs: delete chunk allocation attemp when
                      setting block group ro")

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-05-19 18:04:17 -07:00
Forrest Liu
1b98450816 Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
If device tree has hole, find_free_dev_extent() cannot find available
address properly.

The problem can be reproduce by following script.

    mntpath=/btrfs
    loopdev=/dev/loop0
    filepath=/home/forrest/image

    umount $mntpath
    losetup -d $loopdev
    truncate --size 100g $filepath
    losetup $loopdev $filepath
    mkfs.btrfs -f $loopdev
    mount $loopdev $mntpath

    # make device tree with one big hole
    for i in `seq 1 1 100`; do
        fallocate -l 1g $mntpath/$i
    done
    sync
    for i in `seq 1 1 95`; do
        rm $mntpath/$i
    done
    sync

    # wait cleaner thread remove unused block group
    sleep 300

    fallocate -l 1g $mntpath/aaa

    # failed to allocate new chunk
    fallocate -l 1g $mntpath/bbb

Above script will make device tree with one big hole, and can only allocate
just one chunk in a transaction, so failed to allocate new chunk for $mntpath/bbb

    item 8 key (1 DEV_EXTENT 2185232384) itemoff 15859 itemsize 48
        dev extent chunk_tree 3
        chunk objectid 256 chunk offset 106292051968 length 1073741824
    item 9 key (1 DEV_EXTENT 104190705664) itemoff 15811 itemsize 48
        dev extent chunk_tree 3
        chunk objectid 256 chunk offset 103108575232 length 1073741824

Signed-off-by: Forrest Liu <forrestl@synology.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26 06:26:59 -07:00
Zhao Lei
f2ab76188e btrfs: Fix tail space processing in find_free_dev_extent()
It is another reason for NO_SPACE case.

When we found enough free space in loop and saved them to
max_hole_start/size before, and tail space contains pending extent,
origional innocent max_hole_start/size are reset in retry.

As a result, find_free_dev_extent() returns less space than it can,
and cause NO_SPACE in user program.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-04-13 07:27:18 -07:00
Chris Mason
fc4c3c872f Merge branch 'cleanups-post-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1
Signed-off-by: Chris Mason <clm@fb.com>

Conflicts:
	fs/btrfs/disk-io.c
2015-03-25 10:52:48 -07:00
David Sterba
258ece0212 btrfs: remove shadowing variables in __btrfs_map_block
1) We can safely use the function's 'i'. Fixes warning

fs/btrfs/volumes.c:5257:7: warning: declaration of 'i' shadows a previous local
fs/btrfs/volumes.c:4951:6: warning: shadowed declaration is here

2) A local variable duplicates name of an argument, we can use the value
directly. Fixes warning

fs/btrfs/volumes.c:5433:8: warning: declaration of 'length' shadows a parameter
fs/btrfs/volumes.c:4935:27: warning: shadowed declaration is here

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:35 +01:00
David Sterba
9d644a623e btrfs: cleanup, use correct type in div_u64_rem
div_u64_rem expects u32 for divisior and reminder.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:01 +01:00
David Sterba
47c5713f47 btrfs: replace remaining do_div calls with div_u64 variants
Switch to div_u64_rem that does type checking and has more obvious
semantics than do_div.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:01 +01:00
David Sterba
b8b93addde btrfs: cleanup 64bit/32bit divs, provably bounded values
The divisor is derived from nodesize or PAGE_SIZE, fits into 32bit type.
Get rid of a few more do_div instances.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:24:00 +01:00
David Sterba
31e818fe73 btrfs: cleanup, use kmalloc_array/kcalloc array helpers
Convert kmalloc(nr * size, ..) to kmalloc_array that does additional
overflow checks, the zeroing variant is kcalloc.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:58 +01:00
David Sterba
853d8ec4b2 btrfs: need_resched not needed with cond_resched
Cleanup, no special reason to do

if (need_resched())
        cond_resched();

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:55 +01:00
Chris Mason
e57cf21e97 Btrfs: fix allocation size calculations in alloc_btrfs_bio
Since commit 8e5cfb55d3 (Btrfs: Make raid_map array be inlined in
btrfs_bio structure), the raid map array is allocated along with the
btrfs bio in alloc_btrfs_bio.  The calculation used to decide how much
we need to allocate was using the wrong parameter passed into the
allocation function.

The passed in real_stripes will be zero if a target replace operation
is not currently running.  We want to use total_stripes instead.

Signed-off-by: Chris Mason <clm@fb.com>
Reported-by: David Sterba <dsterba@suse.cz>
Tested-by: David Sterba <dsterba@suse.cz>
2015-02-20 06:55:15 -08:00
Eric Sandeen
9eaed21ef9 btrfs: remove unused fs_info arg from btrfs_close_extra_devices()
The commit:
8dabb74 Btrfs: change core code of btrfs to support the
        device replace operations
added the fs_info argument, but never used it -
just remove it again.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:45 +01:00
Zhao Lei
08da757d3f btrfs: cleanup: use for() loop in btrfs_map_bio()
for() is obviously better in these code block, and remove noused
init-value to reduce about 6 bytes binary size.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
Zhao Lei
a688a04aab btrfs: remove unused chunk_tree argument in several functions
There functions include unused chunk_tree argument from the begining,
it is time to remove them and clean up relative code to prepare value
of this argument in caller.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
David Sterba
e8c9f18603 btrfs: constify structs with op functions or static definitions
There are some op tables that can be easily made const, similarly the
sysfs feature and raid tables. This is motivated by PaX CONSTIFY plugin.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16 18:48:44 +01:00
Zhao Lei
13212b54d1 btrfs: Fix out-of-space bug
Btrfs will report NO_SPACE when we create and remove files for several times,
and we can't write to filesystem until mount it again.

Steps to reproduce:
 1: Create a single-dev btrfs fs with default option
 2: Write a file into it to take up most fs space
 3: Delete above file
 4: Wait about 100s to let chunk removed
 5: goto 2

Script is like following:
 #!/bin/bash

 # Recommend 1.2G space, too large disk will make test slow
 DEV="/dev/sda16"
 MNT="/mnt/tmp"

 dev_size="$(lsblk -bn -o SIZE "$DEV")" || exit 2
 file_size_m=$((dev_size * 75 / 100 / 1024 / 1024))

 echo "Loop write ${file_size_m}M file on $((dev_size / 1024 / 1024))M dev"

 for ((i = 0; i < 10; i++)); do umount "$MNT" 2>/dev/null; done
 echo "mkfs $DEV"
 mkfs.btrfs -f "$DEV" >/dev/null || exit 2
 echo "mount $DEV $MNT"
 mount "$DEV" "$MNT" || exit 2

 for ((loop_i = 0; loop_i < 20; loop_i++)); do
     echo
     echo "loop $loop_i"

     echo "dd file..."
     cmd=(dd if=/dev/zero of="$MNT"/file0 bs=1M count="$file_size_m")
     "${cmd[@]}" 2>/dev/null || {
         # NO_SPACE error triggered
         echo "dd failed: ${cmd[*]}"
         exit 1
     }

     echo "rm file..."
     rm -f "$MNT"/file0 || exit 2

     for ((i = 0; i < 10; i++)); do
         df "$MNT" | tail -1
         sleep 10
     done
 done

Reason:
 It is triggered by commit: 47ab2a6c68
 which is used to remove empty block groups automatically, but the
 reason is not in that patch. Code before works well because btrfs
 don't need to create and delete chunks so many times with high
 complexity.
 Above bug is caused by many reason, any of them can trigger it.

Reason1:
 When we remove some continuous chunks but leave other chunks after,
 these disk space should be used by chunk-recreating, but in current
 code, only first create will successed.
 Fixed by Forrest Liu <forrestl@synology.com> in:
 Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole

Reason2:
 contains_pending_extent() return wrong value in calculation.
 Fixed by Forrest Liu <forrestl@synology.com> in:
 Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole

Reason3:
 btrfs_check_data_free_space() try to commit transaction and retry
 allocating chunk when the first allocating failed, but space_info->full
 is set in first allocating, and prevent second allocating in retry.
 Fixed in this patch by clear space_info->full in commit transaction.

 Tested for severial times by above script.

Changelog v3->v4:
 use light weight int instead of atomic_t to record have_remove_bgs in
 transaction, suggested by:
 Josef Bacik <jbacik@fb.com>

Changelog v2->v3:
 v2 fixed the bug by adding more commit-transaction, but we
 only need to reclaim space when we are really have no space for
 new chunk, noticed by:
 Filipe David Manana <fdmanana@gmail.com>

 Actually, our code already have this type of commit-and-retry,
 we only need to make it working with removed-bgs.
 v3 fixed the bug with above way.

Changelog v1->v2:
 v1 will introduce a new bug when delete and create chunk in same disk
 space in same transaction, noticed by:
 Filipe David Manana <fdmanana@gmail.com>
 V2 fix this bug by commit transaction after remove block grops.

Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Suggested-by: Filipe David Manana <fdmanana@gmail.com>
Suggested-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:19:14 -08:00
David Sterba
e3540eab29 btrfs: add more checks to btrfs_read_sys_array
Verify that the sys_array has enough bytes to read the next item.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:39 -08:00
David Sterba
1ffb22cf8c btrfs: cleanup, rename a few variables in btrfs_read_sys_array
There's a pointer to buffer, integer offset and offset passed as
pointer, try to find matching names for them.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02 19:24:28 -08:00
Zhao Lei
ffe2d2034b Btrfs: Introduce BTRFS_BLOCK_GROUP_RAID56_MASK to check raid56 simply
So we can check raid56 with:
 (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
instead of long:
 (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:49 -08:00
Zhao Lei
10f1190016 Btrfs: Include map_type in raid_bio
Corrent code use many kinds of "clever" way to determine operation
target's raid type, as:
  raid_map != NULL
  or
  raid_map[MAX_NR] == RAID[56]_Q_STRIPE

To make code easy to maintenance, this patch put raid type into
bbio, and we can always get raid type from bbio with a "stupid"
way.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:49 -08:00
Zhao Lei
6e9606d2a2 Btrfs: add ref_count and free function for btrfs_bio
1: ref_count is simple than current RBIO_HOLD_BBIO_MAP_BIT flag
   to keep btrfs_bio's memory in raid56 recovery implement.
2: free function for bbio will make code clean and flexible, plus
   forced data type checking in compile.

Changelog v1->v2:
 Rename following by David Sterba's suggestion:
 put_btrfs_bio() -> btrfs_put_bio()
 get_btrfs_bio() -> btrfs_get_bio()
 bbio->ref_count -> bbio->refs

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:48 -08:00
Zhao Lei
8e5cfb55d3 Btrfs: Make raid_map array be inlined in btrfs_bio structure
It can make code more simple and clear, we need not care about
free bbio and raid_map together.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:47 -08:00
Zhao Lei
cc7539edea Btrfs: sort raid_map before adding tgtdev stripes
It can avoid complex calculation of real stripes in sort,
moreover, we can clean up code of sorting tgtdev_map because it
will be in order initially.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21 18:06:47 -08:00
Chris Mason
57bbddd7fb Merge branch 'cleanup/blocksize-diet-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus 2015-01-21 17:49:35 -08:00
Al Viro
98af592f5b btrfs: filp_open() returns ERR_PTR() on failure, not NULL...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-17 06:43:56 -05:00
David Sterba
a83fffb75d btrfs: sink blocksize parameter to btrfs_find_create_tree_block
Finally it's clear that the requested blocksize is always equal to
nodesize, with one exception, the superblock.

Superblock has fixed size regardless of the metadata block size, but
uses the same helpers to initialize sys array/chunk tree and to work
with the chunk items. So it pretends to be an extent_buffer for a
moment, btrfs_read_sys_array is full of special cases, we're adding one
more.

Signed-off-by: David Sterba <dsterba@suse.cz>
2014-12-12 18:07:21 +01:00
Chris Mason
9627aeee3e Merge branch 'raid56-scrub-replace' of git://github.com/miaoxie/linux-btrfs into for-linus 2014-12-02 18:42:03 -08:00
Filipe Manana
495e64f4fe Btrfs: fix fs mapping extent map leak
On chunk allocation error (label "error_del_extent"), after adding the
extent map to the tree and to the pending chunks list, we would leave
decrementing the extent map's refcount by 2 instead of 3 (our allocation
+ tree reference + list reference).

Also, on chunk/block group removal, if the block group was on the list
pending_chunks we weren't decrementing the respective list reference.

Detected by 'rmmod btrfs':

[20770.105881] kmem_cache_destroy btrfs_extent_map: Slab cache still has objects
[20770.106127] CPU: 2 PID: 11093 Comm: rmmod Tainted: G        W    L 3.17.0-rc5-btrfs-next-1+ #1
[20770.106128] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[20770.106130]  0000000000000000 ffff8800ba867eb8 ffffffff813e7a13 ffff8800a2e11040
[20770.106132]  ffff8800ba867ed0 ffffffff81105d0c 0000000000000000 ffff8800ba867ee0
[20770.106134]  ffffffffa035d65e ffff8800ba867ef0 ffffffffa03b0654 ffff8800ba867f78
[20770.106136] Call Trace:
[20770.106142]  [<ffffffff813e7a13>] dump_stack+0x45/0x56
[20770.106145]  [<ffffffff81105d0c>] kmem_cache_destroy+0x4b/0x90
[20770.106164]  [<ffffffffa035d65e>] extent_map_exit+0x1a/0x1c [btrfs]
[20770.106176]  [<ffffffffa03b0654>] exit_btrfs_fs+0x27/0x9d3 [btrfs]
[20770.106179]  [<ffffffff8109dc97>] SyS_delete_module+0x153/0x1c4
[20770.106182]  [<ffffffff8121261b>] ? trace_hardirqs_on_thunk+0x3a/0x3c
[20770.106184]  [<ffffffff813ebf52>] system_call_fastpath+0x16/0x1b

This applies on top (depends on) of my previous patch titled:
"Btrfs: fix race between fs trimming and block group remove/allocation"

But the issue in fact was already present before that change, it only
became easier to hit after Josef's 3.18 patch that added automatic
removal of empty block groups.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-12-02 18:35:10 -08:00
Filipe Manana
04216820fe Btrfs: fix race between fs trimming and block group remove/allocation
Our fs trim operation, which is completely transactionless (doesn't start
or joins an existing transaction) consists of visiting all block groups
and then for each one to iterate its free space entries and perform a
discard operation against the space range represented by the free space
entries. However before performing a discard, the corresponding free space
entry is removed from the free space rbtree, and when the discard completes
it is added back to the free space rbtree.

If a block group remove operation happens while the discard is ongoing (or
before it starts and after a free space entry is hidden), we end up not
waiting for the discard to complete, remove the extent map that maps
logical address to physical addresses and the corresponding chunk metadata
from the the chunk and device trees. After that and before the discard
completes, the current running transaction can finish and a new one start,
allowing for new block groups that map to the same physical addresses to
be allocated and written to.

So fix this by keeping the extent map in memory until the discard completes
so that the same physical addresses aren't reused before it completes.

If the physical locations that are under a discard operation end up being
used for a new metadata block group for example, and dirty metadata extents
are written before the discard finishes (the VM might call writepages() of
our btree inode's i_mapping for example, or an fsync log commit happens) we
end up overwriting metadata with zeroes, which leads to errors from fsck
like the following:

        checking extents
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        read block failed check_tree_block
        owner ref check failed [833912832 16384]
        Errors found in extent allocation tree or chunk allocation
        checking free space cache
        checking fs roots
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        Check tree block failed, want=833912832, have=0
        read block failed check_tree_block
        root 5 root dir 256 error
        root 5 inode 260 errors 2001, no inode item, link count wrong
                unresolved ref dir 256 index 0 namelen 8 name foobar_3 filetype 1 errors 6, no dir index, no inode ref
        root 5 inode 262 errors 2001, no inode item, link count wrong
                unresolved ref dir 256 index 0 namelen 8 name foobar_5 filetype 1 errors 6, no dir index, no inode ref
        root 5 inode 263 errors 2001, no inode item, link count wrong
        (...)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-12-02 18:35:09 -08:00
Miao Xie
4245215d6a Btrfs, raid56: fix use-after-free problem in the final device replace procedure on raid56
The commit c404e0dc (Btrfs: fix use-after-free in the finishing
procedure of the device replace) fixed a use-after-free problem
which happened when removing the source device at the end of device
replace, but at that time, btrfs didn't support device replace
on raid56, so we didn't fix the problem on the raid56 profile.
Currently, we implemented device replace for raid56, so we need
kick that problem out before we enable that function for raid56.

The fix method is very simple, we just increase the bio per-cpu
counter before we submit a raid56 io, and decrease the counter
when the raid56 io ends.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2014-12-03 10:18:47 +08:00
Miao Xie
2c8cdd6ee4 Btrfs, replace: write dirty pages into the replace target device
The implementation is simple:
- In order to avoid changing the code logic of btrfs_map_bio and
  RAID56, we add the stripes of the replace target devices at the
  end of the stripe array in btrfs bio, and we sort those target
  device stripes in the array. And we keep the number of the target
  device stripes in the btrfs bio.
- Except write operation on RAID56, all the other operation don't
  take the target device stripes into account.
- When we do write operation, we read the data from the common devices
  and calculate the parity. Then write the dirty data and new parity
  out, at this time, we will find the relative replace target stripes
  and wirte the relative data into it.

Note: The function that copying old data on the source device to
the target device was implemented in the past, it is similar to
the other RAID type.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2014-12-03 10:18:46 +08:00
Miao Xie
af8e2d1df9 Btrfs, scrub: repair the common data on RAID5/6 if it is corrupted
This patch implement the RAID5/6 common data repair function, the
implementation is similar to the scrub on the other RAID such as
RAID1, the differentia is that we don't read the data from the
mirror, we use the data repair function of RAID5/6.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2014-12-03 10:18:45 +08:00
Zhao Lei
6de6565075 Btrfs: remove unnecessary code of stripe_index assignment in __btrfs_map_block
stripe_index's value was set again in latter line:
stripe_index = 0;

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
2014-12-03 10:18:44 +08:00
Zhao Lei
f90523d1aa Btrfs: remove noused bbio_ret in __btrfs_map_block in condition
bbio_ret in this condition is always !NULL because previous code
already have a check-and-skip:
4908 if (!bbio_ret)
4909     goto out;

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
2014-12-03 10:18:44 +08:00
Qu Wenruo
084b6e7c76 btrfs: Fix a lockdep warning when running xfstest.
The following lockdep warning is triggered during xfstests:

[ 1702.980872] =========================================================
[ 1702.981181] [ INFO: possible irq lock inversion dependency detected ]
[ 1702.981482] 3.18.0-rc1 #27 Not tainted
[ 1702.981781] ---------------------------------------------------------
[ 1702.982095] kswapd0/77 just changed the state of lock:
[ 1702.982415]  (&delayed_node->mutex){+.+.-.}, at: [<ffffffffa03b0b51>] __btrfs_release_delayed_node+0x41/0x1f0 [btrfs]
[ 1702.982794] but this lock took another, RECLAIM_FS-unsafe lock in the past:
[ 1702.983160]  (&fs_info->dev_replace.lock){+.+.+.}

and interrupts could create inverse lock ordering between them.

[ 1702.984675]
other info that might help us debug this:
[ 1702.985524] Chain exists of:
  &delayed_node->mutex --> &found->groups_sem --> &fs_info->dev_replace.lock

[ 1702.986799]  Possible interrupt unsafe locking scenario:

[ 1702.987681]        CPU0                    CPU1
[ 1702.988137]        ----                    ----
[ 1702.988598]   lock(&fs_info->dev_replace.lock);
[ 1702.989069]                                local_irq_disable();
[ 1702.989534]                                lock(&delayed_node->mutex);
[ 1702.990038]                                lock(&found->groups_sem);
[ 1702.990494]   <Interrupt>
[ 1702.990938]     lock(&delayed_node->mutex);
[ 1702.991407]
 *** DEADLOCK ***

It is because the btrfs_kobj_{add/rm}_device() will call memory
allocation with GFP_KERNEL,
which may flush fs page cache to free space, waiting for it self to do
the commit, causing the deadlock.

To solve the problem, move btrfs_kobj_{add/rm}_device() out of the
dev_replace lock range, also involing split the
btrfs_rm_dev_replace_srcdev() function into remove and free parts.

Now only btrfs_rm_dev_replace_remove_srcdev() is called in dev_replace
lock range, and kobj_{add/rm} and btrfs_rm_dev_replace_free_srcdev() are
called out of the lock range.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-11-25 05:55:38 -08:00
Linus Torvalds
90d0c376f5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "The largest set of changes here come from Miao Xie.  He's cleaning up
  and improving read recovery/repair for raid, and has a number of
  related fixes.

  I've merged another set of fsync fixes from Filipe, and he's also
  improved the way we handle metadata write errors to make sure we force
  the FS readonly if things go wrong.

  Otherwise we have a collection of fixes and cleanups.  Dave Sterba
  gets a cookie for removing the most lines (thanks Dave)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (139 commits)
  btrfs: Fix compile error when CONFIG_SECURITY is not set.
  Btrfs: fix compiles when CONFIG_BTRFS_FS_RUN_SANITY_TESTS is off
  btrfs: Make btrfs handle security mount options internally to avoid losing security label.
  Btrfs: send, don't delay dir move if there's a new parent inode
  btrfs: add more superblock checks
  Btrfs: fix race in WAIT_SYNC ioctl
  Btrfs: be aware of btree inode write errors to avoid fs corruption
  Btrfs: remove redundant btrfs_verify_qgroup_counts declaration.
  btrfs: fix shadow warning on cmp
  Btrfs: fix compilation errors under DEBUG
  Btrfs: fix crash of btrfs_release_extent_buffer_page
  Btrfs: add missing end_page_writeback on submit_extent_page failure
  btrfs: Fix the wrong condition judgment about subset extent map
  Btrfs: fix build_backref_tree issue with multiple shared blocks
  Btrfs: cleanup error handling in build_backref_tree
  btrfs: move checks for DUMMY_ROOT into a helper
  btrfs: new define for the inline extent data start
  btrfs: kill extent_buffer_page helper
  btrfs: drop constant param from btrfs_release_extent_buffer_page
  btrfs: hide typecast to definition of BTRFS_SEND_TRANS_STUB
  ...
2014-10-11 08:03:52 -04:00
Fabian Frederick
1b6e44690d Btrfs: fix compilation errors under DEBUG
bi_sector and bi_size moved to bi_iter since commit 4f024f3797
("block: Abstract out bvec iterator")

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Chris Mason <clm@fb.com>
2014-10-03 16:14:58 -07:00
Josef Bacik
47ab2a6c68 Btrfs: remove empty block groups automatically
One problem that has plagued us is that a user will use up all of his space with
data, remove a bunch of that data, and then try to create a bunch of small files
and run out of space.  This happens because all the chunks were allocated for
data since the metadata requirements were so low.  But now there's a bunch of
empty data block groups and not enough metadata space to do anything.  This
patch solves this problem by automatically deleting empty block groups.  If we
notice the used count go down to 0 when deleting or on mount notice that a block
group has a used count of 0 then we will queue it to be deleted.

When the cleaner thread runs we will double check to make sure the block group
is still empty and then we will delete it.  This patch has the side effect of no
longer having a bunch of BUG_ON()'s in the chunk delete code, which will be
helpful for both this and relocate.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-22 17:13:21 -07:00
Chris Mason
0f23ae74f5 Revert "Btrfs: device_list_add() should not update list when mounted"
This reverts commit b96de000bc.

This commit is triggering failures to mount by subvolume id in some
configurations.  The main problem is how many different ways this
scanning function is used, both for scanning while mounted and
unmounted.  A proper cleanup is too big for late rcs.

For now, just revert the commit and we'll put a better fix into a later
merge window.

Signed-off-by: Chris Mason <clm@fb.com>
2014-09-18 07:49:05 -07:00
Miao Xie
28e1cc7d1b Btrfs: Set real mirror number for read operation on RAID0/5/6
We need real mirror number for RAID0/5/6 when reading data, or if read error
happens, we would pass 0 as the number of the mirror on which the io error
happens. It is wrong and would cause the filesystem read the data from the
corrupted mirror again.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:39:00 -07:00
Miao Xie
c3929c3624 Btrfs: modify rw_devices counter under chunk_mutex context
rw_devices counter is often used to tune the profile when doing chunk allocation,
so we should modify it under the chunk_mutex context to avoid getting wrong
chunk profile.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:49 -07:00
Miao Xie
5f37583569 Btrfs: move the missing device to its own fs device list
For a missing device, we don't know it belong to which fs before we read its
fsid from the chunk tree. So we add them into the current fs device list at first.
When we get its fsid, we should move them to their own fs device list.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:48 -07:00
Miao Xie
416d7b802a Btrfs: stop mounting the fs if the non-ENOENT errors happen when opening seed fs
When we open a seed filesystem, if the degraded mount option is set, we continue to
mount the fs if we don't find some devices in the seed filesystem. But we should stop
mounting if other errors happen. Fix it

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:47 -07:00
Miao Xie
82372bc816 Btrfs: make the logic of source device removing more clear
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:46 -07:00
Miao Xie
67a2c45ee7 Btrfs: fix use-after-free problem of the device during device replace
The problem is:
	Task0(device scan task)		Task1(device replace task)
	scan_one_device()
	mutex_lock(&uuid_mutex)
	device = find_device()
					mutex_lock(&device_list_mutex)
					lock_chunk()
					rm_and_free_source_device
					unlock_chunk()
					mutex_unlock(&device_list_mutex)
	check device

Destroying the target device if device replace fails also has the same problem.

We fix this problem by locking uuid_mutex during destroying source device or
target device, just like the device remove operation.

It is a temporary solution, we can fix this problem and make the code more
clear by atomic counter in the future.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:44 -07:00
Miao Xie
adbbb8631b Btrfs: fix unprotected device list access when cloning fs devices
We can build a new filesystem based a seed filesystem, and we need clone
the fs devices when we open the new filesystem. But someone might clear
the seed flag of the seed filesystem, then mount that filesystem and
remove some device. If we mount the new filesystem, we might access
a device list which was being changed when we clone the fs devices.
Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:43 -07:00
Miao Xie
2196d6e8a7 Btrfs: Fix misuse of chunk mutex
There were several problems about chunk mutex usage:
- Lock chunk mutex when updating metadata. It would cause the nested
  deadlock because updating metadata might need allocate new chunks
  that need acquire chunk mutex. We remove chunk mutex at this case,
  because b-tree lock and other lock mechanism can help us.
- ABBA deadlock occured between device_list_mutex and chunk_mutex.
  When we update device status, we must acquire device_list_mutex at the
  beginning, and then we might get chunk_mutex during the device status
  update because we need allocate new chunks for metadata COW. But at
  most place, we acquire chunk_mutex at first and then acquire device list
  mutex. We need change the lock order.
- Some place we needn't acquire chunk_mutex. For example we needn't get
  chunk_mutex when we free a empty seed fs_devices structure.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:42 -07:00
Miao Xie
fe48a5c00f Btrfs: fix unprotected system chunk array insertion
We didn't protect the system chunk array when we added a new
system chunk into it, it would cause the array be corrupted
if someone remove/add some system chunk into array at the same
time. Fix it by chunk lock.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:40 -07:00
Miao Xie
7cc8e58d53 Btrfs: fix unprotected device's variants on 32bits machine
->total_bytes,->disk_total_bytes,->bytes_used is protected by chunk
lock when we change them, but sometimes we read them without any lock,
and we might get unexpected value. We fix this problem like inode's
i_size.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:38 -07:00
Miao Xie
1c1161870c Btrfs: update free_chunk_space during allocting a new chunk
We should update free_chunk_space in time when we allocate a new chunk,
not when we deal with the pending device update and block group insertion,
because we need the real free_chunk_space data to calculate the reserved
space, if we don't update it in time, we would consider the disk space which
has be allocated as free space, and would use it to do overcommit reservation.
Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:37 -07:00