Before applying this patch, the task had to reclaim the metadata space
by itself if the metadata space was not enough. And When the task started
the space reclamation, all the other tasks which wanted to reserve the
metadata space were blocked. At some cases, they would be blocked for
a long time, it made the performance fluctuate wildly.

So we introduce the background metadata space reclamation, when the space
is about to be exhausted, we insert a reclaim work into the workqueue, the
worker of the workqueue helps us to reclaim the reserved space at the
background. By this way, the tasks needn't reclaim the space by themselves at
most cases, and even if the tasks have to reclaim the space or are blocked
for the space reclamation, they will get enough space more quickly.

Here is my test result(Tested by compilebench):
 Memory:	2GB
 CPU:		2Cores * 1CPU
 Partition:	40GB(SSD)

Test command:
 # compilebench -D <mnt> -m

Without this patch:
 intial create total runs 30 avg 54.36 MB/s (user 0.52s sys 2.44s)
 compile total runs 30 avg 123.72 MB/s (user 0.13s sys 1.17s)
 read compiled tree total runs 3 avg 81.15 MB/s (user 0.74s sys 4.89s)
 delete compiled tree total runs 30 avg 5.32 seconds (user 0.35s sys 4.37s)

With this patch:
 intial create total runs 30 avg 59.80 MB/s (user 0.52s sys 2.53s)
 compile total runs 30 avg 151.44 MB/s (user 0.13s sys 1.11s)
 read compiled tree total runs 3 avg 83.25 MB/s (user 0.76s sys 4.91s)
 delete compiled tree total runs 30 avg 5.29 seconds (user 0.34s sys 4.34s)
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

If we fail to load a free space cache, we can rebuild it from the extent tree,
so it is not a serious error, we should not output a error message that
would make the users uncomfortable. This patch uses warning message instead
of it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

Btrfs will send uevent to udev inform the device change,
but ctime/mtime for the block device inode is not udpated, which cause
libblkid used by btrfs-progs unable to detect device change and use old
cache, causing 'btrfs dev scan; btrfs dev rmove; btrfs dev scan' give an
error message.
Reported-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
Cc: Karel Zak <kzak@redhat.com>
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

CC: Miao Xie <miaox@cn.fujitsu.com>
CC: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

The patch "Btrfs: fix protection between send and root deletion"
(18f687d5) does not actually prevent to delete the snapshot
and just takes care during background cleaning, but this seems rather
user unfriendly, this patch implements the idea presented in

http://www.spinics.net/lists/linux-btrfs/msg30813.html

- add an internal root_item flag to denote a dead root
- check if the send_in_progress is set and refuse to delete, otherwise
  set the flag and proceed
- check the flag in send similar to the btrfs_root_readonly checks, for
  all involved roots

The root lookup in send via btrfs_read_fs_root_no_name will check if the
root is really dead or not. If it is, ENOENT, aborted send. If it's
alive, it's protected by send_in_progress, send can continue.

CC: Miao Xie <miaox@cn.fujitsu.com>
CC: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

It doesn't need to check NULL for kfree()
Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

This implements the tmpfile callback of struct inode_operations, introduced
in the linux kernel 3.11, and implemented already by some filesystems. This
callback is invoked by the VFS when the flag O_TMPFILE is passed to the open
system call.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>

This ioctl provides basic info about the filesystem that can be obtained
in other ways (eg. sysfs), there's no reason to restrict it to
CAP_SYSADMIN.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

This ioctl provides basic info about the devices that can be obtained in
other ways (eg. sysfs), there's no reason to restrict it to
CAP_SYSADMIN.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

Similar to the FS_INFO updates, export the basic filesystem info through
sysfs: node size, sector size and clone alignment.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

Provide the basic information about filesystem through the ioctl:
* b-tree node size (same as leaf size)
* sector size
* expected alignment of CLONE_RANGE and EXTENT_SAME ioctl arguments

Backward compatibility: if the values are 0, kernel does not provide
this information, the applications should ignore them.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

This started as debugging helper, to watch the effects of converting
between raid levels on multiple devices, but could be useful standalone.

In my case the usage filter was not finegrained enough and led to
converting too many chunks at once. Another example use is in connection
with drange+devid or vrange filters that allow to work with a specific
chunk or even with a chunk on a given device.

The limit filter applies last, the value of 0 means no limiting.

CC: Ilya Dryomov <idryomov@gmail.com>
CC: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

While running a stress test with multiple threads writing to the same btrfs
file system, I ended up with a situation where a leaf was corrupted in that
it had 2 file extent item keys that had the same exact key. I was able to
detect this quickly thanks to the following patch which triggers an assertion
as soon as a leaf is marked dirty if there are duplicated keys or out of order
keys:

    Btrfs: check if items are ordered when a leaf is marked dirty
    (https://patchwork.kernel.org/patch/3955431/)

Basically while running the test, I got the following in dmesg:

    [28877.415877] WARNING: CPU: 2 PID: 10706 at fs/btrfs/file.c:553 btrfs_drop_extent_cache+0x435/0x440 [btrfs]()
    (...)
    [28877.415917] Call Trace:
    [28877.415922]  [<ffffffff816f1189>] dump_stack+0x4e/0x68
    [28877.415926]  [<ffffffff8104a32c>] warn_slowpath_common+0x8c/0xc0
    [28877.415929]  [<ffffffff8104a37a>] warn_slowpath_null+0x1a/0x20
    [28877.415944]  [<ffffffffa03775a5>] btrfs_drop_extent_cache+0x435/0x440 [btrfs]
    [28877.415949]  [<ffffffff8118e7be>] ? kmem_cache_alloc+0xfe/0x1c0
    [28877.415962]  [<ffffffffa03777d9>] fill_holes+0x229/0x3e0 [btrfs]
    [28877.415972]  [<ffffffffa0345865>] ? block_rsv_add_bytes+0x55/0x80 [btrfs]
    [28877.415984]  [<ffffffffa03792cb>] btrfs_fallocate+0xb6b/0xc20 [btrfs]
    (...)
    [29854.132560] BTRFS critical (device sdc): corrupt leaf, bad key order: block=955232256,root=1, slot=24
    [29854.132565] BTRFS info (device sdc): leaf 955232256 total ptrs 40 free space 778
    (...)
    [29854.132637] 	item 23 key (3486 108 667648) itemoff 2694 itemsize 53
    [29854.132638] 		extent data disk bytenr 14574411776 nr 286720
    [29854.132639] 		extent data offset 0 nr 286720 ram 286720
    [29854.132640] 	item 24 key (3486 108 954368) itemoff 2641 itemsize 53
    [29854.132641] 		extent data disk bytenr 0 nr 0
    [29854.132643] 		extent data offset 0 nr 0 ram 0
    [29854.132644] 	item 25 key (3486 108 954368) itemoff 2588 itemsize 53
    [29854.132645] 		extent data disk bytenr 8699670528 nr 77824
    [29854.132646] 		extent data offset 0 nr 77824 ram 77824
    [29854.132647] 	item 26 key (3486 108 1146880) itemoff 2535 itemsize 53
    [29854.132648] 		extent data disk bytenr 8699670528 nr 77824
    [29854.132649] 		extent data offset 0 nr 77824 ram 77824
    (...)
    [29854.132707] kernel BUG at fs/btrfs/ctree.h:3901!
    (...)
    [29854.132771] Call Trace:
    [29854.132779]  [<ffffffffa0342b5c>] setup_items_for_insert+0x2dc/0x400 [btrfs]
    [29854.132791]  [<ffffffffa0378537>] __btrfs_drop_extents+0xba7/0xdd0 [btrfs]
    [29854.132794]  [<ffffffff8109c0d6>] ? trace_hardirqs_on_caller+0x16/0x1d0
    [29854.132797]  [<ffffffff8109c29d>] ? trace_hardirqs_on+0xd/0x10
    [29854.132800]  [<ffffffff8118e7be>] ? kmem_cache_alloc+0xfe/0x1c0
    [29854.132810]  [<ffffffffa036783b>] insert_reserved_file_extent.constprop.66+0xab/0x310 [btrfs]
    [29854.132820]  [<ffffffffa036a6c6>] __btrfs_prealloc_file_range+0x116/0x340 [btrfs]
    [29854.132830]  [<ffffffffa0374d53>] btrfs_prealloc_file_range+0x23/0x30 [btrfs]
    (...)

So this is caused by getting an -ENOSPC error while punching a file hole, more
specifically, we get -ENOSPC error from __btrfs_drop_extents in the while loop
of file.c:btrfs_punch_hole() when it's unable to modify the btree to delete one
or more file extent items due to lack of enough free space. When this happens,
in btrfs_punch_hole(), we attempt to reclaim free space by switching our transaction
block reservation object to root->fs_info->trans_block_rsv, end our transaction and
start a new transaction basically - and, we keep increasing our current offset
(cur_offset) as long as it's smaller than the end of the target range (lockend) -
this makes use leave the loop with cur_offset == drop_end which in turn makes us
call fill_holes() for inserting a file extent item that represents a 0 bytes range
hole (and this insertion succeeds, as in the meanwhile more space became available).

This 0 bytes file hole extent item is a problem because any subsequent caller of
__btrfs_drop_extents (regular file writes, or fallocate calls for e.g.), with a
start file offset that is equal to the offset of the hole, will not remove this
extent item due to the following conditional in the while loop of
__btrfs_drop_extents:

    if (extent_end <= search_start) {
            path->slots[0]++;
            goto next_slot;
    }

This later makes the call to setup_items_for_insert() (at the very end of
__btrfs_drop_extents), insert a new file extent item with the same offset as
the 0 bytes file hole extent item that follows it. Needless is to say that this
causes chaos, either when reading the leaf from disk (btree_readpage_end_io_hook),
where we perform leaf sanity checks or in subsequent operations that manipulate
file extent items, as in the fallocate call as shown by the dmesg trace above.

Without my other patch to perform the leaf sanity checks once a leaf is marked
as dirty (if the integrity checker is enabled), it would have been much harder
to debug this issue.

This change might fix a few similar issues reported by users in the mailing
list regarding assertion failures in btrfs_set_item_key_safe calls performed
by __btrfs_drop_extents, such as the following report:

    http://comments.gmane.org/gmane.comp.file-systems.btrfs/32938

Asking fill_holes() to create a 0 bytes wide file hole item also produced the
first warning in the trace above, as we passed a range to btrfs_drop_extent_cache
that has an end smaller (by -1) than its start.

On 3.14 kernels this issue manifests itself through leaf corruption, as we get
duplicated file extent item keys in a leaf when calling setup_items_for_insert(),
but on older kernels, setup_items_for_insert() isn't called by __btrfs_drop_extents(),
instead we have callers of __btrfs_drop_extents(), namely the functions
inode.c:insert_inline_extent() and inode.c:insert_reserved_file_extent(), calling
btrfs_insert_empty_item() to insert the new file extent item, which would fail with
error -EEXIST, instead of inserting a duplicated key - which is still a serious
issue as it would make all similar file extent item replace operations keep
failing if they target the same file range.

Cc: stable@vger.kernel.org
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

'bio_index' is just a index, it's really not necessary to do increment
one by one.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

In a previous change, commit 12870f1c,
I accidentally moved the roundup of inode->i_size to outside of the
critical section delimited by the inode mutex, which is not atomic and
not correct since the size can be changed by other task before we acquire
the mutex. Therefore fix it.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

iput() already checks for the inode being NULL, thus it's unnecessary to
check before calling.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NChris Mason <clm@fb.com>

uncompress_inline() is dropping the error from btrfs_decompress() after
testing it and zeroing the page that was supposed to hold decompressed
data.  This can silently turn compressed inline data in to zeros if
decompression fails due to corrupt compressed data or memory allocation
failure.

I verified this by manually forcing the error from btrfs_decompress()
for a silly named copy of od:

	if (!strcmp(current->comm, "failod"))
		ret = -ENOMEM;

  # od -x /mnt/btrfs/dir/80 | head -1
  0000000 3031 3038 310a 2d30 6f70 6e69 0a74 3031
  # echo 3 > /proc/sys/vm/drop_caches
  # cp $(which od) /tmp/failod
  # /tmp/failod -x /mnt/btrfs/dir/80 | head -1
  0000000 0000 0000 0000 0000 0000 0000 0000 0000

The fix is to pass the error to its caller.  Which still has a BUG_ON().
So we fix that too.

There seems to be no reason for the zeroing of the page on the error
from btrfs_decompress() but not from the allocation error a few lines
above.  So the page zeroing is removed.
Signed-off-by: NZach Brown <zab@redhat.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

The btrfs compression wrappers translated errors from workspace
allocation to either -ENOMEM or -1.  The compression type workspace
allocators are already returning a ERR_PTR(-ENOMEM).  Just return that
and get rid of the magical -1.

This helps a future patch return errors from the compression wrappers.
Signed-off-by: NZach Brown <zab@redhat.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

The compression layer seems to have been built to return -1 and have
callers make up errors that make sense.  This isn't great because there
are different errors that originate down in the compression layer.

Let's return real negative errnos from the compression layer so that
callers can pass on the error without having to guess what happened.
ENOMEM for allocation failure, E2BIG when compression exceeds the
uncompressed input, and EIO for everything else.

This helps a future path return errors from btrfs_decompress().
Signed-off-by: NZach Brown <zab@redhat.com>
Signed-off-by: NChris Mason <clm@fb.com>

This issue was not causing any harm but IMO (and in the opinion of the
static code checker) it is better to propagate this error status upwards.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NChris Mason <clm@fb.com>

When running low on available disk space and having several processes
doing buffered file IO, I got the following trace in dmesg:

[ 4202.720152] INFO: task kworker/u8:1:5450 blocked for more than 120 seconds.
[ 4202.720401]       Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.720596] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.720874] kworker/u8:1    D 0000000000000001     0  5450      2 0x00000000
[ 4202.720904] Workqueue: btrfs-flush_delalloc normal_work_helper [btrfs]
[ 4202.720908]  ffff8801f62ddc38 0000000000000082 ffff880203ac2490 00000000001d3f40
[ 4202.720913]  ffff8801f62ddfd8 00000000001d3f40 ffff8800c4f0c920 ffff880203ac2490
[ 4202.720918]  00000000001d4a40 ffff88020fe85a40 ffff88020fe85ab8 0000000000000001
[ 4202.720922] Call Trace:
[ 4202.720931]  [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.720950]  [<ffffffffa01ec48d>] btrfs_start_ordered_extent+0x6d/0x110 [btrfs]
[ 4202.720956]  [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.720972]  [<ffffffffa01ec559>] btrfs_run_ordered_extent_work+0x29/0x40 [btrfs]
[ 4202.720988]  [<ffffffffa0201987>] normal_work_helper+0x137/0x2c0 [btrfs]
[ 4202.720994]  [<ffffffff810680e5>] process_one_work+0x1f5/0x530
(...)
[ 4202.721027] 2 locks held by kworker/u8:1/5450:
[ 4202.721028]  #0:  (%s-%s){++++..}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721037]  #1:  ((&work->normal_work)){+.+...}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721054] INFO: task btrfs:7891 blocked for more than 120 seconds.
[ 4202.721258]       Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.721444] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.721699] btrfs           D 0000000000000001     0  7891   7890 0x00000001
[ 4202.721704]  ffff88018c2119e8 0000000000000086 ffff8800a33d2490 00000000001d3f40
[ 4202.721710]  ffff88018c211fd8 00000000001d3f40 ffff8802144b0000 ffff8800a33d2490
[ 4202.721714]  ffff8800d8576640 ffff88020fe85bc0 ffff88020fe85bc8 7fffffffffffffff
[ 4202.721718] Call Trace:
[ 4202.721723]  [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.721727]  [<ffffffff816a2ebc>] schedule_timeout+0x1dc/0x270
[ 4202.721732]  [<ffffffff8109bd79>] ? mark_held_locks+0xb9/0x140
[ 4202.721736]  [<ffffffff816a90c0>] ? _raw_spin_unlock_irq+0x30/0x40
[ 4202.721740]  [<ffffffff8109bf0d>] ? trace_hardirqs_on_caller+0x10d/0x1d0
[ 4202.721744]  [<ffffffff816a488f>] wait_for_completion+0xdf/0x120
[ 4202.721749]  [<ffffffff8107fa90>] ? try_to_wake_up+0x310/0x310
[ 4202.721765]  [<ffffffffa01ebee4>] btrfs_wait_ordered_extents+0x1f4/0x280 [btrfs]
[ 4202.721781]  [<ffffffffa020526e>] btrfs_mksubvol.isra.62+0x30e/0x5a0 [btrfs]
[ 4202.721786]  [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.721799]  [<ffffffffa02056a9>] btrfs_ioctl_snap_create_transid+0x1a9/0x1b0 [btrfs]
[ 4202.721813]  [<ffffffffa020583a>] btrfs_ioctl_snap_create_v2+0x10a/0x170 [btrfs]
(...)

It turns out that extent_io.c:__extent_writepage(), which ends up being called
through filemap_fdatawrite_range() in btrfs_start_ordered_extent(), was getting
-ENOSPC when calling the fill_delalloc callback. In this situation, it returned
without the writepage_end_io_hook callback (inode.c:btrfs_writepage_end_io_hook)
ever being called for the respective page, which prevents the ordered extent's
bytes_left count from ever reaching 0, and therefore a finish_ordered_fn work
is never queued into the endio_write_workers queue. This makes the task that
called btrfs_start_ordered_extent() hang forever on the wait queue of the ordered
extent.

This is fairly easy to reproduce using a small filesystem and fsstress on
a quad core vm:

    mkfs.btrfs -f -b `expr 2100 \* 1024 \* 1024` /dev/sdd
    mount /dev/sdd /mnt

    fsstress -p 6 -d /mnt -n 100000 -x \
        "btrfs subvolume snapshot -r /mnt /mnt/mysnap" \
	    -f allocsp=0 \
	    -f bulkstat=0 \
	    -f bulkstat1=0 \
	    -f chown=0 \
	    -f creat=1 \
	    -f dread=0 \
	    -f dwrite=0 \
	    -f fallocate=1 \
	    -f fdatasync=0 \
	    -f fiemap=0 \
	    -f freesp=0 \
	    -f fsync=0 \
	    -f getattr=0 \
	    -f getdents=0 \
	    -f link=0 \
	    -f mkdir=0 \
	    -f mknod=0 \
	    -f punch=1 \
	    -f read=0 \
	    -f readlink=0 \
	    -f rename=0 \
	    -f resvsp=0 \
	    -f rmdir=0 \
	    -f setxattr=0 \
	    -f stat=0 \
	    -f symlink=0 \
	    -f sync=0 \
	    -f truncate=1 \
	    -f unlink=0 \
	    -f unresvsp=0 \
	    -f write=4

So just ensure that if an error happens while writing the extent page
we call the writepage_end_io_hook callback. Also make it return the
error code and ensure the caller (extent_write_cache_pages) processes
all pages in the page vector even if an error happens only for some
of them, so that ordered extents end up released.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

If a path has more than 230 characters, we allocate a new buffer to
use for the path, but we were forgotting to copy the contents of the
previous buffer into the new one, which has random content from the
kmalloc call.

Test:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    TEST_PATH="/mnt/fdmanana/.config/google-chrome-mysetup/Default/Pepper_Data/Shockwave_Flash/WritableRoot/#SharedObjects/JSHJ4ZKN/s.wsj.net/[[IMPORT]]/players.edgesuite.net/flash/plugins/osmf/advanced-streaming-plugin/v2.7/osmf1.6/Ak#"
    mkdir -p $TEST_PATH
    echo "hello world" > $TEST_PATH/amaiAdvancedStreamingPlugin.txt

    btrfs subvolume snapshot -r /mnt /mnt/mysnap1
    btrfs send /mnt/mysnap1 -f /tmp/1.snap

A test for xfstests follows.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Cc: Marc Merlin <marc@merlins.org>
Tested-by: NMarc MERLIN <marc@merlins.org>
Signed-off-by: NChris Mason <clm@fb.com>

When running send, if an inode only has extended reference items
associated to it and no regular references, send.c:get_first_ref()
was incorrectly assuming the reference it found was of type
BTRFS_INODE_REF_KEY due to use of the wrong key variable.
This caused weird behaviour when using the found item has a regular
reference, such as weird path string, and occasionally (when lucky)
a crash:

[  190.600652] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[  190.600994] Modules linked in: btrfs xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc psmouse serio_raw evbug pcspkr i2c_piix4 e1000 floppy
[  190.602565] CPU: 2 PID: 14520 Comm: btrfs Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[  190.602728] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  190.602868] task: ffff8800d447c920 ti: ffff8801fa79e000 task.ti: ffff8801fa79e000
[  190.603030] RIP: 0010:[<ffffffff813266b4>]  [<ffffffff813266b4>] memcpy+0x54/0x110
[  190.603262] RSP: 0018:ffff8801fa79f880  EFLAGS: 00010202
[  190.603395] RAX: ffff8800d4326e3f RBX: 000000000000036a RCX: ffff880000000000
[  190.603553] RDX: 000000000000032a RSI: ffe708844042936a RDI: ffff8800d43271a9
[  190.603710] RBP: ffff8801fa79f8c8 R08: 00000000003a4ef0 R09: 0000000000000000
[  190.603867] R10: 793a4ef09f000000 R11: 9f0000000053726f R12: ffff8800d43271a9
[  190.604020] R13: 0000160000000000 R14: ffff8802110134f0 R15: 000000000000036a
[  190.604020] FS:  00007fb423d09b80(0000) GS:ffff880216200000(0000) knlGS:0000000000000000
[  190.604020] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  190.604020] CR2: 00007fb4229d4b78 CR3: 00000001f5d76000 CR4: 00000000000006e0
[  190.604020] Stack:
[  190.604020]  ffffffffa01f4d49 ffff8801fa79f8f0 00000000000009f9 ffff8801fa79f8c8
[  190.604020]  00000000000009f9 ffff880211013260 000000000000f971 ffff88021147dba8
[  190.604020]  00000000000009f9 ffff8801fa79f918 ffffffffa02367f5 ffff8801fa79f928
[  190.604020] Call Trace:
[  190.604020]  [<ffffffffa01f4d49>] ? read_extent_buffer+0xb9/0x120 [btrfs]
[  190.604020]  [<ffffffffa02367f5>] fs_path_add_from_extent_buffer+0x45/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238806>] get_first_ref+0x1f6/0x210 [btrfs]
[  190.604020]  [<ffffffffa0238994>] __get_cur_name_and_parent+0x174/0x3a0 [btrfs]
[  190.604020]  [<ffffffff8118df3d>] ? kmem_cache_alloc_trace+0x11d/0x1e0
[  190.604020]  [<ffffffffa0236674>] ? fs_path_alloc+0x24/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238c91>] get_cur_path+0xd1/0x240 [btrfs]
(...)

Steps to reproduce (either crash or some weirdness like an odd path string):

    mkfs.btrfs -f -O extref /dev/sdd
    mount /dev/sdd /mnt

    mkdir /mnt/testdir
    touch /mnt/testdir/foobar

    for i in `seq 1 2550`; do
        ln /mnt/testdir/foobar /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    ln /mnt/testdir/foobar /mnt/testdir/final_foobar_name

    rm -f /mnt/testdir/foobar
    for i in `seq 1 2550`; do
        rm -f /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    btrfs subvolume snapshot -r /mnt /mnt/mysnap
    btrfs send /mnt/mysnap -f /tmp/mysnap.send
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>

For inline data extent, we need to make its length aligned, otherwise,
we can get a phantom extent map which confuses readpages() to return -EIO.

This can be detected by xfstests/btrfs/035.
Reported-by: NDavid Disseldorp <ddiss@suse.de>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <clm@fb.com>

fs_path_ensure_buf is used to make sure our path buffers for
send are big enough for the path names as we construct them.
The buffer size is limited to 32K by the length field in
the struct.

But bugs in the path construction can end up trying to build
a huge buffer, and we'll do invalid memmmoves when the
buffer length field wraps.

This patch is step one, preventing the overflows.
Signed-off-by: NChris Mason <clm@fb.com>

If we had to retry on the profiles seqlock (due to a concurrent write), we
would set bits on the input flags that corresponded both to the current
profile and to previous values of the profile.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

If skinny metadata is enabled and our first tree search fails to find a
skinny extent item, we may repeat a tree search for a "fat" extent item
(if the previous item in the leaf is not the "fat" extent we're looking
for). However we were not setting the new key's objectid to the right
value, as we previously used the same key variable to peek at the previous
item in the leaf, which has a different objectid. So just set the right
objectid to avoid modifying/deleting a wrong item if we repeat the tree
search.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

Currently, with inode cache enabled, we will reuse its inode id immediately
after unlinking file, we may hit something like following:

|->iput inode
|->return inode id into inode cache
|->create dir,fsync
|->power off

An easy way to reproduce this problem is:

mkfs.btrfs -f /dev/sdb
mount /dev/sdb /mnt -o inode_cache,commit=100
dd if=/dev/zero of=/mnt/data bs=1M count=10 oflag=sync
inode_id=`ls -i /mnt/data | awk '{print $1}'`
rm -f /mnt/data

i=1
while [ 1 ]
do
        mkdir /mnt/dir_$i
        test1=`stat /mnt/dir_$i | grep Inode: | awk '{print $4}'`
        if [ $test1 -eq $inode_id ]
        then
		dd if=/dev/zero of=/mnt/dir_$i/data bs=1M count=1 oflag=sync
		echo b > /proc/sysrq-trigger
	fi
	sleep 1
        i=$(($i+1))
done

mount /dev/sdb /mnt
umount /dev/sdb
btrfs check /dev/sdb

We fix this problem by adding unlinked inode's id into pinned tree,
and we can not reuse them until committing transaction.

Cc: stable@vger.kernel.org
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

Fix possible memory leaks in the following error handling paths:

read_tree_block()
btrfs_recover_log_trees
btrfs_commit_super()
btrfs_find_orphan_roots()
btrfs_cleanup_fs_roots()
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

When running stress test(including snapshots,balance,fstress), we trigger
the following BUG_ON() which is because we fail to start inode caching task.

[  181.131945] kernel BUG at fs/btrfs/inode-map.c:179!
[  181.137963] invalid opcode: 0000 [#1] SMP
[  181.217096] CPU: 11 PID: 2532 Comm: btrfs Not tainted 3.14.0 #1
[  181.240521] task: ffff88013b621b30 ti: ffff8800b6ada000 task.ti: ffff8800b6ada000
[  181.367506] Call Trace:
[  181.371107]  [<ffffffffa036c1be>] btrfs_return_ino+0x9e/0x110 [btrfs]
[  181.379191]  [<ffffffffa038082b>] btrfs_evict_inode+0x46b/0x4c0 [btrfs]
[  181.387464]  [<ffffffff810b5a70>] ? autoremove_wake_function+0x40/0x40
[  181.395642]  [<ffffffff811dc5fe>] evict+0x9e/0x190
[  181.401882]  [<ffffffff811dcde3>] iput+0xf3/0x180
[  181.408025]  [<ffffffffa03812de>] btrfs_orphan_cleanup+0x1ee/0x430 [btrfs]
[  181.416614]  [<ffffffffa03a6abd>] btrfs_mksubvol.isra.29+0x3bd/0x450 [btrfs]
[  181.425399]  [<ffffffffa03a6cd6>] btrfs_ioctl_snap_create_transid+0x186/0x190 [btrfs]
[  181.435059]  [<ffffffffa03a6e3b>] btrfs_ioctl_snap_create_v2+0xeb/0x130 [btrfs]
[  181.444148]  [<ffffffffa03a9656>] btrfs_ioctl+0xf76/0x2b90 [btrfs]
[  181.451971]  [<ffffffff8117e565>] ? handle_mm_fault+0x475/0xe80
[  181.459509]  [<ffffffff8167ba0c>] ? __do_page_fault+0x1ec/0x520
[  181.467046]  [<ffffffff81185b35>] ? do_mmap_pgoff+0x2f5/0x3c0
[  181.474393]  [<ffffffff811d4da8>] do_vfs_ioctl+0x2d8/0x4b0
[  181.481450]  [<ffffffff811d5001>] SyS_ioctl+0x81/0xa0
[  181.488021]  [<ffffffff81680b69>] system_call_fastpath+0x16/0x1b

We should avoid triggering BUG_ON() here, instead, we output warning messages
and clear inode_cache option.
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

There's a case which clone does not handle and used to BUG_ON instead,
(testcase xfstests/btrfs/035), now returns EINVAL. This error code is
confusing to the ioctl caller, as it normally signifies errorneous
arguments.

Change it to ENOPNOTSUPP which allows a fall back to copy instead of
clone. This does not affect the common reflink operation.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

Commit 3ac0d7b9 fixed the btrfs expanding
write problem but the hole punched is sometimes too large for some
iovec, which has unmapped data ranges.
This patch will change to hole range to a more accurate value using the
counts checked by the write check routines.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

Pointer 'newargs' is used after the memory that it points to has already
been freed.

Picked up by Coverity - CID 1201425.

Fixes: 0723a047 ("btrfs: allow mounting btrfs subvolumes with
different ro/rw options")
Signed-off-by: NChristoph Jaeger <christophjaeger@linux.com>
Signed-off-by: NChris Mason <clm@fb.com>

fs/btrfs/scrub.c: In function 'get_raid56_logic_offset':
fs/btrfs/scrub.c:2269: warning: comparison of distinct pointer types lacks a cast
fs/btrfs/scrub.c:2269: warning: right shift count >= width of type
fs/btrfs/scrub.c:2269: warning: passing argument 1 of '__div64_32' from incompatible pointer type

Since @rot is an int type, we should not use do_div(), fix it.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NWang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: NChris Mason <clm@fb.com>

Given the following /etc/fstab entries:

/dev/sda3 /mnt/foo btrfs subvol=foo,ro 0 0
/dev/sda3 /mnt/bar btrfs subvol=bar,rw 0 0

you can't issue:

$ mount /mnt/foo
$ mount /mnt/bar

You would have to do:

$ mount /mnt/foo
$ mount -o remount,rw /mnt/foo
$ mount --bind -o remount,ro /mnt/foo
$ mount /mnt/bar

or

$ mount /mnt/bar
$ mount --rw /mnt/foo
$ mount --bind -o remount,ro /mnt/foo

With this patch you can do

$ mount /mnt/foo
$ mount /mnt/bar

$ cat /proc/self/mountinfo
49 33 0:41 /foo /mnt/foo ro,relatime shared:36 - btrfs /dev/sda3 rw,ssd,space_cache
87 33 0:41 /bar /mnt/bar rw,relatime shared:74 - btrfs /dev/sda3 rw,ssd,space_cache
Signed-off-by: NChris Mason <clm@fb.com>

filemap_map_pages() is generic implementation of ->map_pages() for
filesystems who uses page cache.

It should be safe to use filemap_map_pages() for ->map_pages() if
filesystem use filemap_fault() for ->fault().
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ning Qu <quning@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduce a block group type bit for a global reserve and fill the space
info for SPACE_INFO ioctl. This should replace the newly added ioctl
(01e219e8) to get just the 'size' part
of the global reserve, while the actual usage can be now visible in the
'btrfs fi df' output during ENOSPC stress.

The unpatched userspace tools will show the blockgroup as 'unknown'.

CC: Jeff Mahoney <jeffm@suse.com>
CC: Josef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

Reproducer:
    mount /dev/ubda /mnt
    mount -oremount,thread_pool=42 /mnt

Gives a crash:
    ? btrfs_workqueue_set_max+0x0/0x70
    btrfs_resize_thread_pool+0xe3/0xf0
    ? sync_filesystem+0x0/0xc0
    ? btrfs_resize_thread_pool+0x0/0xf0
    btrfs_remount+0x1d2/0x570
    ? kern_path+0x0/0x80
    do_remount_sb+0xd9/0x1c0
    do_mount+0x26a/0xbf0
    ? kfree+0x0/0x1b0
    SyS_mount+0xc4/0x110

It's a call
    btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, new_pool_size);
with
    fs_info->scrub_wr_completion_workers = NULL;

as scrub wqs get created only on user's demand.

Patch skips not-created-yet workqueues.
Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
CC: Qu Wenruo <quwenruo@cn.fujitsu.com>
CC: Chris Mason <clm@fb.com>
CC: Josef Bacik <jbacik@fb.com>
CC: linux-btrfs@vger.kernel.org
Signed-off-by: NChris Mason <clm@fb.com>

I'm not sure why we weren't aborting here in the first place, it is obviously a
bad time from the fact that we print the leaf and yell loudly about it.  Fix
this up, otherwise we panic because our path could be pointing into oblivion.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>